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llvm-6502/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
Daniel Jasper 40838f84f4 Inline local variable to silence unused warning. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236212 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-30 08:51:13 +00:00

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//===-- SelectionDAGBuilder.cpp - Selection-DAG building ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements routines for translating from LLVM IR into SelectionDAG IR.
//
//===----------------------------------------------------------------------===//
#include "SelectionDAGBuilder.h"
#include "SDNodeDbgValue.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Statepoint.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetIntrinsicInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetSelectionDAGInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include <algorithm>
using namespace llvm;
#define DEBUG_TYPE "isel"
/// LimitFloatPrecision - Generate low-precision inline sequences for
/// some float libcalls (6, 8 or 12 bits).
static unsigned LimitFloatPrecision;
static cl::opt<unsigned, true>
LimitFPPrecision("limit-float-precision",
cl::desc("Generate low-precision inline sequences "
"for some float libcalls"),
cl::location(LimitFloatPrecision),
cl::init(0));
// Limit the width of DAG chains. This is important in general to prevent
// prevent DAG-based analysis from blowing up. For example, alias analysis and
// load clustering may not complete in reasonable time. It is difficult to
// recognize and avoid this situation within each individual analysis, and
// future analyses are likely to have the same behavior. Limiting DAG width is
// the safe approach, and will be especially important with global DAGs.
//
// MaxParallelChains default is arbitrarily high to avoid affecting
// optimization, but could be lowered to improve compile time. Any ld-ld-st-st
// sequence over this should have been converted to llvm.memcpy by the
// frontend. It easy to induce this behavior with .ll code such as:
// %buffer = alloca [4096 x i8]
// %data = load [4096 x i8]* %argPtr
// store [4096 x i8] %data, [4096 x i8]* %buffer
static const unsigned MaxParallelChains = 64;
static SDValue getCopyFromPartsVector(SelectionDAG &DAG, SDLoc DL,
const SDValue *Parts, unsigned NumParts,
MVT PartVT, EVT ValueVT, const Value *V);
/// getCopyFromParts - Create a value that contains the specified legal parts
/// combined into the value they represent. If the parts combine to a type
/// larger then ValueVT then AssertOp can be used to specify whether the extra
/// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT
/// (ISD::AssertSext).
static SDValue getCopyFromParts(SelectionDAG &DAG, SDLoc DL,
const SDValue *Parts,
unsigned NumParts, MVT PartVT, EVT ValueVT,
const Value *V,
ISD::NodeType AssertOp = ISD::DELETED_NODE) {
if (ValueVT.isVector())
return getCopyFromPartsVector(DAG, DL, Parts, NumParts,
PartVT, ValueVT, V);
assert(NumParts > 0 && "No parts to assemble!");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Val = Parts[0];
if (NumParts > 1) {
// Assemble the value from multiple parts.
if (ValueVT.isInteger()) {
unsigned PartBits = PartVT.getSizeInBits();
unsigned ValueBits = ValueVT.getSizeInBits();
// Assemble the power of 2 part.
unsigned RoundParts = NumParts & (NumParts - 1) ?
1 << Log2_32(NumParts) : NumParts;
unsigned RoundBits = PartBits * RoundParts;
EVT RoundVT = RoundBits == ValueBits ?
ValueVT : EVT::getIntegerVT(*DAG.getContext(), RoundBits);
SDValue Lo, Hi;
EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), RoundBits/2);
if (RoundParts > 2) {
Lo = getCopyFromParts(DAG, DL, Parts, RoundParts / 2,
PartVT, HalfVT, V);
Hi = getCopyFromParts(DAG, DL, Parts + RoundParts / 2,
RoundParts / 2, PartVT, HalfVT, V);
} else {
Lo = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[0]);
Hi = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[1]);
}
if (TLI.isBigEndian())
std::swap(Lo, Hi);
Val = DAG.getNode(ISD::BUILD_PAIR, DL, RoundVT, Lo, Hi);
if (RoundParts < NumParts) {
// Assemble the trailing non-power-of-2 part.
unsigned OddParts = NumParts - RoundParts;
EVT OddVT = EVT::getIntegerVT(*DAG.getContext(), OddParts * PartBits);
Hi = getCopyFromParts(DAG, DL,
Parts + RoundParts, OddParts, PartVT, OddVT, V);
// Combine the round and odd parts.
Lo = Val;
if (TLI.isBigEndian())
std::swap(Lo, Hi);
EVT TotalVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Hi = DAG.getNode(ISD::ANY_EXTEND, DL, TotalVT, Hi);
Hi = DAG.getNode(ISD::SHL, DL, TotalVT, Hi,
DAG.getConstant(Lo.getValueType().getSizeInBits(), DL,
TLI.getPointerTy()));
Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, TotalVT, Lo);
Val = DAG.getNode(ISD::OR, DL, TotalVT, Lo, Hi);
}
} else if (PartVT.isFloatingPoint()) {
// FP split into multiple FP parts (for ppcf128)
assert(ValueVT == EVT(MVT::ppcf128) && PartVT == MVT::f64 &&
"Unexpected split");
SDValue Lo, Hi;
Lo = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[0]);
Hi = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[1]);
if (TLI.hasBigEndianPartOrdering(ValueVT))
std::swap(Lo, Hi);
Val = DAG.getNode(ISD::BUILD_PAIR, DL, ValueVT, Lo, Hi);
} else {
// FP split into integer parts (soft fp)
assert(ValueVT.isFloatingPoint() && PartVT.isInteger() &&
!PartVT.isVector() && "Unexpected split");
EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits());
Val = getCopyFromParts(DAG, DL, Parts, NumParts, PartVT, IntVT, V);
}
}
// There is now one part, held in Val. Correct it to match ValueVT.
EVT PartEVT = Val.getValueType();
if (PartEVT == ValueVT)
return Val;
if (PartEVT.isInteger() && ValueVT.isInteger()) {
if (ValueVT.bitsLT(PartEVT)) {
// For a truncate, see if we have any information to
// indicate whether the truncated bits will always be
// zero or sign-extension.
if (AssertOp != ISD::DELETED_NODE)
Val = DAG.getNode(AssertOp, DL, PartEVT, Val,
DAG.getValueType(ValueVT));
return DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
}
return DAG.getNode(ISD::ANY_EXTEND, DL, ValueVT, Val);
}
if (PartEVT.isFloatingPoint() && ValueVT.isFloatingPoint()) {
// FP_ROUND's are always exact here.
if (ValueVT.bitsLT(Val.getValueType()))
return DAG.getNode(ISD::FP_ROUND, DL, ValueVT, Val,
DAG.getTargetConstant(1, DL, TLI.getPointerTy()));
return DAG.getNode(ISD::FP_EXTEND, DL, ValueVT, Val);
}
if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits())
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
llvm_unreachable("Unknown mismatch!");
}
static void diagnosePossiblyInvalidConstraint(LLVMContext &Ctx, const Value *V,
const Twine &ErrMsg) {
const Instruction *I = dyn_cast_or_null<Instruction>(V);
if (!V)
return Ctx.emitError(ErrMsg);
const char *AsmError = ", possible invalid constraint for vector type";
if (const CallInst *CI = dyn_cast<CallInst>(I))
if (isa<InlineAsm>(CI->getCalledValue()))
return Ctx.emitError(I, ErrMsg + AsmError);
return Ctx.emitError(I, ErrMsg);
}
/// getCopyFromPartsVector - Create a value that contains the specified legal
/// parts combined into the value they represent. If the parts combine to a
/// type larger then ValueVT then AssertOp can be used to specify whether the
/// extra bits are known to be zero (ISD::AssertZext) or sign extended from
/// ValueVT (ISD::AssertSext).
static SDValue getCopyFromPartsVector(SelectionDAG &DAG, SDLoc DL,
const SDValue *Parts, unsigned NumParts,
MVT PartVT, EVT ValueVT, const Value *V) {
assert(ValueVT.isVector() && "Not a vector value");
assert(NumParts > 0 && "No parts to assemble!");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Val = Parts[0];
// Handle a multi-element vector.
if (NumParts > 1) {
EVT IntermediateVT;
MVT RegisterVT;
unsigned NumIntermediates;
unsigned NumRegs =
TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT, IntermediateVT,
NumIntermediates, RegisterVT);
assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!");
NumParts = NumRegs; // Silence a compiler warning.
assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!");
assert(RegisterVT == Parts[0].getSimpleValueType() &&
"Part type doesn't match part!");
// Assemble the parts into intermediate operands.
SmallVector<SDValue, 8> Ops(NumIntermediates);
if (NumIntermediates == NumParts) {
// If the register was not expanded, truncate or copy the value,
// as appropriate.
for (unsigned i = 0; i != NumParts; ++i)
Ops[i] = getCopyFromParts(DAG, DL, &Parts[i], 1,
PartVT, IntermediateVT, V);
} else if (NumParts > 0) {
// If the intermediate type was expanded, build the intermediate
// operands from the parts.
assert(NumParts % NumIntermediates == 0 &&
"Must expand into a divisible number of parts!");
unsigned Factor = NumParts / NumIntermediates;
for (unsigned i = 0; i != NumIntermediates; ++i)
Ops[i] = getCopyFromParts(DAG, DL, &Parts[i * Factor], Factor,
PartVT, IntermediateVT, V);
}
// Build a vector with BUILD_VECTOR or CONCAT_VECTORS from the
// intermediate operands.
Val = DAG.getNode(IntermediateVT.isVector() ? ISD::CONCAT_VECTORS
: ISD::BUILD_VECTOR,
DL, ValueVT, Ops);
}
// There is now one part, held in Val. Correct it to match ValueVT.
EVT PartEVT = Val.getValueType();
if (PartEVT == ValueVT)
return Val;
if (PartEVT.isVector()) {
// If the element type of the source/dest vectors are the same, but the
// parts vector has more elements than the value vector, then we have a
// vector widening case (e.g. <2 x float> -> <4 x float>). Extract the
// elements we want.
if (PartEVT.getVectorElementType() == ValueVT.getVectorElementType()) {
assert(PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements() &&
"Cannot narrow, it would be a lossy transformation");
return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, ValueVT, Val,
DAG.getConstant(0, DL, TLI.getVectorIdxTy()));
}
// Vector/Vector bitcast.
if (ValueVT.getSizeInBits() == PartEVT.getSizeInBits())
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
assert(PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements() &&
"Cannot handle this kind of promotion");
// Promoted vector extract
bool Smaller = ValueVT.bitsLE(PartEVT);
return DAG.getNode((Smaller ? ISD::TRUNCATE : ISD::ANY_EXTEND),
DL, ValueVT, Val);
}
// Trivial bitcast if the types are the same size and the destination
// vector type is legal.
if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits() &&
TLI.isTypeLegal(ValueVT))
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
// Handle cases such as i8 -> <1 x i1>
if (ValueVT.getVectorNumElements() != 1) {
diagnosePossiblyInvalidConstraint(*DAG.getContext(), V,
"non-trivial scalar-to-vector conversion");
return DAG.getUNDEF(ValueVT);
}
if (ValueVT.getVectorNumElements() == 1 &&
ValueVT.getVectorElementType() != PartEVT) {
bool Smaller = ValueVT.bitsLE(PartEVT);
Val = DAG.getNode((Smaller ? ISD::TRUNCATE : ISD::ANY_EXTEND),
DL, ValueVT.getScalarType(), Val);
}
return DAG.getNode(ISD::BUILD_VECTOR, DL, ValueVT, Val);
}
static void getCopyToPartsVector(SelectionDAG &DAG, SDLoc dl,
SDValue Val, SDValue *Parts, unsigned NumParts,
MVT PartVT, const Value *V);
/// getCopyToParts - Create a series of nodes that contain the specified value
/// split into legal parts. If the parts contain more bits than Val, then, for
/// integers, ExtendKind can be used to specify how to generate the extra bits.
static void getCopyToParts(SelectionDAG &DAG, SDLoc DL,
SDValue Val, SDValue *Parts, unsigned NumParts,
MVT PartVT, const Value *V,
ISD::NodeType ExtendKind = ISD::ANY_EXTEND) {
EVT ValueVT = Val.getValueType();
// Handle the vector case separately.
if (ValueVT.isVector())
return getCopyToPartsVector(DAG, DL, Val, Parts, NumParts, PartVT, V);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned PartBits = PartVT.getSizeInBits();
unsigned OrigNumParts = NumParts;
assert(TLI.isTypeLegal(PartVT) && "Copying to an illegal type!");
if (NumParts == 0)
return;
assert(!ValueVT.isVector() && "Vector case handled elsewhere");
EVT PartEVT = PartVT;
if (PartEVT == ValueVT) {
assert(NumParts == 1 && "No-op copy with multiple parts!");
Parts[0] = Val;
return;
}
if (NumParts * PartBits > ValueVT.getSizeInBits()) {
// If the parts cover more bits than the value has, promote the value.
if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) {
assert(NumParts == 1 && "Do not know what to promote to!");
Val = DAG.getNode(ISD::FP_EXTEND, DL, PartVT, Val);
} else {
assert((PartVT.isInteger() || PartVT == MVT::x86mmx) &&
ValueVT.isInteger() &&
"Unknown mismatch!");
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ExtendKind, DL, ValueVT, Val);
if (PartVT == MVT::x86mmx)
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
}
} else if (PartBits == ValueVT.getSizeInBits()) {
// Different types of the same size.
assert(NumParts == 1 && PartEVT != ValueVT);
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
} else if (NumParts * PartBits < ValueVT.getSizeInBits()) {
// If the parts cover less bits than value has, truncate the value.
assert((PartVT.isInteger() || PartVT == MVT::x86mmx) &&
ValueVT.isInteger() &&
"Unknown mismatch!");
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
if (PartVT == MVT::x86mmx)
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
}
// The value may have changed - recompute ValueVT.
ValueVT = Val.getValueType();
assert(NumParts * PartBits == ValueVT.getSizeInBits() &&
"Failed to tile the value with PartVT!");
if (NumParts == 1) {
if (PartEVT != ValueVT)
diagnosePossiblyInvalidConstraint(*DAG.getContext(), V,
"scalar-to-vector conversion failed");
Parts[0] = Val;
return;
}
// Expand the value into multiple parts.
if (NumParts & (NumParts - 1)) {
// The number of parts is not a power of 2. Split off and copy the tail.
assert(PartVT.isInteger() && ValueVT.isInteger() &&
"Do not know what to expand to!");
unsigned RoundParts = 1 << Log2_32(NumParts);
unsigned RoundBits = RoundParts * PartBits;
unsigned OddParts = NumParts - RoundParts;
SDValue OddVal = DAG.getNode(ISD::SRL, DL, ValueVT, Val,
DAG.getIntPtrConstant(RoundBits, DL));
getCopyToParts(DAG, DL, OddVal, Parts + RoundParts, OddParts, PartVT, V);
if (TLI.isBigEndian())
// The odd parts were reversed by getCopyToParts - unreverse them.
std::reverse(Parts + RoundParts, Parts + NumParts);
NumParts = RoundParts;
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
}
// The number of parts is a power of 2. Repeatedly bisect the value using
// EXTRACT_ELEMENT.
Parts[0] = DAG.getNode(ISD::BITCAST, DL,
EVT::getIntegerVT(*DAG.getContext(),
ValueVT.getSizeInBits()),
Val);
for (unsigned StepSize = NumParts; StepSize > 1; StepSize /= 2) {
for (unsigned i = 0; i < NumParts; i += StepSize) {
unsigned ThisBits = StepSize * PartBits / 2;
EVT ThisVT = EVT::getIntegerVT(*DAG.getContext(), ThisBits);
SDValue &Part0 = Parts[i];
SDValue &Part1 = Parts[i+StepSize/2];
Part1 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL,
ThisVT, Part0, DAG.getIntPtrConstant(1, DL));
Part0 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL,
ThisVT, Part0, DAG.getIntPtrConstant(0, DL));
if (ThisBits == PartBits && ThisVT != PartVT) {
Part0 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part0);
Part1 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part1);
}
}
}
if (TLI.isBigEndian())
std::reverse(Parts, Parts + OrigNumParts);
}
/// getCopyToPartsVector - Create a series of nodes that contain the specified
/// value split into legal parts.
static void getCopyToPartsVector(SelectionDAG &DAG, SDLoc DL,
SDValue Val, SDValue *Parts, unsigned NumParts,
MVT PartVT, const Value *V) {
EVT ValueVT = Val.getValueType();
assert(ValueVT.isVector() && "Not a vector");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (NumParts == 1) {
EVT PartEVT = PartVT;
if (PartEVT == ValueVT) {
// Nothing to do.
} else if (PartVT.getSizeInBits() == ValueVT.getSizeInBits()) {
// Bitconvert vector->vector case.
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
} else if (PartVT.isVector() &&
PartEVT.getVectorElementType() == ValueVT.getVectorElementType() &&
PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements()) {
EVT ElementVT = PartVT.getVectorElementType();
// Vector widening case, e.g. <2 x float> -> <4 x float>. Shuffle in
// undef elements.
SmallVector<SDValue, 16> Ops;
for (unsigned i = 0, e = ValueVT.getVectorNumElements(); i != e; ++i)
Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
ElementVT, Val, DAG.getConstant(i, DL,
TLI.getVectorIdxTy())));
for (unsigned i = ValueVT.getVectorNumElements(),
e = PartVT.getVectorNumElements(); i != e; ++i)
Ops.push_back(DAG.getUNDEF(ElementVT));
Val = DAG.getNode(ISD::BUILD_VECTOR, DL, PartVT, Ops);
// FIXME: Use CONCAT for 2x -> 4x.
//SDValue UndefElts = DAG.getUNDEF(VectorTy);
//Val = DAG.getNode(ISD::CONCAT_VECTORS, DL, PartVT, Val, UndefElts);
} else if (PartVT.isVector() &&
PartEVT.getVectorElementType().bitsGE(
ValueVT.getVectorElementType()) &&
PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements()) {
// Promoted vector extract
bool Smaller = PartEVT.bitsLE(ValueVT);
Val = DAG.getNode((Smaller ? ISD::TRUNCATE : ISD::ANY_EXTEND),
DL, PartVT, Val);
} else{
// Vector -> scalar conversion.
assert(ValueVT.getVectorNumElements() == 1 &&
"Only trivial vector-to-scalar conversions should get here!");
Val = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
PartVT, Val,
DAG.getConstant(0, DL, TLI.getVectorIdxTy()));
bool Smaller = ValueVT.bitsLE(PartVT);
Val = DAG.getNode((Smaller ? ISD::TRUNCATE : ISD::ANY_EXTEND),
DL, PartVT, Val);
}
Parts[0] = Val;
return;
}
// Handle a multi-element vector.
EVT IntermediateVT;
MVT RegisterVT;
unsigned NumIntermediates;
unsigned NumRegs = TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT,
IntermediateVT,
NumIntermediates, RegisterVT);
unsigned NumElements = ValueVT.getVectorNumElements();
assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!");
NumParts = NumRegs; // Silence a compiler warning.
assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!");
// Split the vector into intermediate operands.
SmallVector<SDValue, 8> Ops(NumIntermediates);
for (unsigned i = 0; i != NumIntermediates; ++i) {
if (IntermediateVT.isVector())
Ops[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL,
IntermediateVT, Val,
DAG.getConstant(i * (NumElements / NumIntermediates), DL,
TLI.getVectorIdxTy()));
else
Ops[i] = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
IntermediateVT, Val,
DAG.getConstant(i, DL, TLI.getVectorIdxTy()));
}
// Split the intermediate operands into legal parts.
if (NumParts == NumIntermediates) {
// If the register was not expanded, promote or copy the value,
// as appropriate.
for (unsigned i = 0; i != NumParts; ++i)
getCopyToParts(DAG, DL, Ops[i], &Parts[i], 1, PartVT, V);
} else if (NumParts > 0) {
// If the intermediate type was expanded, split each the value into
// legal parts.
assert(NumIntermediates != 0 && "division by zero");
assert(NumParts % NumIntermediates == 0 &&
"Must expand into a divisible number of parts!");
unsigned Factor = NumParts / NumIntermediates;
for (unsigned i = 0; i != NumIntermediates; ++i)
getCopyToParts(DAG, DL, Ops[i], &Parts[i*Factor], Factor, PartVT, V);
}
}
namespace {
/// RegsForValue - This struct represents the registers (physical or virtual)
/// that a particular set of values is assigned, and the type information
/// about the value. The most common situation is to represent one value at a
/// time, but struct or array values are handled element-wise as multiple
/// values. The splitting of aggregates is performed recursively, so that we
/// never have aggregate-typed registers. The values at this point do not
/// necessarily have legal types, so each value may require one or more
/// registers of some legal type.
///
struct RegsForValue {
/// ValueVTs - The value types of the values, which may not be legal, and
/// may need be promoted or synthesized from one or more registers.
///
SmallVector<EVT, 4> ValueVTs;
/// RegVTs - The value types of the registers. This is the same size as
/// ValueVTs and it records, for each value, what the type of the assigned
/// register or registers are. (Individual values are never synthesized
/// from more than one type of register.)
///
/// With virtual registers, the contents of RegVTs is redundant with TLI's
/// getRegisterType member function, however when with physical registers
/// it is necessary to have a separate record of the types.
///
SmallVector<MVT, 4> RegVTs;
/// Regs - This list holds the registers assigned to the values.
/// Each legal or promoted value requires one register, and each
/// expanded value requires multiple registers.
///
SmallVector<unsigned, 4> Regs;
RegsForValue() {}
RegsForValue(const SmallVector<unsigned, 4> &regs,
MVT regvt, EVT valuevt)
: ValueVTs(1, valuevt), RegVTs(1, regvt), Regs(regs) {}
RegsForValue(LLVMContext &Context, const TargetLowering &tli,
unsigned Reg, Type *Ty) {
ComputeValueVTs(tli, Ty, ValueVTs);
for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
EVT ValueVT = ValueVTs[Value];
unsigned NumRegs = tli.getNumRegisters(Context, ValueVT);
MVT RegisterVT = tli.getRegisterType(Context, ValueVT);
for (unsigned i = 0; i != NumRegs; ++i)
Regs.push_back(Reg + i);
RegVTs.push_back(RegisterVT);
Reg += NumRegs;
}
}
/// append - Add the specified values to this one.
void append(const RegsForValue &RHS) {
ValueVTs.append(RHS.ValueVTs.begin(), RHS.ValueVTs.end());
RegVTs.append(RHS.RegVTs.begin(), RHS.RegVTs.end());
Regs.append(RHS.Regs.begin(), RHS.Regs.end());
}
/// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from
/// this value and returns the result as a ValueVTs value. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
SDValue getCopyFromRegs(SelectionDAG &DAG, FunctionLoweringInfo &FuncInfo,
SDLoc dl,
SDValue &Chain, SDValue *Flag,
const Value *V = nullptr) const;
/// getCopyToRegs - Emit a series of CopyToReg nodes that copies the
/// specified value into the registers specified by this object. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
void
getCopyToRegs(SDValue Val, SelectionDAG &DAG, SDLoc dl, SDValue &Chain,
SDValue *Flag, const Value *V,
ISD::NodeType PreferredExtendType = ISD::ANY_EXTEND) const;
/// AddInlineAsmOperands - Add this value to the specified inlineasm node
/// operand list. This adds the code marker, matching input operand index
/// (if applicable), and includes the number of values added into it.
void AddInlineAsmOperands(unsigned Kind,
bool HasMatching, unsigned MatchingIdx, SDLoc dl,
SelectionDAG &DAG,
std::vector<SDValue> &Ops) const;
};
}
/// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from
/// this value and returns the result as a ValueVT value. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG,
FunctionLoweringInfo &FuncInfo,
SDLoc dl,
SDValue &Chain, SDValue *Flag,
const Value *V) const {
// A Value with type {} or [0 x %t] needs no registers.
if (ValueVTs.empty())
return SDValue();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// Assemble the legal parts into the final values.
SmallVector<SDValue, 4> Values(ValueVTs.size());
SmallVector<SDValue, 8> Parts;
for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) {
// Copy the legal parts from the registers.
EVT ValueVT = ValueVTs[Value];
unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVT);
MVT RegisterVT = RegVTs[Value];
Parts.resize(NumRegs);
for (unsigned i = 0; i != NumRegs; ++i) {
SDValue P;
if (!Flag) {
P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT);
} else {
P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT, *Flag);
*Flag = P.getValue(2);
}
Chain = P.getValue(1);
Parts[i] = P;
// If the source register was virtual and if we know something about it,
// add an assert node.
if (!TargetRegisterInfo::isVirtualRegister(Regs[Part+i]) ||
!RegisterVT.isInteger() || RegisterVT.isVector())
continue;
const FunctionLoweringInfo::LiveOutInfo *LOI =
FuncInfo.GetLiveOutRegInfo(Regs[Part+i]);
if (!LOI)
continue;
unsigned RegSize = RegisterVT.getSizeInBits();
unsigned NumSignBits = LOI->NumSignBits;
unsigned NumZeroBits = LOI->KnownZero.countLeadingOnes();
if (NumZeroBits == RegSize) {
// The current value is a zero.
// Explicitly express that as it would be easier for
// optimizations to kick in.
Parts[i] = DAG.getConstant(0, dl, RegisterVT);
continue;
}
// FIXME: We capture more information than the dag can represent. For
// now, just use the tightest assertzext/assertsext possible.
bool isSExt = true;
EVT FromVT(MVT::Other);
if (NumSignBits == RegSize)
isSExt = true, FromVT = MVT::i1; // ASSERT SEXT 1
else if (NumZeroBits >= RegSize-1)
isSExt = false, FromVT = MVT::i1; // ASSERT ZEXT 1
else if (NumSignBits > RegSize-8)
isSExt = true, FromVT = MVT::i8; // ASSERT SEXT 8
else if (NumZeroBits >= RegSize-8)
isSExt = false, FromVT = MVT::i8; // ASSERT ZEXT 8
else if (NumSignBits > RegSize-16)
isSExt = true, FromVT = MVT::i16; // ASSERT SEXT 16
else if (NumZeroBits >= RegSize-16)
isSExt = false, FromVT = MVT::i16; // ASSERT ZEXT 16
else if (NumSignBits > RegSize-32)
isSExt = true, FromVT = MVT::i32; // ASSERT SEXT 32
else if (NumZeroBits >= RegSize-32)
isSExt = false, FromVT = MVT::i32; // ASSERT ZEXT 32
else
continue;
// Add an assertion node.
assert(FromVT != MVT::Other);
Parts[i] = DAG.getNode(isSExt ? ISD::AssertSext : ISD::AssertZext, dl,
RegisterVT, P, DAG.getValueType(FromVT));
}
Values[Value] = getCopyFromParts(DAG, dl, Parts.begin(),
NumRegs, RegisterVT, ValueVT, V);
Part += NumRegs;
Parts.clear();
}
return DAG.getNode(ISD::MERGE_VALUES, dl, DAG.getVTList(ValueVTs), Values);
}
/// getCopyToRegs - Emit a series of CopyToReg nodes that copies the
/// specified value into the registers specified by this object. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
void RegsForValue::getCopyToRegs(SDValue Val, SelectionDAG &DAG, SDLoc dl,
SDValue &Chain, SDValue *Flag, const Value *V,
ISD::NodeType PreferredExtendType) const {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
ISD::NodeType ExtendKind = PreferredExtendType;
// Get the list of the values's legal parts.
unsigned NumRegs = Regs.size();
SmallVector<SDValue, 8> Parts(NumRegs);
for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) {
EVT ValueVT = ValueVTs[Value];
unsigned NumParts = TLI.getNumRegisters(*DAG.getContext(), ValueVT);
MVT RegisterVT = RegVTs[Value];
if (ExtendKind == ISD::ANY_EXTEND && TLI.isZExtFree(Val, RegisterVT))
ExtendKind = ISD::ZERO_EXTEND;
getCopyToParts(DAG, dl, Val.getValue(Val.getResNo() + Value),
&Parts[Part], NumParts, RegisterVT, V, ExtendKind);
Part += NumParts;
}
// Copy the parts into the registers.
SmallVector<SDValue, 8> Chains(NumRegs);
for (unsigned i = 0; i != NumRegs; ++i) {
SDValue Part;
if (!Flag) {
Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i]);
} else {
Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i], *Flag);
*Flag = Part.getValue(1);
}
Chains[i] = Part.getValue(0);
}
if (NumRegs == 1 || Flag)
// If NumRegs > 1 && Flag is used then the use of the last CopyToReg is
// flagged to it. That is the CopyToReg nodes and the user are considered
// a single scheduling unit. If we create a TokenFactor and return it as
// chain, then the TokenFactor is both a predecessor (operand) of the
// user as well as a successor (the TF operands are flagged to the user).
// c1, f1 = CopyToReg
// c2, f2 = CopyToReg
// c3 = TokenFactor c1, c2
// ...
// = op c3, ..., f2
Chain = Chains[NumRegs-1];
else
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Chains);
}
/// AddInlineAsmOperands - Add this value to the specified inlineasm node
/// operand list. This adds the code marker and includes the number of
/// values added into it.
void RegsForValue::AddInlineAsmOperands(unsigned Code, bool HasMatching,
unsigned MatchingIdx, SDLoc dl,
SelectionDAG &DAG,
std::vector<SDValue> &Ops) const {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned Flag = InlineAsm::getFlagWord(Code, Regs.size());
if (HasMatching)
Flag = InlineAsm::getFlagWordForMatchingOp(Flag, MatchingIdx);
else if (!Regs.empty() &&
TargetRegisterInfo::isVirtualRegister(Regs.front())) {
// Put the register class of the virtual registers in the flag word. That
// way, later passes can recompute register class constraints for inline
// assembly as well as normal instructions.
// Don't do this for tied operands that can use the regclass information
// from the def.
const MachineRegisterInfo &MRI = DAG.getMachineFunction().getRegInfo();
const TargetRegisterClass *RC = MRI.getRegClass(Regs.front());
Flag = InlineAsm::getFlagWordForRegClass(Flag, RC->getID());
}
SDValue Res = DAG.getTargetConstant(Flag, dl, MVT::i32);
Ops.push_back(Res);
unsigned SP = TLI.getStackPointerRegisterToSaveRestore();
for (unsigned Value = 0, Reg = 0, e = ValueVTs.size(); Value != e; ++Value) {
unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVTs[Value]);
MVT RegisterVT = RegVTs[Value];
for (unsigned i = 0; i != NumRegs; ++i) {
assert(Reg < Regs.size() && "Mismatch in # registers expected");
unsigned TheReg = Regs[Reg++];
Ops.push_back(DAG.getRegister(TheReg, RegisterVT));
if (TheReg == SP && Code == InlineAsm::Kind_Clobber) {
// If we clobbered the stack pointer, MFI should know about it.
assert(DAG.getMachineFunction().getFrameInfo()->
hasInlineAsmWithSPAdjust());
}
}
}
}
void SelectionDAGBuilder::init(GCFunctionInfo *gfi, AliasAnalysis &aa,
const TargetLibraryInfo *li) {
AA = &aa;
GFI = gfi;
LibInfo = li;
DL = DAG.getTarget().getDataLayout();
Context = DAG.getContext();
LPadToCallSiteMap.clear();
}
/// clear - Clear out the current SelectionDAG and the associated
/// state and prepare this SelectionDAGBuilder object to be used
/// for a new block. This doesn't clear out information about
/// additional blocks that are needed to complete switch lowering
/// or PHI node updating; that information is cleared out as it is
/// consumed.
void SelectionDAGBuilder::clear() {
NodeMap.clear();
UnusedArgNodeMap.clear();
PendingLoads.clear();
PendingExports.clear();
CurInst = nullptr;
HasTailCall = false;
SDNodeOrder = LowestSDNodeOrder;
StatepointLowering.clear();
}
/// clearDanglingDebugInfo - Clear the dangling debug information
/// map. This function is separated from the clear so that debug
/// information that is dangling in a basic block can be properly
/// resolved in a different basic block. This allows the
/// SelectionDAG to resolve dangling debug information attached
/// to PHI nodes.
void SelectionDAGBuilder::clearDanglingDebugInfo() {
DanglingDebugInfoMap.clear();
}
/// getRoot - Return the current virtual root of the Selection DAG,
/// flushing any PendingLoad items. This must be done before emitting
/// a store or any other node that may need to be ordered after any
/// prior load instructions.
///
SDValue SelectionDAGBuilder::getRoot() {
if (PendingLoads.empty())
return DAG.getRoot();
if (PendingLoads.size() == 1) {
SDValue Root = PendingLoads[0];
DAG.setRoot(Root);
PendingLoads.clear();
return Root;
}
// Otherwise, we have to make a token factor node.
SDValue Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other,
PendingLoads);
PendingLoads.clear();
DAG.setRoot(Root);
return Root;
}
/// getControlRoot - Similar to getRoot, but instead of flushing all the
/// PendingLoad items, flush all the PendingExports items. It is necessary
/// to do this before emitting a terminator instruction.
///
SDValue SelectionDAGBuilder::getControlRoot() {
SDValue Root = DAG.getRoot();
if (PendingExports.empty())
return Root;
// Turn all of the CopyToReg chains into one factored node.
if (Root.getOpcode() != ISD::EntryToken) {
unsigned i = 0, e = PendingExports.size();
for (; i != e; ++i) {
assert(PendingExports[i].getNode()->getNumOperands() > 1);
if (PendingExports[i].getNode()->getOperand(0) == Root)
break; // Don't add the root if we already indirectly depend on it.
}
if (i == e)
PendingExports.push_back(Root);
}
Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other,
PendingExports);
PendingExports.clear();
DAG.setRoot(Root);
return Root;
}
void SelectionDAGBuilder::visit(const Instruction &I) {
// Set up outgoing PHI node register values before emitting the terminator.
if (isa<TerminatorInst>(&I))
HandlePHINodesInSuccessorBlocks(I.getParent());
++SDNodeOrder;
CurInst = &I;
visit(I.getOpcode(), I);
if (!isa<TerminatorInst>(&I) && !HasTailCall)
CopyToExportRegsIfNeeded(&I);
CurInst = nullptr;
}
void SelectionDAGBuilder::visitPHI(const PHINode &) {
llvm_unreachable("SelectionDAGBuilder shouldn't visit PHI nodes!");
}
void SelectionDAGBuilder::visit(unsigned Opcode, const User &I) {
// Note: this doesn't use InstVisitor, because it has to work with
// ConstantExpr's in addition to instructions.
switch (Opcode) {
default: llvm_unreachable("Unknown instruction type encountered!");
// Build the switch statement using the Instruction.def file.
#define HANDLE_INST(NUM, OPCODE, CLASS) \
case Instruction::OPCODE: visit##OPCODE((const CLASS&)I); break;
#include "llvm/IR/Instruction.def"
}
}
// resolveDanglingDebugInfo - if we saw an earlier dbg_value referring to V,
// generate the debug data structures now that we've seen its definition.
void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
SDValue Val) {
DanglingDebugInfo &DDI = DanglingDebugInfoMap[V];
if (DDI.getDI()) {
const DbgValueInst *DI = DDI.getDI();
DebugLoc dl = DDI.getdl();
unsigned DbgSDNodeOrder = DDI.getSDNodeOrder();
DILocalVariable *Variable = DI->getVariable();
DIExpression *Expr = DI->getExpression();
assert(Variable->isValidLocationForIntrinsic(dl) &&
"Expected inlined-at fields to agree");
uint64_t Offset = DI->getOffset();
// A dbg.value for an alloca is always indirect.
bool IsIndirect = isa<AllocaInst>(V) || Offset != 0;
SDDbgValue *SDV;
if (Val.getNode()) {
if (!EmitFuncArgumentDbgValue(V, Variable, Expr, dl, Offset, IsIndirect,
Val)) {
SDV = DAG.getDbgValue(Variable, Expr, Val.getNode(), Val.getResNo(),
IsIndirect, Offset, dl, DbgSDNodeOrder);
DAG.AddDbgValue(SDV, Val.getNode(), false);
}
} else
DEBUG(dbgs() << "Dropping debug info for " << *DI << "\n");
DanglingDebugInfoMap[V] = DanglingDebugInfo();
}
}
/// getCopyFromRegs - If there was virtual register allocated for the value V
/// emit CopyFromReg of the specified type Ty. Return empty SDValue() otherwise.
SDValue SelectionDAGBuilder::getCopyFromRegs(const Value *V, Type *Ty) {
DenseMap<const Value *, unsigned>::iterator It = FuncInfo.ValueMap.find(V);
SDValue res;
if (It != FuncInfo.ValueMap.end()) {
unsigned InReg = It->second;
RegsForValue RFV(*DAG.getContext(), DAG.getTargetLoweringInfo(), InReg,
Ty);
SDValue Chain = DAG.getEntryNode();
res = RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V);
resolveDanglingDebugInfo(V, res);
}
return res;
}
/// getValue - Return an SDValue for the given Value.
SDValue SelectionDAGBuilder::getValue(const Value *V) {
// If we already have an SDValue for this value, use it. It's important
// to do this first, so that we don't create a CopyFromReg if we already
// have a regular SDValue.
SDValue &N = NodeMap[V];
if (N.getNode()) return N;
// If there's a virtual register allocated and initialized for this
// value, use it.
SDValue copyFromReg = getCopyFromRegs(V, V->getType());
if (copyFromReg.getNode()) {
return copyFromReg;
}
// Otherwise create a new SDValue and remember it.
SDValue Val = getValueImpl(V);
NodeMap[V] = Val;
resolveDanglingDebugInfo(V, Val);
return Val;
}
// Return true if SDValue exists for the given Value
bool SelectionDAGBuilder::findValue(const Value *V) const {
return (NodeMap.find(V) != NodeMap.end()) ||
(FuncInfo.ValueMap.find(V) != FuncInfo.ValueMap.end());
}
/// getNonRegisterValue - Return an SDValue for the given Value, but
/// don't look in FuncInfo.ValueMap for a virtual register.
SDValue SelectionDAGBuilder::getNonRegisterValue(const Value *V) {
// If we already have an SDValue for this value, use it.
SDValue &N = NodeMap[V];
if (N.getNode()) return N;
// Otherwise create a new SDValue and remember it.
SDValue Val = getValueImpl(V);
NodeMap[V] = Val;
resolveDanglingDebugInfo(V, Val);
return Val;
}
/// getValueImpl - Helper function for getValue and getNonRegisterValue.
/// Create an SDValue for the given value.
SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (const Constant *C = dyn_cast<Constant>(V)) {
EVT VT = TLI.getValueType(V->getType(), true);
if (const ConstantInt *CI = dyn_cast<ConstantInt>(C))
return DAG.getConstant(*CI, getCurSDLoc(), VT);
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
return DAG.getGlobalAddress(GV, getCurSDLoc(), VT);
if (isa<ConstantPointerNull>(C)) {
unsigned AS = V->getType()->getPointerAddressSpace();
return DAG.getConstant(0, getCurSDLoc(), TLI.getPointerTy(AS));
}
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
return DAG.getConstantFP(*CFP, getCurSDLoc(), VT);
if (isa<UndefValue>(C) && !V->getType()->isAggregateType())
return DAG.getUNDEF(VT);
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
visit(CE->getOpcode(), *CE);
SDValue N1 = NodeMap[V];
assert(N1.getNode() && "visit didn't populate the NodeMap!");
return N1;
}
if (isa<ConstantStruct>(C) || isa<ConstantArray>(C)) {
SmallVector<SDValue, 4> Constants;
for (User::const_op_iterator OI = C->op_begin(), OE = C->op_end();
OI != OE; ++OI) {
SDNode *Val = getValue(*OI).getNode();
// If the operand is an empty aggregate, there are no values.
if (!Val) continue;
// Add each leaf value from the operand to the Constants list
// to form a flattened list of all the values.
for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i)
Constants.push_back(SDValue(Val, i));
}
return DAG.getMergeValues(Constants, getCurSDLoc());
}
if (const ConstantDataSequential *CDS =
dyn_cast<ConstantDataSequential>(C)) {
SmallVector<SDValue, 4> Ops;
for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
SDNode *Val = getValue(CDS->getElementAsConstant(i)).getNode();
// Add each leaf value from the operand to the Constants list
// to form a flattened list of all the values.
for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i)
Ops.push_back(SDValue(Val, i));
}
if (isa<ArrayType>(CDS->getType()))
return DAG.getMergeValues(Ops, getCurSDLoc());
return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, getCurSDLoc(),
VT, Ops);
}
if (C->getType()->isStructTy() || C->getType()->isArrayTy()) {
assert((isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) &&
"Unknown struct or array constant!");
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, C->getType(), ValueVTs);
unsigned NumElts = ValueVTs.size();
if (NumElts == 0)
return SDValue(); // empty struct
SmallVector<SDValue, 4> Constants(NumElts);
for (unsigned i = 0; i != NumElts; ++i) {
EVT EltVT = ValueVTs[i];
if (isa<UndefValue>(C))
Constants[i] = DAG.getUNDEF(EltVT);
else if (EltVT.isFloatingPoint())
Constants[i] = DAG.getConstantFP(0, getCurSDLoc(), EltVT);
else
Constants[i] = DAG.getConstant(0, getCurSDLoc(), EltVT);
}
return DAG.getMergeValues(Constants, getCurSDLoc());
}
if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
return DAG.getBlockAddress(BA, VT);
VectorType *VecTy = cast<VectorType>(V->getType());
unsigned NumElements = VecTy->getNumElements();
// Now that we know the number and type of the elements, get that number of
// elements into the Ops array based on what kind of constant it is.
SmallVector<SDValue, 16> Ops;
if (const ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
for (unsigned i = 0; i != NumElements; ++i)
Ops.push_back(getValue(CV->getOperand(i)));
} else {
assert(isa<ConstantAggregateZero>(C) && "Unknown vector constant!");
EVT EltVT = TLI.getValueType(VecTy->getElementType());
SDValue Op;
if (EltVT.isFloatingPoint())
Op = DAG.getConstantFP(0, getCurSDLoc(), EltVT);
else
Op = DAG.getConstant(0, getCurSDLoc(), EltVT);
Ops.assign(NumElements, Op);
}
// Create a BUILD_VECTOR node.
return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, getCurSDLoc(), VT, Ops);
}
// If this is a static alloca, generate it as the frameindex instead of
// computation.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end())
return DAG.getFrameIndex(SI->second, TLI.getPointerTy());
}
// If this is an instruction which fast-isel has deferred, select it now.
if (const Instruction *Inst = dyn_cast<Instruction>(V)) {
unsigned InReg = FuncInfo.InitializeRegForValue(Inst);
RegsForValue RFV(*DAG.getContext(), TLI, InReg, Inst->getType());
SDValue Chain = DAG.getEntryNode();
return RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V);
}
llvm_unreachable("Can't get register for value!");
}
void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Chain = getControlRoot();
SmallVector<ISD::OutputArg, 8> Outs;
SmallVector<SDValue, 8> OutVals;
if (!FuncInfo.CanLowerReturn) {
unsigned DemoteReg = FuncInfo.DemoteRegister;
const Function *F = I.getParent()->getParent();
// Emit a store of the return value through the virtual register.
// Leave Outs empty so that LowerReturn won't try to load return
// registers the usual way.
SmallVector<EVT, 1> PtrValueVTs;
ComputeValueVTs(TLI, PointerType::getUnqual(F->getReturnType()),
PtrValueVTs);
SDValue RetPtr = DAG.getRegister(DemoteReg, PtrValueVTs[0]);
SDValue RetOp = getValue(I.getOperand(0));
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(TLI, I.getOperand(0)->getType(), ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
SmallVector<SDValue, 4> Chains(NumValues);
for (unsigned i = 0; i != NumValues; ++i) {
SDValue Add = DAG.getNode(ISD::ADD, getCurSDLoc(),
RetPtr.getValueType(), RetPtr,
DAG.getIntPtrConstant(Offsets[i],
getCurSDLoc()));
Chains[i] =
DAG.getStore(Chain, getCurSDLoc(),
SDValue(RetOp.getNode(), RetOp.getResNo() + i),
// FIXME: better loc info would be nice.
Add, MachinePointerInfo(), false, false, 0);
}
Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(),
MVT::Other, Chains);
} else if (I.getNumOperands() != 0) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I.getOperand(0)->getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues) {
SDValue RetOp = getValue(I.getOperand(0));
const Function *F = I.getParent()->getParent();
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (F->getAttributes().hasAttribute(AttributeSet::ReturnIndex,
Attribute::SExt))
ExtendKind = ISD::SIGN_EXTEND;
else if (F->getAttributes().hasAttribute(AttributeSet::ReturnIndex,
Attribute::ZExt))
ExtendKind = ISD::ZERO_EXTEND;
LLVMContext &Context = F->getContext();
bool RetInReg = F->getAttributes().hasAttribute(AttributeSet::ReturnIndex,
Attribute::InReg);
for (unsigned j = 0; j != NumValues; ++j) {
EVT VT = ValueVTs[j];
if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
VT = TLI.getTypeForExtArgOrReturn(Context, VT, ExtendKind);
unsigned NumParts = TLI.getNumRegisters(Context, VT);
MVT PartVT = TLI.getRegisterType(Context, VT);
SmallVector<SDValue, 4> Parts(NumParts);
getCopyToParts(DAG, getCurSDLoc(),
SDValue(RetOp.getNode(), RetOp.getResNo() + j),
&Parts[0], NumParts, PartVT, &I, ExtendKind);
// 'inreg' on function refers to return value
ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
if (RetInReg)
Flags.setInReg();
// Propagate extension type if any
if (ExtendKind == ISD::SIGN_EXTEND)
Flags.setSExt();
else if (ExtendKind == ISD::ZERO_EXTEND)
Flags.setZExt();
for (unsigned i = 0; i < NumParts; ++i) {
Outs.push_back(ISD::OutputArg(Flags, Parts[i].getValueType(),
VT, /*isfixed=*/true, 0, 0));
OutVals.push_back(Parts[i]);
}
}
}
}
bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg();
CallingConv::ID CallConv =
DAG.getMachineFunction().getFunction()->getCallingConv();
Chain = DAG.getTargetLoweringInfo().LowerReturn(
Chain, CallConv, isVarArg, Outs, OutVals, getCurSDLoc(), DAG);
// Verify that the target's LowerReturn behaved as expected.
assert(Chain.getNode() && Chain.getValueType() == MVT::Other &&
"LowerReturn didn't return a valid chain!");
// Update the DAG with the new chain value resulting from return lowering.
DAG.setRoot(Chain);
}
/// CopyToExportRegsIfNeeded - If the given value has virtual registers
/// created for it, emit nodes to copy the value into the virtual
/// registers.
void SelectionDAGBuilder::CopyToExportRegsIfNeeded(const Value *V) {
// Skip empty types
if (V->getType()->isEmptyTy())
return;
DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
if (VMI != FuncInfo.ValueMap.end()) {
assert(!V->use_empty() && "Unused value assigned virtual registers!");
CopyValueToVirtualRegister(V, VMI->second);
}
}
/// ExportFromCurrentBlock - If this condition isn't known to be exported from
/// the current basic block, add it to ValueMap now so that we'll get a
/// CopyTo/FromReg.
void SelectionDAGBuilder::ExportFromCurrentBlock(const Value *V) {
// No need to export constants.
if (!isa<Instruction>(V) && !isa<Argument>(V)) return;
// Already exported?
if (FuncInfo.isExportedInst(V)) return;
unsigned Reg = FuncInfo.InitializeRegForValue(V);
CopyValueToVirtualRegister(V, Reg);
}
bool SelectionDAGBuilder::isExportableFromCurrentBlock(const Value *V,
const BasicBlock *FromBB) {
// The operands of the setcc have to be in this block. We don't know
// how to export them from some other block.
if (const Instruction *VI = dyn_cast<Instruction>(V)) {
// Can export from current BB.
if (VI->getParent() == FromBB)
return true;
// Is already exported, noop.
return FuncInfo.isExportedInst(V);
}
// If this is an argument, we can export it if the BB is the entry block or
// if it is already exported.
if (isa<Argument>(V)) {
if (FromBB == &FromBB->getParent()->getEntryBlock())
return true;
// Otherwise, can only export this if it is already exported.
return FuncInfo.isExportedInst(V);
}
// Otherwise, constants can always be exported.
return true;
}
/// Return branch probability calculated by BranchProbabilityInfo for IR blocks.
uint32_t SelectionDAGBuilder::getEdgeWeight(const MachineBasicBlock *Src,
const MachineBasicBlock *Dst) const {
BranchProbabilityInfo *BPI = FuncInfo.BPI;
if (!BPI)
return 0;
const BasicBlock *SrcBB = Src->getBasicBlock();
const BasicBlock *DstBB = Dst->getBasicBlock();
return BPI->getEdgeWeight(SrcBB, DstBB);
}
void SelectionDAGBuilder::
addSuccessorWithWeight(MachineBasicBlock *Src, MachineBasicBlock *Dst,
uint32_t Weight /* = 0 */) {
if (!Weight)
Weight = getEdgeWeight(Src, Dst);
Src->addSuccessor(Dst, Weight);
}
static bool InBlock(const Value *V, const BasicBlock *BB) {
if (const Instruction *I = dyn_cast<Instruction>(V))
return I->getParent() == BB;
return true;
}
/// EmitBranchForMergedCondition - Helper method for FindMergedConditions.
/// This function emits a branch and is used at the leaves of an OR or an
/// AND operator tree.
///
void
SelectionDAGBuilder::EmitBranchForMergedCondition(const Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB,
uint32_t TWeight,
uint32_t FWeight) {
const BasicBlock *BB = CurBB->getBasicBlock();
// If the leaf of the tree is a comparison, merge the condition into
// the caseblock.
if (const CmpInst *BOp = dyn_cast<CmpInst>(Cond)) {
// The operands of the cmp have to be in this block. We don't know
// how to export them from some other block. If this is the first block
// of the sequence, no exporting is needed.
if (CurBB == SwitchBB ||
(isExportableFromCurrentBlock(BOp->getOperand(0), BB) &&
isExportableFromCurrentBlock(BOp->getOperand(1), BB))) {
ISD::CondCode Condition;
if (const ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) {
Condition = getICmpCondCode(IC->getPredicate());
} else if (const FCmpInst *FC = dyn_cast<FCmpInst>(Cond)) {
Condition = getFCmpCondCode(FC->getPredicate());
if (TM.Options.NoNaNsFPMath)
Condition = getFCmpCodeWithoutNaN(Condition);
} else {
(void)Condition; // silence warning.
llvm_unreachable("Unknown compare instruction");
}
CaseBlock CB(Condition, BOp->getOperand(0), BOp->getOperand(1), nullptr,
TBB, FBB, CurBB, TWeight, FWeight);
SwitchCases.push_back(CB);
return;
}
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, Cond, ConstantInt::getTrue(*DAG.getContext()),
nullptr, TBB, FBB, CurBB, TWeight, FWeight);
SwitchCases.push_back(CB);
}
/// Scale down both weights to fit into uint32_t.
static void ScaleWeights(uint64_t &NewTrue, uint64_t &NewFalse) {
uint64_t NewMax = (NewTrue > NewFalse) ? NewTrue : NewFalse;
uint32_t Scale = (NewMax / UINT32_MAX) + 1;
NewTrue = NewTrue / Scale;
NewFalse = NewFalse / Scale;
}
/// FindMergedConditions - If Cond is an expression like
void SelectionDAGBuilder::FindMergedConditions(const Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB,
unsigned Opc, uint32_t TWeight,
uint32_t FWeight) {
// If this node is not part of the or/and tree, emit it as a branch.
const Instruction *BOp = dyn_cast<Instruction>(Cond);
if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) ||
(unsigned)BOp->getOpcode() != Opc || !BOp->hasOneUse() ||
BOp->getParent() != CurBB->getBasicBlock() ||
!InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) ||
!InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) {
EmitBranchForMergedCondition(Cond, TBB, FBB, CurBB, SwitchBB,
TWeight, FWeight);
return;
}
// Create TmpBB after CurBB.
MachineFunction::iterator BBI = CurBB;
MachineFunction &MF = DAG.getMachineFunction();
MachineBasicBlock *TmpBB = MF.CreateMachineBasicBlock(CurBB->getBasicBlock());
CurBB->getParent()->insert(++BBI, TmpBB);
if (Opc == Instruction::Or) {
// Codegen X | Y as:
// BB1:
// jmp_if_X TBB
// jmp TmpBB
// TmpBB:
// jmp_if_Y TBB
// jmp FBB
//
// We have flexibility in setting Prob for BB1 and Prob for TmpBB.
// The requirement is that
// TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB)
// = TrueProb for orignal BB.
// Assuming the orignal weights are A and B, one choice is to set BB1's
// weights to A and A+2B, and set TmpBB's weights to A and 2B. This choice
// assumes that
// TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB.
// Another choice is to assume TrueProb for BB1 equals to TrueProb for
// TmpBB, but the math is more complicated.
uint64_t NewTrueWeight = TWeight;
uint64_t NewFalseWeight = (uint64_t)TWeight + 2 * (uint64_t)FWeight;
ScaleWeights(NewTrueWeight, NewFalseWeight);
// Emit the LHS condition.
FindMergedConditions(BOp->getOperand(0), TBB, TmpBB, CurBB, SwitchBB, Opc,
NewTrueWeight, NewFalseWeight);
NewTrueWeight = TWeight;
NewFalseWeight = 2 * (uint64_t)FWeight;
ScaleWeights(NewTrueWeight, NewFalseWeight);
// Emit the RHS condition into TmpBB.
FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc,
NewTrueWeight, NewFalseWeight);
} else {
assert(Opc == Instruction::And && "Unknown merge op!");
// Codegen X & Y as:
// BB1:
// jmp_if_X TmpBB
// jmp FBB
// TmpBB:
// jmp_if_Y TBB
// jmp FBB
//
// This requires creation of TmpBB after CurBB.
// We have flexibility in setting Prob for BB1 and Prob for TmpBB.
// The requirement is that
// FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB)
// = FalseProb for orignal BB.
// Assuming the orignal weights are A and B, one choice is to set BB1's
// weights to 2A+B and B, and set TmpBB's weights to 2A and B. This choice
// assumes that
// FalseProb for BB1 == TrueProb for BB1 * FalseProb for TmpBB.
uint64_t NewTrueWeight = 2 * (uint64_t)TWeight + (uint64_t)FWeight;
uint64_t NewFalseWeight = FWeight;
ScaleWeights(NewTrueWeight, NewFalseWeight);
// Emit the LHS condition.
FindMergedConditions(BOp->getOperand(0), TmpBB, FBB, CurBB, SwitchBB, Opc,
NewTrueWeight, NewFalseWeight);
NewTrueWeight = 2 * (uint64_t)TWeight;
NewFalseWeight = FWeight;
ScaleWeights(NewTrueWeight, NewFalseWeight);
// Emit the RHS condition into TmpBB.
FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc,
NewTrueWeight, NewFalseWeight);
}
}
/// If the set of cases should be emitted as a series of branches, return true.
/// If we should emit this as a bunch of and/or'd together conditions, return
/// false.
bool
SelectionDAGBuilder::ShouldEmitAsBranches(const std::vector<CaseBlock> &Cases) {
if (Cases.size() != 2) return true;
// If this is two comparisons of the same values or'd or and'd together, they
// will get folded into a single comparison, so don't emit two blocks.
if ((Cases[0].CmpLHS == Cases[1].CmpLHS &&
Cases[0].CmpRHS == Cases[1].CmpRHS) ||
(Cases[0].CmpRHS == Cases[1].CmpLHS &&
Cases[0].CmpLHS == Cases[1].CmpRHS)) {
return false;
}
// Handle: (X != null) | (Y != null) --> (X|Y) != 0
// Handle: (X == null) & (Y == null) --> (X|Y) == 0
if (Cases[0].CmpRHS == Cases[1].CmpRHS &&
Cases[0].CC == Cases[1].CC &&
isa<Constant>(Cases[0].CmpRHS) &&
cast<Constant>(Cases[0].CmpRHS)->isNullValue()) {
if (Cases[0].CC == ISD::SETEQ && Cases[0].TrueBB == Cases[1].ThisBB)
return false;
if (Cases[0].CC == ISD::SETNE && Cases[0].FalseBB == Cases[1].ThisBB)
return false;
}
return true;
}
void SelectionDAGBuilder::visitBr(const BranchInst &I) {
MachineBasicBlock *BrMBB = FuncInfo.MBB;
// Update machine-CFG edges.
MachineBasicBlock *Succ0MBB = FuncInfo.MBBMap[I.getSuccessor(0)];
if (I.isUnconditional()) {
// Update machine-CFG edges.
BrMBB->addSuccessor(Succ0MBB);
// If this is not a fall-through branch or optimizations are switched off,
// emit the branch.
if (Succ0MBB != NextBlock(BrMBB) || TM.getOptLevel() == CodeGenOpt::None)
DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(),
MVT::Other, getControlRoot(),
DAG.getBasicBlock(Succ0MBB)));
return;
}
// If this condition is one of the special cases we handle, do special stuff
// now.
const Value *CondVal = I.getCondition();
MachineBasicBlock *Succ1MBB = FuncInfo.MBBMap[I.getSuccessor(1)];
// If this is a series of conditions that are or'd or and'd together, emit
// this as a sequence of branches instead of setcc's with and/or operations.
// As long as jumps are not expensive, this should improve performance.
// For example, instead of something like:
// cmp A, B
// C = seteq
// cmp D, E
// F = setle
// or C, F
// jnz foo
// Emit:
// cmp A, B
// je foo
// cmp D, E
// jle foo
//
if (const BinaryOperator *BOp = dyn_cast<BinaryOperator>(CondVal)) {
if (!DAG.getTargetLoweringInfo().isJumpExpensive() &&
BOp->hasOneUse() && (BOp->getOpcode() == Instruction::And ||
BOp->getOpcode() == Instruction::Or)) {
FindMergedConditions(BOp, Succ0MBB, Succ1MBB, BrMBB, BrMBB,
BOp->getOpcode(), getEdgeWeight(BrMBB, Succ0MBB),
getEdgeWeight(BrMBB, Succ1MBB));
// If the compares in later blocks need to use values not currently
// exported from this block, export them now. This block should always
// be the first entry.
assert(SwitchCases[0].ThisBB == BrMBB && "Unexpected lowering!");
// Allow some cases to be rejected.
if (ShouldEmitAsBranches(SwitchCases)) {
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) {
ExportFromCurrentBlock(SwitchCases[i].CmpLHS);
ExportFromCurrentBlock(SwitchCases[i].CmpRHS);
}
// Emit the branch for this block.
visitSwitchCase(SwitchCases[0], BrMBB);
SwitchCases.erase(SwitchCases.begin());
return;
}
// Okay, we decided not to do this, remove any inserted MBB's and clear
// SwitchCases.
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i)
FuncInfo.MF->erase(SwitchCases[i].ThisBB);
SwitchCases.clear();
}
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, CondVal, ConstantInt::getTrue(*DAG.getContext()),
nullptr, Succ0MBB, Succ1MBB, BrMBB);
// Use visitSwitchCase to actually insert the fast branch sequence for this
// cond branch.
visitSwitchCase(CB, BrMBB);
}
/// visitSwitchCase - Emits the necessary code to represent a single node in
/// the binary search tree resulting from lowering a switch instruction.
void SelectionDAGBuilder::visitSwitchCase(CaseBlock &CB,
MachineBasicBlock *SwitchBB) {
SDValue Cond;
SDValue CondLHS = getValue(CB.CmpLHS);
SDLoc dl = getCurSDLoc();
// Build the setcc now.
if (!CB.CmpMHS) {
// Fold "(X == true)" to X and "(X == false)" to !X to
// handle common cases produced by branch lowering.
if (CB.CmpRHS == ConstantInt::getTrue(*DAG.getContext()) &&
CB.CC == ISD::SETEQ)
Cond = CondLHS;
else if (CB.CmpRHS == ConstantInt::getFalse(*DAG.getContext()) &&
CB.CC == ISD::SETEQ) {
SDValue True = DAG.getConstant(1, dl, CondLHS.getValueType());
Cond = DAG.getNode(ISD::XOR, dl, CondLHS.getValueType(), CondLHS, True);
} else
Cond = DAG.getSetCC(dl, MVT::i1, CondLHS, getValue(CB.CmpRHS), CB.CC);
} else {
assert(CB.CC == ISD::SETLE && "Can handle only LE ranges now");
const APInt& Low = cast<ConstantInt>(CB.CmpLHS)->getValue();
const APInt& High = cast<ConstantInt>(CB.CmpRHS)->getValue();
SDValue CmpOp = getValue(CB.CmpMHS);
EVT VT = CmpOp.getValueType();
if (cast<ConstantInt>(CB.CmpLHS)->isMinValue(true)) {
Cond = DAG.getSetCC(dl, MVT::i1, CmpOp, DAG.getConstant(High, dl, VT),
ISD::SETLE);
} else {
SDValue SUB = DAG.getNode(ISD::SUB, dl,
VT, CmpOp, DAG.getConstant(Low, dl, VT));
Cond = DAG.getSetCC(dl, MVT::i1, SUB,
DAG.getConstant(High-Low, dl, VT), ISD::SETULE);
}
}
// Update successor info
addSuccessorWithWeight(SwitchBB, CB.TrueBB, CB.TrueWeight);
// TrueBB and FalseBB are always different unless the incoming IR is
// degenerate. This only happens when running llc on weird IR.
if (CB.TrueBB != CB.FalseBB)
addSuccessorWithWeight(SwitchBB, CB.FalseBB, CB.FalseWeight);
// If the lhs block is the next block, invert the condition so that we can
// fall through to the lhs instead of the rhs block.
if (CB.TrueBB == NextBlock(SwitchBB)) {
std::swap(CB.TrueBB, CB.FalseBB);
SDValue True = DAG.getConstant(1, dl, Cond.getValueType());
Cond = DAG.getNode(ISD::XOR, dl, Cond.getValueType(), Cond, True);
}
SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, getControlRoot(), Cond,
DAG.getBasicBlock(CB.TrueBB));
// Insert the false branch. Do this even if it's a fall through branch,
// this makes it easier to do DAG optimizations which require inverting
// the branch condition.
BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond,
DAG.getBasicBlock(CB.FalseBB));
DAG.setRoot(BrCond);
}
/// visitJumpTable - Emit JumpTable node in the current MBB
void SelectionDAGBuilder::visitJumpTable(JumpTable &JT) {
// Emit the code for the jump table
assert(JT.Reg != -1U && "Should lower JT Header first!");
EVT PTy = DAG.getTargetLoweringInfo().getPointerTy();
SDValue Index = DAG.getCopyFromReg(getControlRoot(), getCurSDLoc(),
JT.Reg, PTy);
SDValue Table = DAG.getJumpTable(JT.JTI, PTy);
SDValue BrJumpTable = DAG.getNode(ISD::BR_JT, getCurSDLoc(),
MVT::Other, Index.getValue(1),
Table, Index);
DAG.setRoot(BrJumpTable);
}
/// visitJumpTableHeader - This function emits necessary code to produce index
/// in the JumpTable from switch case.
void SelectionDAGBuilder::visitJumpTableHeader(JumpTable &JT,
JumpTableHeader &JTH,
MachineBasicBlock *SwitchBB) {
SDLoc dl = getCurSDLoc();
// Subtract the lowest switch case value from the value being switched on and
// conditional branch to default mbb if the result is greater than the
// difference between smallest and largest cases.
SDValue SwitchOp = getValue(JTH.SValue);
EVT VT = SwitchOp.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp,
DAG.getConstant(JTH.First, dl, VT));
// The SDNode we just created, which holds the value being switched on minus
// the smallest case value, needs to be copied to a virtual register so it
// can be used as an index into the jump table in a subsequent basic block.
// This value may be smaller or larger than the target's pointer type, and
// therefore require extension or truncating.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SwitchOp = DAG.getZExtOrTrunc(Sub, dl, TLI.getPointerTy());
unsigned JumpTableReg = FuncInfo.CreateReg(TLI.getPointerTy());
SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl,
JumpTableReg, SwitchOp);
JT.Reg = JumpTableReg;
// Emit the range check for the jump table, and branch to the default block
// for the switch statement if the value being switched on exceeds the largest
// case in the switch.
SDValue CMP =
DAG.getSetCC(dl, TLI.getSetCCResultType(*DAG.getContext(),
Sub.getValueType()),
Sub, DAG.getConstant(JTH.Last - JTH.First, dl, VT),
ISD::SETUGT);
SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, CopyTo, CMP,
DAG.getBasicBlock(JT.Default));
// Avoid emitting unnecessary branches to the next block.
if (JT.MBB != NextBlock(SwitchBB))
BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond,
DAG.getBasicBlock(JT.MBB));
DAG.setRoot(BrCond);
}
/// Codegen a new tail for a stack protector check ParentMBB which has had its
/// tail spliced into a stack protector check success bb.
///
/// For a high level explanation of how this fits into the stack protector
/// generation see the comment on the declaration of class
/// StackProtectorDescriptor.
void SelectionDAGBuilder::visitSPDescriptorParent(StackProtectorDescriptor &SPD,
MachineBasicBlock *ParentBB) {
// First create the loads to the guard/stack slot for the comparison.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT PtrTy = TLI.getPointerTy();
MachineFrameInfo *MFI = ParentBB->getParent()->getFrameInfo();
int FI = MFI->getStackProtectorIndex();
const Value *IRGuard = SPD.getGuard();
SDValue GuardPtr = getValue(IRGuard);
SDValue StackSlotPtr = DAG.getFrameIndex(FI, PtrTy);
unsigned Align =
TLI.getDataLayout()->getPrefTypeAlignment(IRGuard->getType());
SDValue Guard;
SDLoc dl = getCurSDLoc();
// If GuardReg is set and useLoadStackGuardNode returns true, retrieve the
// guard value from the virtual register holding the value. Otherwise, emit a
// volatile load to retrieve the stack guard value.
unsigned GuardReg = SPD.getGuardReg();
if (GuardReg && TLI.useLoadStackGuardNode())
Guard = DAG.getCopyFromReg(DAG.getEntryNode(), dl, GuardReg,
PtrTy);
else
Guard = DAG.getLoad(PtrTy, dl, DAG.getEntryNode(),
GuardPtr, MachinePointerInfo(IRGuard, 0),
true, false, false, Align);
SDValue StackSlot = DAG.getLoad(PtrTy, dl, DAG.getEntryNode(),
StackSlotPtr,
MachinePointerInfo::getFixedStack(FI),
true, false, false, Align);
// Perform the comparison via a subtract/getsetcc.
EVT VT = Guard.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, Guard, StackSlot);
SDValue Cmp =
DAG.getSetCC(dl, TLI.getSetCCResultType(*DAG.getContext(),
Sub.getValueType()),
Sub, DAG.getConstant(0, dl, VT), ISD::SETNE);
// If the sub is not 0, then we know the guard/stackslot do not equal, so
// branch to failure MBB.
SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, StackSlot.getOperand(0),
Cmp, DAG.getBasicBlock(SPD.getFailureMBB()));
// Otherwise branch to success MBB.
SDValue Br = DAG.getNode(ISD::BR, dl,
MVT::Other, BrCond,
DAG.getBasicBlock(SPD.getSuccessMBB()));
DAG.setRoot(Br);
}
/// Codegen the failure basic block for a stack protector check.
///
/// A failure stack protector machine basic block consists simply of a call to
/// __stack_chk_fail().
///
/// For a high level explanation of how this fits into the stack protector
/// generation see the comment on the declaration of class
/// StackProtectorDescriptor.
void
SelectionDAGBuilder::visitSPDescriptorFailure(StackProtectorDescriptor &SPD) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Chain =
TLI.makeLibCall(DAG, RTLIB::STACKPROTECTOR_CHECK_FAIL, MVT::isVoid,
nullptr, 0, false, getCurSDLoc(), false, false).second;
DAG.setRoot(Chain);
}
/// visitBitTestHeader - This function emits necessary code to produce value
/// suitable for "bit tests"
void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B,
MachineBasicBlock *SwitchBB) {
SDLoc dl = getCurSDLoc();
// Subtract the minimum value
SDValue SwitchOp = getValue(B.SValue);
EVT VT = SwitchOp.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp,
DAG.getConstant(B.First, dl, VT));
// Check range
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue RangeCmp =
DAG.getSetCC(dl, TLI.getSetCCResultType(*DAG.getContext(),
Sub.getValueType()),
Sub, DAG.getConstant(B.Range, dl, VT), ISD::SETUGT);
// Determine the type of the test operands.
bool UsePtrType = false;
if (!TLI.isTypeLegal(VT))
UsePtrType = true;
else {
for (unsigned i = 0, e = B.Cases.size(); i != e; ++i)
if (!isUIntN(VT.getSizeInBits(), B.Cases[i].Mask)) {
// Switch table case range are encoded into series of masks.
// Just use pointer type, it's guaranteed to fit.
UsePtrType = true;
break;
}
}
if (UsePtrType) {
VT = TLI.getPointerTy();
Sub = DAG.getZExtOrTrunc(Sub, dl, VT);
}
B.RegVT = VT.getSimpleVT();
B.Reg = FuncInfo.CreateReg(B.RegVT);
SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl, B.Reg, Sub);
MachineBasicBlock* MBB = B.Cases[0].ThisBB;
addSuccessorWithWeight(SwitchBB, B.Default);
addSuccessorWithWeight(SwitchBB, MBB);
SDValue BrRange = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, CopyTo, RangeCmp,
DAG.getBasicBlock(B.Default));
// Avoid emitting unnecessary branches to the next block.
if (MBB != NextBlock(SwitchBB))
BrRange = DAG.getNode(ISD::BR, dl, MVT::Other, BrRange,
DAG.getBasicBlock(MBB));
DAG.setRoot(BrRange);
}
/// visitBitTestCase - this function produces one "bit test"
void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB,
MachineBasicBlock* NextMBB,
uint32_t BranchWeightToNext,
unsigned Reg,
BitTestCase &B,
MachineBasicBlock *SwitchBB) {
SDLoc dl = getCurSDLoc();
MVT VT = BB.RegVT;
SDValue ShiftOp = DAG.getCopyFromReg(getControlRoot(), dl, Reg, VT);
SDValue Cmp;
unsigned PopCount = countPopulation(B.Mask);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (PopCount == 1) {
// Testing for a single bit; just compare the shift count with what it
// would need to be to shift a 1 bit in that position.
Cmp = DAG.getSetCC(
dl, TLI.getSetCCResultType(*DAG.getContext(), VT), ShiftOp,
DAG.getConstant(countTrailingZeros(B.Mask), dl, VT), ISD::SETEQ);
} else if (PopCount == BB.Range) {
// There is only one zero bit in the range, test for it directly.
Cmp = DAG.getSetCC(
dl, TLI.getSetCCResultType(*DAG.getContext(), VT), ShiftOp,
DAG.getConstant(countTrailingOnes(B.Mask), dl, VT), ISD::SETNE);
} else {
// Make desired shift
SDValue SwitchVal = DAG.getNode(ISD::SHL, dl, VT,
DAG.getConstant(1, dl, VT), ShiftOp);
// Emit bit tests and jumps
SDValue AndOp = DAG.getNode(ISD::AND, dl,
VT, SwitchVal, DAG.getConstant(B.Mask, dl, VT));
Cmp = DAG.getSetCC(dl, TLI.getSetCCResultType(*DAG.getContext(), VT), AndOp,
DAG.getConstant(0, dl, VT), ISD::SETNE);
}
// The branch weight from SwitchBB to B.TargetBB is B.ExtraWeight.
addSuccessorWithWeight(SwitchBB, B.TargetBB, B.ExtraWeight);
// The branch weight from SwitchBB to NextMBB is BranchWeightToNext.
addSuccessorWithWeight(SwitchBB, NextMBB, BranchWeightToNext);
SDValue BrAnd = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, getControlRoot(),
Cmp, DAG.getBasicBlock(B.TargetBB));
// Avoid emitting unnecessary branches to the next block.
if (NextMBB != NextBlock(SwitchBB))
BrAnd = DAG.getNode(ISD::BR, dl, MVT::Other, BrAnd,
DAG.getBasicBlock(NextMBB));
DAG.setRoot(BrAnd);
}
void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
MachineBasicBlock *InvokeMBB = FuncInfo.MBB;
// Retrieve successors.
MachineBasicBlock *Return = FuncInfo.MBBMap[I.getSuccessor(0)];
MachineBasicBlock *LandingPad = FuncInfo.MBBMap[I.getSuccessor(1)];
const Value *Callee(I.getCalledValue());
const Function *Fn = dyn_cast<Function>(Callee);
if (isa<InlineAsm>(Callee))
visitInlineAsm(&I);
else if (Fn && Fn->isIntrinsic()) {
switch (Fn->getIntrinsicID()) {
default:
llvm_unreachable("Cannot invoke this intrinsic");
case Intrinsic::donothing:
// Ignore invokes to @llvm.donothing: jump directly to the next BB.
break;
case Intrinsic::experimental_patchpoint_void:
case Intrinsic::experimental_patchpoint_i64:
visitPatchpoint(&I, LandingPad);
break;
case Intrinsic::experimental_gc_statepoint:
LowerStatepoint(ImmutableStatepoint(&I), LandingPad);
break;
}
} else
LowerCallTo(&I, getValue(Callee), false, LandingPad);
// If the value of the invoke is used outside of its defining block, make it
// available as a virtual register.
// We already took care of the exported value for the statepoint instruction
// during call to the LowerStatepoint.
if (!isStatepoint(I)) {
CopyToExportRegsIfNeeded(&I);
}
// Update successor info
addSuccessorWithWeight(InvokeMBB, Return);
addSuccessorWithWeight(InvokeMBB, LandingPad);
// Drop into normal successor.
DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(),
MVT::Other, getControlRoot(),
DAG.getBasicBlock(Return)));
}
void SelectionDAGBuilder::visitResume(const ResumeInst &RI) {
llvm_unreachable("SelectionDAGBuilder shouldn't visit resume instructions!");
}
void SelectionDAGBuilder::visitLandingPad(const LandingPadInst &LP) {
assert(FuncInfo.MBB->isLandingPad() &&
"Call to landingpad not in landing pad!");
MachineBasicBlock *MBB = FuncInfo.MBB;
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
AddLandingPadInfo(LP, MMI, MBB);
// If there aren't registers to copy the values into (e.g., during SjLj
// exceptions), then don't bother to create these DAG nodes.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (TLI.getExceptionPointerRegister() == 0 &&
TLI.getExceptionSelectorRegister() == 0)
return;
SmallVector<EVT, 2> ValueVTs;
SDLoc dl = getCurSDLoc();
ComputeValueVTs(TLI, LP.getType(), ValueVTs);
assert(ValueVTs.size() == 2 && "Only two-valued landingpads are supported");
// Get the two live-in registers as SDValues. The physregs have already been
// copied into virtual registers.
SDValue Ops[2];
if (FuncInfo.ExceptionPointerVirtReg) {
Ops[0] = DAG.getZExtOrTrunc(
DAG.getCopyFromReg(DAG.getEntryNode(), dl,
FuncInfo.ExceptionPointerVirtReg, TLI.getPointerTy()),
dl, ValueVTs[0]);
} else {
Ops[0] = DAG.getConstant(0, dl, TLI.getPointerTy());
}
Ops[1] = DAG.getZExtOrTrunc(
DAG.getCopyFromReg(DAG.getEntryNode(), dl,
FuncInfo.ExceptionSelectorVirtReg, TLI.getPointerTy()),
dl, ValueVTs[1]);
// Merge into one.
SDValue Res = DAG.getNode(ISD::MERGE_VALUES, dl,
DAG.getVTList(ValueVTs), Ops);
setValue(&LP, Res);
}
unsigned
SelectionDAGBuilder::visitLandingPadClauseBB(GlobalValue *ClauseGV,
MachineBasicBlock *LPadBB) {
SDValue Chain = getControlRoot();
SDLoc dl = getCurSDLoc();
// Get the typeid that we will dispatch on later.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
const TargetRegisterClass *RC = TLI.getRegClassFor(TLI.getPointerTy());
unsigned VReg = FuncInfo.MF->getRegInfo().createVirtualRegister(RC);
unsigned TypeID = DAG.getMachineFunction().getMMI().getTypeIDFor(ClauseGV);
SDValue Sel = DAG.getConstant(TypeID, dl, TLI.getPointerTy());
Chain = DAG.getCopyToReg(Chain, dl, VReg, Sel);
// Branch to the main landing pad block.
MachineBasicBlock *ClauseMBB = FuncInfo.MBB;
ClauseMBB->addSuccessor(LPadBB);
DAG.setRoot(DAG.getNode(ISD::BR, dl, MVT::Other, Chain,
DAG.getBasicBlock(LPadBB)));
return VReg;
}
void SelectionDAGBuilder::sortAndRangeify(CaseClusterVector &Clusters) {
#ifndef NDEBUG
for (const CaseCluster &CC : Clusters)
assert(CC.Low == CC.High && "Input clusters must be single-case");
#endif
std::sort(Clusters.begin(), Clusters.end(),
[](const CaseCluster &a, const CaseCluster &b) {
return a.Low->getValue().slt(b.Low->getValue());
});
// Merge adjacent clusters with the same destination.
const unsigned N = Clusters.size();
unsigned DstIndex = 0;
for (unsigned SrcIndex = 0; SrcIndex < N; ++SrcIndex) {
CaseCluster &CC = Clusters[SrcIndex];
const ConstantInt *CaseVal = CC.Low;
MachineBasicBlock *Succ = CC.MBB;
if (DstIndex != 0 && Clusters[DstIndex - 1].MBB == Succ &&
(CaseVal->getValue() - Clusters[DstIndex - 1].High->getValue()) == 1) {
// If this case has the same successor and is a neighbour, merge it into
// the previous cluster.
Clusters[DstIndex - 1].High = CaseVal;
Clusters[DstIndex - 1].Weight += CC.Weight;
assert(Clusters[DstIndex - 1].Weight >= CC.Weight && "Weight overflow!");
} else {
std::memmove(&Clusters[DstIndex++], &Clusters[SrcIndex],
sizeof(Clusters[SrcIndex]));
}
}
Clusters.resize(DstIndex);
}
void SelectionDAGBuilder::UpdateSplitBlock(MachineBasicBlock *First,
MachineBasicBlock *Last) {
// Update JTCases.
for (unsigned i = 0, e = JTCases.size(); i != e; ++i)
if (JTCases[i].first.HeaderBB == First)
JTCases[i].first.HeaderBB = Last;
// Update BitTestCases.
for (unsigned i = 0, e = BitTestCases.size(); i != e; ++i)
if (BitTestCases[i].Parent == First)
BitTestCases[i].Parent = Last;
}
void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) {
MachineBasicBlock *IndirectBrMBB = FuncInfo.MBB;
// Update machine-CFG edges with unique successors.
SmallSet<BasicBlock*, 32> Done;
for (unsigned i = 0, e = I.getNumSuccessors(); i != e; ++i) {
BasicBlock *BB = I.getSuccessor(i);
bool Inserted = Done.insert(BB).second;
if (!Inserted)
continue;
MachineBasicBlock *Succ = FuncInfo.MBBMap[BB];
addSuccessorWithWeight(IndirectBrMBB, Succ);
}
DAG.setRoot(DAG.getNode(ISD::BRIND, getCurSDLoc(),
MVT::Other, getControlRoot(),
getValue(I.getAddress())));
}
void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {
if (DAG.getTarget().Options.TrapUnreachable)
DAG.setRoot(DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot()));
}
void SelectionDAGBuilder::visitFSub(const User &I) {
// -0.0 - X --> fneg
Type *Ty = I.getType();
if (isa<Constant>(I.getOperand(0)) &&
I.getOperand(0) == ConstantFP::getZeroValueForNegation(Ty)) {
SDValue Op2 = getValue(I.getOperand(1));
setValue(&I, DAG.getNode(ISD::FNEG, getCurSDLoc(),
Op2.getValueType(), Op2));
return;
}
visitBinary(I, ISD::FSUB);
}
void SelectionDAGBuilder::visitBinary(const User &I, unsigned OpCode) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
bool nuw = false;
bool nsw = false;
bool exact = false;
if (const OverflowingBinaryOperator *OFBinOp =
dyn_cast<const OverflowingBinaryOperator>(&I)) {
nuw = OFBinOp->hasNoUnsignedWrap();
nsw = OFBinOp->hasNoSignedWrap();
}
if (const PossiblyExactOperator *ExactOp =
dyn_cast<const PossiblyExactOperator>(&I))
exact = ExactOp->isExact();
SDValue BinNodeValue = DAG.getNode(OpCode, getCurSDLoc(), Op1.getValueType(),
Op1, Op2, nuw, nsw, exact);
setValue(&I, BinNodeValue);
}
void SelectionDAGBuilder::visitShift(const User &I, unsigned Opcode) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
EVT ShiftTy =
DAG.getTargetLoweringInfo().getShiftAmountTy(Op2.getValueType());
// Coerce the shift amount to the right type if we can.
if (!I.getType()->isVectorTy() && Op2.getValueType() != ShiftTy) {
unsigned ShiftSize = ShiftTy.getSizeInBits();
unsigned Op2Size = Op2.getValueType().getSizeInBits();
SDLoc DL = getCurSDLoc();
// If the operand is smaller than the shift count type, promote it.
if (ShiftSize > Op2Size)
Op2 = DAG.getNode(ISD::ZERO_EXTEND, DL, ShiftTy, Op2);
// If the operand is larger than the shift count type but the shift
// count type has enough bits to represent any shift value, truncate
// it now. This is a common case and it exposes the truncate to
// optimization early.
else if (ShiftSize >= Log2_32_Ceil(Op2.getValueType().getSizeInBits()))
Op2 = DAG.getNode(ISD::TRUNCATE, DL, ShiftTy, Op2);
// Otherwise we'll need to temporarily settle for some other convenient
// type. Type legalization will make adjustments once the shiftee is split.
else
Op2 = DAG.getZExtOrTrunc(Op2, DL, MVT::i32);
}
bool nuw = false;
bool nsw = false;
bool exact = false;
if (Opcode == ISD::SRL || Opcode == ISD::SRA || Opcode == ISD::SHL) {
if (const OverflowingBinaryOperator *OFBinOp =
dyn_cast<const OverflowingBinaryOperator>(&I)) {
nuw = OFBinOp->hasNoUnsignedWrap();
nsw = OFBinOp->hasNoSignedWrap();
}
if (const PossiblyExactOperator *ExactOp =
dyn_cast<const PossiblyExactOperator>(&I))
exact = ExactOp->isExact();
}
SDValue Res = DAG.getNode(Opcode, getCurSDLoc(), Op1.getValueType(), Op1, Op2,
nuw, nsw, exact);
setValue(&I, Res);
}
void SelectionDAGBuilder::visitSDiv(const User &I) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
// Turn exact SDivs into multiplications.
// FIXME: This should be in DAGCombiner, but it doesn't have access to the
// exact bit.
if (isa<BinaryOperator>(&I) && cast<BinaryOperator>(&I)->isExact() &&
!isa<ConstantSDNode>(Op1) &&
isa<ConstantSDNode>(Op2) && !cast<ConstantSDNode>(Op2)->isNullValue())
setValue(&I, DAG.getTargetLoweringInfo()
.BuildExactSDIV(Op1, Op2, getCurSDLoc(), DAG));
else
setValue(&I, DAG.getNode(ISD::SDIV, getCurSDLoc(), Op1.getValueType(),
Op1, Op2));
}
void SelectionDAGBuilder::visitICmp(const User &I) {
ICmpInst::Predicate predicate = ICmpInst::BAD_ICMP_PREDICATE;
if (const ICmpInst *IC = dyn_cast<ICmpInst>(&I))
predicate = IC->getPredicate();
else if (const ConstantExpr *IC = dyn_cast<ConstantExpr>(&I))
predicate = ICmpInst::Predicate(IC->getPredicate());
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
ISD::CondCode Opcode = getICmpCondCode(predicate);
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Opcode));
}
void SelectionDAGBuilder::visitFCmp(const User &I) {
FCmpInst::Predicate predicate = FCmpInst::BAD_FCMP_PREDICATE;
if (const FCmpInst *FC = dyn_cast<FCmpInst>(&I))
predicate = FC->getPredicate();
else if (const ConstantExpr *FC = dyn_cast<ConstantExpr>(&I))
predicate = FCmpInst::Predicate(FC->getPredicate());
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
ISD::CondCode Condition = getFCmpCondCode(predicate);
if (TM.Options.NoNaNsFPMath)
Condition = getFCmpCodeWithoutNaN(Condition);
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Condition));
}
void SelectionDAGBuilder::visitSelect(const User &I) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(DAG.getTargetLoweringInfo(), I.getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0) return;
SmallVector<SDValue, 4> Values(NumValues);
SDValue Cond = getValue(I.getOperand(0));
SDValue TrueVal = getValue(I.getOperand(1));
SDValue FalseVal = getValue(I.getOperand(2));
ISD::NodeType OpCode = Cond.getValueType().isVector() ?
ISD::VSELECT : ISD::SELECT;
for (unsigned i = 0; i != NumValues; ++i)
Values[i] = DAG.getNode(OpCode, getCurSDLoc(),
TrueVal.getNode()->getValueType(TrueVal.getResNo()+i),
Cond,
SDValue(TrueVal.getNode(),
TrueVal.getResNo() + i),
SDValue(FalseVal.getNode(),
FalseVal.getResNo() + i));
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(),
DAG.getVTList(ValueVTs), Values));
}
void SelectionDAGBuilder::visitTrunc(const User &I) {
// TruncInst cannot be a no-op cast because sizeof(src) > sizeof(dest).
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitZExt(const User &I) {
// ZExt cannot be a no-op cast because sizeof(src) < sizeof(dest).
// ZExt also can't be a cast to bool for same reason. So, nothing much to do
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::ZERO_EXTEND, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitSExt(const User &I) {
// SExt cannot be a no-op cast because sizeof(src) < sizeof(dest).
// SExt also can't be a cast to bool for same reason. So, nothing much to do
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::SIGN_EXTEND, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPTrunc(const User &I) {
// FPTrunc is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
SDLoc dl = getCurSDLoc();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT DestVT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_ROUND, dl, DestVT, N,
DAG.getTargetConstant(0, dl, TLI.getPointerTy())));
}
void SelectionDAGBuilder::visitFPExt(const User &I) {
// FPExt is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_EXTEND, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPToUI(const User &I) {
// FPToUI is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_TO_UINT, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPToSI(const User &I) {
// FPToSI is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::FP_TO_SINT, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitUIToFP(const User &I) {
// UIToFP is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::UINT_TO_FP, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitSIToFP(const User &I) {
// SIToFP is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::SINT_TO_FP, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitPtrToInt(const User &I) {
// What to do depends on the size of the integer and the size of the pointer.
// We can either truncate, zero extend, or no-op, accordingly.
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT));
}
void SelectionDAGBuilder::visitIntToPtr(const User &I) {
// What to do depends on the size of the integer and the size of the pointer.
// We can either truncate, zero extend, or no-op, accordingly.
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT));
}
void SelectionDAGBuilder::visitBitCast(const User &I) {
SDValue N = getValue(I.getOperand(0));
SDLoc dl = getCurSDLoc();
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(I.getType());
// BitCast assures us that source and destination are the same size so this is
// either a BITCAST or a no-op.
if (DestVT != N.getValueType())
setValue(&I, DAG.getNode(ISD::BITCAST, dl,
DestVT, N)); // convert types.
// Check if the original LLVM IR Operand was a ConstantInt, because getValue()
// might fold any kind of constant expression to an integer constant and that
// is not what we are looking for. Only regcognize a bitcast of a genuine
// constant integer as an opaque constant.
else if(ConstantInt *C = dyn_cast<ConstantInt>(I.getOperand(0)))
setValue(&I, DAG.getConstant(C->getValue(), dl, DestVT, /*isTarget=*/false,
/*isOpaque*/true));
else
setValue(&I, N); // noop cast.
}
void SelectionDAGBuilder::visitAddrSpaceCast(const User &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
const Value *SV = I.getOperand(0);
SDValue N = getValue(SV);
EVT DestVT = TLI.getValueType(I.getType());
unsigned SrcAS = SV->getType()->getPointerAddressSpace();
unsigned DestAS = I.getType()->getPointerAddressSpace();
if (!TLI.isNoopAddrSpaceCast(SrcAS, DestAS))
N = DAG.getAddrSpaceCast(getCurSDLoc(), DestVT, N, SrcAS, DestAS);
setValue(&I, N);
}
void SelectionDAGBuilder::visitInsertElement(const User &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue InVec = getValue(I.getOperand(0));
SDValue InVal = getValue(I.getOperand(1));
SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(2)),
getCurSDLoc(), TLI.getVectorIdxTy());
setValue(&I, DAG.getNode(ISD::INSERT_VECTOR_ELT, getCurSDLoc(),
TLI.getValueType(I.getType()), InVec, InVal, InIdx));
}
void SelectionDAGBuilder::visitExtractElement(const User &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue InVec = getValue(I.getOperand(0));
SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(1)),
getCurSDLoc(), TLI.getVectorIdxTy());
setValue(&I, DAG.getNode(ISD::EXTRACT_VECTOR_ELT, getCurSDLoc(),
TLI.getValueType(I.getType()), InVec, InIdx));
}
// Utility for visitShuffleVector - Return true if every element in Mask,
// beginning from position Pos and ending in Pos+Size, falls within the
// specified sequential range [L, L+Pos). or is undef.
static bool isSequentialInRange(const SmallVectorImpl<int> &Mask,
unsigned Pos, unsigned Size, int Low) {
for (unsigned i = Pos, e = Pos+Size; i != e; ++i, ++Low)
if (Mask[i] >= 0 && Mask[i] != Low)
return false;
return true;
}
void SelectionDAGBuilder::visitShuffleVector(const User &I) {
SDValue Src1 = getValue(I.getOperand(0));
SDValue Src2 = getValue(I.getOperand(1));
SmallVector<int, 8> Mask;
ShuffleVectorInst::getShuffleMask(cast<Constant>(I.getOperand(2)), Mask);
unsigned MaskNumElts = Mask.size();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(I.getType());
EVT SrcVT = Src1.getValueType();
unsigned SrcNumElts = SrcVT.getVectorNumElements();
if (SrcNumElts == MaskNumElts) {
setValue(&I, DAG.getVectorShuffle(VT, getCurSDLoc(), Src1, Src2,
&Mask[0]));
return;
}
// Normalize the shuffle vector since mask and vector length don't match.
if (SrcNumElts < MaskNumElts && MaskNumElts % SrcNumElts == 0) {
// Mask is longer than the source vectors and is a multiple of the source
// vectors. We can use concatenate vector to make the mask and vectors
// lengths match.
if (SrcNumElts*2 == MaskNumElts) {
// First check for Src1 in low and Src2 in high
if (isSequentialInRange(Mask, 0, SrcNumElts, 0) &&
isSequentialInRange(Mask, SrcNumElts, SrcNumElts, SrcNumElts)) {
// The shuffle is concatenating two vectors together.
setValue(&I, DAG.getNode(ISD::CONCAT_VECTORS, getCurSDLoc(),
VT, Src1, Src2));
return;
}
// Then check for Src2 in low and Src1 in high
if (isSequentialInRange(Mask, 0, SrcNumElts, SrcNumElts) &&
isSequentialInRange(Mask, SrcNumElts, SrcNumElts, 0)) {
// The shuffle is concatenating two vectors together.
setValue(&I, DAG.getNode(ISD::CONCAT_VECTORS, getCurSDLoc(),
VT, Src2, Src1));
return;
}
}
// Pad both vectors with undefs to make them the same length as the mask.
unsigned NumConcat = MaskNumElts / SrcNumElts;
bool Src1U = Src1.getOpcode() == ISD::UNDEF;
bool Src2U = Src2.getOpcode() == ISD::UNDEF;
SDValue UndefVal = DAG.getUNDEF(SrcVT);
SmallVector<SDValue, 8> MOps1(NumConcat, UndefVal);
SmallVector<SDValue, 8> MOps2(NumConcat, UndefVal);
MOps1[0] = Src1;
MOps2[0] = Src2;
Src1 = Src1U ? DAG.getUNDEF(VT) : DAG.getNode(ISD::CONCAT_VECTORS,
getCurSDLoc(), VT, MOps1);
Src2 = Src2U ? DAG.getUNDEF(VT) : DAG.getNode(ISD::CONCAT_VECTORS,
getCurSDLoc(), VT, MOps2);
// Readjust mask for new input vector length.
SmallVector<int, 8> MappedOps;
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
if (Idx >= (int)SrcNumElts)
Idx -= SrcNumElts - MaskNumElts;
MappedOps.push_back(Idx);
}
setValue(&I, DAG.getVectorShuffle(VT, getCurSDLoc(), Src1, Src2,
&MappedOps[0]));
return;
}
if (SrcNumElts > MaskNumElts) {
// Analyze the access pattern of the vector to see if we can extract
// two subvectors and do the shuffle. The analysis is done by calculating
// the range of elements the mask access on both vectors.
int MinRange[2] = { static_cast<int>(SrcNumElts),
static_cast<int>(SrcNumElts)};
int MaxRange[2] = {-1, -1};
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
unsigned Input = 0;
if (Idx < 0)
continue;
if (Idx >= (int)SrcNumElts) {
Input = 1;
Idx -= SrcNumElts;
}
if (Idx > MaxRange[Input])
MaxRange[Input] = Idx;
if (Idx < MinRange[Input])
MinRange[Input] = Idx;
}
// Check if the access is smaller than the vector size and can we find
// a reasonable extract index.
int RangeUse[2] = { -1, -1 }; // 0 = Unused, 1 = Extract, -1 = Can not
// Extract.
int StartIdx[2]; // StartIdx to extract from
for (unsigned Input = 0; Input < 2; ++Input) {
if (MinRange[Input] >= (int)SrcNumElts && MaxRange[Input] < 0) {
RangeUse[Input] = 0; // Unused
StartIdx[Input] = 0;
continue;
}
// Find a good start index that is a multiple of the mask length. Then
// see if the rest of the elements are in range.
StartIdx[Input] = (MinRange[Input]/MaskNumElts)*MaskNumElts;
if (MaxRange[Input] - StartIdx[Input] < (int)MaskNumElts &&
StartIdx[Input] + MaskNumElts <= SrcNumElts)
RangeUse[Input] = 1; // Extract from a multiple of the mask length.
}
if (RangeUse[0] == 0 && RangeUse[1] == 0) {
setValue(&I, DAG.getUNDEF(VT)); // Vectors are not used.
return;
}
if (RangeUse[0] >= 0 && RangeUse[1] >= 0) {
// Extract appropriate subvector and generate a vector shuffle
for (unsigned Input = 0; Input < 2; ++Input) {
SDValue &Src = Input == 0 ? Src1 : Src2;
if (RangeUse[Input] == 0)
Src = DAG.getUNDEF(VT);
else {
SDLoc dl = getCurSDLoc();
Src = DAG.getNode(
ISD::EXTRACT_SUBVECTOR, dl, VT, Src,
DAG.getConstant(StartIdx[Input], dl, TLI.getVectorIdxTy()));
}
}
// Calculate new mask.
SmallVector<int, 8> MappedOps;
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
if (Idx >= 0) {
if (Idx < (int)SrcNumElts)
Idx -= StartIdx[0];
else
Idx -= SrcNumElts + StartIdx[1] - MaskNumElts;
}
MappedOps.push_back(Idx);
}
setValue(&I, DAG.getVectorShuffle(VT, getCurSDLoc(), Src1, Src2,
&MappedOps[0]));
return;
}
}
// We can't use either concat vectors or extract subvectors so fall back to
// replacing the shuffle with extract and build vector.
// to insert and build vector.
EVT EltVT = VT.getVectorElementType();
EVT IdxVT = TLI.getVectorIdxTy();
SDLoc dl = getCurSDLoc();
SmallVector<SDValue,8> Ops;
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
SDValue Res;
if (Idx < 0) {
Res = DAG.getUNDEF(EltVT);
} else {
SDValue &Src = Idx < (int)SrcNumElts ? Src1 : Src2;
if (Idx >= (int)SrcNumElts) Idx -= SrcNumElts;
Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
EltVT, Src, DAG.getConstant(Idx, dl, IdxVT));
}
Ops.push_back(Res);
}
setValue(&I, DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops));
}
void SelectionDAGBuilder::visitInsertValue(const InsertValueInst &I) {
const Value *Op0 = I.getOperand(0);
const Value *Op1 = I.getOperand(1);
Type *AggTy = I.getType();
Type *ValTy = Op1->getType();
bool IntoUndef = isa<UndefValue>(Op0);
bool FromUndef = isa<UndefValue>(Op1);
unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices());
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SmallVector<EVT, 4> AggValueVTs;
ComputeValueVTs(TLI, AggTy, AggValueVTs);
SmallVector<EVT, 4> ValValueVTs;
ComputeValueVTs(TLI, ValTy, ValValueVTs);
unsigned NumAggValues = AggValueVTs.size();
unsigned NumValValues = ValValueVTs.size();
SmallVector<SDValue, 4> Values(NumAggValues);
// Ignore an insertvalue that produces an empty object
if (!NumAggValues) {
setValue(&I, DAG.getUNDEF(MVT(MVT::Other)));
return;
}
SDValue Agg = getValue(Op0);
unsigned i = 0;
// Copy the beginning value(s) from the original aggregate.
for (; i != LinearIndex; ++i)
Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
// Copy values from the inserted value(s).
if (NumValValues) {
SDValue Val = getValue(Op1);
for (; i != LinearIndex + NumValValues; ++i)
Values[i] = FromUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Val.getNode(), Val.getResNo() + i - LinearIndex);
}
// Copy remaining value(s) from the original aggregate.
for (; i != NumAggValues; ++i)
Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(),
DAG.getVTList(AggValueVTs), Values));
}
void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) {
const Value *Op0 = I.getOperand(0);
Type *AggTy = Op0->getType();
Type *ValTy = I.getType();
bool OutOfUndef = isa<UndefValue>(Op0);
unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices());
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SmallVector<EVT, 4> ValValueVTs;
ComputeValueVTs(TLI, ValTy, ValValueVTs);
unsigned NumValValues = ValValueVTs.size();
// Ignore a extractvalue that produces an empty object
if (!NumValValues) {
setValue(&I, DAG.getUNDEF(MVT(MVT::Other)));
return;
}
SmallVector<SDValue, 4> Values(NumValValues);
SDValue Agg = getValue(Op0);
// Copy out the selected value(s).
for (unsigned i = LinearIndex; i != LinearIndex + NumValValues; ++i)
Values[i - LinearIndex] =
OutOfUndef ?
DAG.getUNDEF(Agg.getNode()->getValueType(Agg.getResNo() + i)) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(),
DAG.getVTList(ValValueVTs), Values));
}
void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
Value *Op0 = I.getOperand(0);
// Note that the pointer operand may be a vector of pointers. Take the scalar
// element which holds a pointer.
Type *Ty = Op0->getType()->getScalarType();
unsigned AS = Ty->getPointerAddressSpace();
SDValue N = getValue(Op0);
SDLoc dl = getCurSDLoc();
for (GetElementPtrInst::const_op_iterator OI = I.op_begin()+1, E = I.op_end();
OI != E; ++OI) {
const Value *Idx = *OI;
if (StructType *StTy = dyn_cast<StructType>(Ty)) {
unsigned Field = cast<Constant>(Idx)->getUniqueInteger().getZExtValue();
if (Field) {
// N = N + Offset
uint64_t Offset = DL->getStructLayout(StTy)->getElementOffset(Field);
N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N,
DAG.getConstant(Offset, dl, N.getValueType()));
}
Ty = StTy->getElementType(Field);
} else {
Ty = cast<SequentialType>(Ty)->getElementType();
MVT PtrTy = DAG.getTargetLoweringInfo().getPointerTy(AS);
unsigned PtrSize = PtrTy.getSizeInBits();
APInt ElementSize(PtrSize, DL->getTypeAllocSize(Ty));
// If this is a constant subscript, handle it quickly.
if (const auto *CI = dyn_cast<ConstantInt>(Idx)) {
if (CI->isZero())
continue;
APInt Offs = ElementSize * CI->getValue().sextOrTrunc(PtrSize);
SDValue OffsVal = DAG.getConstant(Offs, dl, PtrTy);
N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N, OffsVal);
continue;
}
// N = N + Idx * ElementSize;
SDValue IdxN = getValue(Idx);
// If the index is smaller or larger than intptr_t, truncate or extend
// it.
IdxN = DAG.getSExtOrTrunc(IdxN, dl, N.getValueType());
// If this is a multiply by a power of two, turn it into a shl
// immediately. This is a very common case.
if (ElementSize != 1) {
if (ElementSize.isPowerOf2()) {
unsigned Amt = ElementSize.logBase2();
IdxN = DAG.getNode(ISD::SHL, dl,
N.getValueType(), IdxN,
DAG.getConstant(Amt, dl, IdxN.getValueType()));
} else {
SDValue Scale = DAG.getConstant(ElementSize, dl, IdxN.getValueType());
IdxN = DAG.getNode(ISD::MUL, dl,
N.getValueType(), IdxN, Scale);
}
}
N = DAG.getNode(ISD::ADD, dl,
N.getValueType(), N, IdxN);
}
}
setValue(&I, N);
}
void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) {
// If this is a fixed sized alloca in the entry block of the function,
// allocate it statically on the stack.
if (FuncInfo.StaticAllocaMap.count(&I))
return; // getValue will auto-populate this.
SDLoc dl = getCurSDLoc();
Type *Ty = I.getAllocatedType();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
uint64_t TySize = TLI.getDataLayout()->getTypeAllocSize(Ty);
unsigned Align =
std::max((unsigned)TLI.getDataLayout()->getPrefTypeAlignment(Ty),
I.getAlignment());
SDValue AllocSize = getValue(I.getArraySize());
EVT IntPtr = TLI.getPointerTy();
if (AllocSize.getValueType() != IntPtr)
AllocSize = DAG.getZExtOrTrunc(AllocSize, dl, IntPtr);
AllocSize = DAG.getNode(ISD::MUL, dl, IntPtr,
AllocSize,
DAG.getConstant(TySize, dl, IntPtr));
// Handle alignment. If the requested alignment is less than or equal to
// the stack alignment, ignore it. If the size is greater than or equal to
// the stack alignment, we note this in the DYNAMIC_STACKALLOC node.
unsigned StackAlign =
DAG.getSubtarget().getFrameLowering()->getStackAlignment();
if (Align <= StackAlign)
Align = 0;
// Round the size of the allocation up to the stack alignment size
// by add SA-1 to the size.
AllocSize = DAG.getNode(ISD::ADD, dl,
AllocSize.getValueType(), AllocSize,
DAG.getIntPtrConstant(StackAlign - 1, dl));
// Mask out the low bits for alignment purposes.
AllocSize = DAG.getNode(ISD::AND, dl,
AllocSize.getValueType(), AllocSize,
DAG.getIntPtrConstant(~(uint64_t)(StackAlign - 1),
dl));
SDValue Ops[] = { getRoot(), AllocSize, DAG.getIntPtrConstant(Align, dl) };
SDVTList VTs = DAG.getVTList(AllocSize.getValueType(), MVT::Other);
SDValue DSA = DAG.getNode(ISD::DYNAMIC_STACKALLOC, dl, VTs, Ops);
setValue(&I, DSA);
DAG.setRoot(DSA.getValue(1));
assert(FuncInfo.MF->getFrameInfo()->hasVarSizedObjects());
}
void SelectionDAGBuilder::visitLoad(const LoadInst &I) {
if (I.isAtomic())
return visitAtomicLoad(I);
const Value *SV = I.getOperand(0);
SDValue Ptr = getValue(SV);
Type *Ty = I.getType();
bool isVolatile = I.isVolatile();
bool isNonTemporal = I.getMetadata(LLVMContext::MD_nontemporal) != nullptr;
bool isInvariant = I.getMetadata(LLVMContext::MD_invariant_load) != nullptr;
unsigned Alignment = I.getAlignment();
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(TLI, Ty, ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0)
return;
SDValue Root;
bool ConstantMemory = false;
if (isVolatile || NumValues > MaxParallelChains)
// Serialize volatile loads with other side effects.
Root = getRoot();
else if (AA->pointsToConstantMemory(
AliasAnalysis::Location(SV, AA->getTypeStoreSize(Ty), AAInfo))) {
// Do not serialize (non-volatile) loads of constant memory with anything.
Root = DAG.getEntryNode();
ConstantMemory = true;
} else {
// Do not serialize non-volatile loads against each other.
Root = DAG.getRoot();
}
SDLoc dl = getCurSDLoc();
if (isVolatile)
Root = TLI.prepareVolatileOrAtomicLoad(Root, dl, DAG);
SmallVector<SDValue, 4> Values(NumValues);
SmallVector<SDValue, 4> Chains(std::min(unsigned(MaxParallelChains),
NumValues));
EVT PtrVT = Ptr.getValueType();
unsigned ChainI = 0;
for (unsigned i = 0; i != NumValues; ++i, ++ChainI) {
// Serializing loads here may result in excessive register pressure, and
// TokenFactor places arbitrary choke points on the scheduler. SD scheduling
// could recover a bit by hoisting nodes upward in the chain by recognizing
// they are side-effect free or do not alias. The optimizer should really
// avoid this case by converting large object/array copies to llvm.memcpy
// (MaxParallelChains should always remain as failsafe).
if (ChainI == MaxParallelChains) {
assert(PendingLoads.empty() && "PendingLoads must be serialized first");
SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
Root = Chain;
ChainI = 0;
}
SDValue A = DAG.getNode(ISD::ADD, dl,
PtrVT, Ptr,
DAG.getConstant(Offsets[i], dl, PtrVT));
SDValue L = DAG.getLoad(ValueVTs[i], dl, Root,
A, MachinePointerInfo(SV, Offsets[i]), isVolatile,
isNonTemporal, isInvariant, Alignment, AAInfo,
Ranges);
Values[i] = L;
Chains[ChainI] = L.getValue(1);
}
if (!ConstantMemory) {
SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
if (isVolatile)
DAG.setRoot(Chain);
else
PendingLoads.push_back(Chain);
}
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, dl,
DAG.getVTList(ValueVTs), Values));
}
void SelectionDAGBuilder::visitStore(const StoreInst &I) {
if (I.isAtomic())
return visitAtomicStore(I);
const Value *SrcV = I.getOperand(0);
const Value *PtrV = I.getOperand(1);
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(DAG.getTargetLoweringInfo(), SrcV->getType(),
ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0)
return;
// Get the lowered operands. Note that we do this after
// checking if NumResults is zero, because with zero results
// the operands won't have values in the map.
SDValue Src = getValue(SrcV);
SDValue Ptr = getValue(PtrV);
SDValue Root = getRoot();
SmallVector<SDValue, 4> Chains(std::min(unsigned(MaxParallelChains),
NumValues));
EVT PtrVT = Ptr.getValueType();
bool isVolatile = I.isVolatile();
bool isNonTemporal = I.getMetadata(LLVMContext::MD_nontemporal) != nullptr;
unsigned Alignment = I.getAlignment();
SDLoc dl = getCurSDLoc();
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
unsigned ChainI = 0;
for (unsigned i = 0; i != NumValues; ++i, ++ChainI) {
// See visitLoad comments.
if (ChainI == MaxParallelChains) {
SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
Root = Chain;
ChainI = 0;
}
SDValue Add = DAG.getNode(ISD::ADD, dl, PtrVT, Ptr,
DAG.getConstant(Offsets[i], dl, PtrVT));
SDValue St = DAG.getStore(Root, dl,
SDValue(Src.getNode(), Src.getResNo() + i),
Add, MachinePointerInfo(PtrV, Offsets[i]),
isVolatile, isNonTemporal, Alignment, AAInfo);
Chains[ChainI] = St;
}
SDValue StoreNode = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
DAG.setRoot(StoreNode);
}
void SelectionDAGBuilder::visitMaskedStore(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// llvm.masked.store.*(Src0, Ptr, alignemt, Mask)
Value *PtrOperand = I.getArgOperand(1);
SDValue Ptr = getValue(PtrOperand);
SDValue Src0 = getValue(I.getArgOperand(0));
SDValue Mask = getValue(I.getArgOperand(3));
EVT VT = Src0.getValueType();
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(2)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(PtrOperand),
MachineMemOperand::MOStore, VT.getStoreSize(),
Alignment, AAInfo);
SDValue StoreNode = DAG.getMaskedStore(getRoot(), sdl, Src0, Ptr, Mask, VT,
MMO, false);
DAG.setRoot(StoreNode);
setValue(&I, StoreNode);
}
// Gather/scatter receive a vector of pointers.
// This vector of pointers may be represented as a base pointer + vector of
// indices, it depends on GEP and instruction preceeding GEP
// that calculates indices
static bool getUniformBase(Value *& Ptr, SDValue& Base, SDValue& Index,
SelectionDAGBuilder* SDB) {
assert (Ptr->getType()->isVectorTy() && "Uexpected pointer type");
GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr);
if (!Gep || Gep->getNumOperands() > 2)
return false;
ShuffleVectorInst *ShuffleInst =
dyn_cast<ShuffleVectorInst>(Gep->getPointerOperand());
if (!ShuffleInst || !ShuffleInst->getMask()->isNullValue() ||
cast<Instruction>(ShuffleInst->getOperand(0))->getOpcode() !=
Instruction::InsertElement)
return false;
Ptr = cast<InsertElementInst>(ShuffleInst->getOperand(0))->getOperand(1);
SelectionDAG& DAG = SDB->DAG;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// Check is the Ptr is inside current basic block
// If not, look for the shuffle instruction
if (SDB->findValue(Ptr))
Base = SDB->getValue(Ptr);
else if (SDB->findValue(ShuffleInst)) {
SDValue ShuffleNode = SDB->getValue(ShuffleInst);
SDLoc sdl = ShuffleNode;
Base = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, sdl,
ShuffleNode.getValueType().getScalarType(), ShuffleNode,
DAG.getConstant(0, sdl, TLI.getVectorIdxTy()));
SDB->setValue(Ptr, Base);
}
else
return false;
Value *IndexVal = Gep->getOperand(1);
if (SDB->findValue(IndexVal)) {
Index = SDB->getValue(IndexVal);
if (SExtInst* Sext = dyn_cast<SExtInst>(IndexVal)) {
IndexVal = Sext->getOperand(0);
if (SDB->findValue(IndexVal))
Index = SDB->getValue(IndexVal);
}
return true;
}
return false;
}
void SelectionDAGBuilder::visitMaskedScatter(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// llvm.masked.scatter.*(Src0, Ptrs, alignemt, Mask)
Value *Ptr = I.getArgOperand(1);
SDValue Src0 = getValue(I.getArgOperand(0));
SDValue Mask = getValue(I.getArgOperand(3));
EVT VT = Src0.getValueType();
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(2)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
SDValue Base;
SDValue Index;
Value *BasePtr = Ptr;
bool UniformBase = getUniformBase(BasePtr, Base, Index, this);
Value *MemOpBasePtr = UniformBase ? BasePtr : nullptr;
MachineMemOperand *MMO = DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(MemOpBasePtr),
MachineMemOperand::MOStore, VT.getStoreSize(),
Alignment, AAInfo);
if (!UniformBase) {
Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy());
Index = getValue(Ptr);
}
SDValue Ops[] = { getRoot(), Src0, Mask, Base, Index };
SDValue Scatter = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), VT, sdl,
Ops, MMO);
DAG.setRoot(Scatter);
setValue(&I, Scatter);
}
void SelectionDAGBuilder::visitMaskedLoad(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// @llvm.masked.load.*(Ptr, alignment, Mask, Src0)
Value *PtrOperand = I.getArgOperand(0);
SDValue Ptr = getValue(PtrOperand);
SDValue Src0 = getValue(I.getArgOperand(3));
SDValue Mask = getValue(I.getArgOperand(2));
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(I.getType());
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(1)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range);
SDValue InChain = DAG.getRoot();
if (AA->pointsToConstantMemory(
AliasAnalysis::Location(PtrOperand,
AA->getTypeStoreSize(I.getType()),
AAInfo))) {
// Do not serialize (non-volatile) loads of constant memory with anything.
InChain = DAG.getEntryNode();
}
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(PtrOperand),
MachineMemOperand::MOLoad, VT.getStoreSize(),
Alignment, AAInfo, Ranges);
SDValue Load = DAG.getMaskedLoad(VT, sdl, InChain, Ptr, Mask, Src0, VT, MMO,
ISD::NON_EXTLOAD);
SDValue OutChain = Load.getValue(1);
DAG.setRoot(OutChain);
setValue(&I, Load);
}
void SelectionDAGBuilder::visitMaskedGather(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// @llvm.masked.gather.*(Ptrs, alignment, Mask, Src0)
Value *Ptr = I.getArgOperand(0);
SDValue Src0 = getValue(I.getArgOperand(3));
SDValue Mask = getValue(I.getArgOperand(2));
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(I.getType());
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(1)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range);
SDValue Root = DAG.getRoot();
SDValue Base;
SDValue Index;
Value *BasePtr = Ptr;
bool UniformBase = getUniformBase(BasePtr, Base, Index, this);
bool ConstantMemory = false;
if (UniformBase && AA->pointsToConstantMemory(
AliasAnalysis::Location(BasePtr,
AA->getTypeStoreSize(I.getType()),
AAInfo))) {
// Do not serialize (non-volatile) loads of constant memory with anything.
Root = DAG.getEntryNode();
ConstantMemory = true;
}
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(UniformBase ? BasePtr : nullptr),
MachineMemOperand::MOLoad, VT.getStoreSize(),
Alignment, AAInfo, Ranges);
if (!UniformBase) {
Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy());
Index = getValue(Ptr);
}
SDValue Ops[] = { Root, Src0, Mask, Base, Index };
SDValue Gather = DAG.getMaskedGather(DAG.getVTList(VT, MVT::Other), VT, sdl,
Ops, MMO);
SDValue OutChain = Gather.getValue(1);
if (!ConstantMemory)
PendingLoads.push_back(OutChain);
setValue(&I, Gather);
}
void SelectionDAGBuilder::visitAtomicCmpXchg(const AtomicCmpXchgInst &I) {
SDLoc dl = getCurSDLoc();
AtomicOrdering SuccessOrder = I.getSuccessOrdering();
AtomicOrdering FailureOrder = I.getFailureOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
MVT MemVT = getValue(I.getCompareOperand()).getSimpleValueType();
SDVTList VTs = DAG.getVTList(MemVT, MVT::i1, MVT::Other);
SDValue L = DAG.getAtomicCmpSwap(
ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, dl, MemVT, VTs, InChain,
getValue(I.getPointerOperand()), getValue(I.getCompareOperand()),
getValue(I.getNewValOperand()), MachinePointerInfo(I.getPointerOperand()),
/*Alignment=*/ 0, SuccessOrder, FailureOrder, Scope);
SDValue OutChain = L.getValue(2);
setValue(&I, L);
DAG.setRoot(OutChain);
}
void SelectionDAGBuilder::visitAtomicRMW(const AtomicRMWInst &I) {
SDLoc dl = getCurSDLoc();
ISD::NodeType NT;
switch (I.getOperation()) {
default: llvm_unreachable("Unknown atomicrmw operation");
case AtomicRMWInst::Xchg: NT = ISD::ATOMIC_SWAP; break;
case AtomicRMWInst::Add: NT = ISD::ATOMIC_LOAD_ADD; break;
case AtomicRMWInst::Sub: NT = ISD::ATOMIC_LOAD_SUB; break;
case AtomicRMWInst::And: NT = ISD::ATOMIC_LOAD_AND; break;
case AtomicRMWInst::Nand: NT = ISD::ATOMIC_LOAD_NAND; break;
case AtomicRMWInst::Or: NT = ISD::ATOMIC_LOAD_OR; break;
case AtomicRMWInst::Xor: NT = ISD::ATOMIC_LOAD_XOR; break;
case AtomicRMWInst::Max: NT = ISD::ATOMIC_LOAD_MAX; break;
case AtomicRMWInst::Min: NT = ISD::ATOMIC_LOAD_MIN; break;
case AtomicRMWInst::UMax: NT = ISD::ATOMIC_LOAD_UMAX; break;
case AtomicRMWInst::UMin: NT = ISD::ATOMIC_LOAD_UMIN; break;
}
AtomicOrdering Order = I.getOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
SDValue L =
DAG.getAtomic(NT, dl,
getValue(I.getValOperand()).getSimpleValueType(),
InChain,
getValue(I.getPointerOperand()),
getValue(I.getValOperand()),
I.getPointerOperand(),
/* Alignment=*/ 0, Order, Scope);
SDValue OutChain = L.getValue(1);
setValue(&I, L);
DAG.setRoot(OutChain);
}
void SelectionDAGBuilder::visitFence(const FenceInst &I) {
SDLoc dl = getCurSDLoc();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Ops[3];
Ops[0] = getRoot();
Ops[1] = DAG.getConstant(I.getOrdering(), dl, TLI.getPointerTy());
Ops[2] = DAG.getConstant(I.getSynchScope(), dl, TLI.getPointerTy());
DAG.setRoot(DAG.getNode(ISD::ATOMIC_FENCE, dl, MVT::Other, Ops));
}
void SelectionDAGBuilder::visitAtomicLoad(const LoadInst &I) {
SDLoc dl = getCurSDLoc();
AtomicOrdering Order = I.getOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(I.getType());
if (I.getAlignment() < VT.getSizeInBits() / 8)
report_fatal_error("Cannot generate unaligned atomic load");
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(I.getPointerOperand()),
MachineMemOperand::MOVolatile |
MachineMemOperand::MOLoad,
VT.getStoreSize(),
I.getAlignment() ? I.getAlignment() :
DAG.getEVTAlignment(VT));
InChain = TLI.prepareVolatileOrAtomicLoad(InChain, dl, DAG);
SDValue L =
DAG.getAtomic(ISD::ATOMIC_LOAD, dl, VT, VT, InChain,
getValue(I.getPointerOperand()), MMO,
Order, Scope);
SDValue OutChain = L.getValue(1);
setValue(&I, L);
DAG.setRoot(OutChain);
}
void SelectionDAGBuilder::visitAtomicStore(const StoreInst &I) {
SDLoc dl = getCurSDLoc();
AtomicOrdering Order = I.getOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(I.getValueOperand()->getType());
if (I.getAlignment() < VT.getSizeInBits() / 8)
report_fatal_error("Cannot generate unaligned atomic store");
SDValue OutChain =
DAG.getAtomic(ISD::ATOMIC_STORE, dl, VT,
InChain,
getValue(I.getPointerOperand()),
getValue(I.getValueOperand()),
I.getPointerOperand(), I.getAlignment(),
Order, Scope);
DAG.setRoot(OutChain);
}
/// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC
/// node.
void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I,
unsigned Intrinsic) {
bool HasChain = !I.doesNotAccessMemory();
bool OnlyLoad = HasChain && I.onlyReadsMemory();
// Build the operand list.
SmallVector<SDValue, 8> Ops;
if (HasChain) { // If this intrinsic has side-effects, chainify it.
if (OnlyLoad) {
// We don't need to serialize loads against other loads.
Ops.push_back(DAG.getRoot());
} else {
Ops.push_back(getRoot());
}
}
// Info is set by getTgtMemInstrinsic
TargetLowering::IntrinsicInfo Info;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
bool IsTgtIntrinsic = TLI.getTgtMemIntrinsic(Info, I, Intrinsic);
// Add the intrinsic ID as an integer operand if it's not a target intrinsic.
if (!IsTgtIntrinsic || Info.opc == ISD::INTRINSIC_VOID ||
Info.opc == ISD::INTRINSIC_W_CHAIN)
Ops.push_back(DAG.getTargetConstant(Intrinsic, getCurSDLoc(),
TLI.getPointerTy()));
// Add all operands of the call to the operand list.
for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
SDValue Op = getValue(I.getArgOperand(i));
Ops.push_back(Op);
}
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, I.getType(), ValueVTs);
if (HasChain)
ValueVTs.push_back(MVT::Other);
SDVTList VTs = DAG.getVTList(ValueVTs);
// Create the node.
SDValue Result;
if (IsTgtIntrinsic) {
// This is target intrinsic that touches memory
Result = DAG.getMemIntrinsicNode(Info.opc, getCurSDLoc(),
VTs, Ops, Info.memVT,
MachinePointerInfo(Info.ptrVal, Info.offset),
Info.align, Info.vol,
Info.readMem, Info.writeMem, Info.size);
} else if (!HasChain) {
Result = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, getCurSDLoc(), VTs, Ops);
} else if (!I.getType()->isVoidTy()) {
Result = DAG.getNode(ISD::INTRINSIC_W_CHAIN, getCurSDLoc(), VTs, Ops);
} else {
Result = DAG.getNode(ISD::INTRINSIC_VOID, getCurSDLoc(), VTs, Ops);
}
if (HasChain) {
SDValue Chain = Result.getValue(Result.getNode()->getNumValues()-1);
if (OnlyLoad)
PendingLoads.push_back(Chain);
else
DAG.setRoot(Chain);
}
if (!I.getType()->isVoidTy()) {
if (VectorType *PTy = dyn_cast<VectorType>(I.getType())) {
EVT VT = TLI.getValueType(PTy);
Result = DAG.getNode(ISD::BITCAST, getCurSDLoc(), VT, Result);
}
setValue(&I, Result);
}
}
/// GetSignificand - Get the significand and build it into a floating-point
/// number with exponent of 1:
///
/// Op = (Op & 0x007fffff) | 0x3f800000;
///
/// where Op is the hexadecimal representation of floating point value.
static SDValue
GetSignificand(SelectionDAG &DAG, SDValue Op, SDLoc dl) {
SDValue t1 = DAG.getNode(ISD::AND, dl, MVT::i32, Op,
DAG.getConstant(0x007fffff, dl, MVT::i32));
SDValue t2 = DAG.getNode(ISD::OR, dl, MVT::i32, t1,
DAG.getConstant(0x3f800000, dl, MVT::i32));
return DAG.getNode(ISD::BITCAST, dl, MVT::f32, t2);
}
/// GetExponent - Get the exponent:
///
/// (float)(int)(((Op & 0x7f800000) >> 23) - 127);
///
/// where Op is the hexadecimal representation of floating point value.
static SDValue
GetExponent(SelectionDAG &DAG, SDValue Op, const TargetLowering &TLI,
SDLoc dl) {
SDValue t0 = DAG.getNode(ISD::AND, dl, MVT::i32, Op,
DAG.getConstant(0x7f800000, dl, MVT::i32));
SDValue t1 = DAG.getNode(ISD::SRL, dl, MVT::i32, t0,
DAG.getConstant(23, dl, TLI.getPointerTy()));
SDValue t2 = DAG.getNode(ISD::SUB, dl, MVT::i32, t1,
DAG.getConstant(127, dl, MVT::i32));
return DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, t2);
}
/// getF32Constant - Get 32-bit floating point constant.
static SDValue
getF32Constant(SelectionDAG &DAG, unsigned Flt, SDLoc dl) {
return DAG.getConstantFP(APFloat(APFloat::IEEEsingle, APInt(32, Flt)), dl,
MVT::f32);
}
static SDValue getLimitedPrecisionExp2(SDValue t0, SDLoc dl,
SelectionDAG &DAG) {
// IntegerPartOfX = ((int32_t)(t0);
SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, t0);
// FractionalPartOfX = t0 - (float)IntegerPartOfX;
SDValue t1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, IntegerPartOfX);
SDValue X = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, t1);
// IntegerPartOfX <<= 23;
IntegerPartOfX = DAG.getNode(
ISD::SHL, dl, MVT::i32, IntegerPartOfX,
DAG.getConstant(23, dl, DAG.getTargetLoweringInfo().getPointerTy()));
SDValue TwoToFractionalPartOfX;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// TwoToFractionalPartOfX =
// 0.997535578f +
// (0.735607626f + 0.252464424f * x) * x;
//
// error 0.0144103317, which is 6 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3e814304, dl));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f3c50c8, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f7f5e7e, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// TwoToFractionalPartOfX =
// 0.999892986f +
// (0.696457318f +
// (0.224338339f + 0.792043434e-1f * x) * x) * x;
//
// error 0.000107046256, which is 13 to 14 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3da235e3, dl));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3e65b8f3, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f324b07, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3f7ff8fd, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// TwoToFractionalPartOfX =
// 0.999999982f +
// (0.693148872f +
// (0.240227044f +
// (0.554906021e-1f +
// (0.961591928e-2f +
// (0.136028312e-2f + 0.157059148e-3f *x)*x)*x)*x)*x)*x;
// error 2.47208000*10^(-7), which is better than 18 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3924b03e, dl));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3ab24b87, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3c1d8c17, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3d634a1d, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3e75fe14, dl));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
SDValue t11 = DAG.getNode(ISD::FADD, dl, MVT::f32, t10,
getF32Constant(DAG, 0x3f317234, dl));
SDValue t12 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t11, X);
TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t12,
getF32Constant(DAG, 0x3f800000, dl));
}
// Add the exponent into the result in integer domain.
SDValue t13 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, TwoToFractionalPartOfX);
return DAG.getNode(ISD::BITCAST, dl, MVT::f32,
DAG.getNode(ISD::ADD, dl, MVT::i32, t13, IntegerPartOfX));
}
/// expandExp - Lower an exp intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandExp(SDLoc dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
// Put the exponent in the right bit position for later addition to the
// final result:
//
// #define LOG2OFe 1.4426950f
// t0 = Op * LOG2OFe
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, Op,
getF32Constant(DAG, 0x3fb8aa3b, dl));
return getLimitedPrecisionExp2(t0, dl, DAG);
}
// No special expansion.
return DAG.getNode(ISD::FEXP, dl, Op.getValueType(), Op);
}
/// expandLog - Lower a log intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog(SDLoc dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Scale the exponent by log(2) [0.69314718f].
SDValue Exp = GetExponent(DAG, Op1, TLI, dl);
SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp,
getF32Constant(DAG, 0x3f317218, dl));
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
SDValue LogOfMantissa;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// LogofMantissa =
// -1.1609546f +
// (1.4034025f - 0.23903021f * x) * x;
//
// error 0.0034276066, which is better than 8 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbe74c456, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3fb3a2b1, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f949a29, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// LogOfMantissa =
// -1.7417939f +
// (2.8212026f +
// (-1.4699568f +
// (0.44717955f - 0.56570851e-1f * x) * x) * x) * x;
//
// error 0.000061011436, which is 14 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbd67b6d6, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3ee4f4b8, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fbc278b, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40348e95, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3fdef31a, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// LogOfMantissa =
// -2.1072184f +
// (4.2372794f +
// (-3.7029485f +
// (2.2781945f +
// (-0.87823314f +
// (0.19073739f - 0.17809712e-1f * x) * x) * x) * x) * x)*x;
//
// error 0.0000023660568, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbc91e5ac, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e4350aa, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f60d3e3, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x4011cdf0, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x406cfd1c, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x408797cb, dl));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10,
getF32Constant(DAG, 0x4006dcab, dl));
}
return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, LogOfMantissa);
}
// No special expansion.
return DAG.getNode(ISD::FLOG, dl, Op.getValueType(), Op);
}
/// expandLog2 - Lower a log2 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog2(SDLoc dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Get the exponent.
SDValue LogOfExponent = GetExponent(DAG, Op1, TLI, dl);
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
// Different possible minimax approximations of significand in
// floating-point for various degrees of accuracy over [1,2].
SDValue Log2ofMantissa;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// Log2ofMantissa = -1.6749035f + (2.0246817f - .34484768f * x) * x;
//
// error 0.0049451742, which is more than 7 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbeb08fe0, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x40019463, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fd6633d, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// Log2ofMantissa =
// -2.51285454f +
// (4.07009056f +
// (-2.12067489f +
// (.645142248f - 0.816157886e-1f * x) * x) * x) * x;
//
// error 0.0000876136000, which is better than 13 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbda7262e, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3f25280b, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x4007b923, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40823e2f, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x4020d29c, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// Log2ofMantissa =
// -3.0400495f +
// (6.1129976f +
// (-5.3420409f +
// (3.2865683f +
// (-1.2669343f +
// (0.27515199f -
// 0.25691327e-1f * x) * x) * x) * x) * x) * x;
//
// error 0.0000018516, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbcd2769e, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e8ce0b9, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fa22ae7, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40525723, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x40aaf200, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x40c39dad, dl));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10,
getF32Constant(DAG, 0x4042902c, dl));
}
return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log2ofMantissa);
}
// No special expansion.
return DAG.getNode(ISD::FLOG2, dl, Op.getValueType(), Op);
}
/// expandLog10 - Lower a log10 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog10(SDLoc dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Scale the exponent by log10(2) [0.30102999f].
SDValue Exp = GetExponent(DAG, Op1, TLI, dl);
SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp,
getF32Constant(DAG, 0x3e9a209a, dl));
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
SDValue Log10ofMantissa;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// Log10ofMantissa =
// -0.50419619f +
// (0.60948995f - 0.10380950f * x) * x;
//
// error 0.0014886165, which is 6 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbdd49a13, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3f1c0789, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f011300, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// Log10ofMantissa =
// -0.64831180f +
// (0.91751397f +
// (-0.31664806f + 0.47637168e-1f * x) * x) * x;
//
// error 0.00019228036, which is better than 12 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3d431f31, dl));
SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3ea21fb2, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f6ae232, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f25f7c3, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// Log10ofMantissa =
// -0.84299375f +
// (1.5327582f +
// (-1.0688956f +
// (0.49102474f +
// (-0.12539807f + 0.13508273e-1f * x) * x) * x) * x) * x;
//
// error 0.0000037995730, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3c5d51ce, dl));
SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e00685a, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3efb6798, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f88d192, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3fc4316c, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3f57ce70, dl));
}
return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log10ofMantissa);
}
// No special expansion.
return DAG.getNode(ISD::FLOG10, dl, Op.getValueType(), Op);
}
/// expandExp2 - Lower an exp2 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandExp2(SDLoc dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18)
return getLimitedPrecisionExp2(Op, dl, DAG);
// No special expansion.
return DAG.getNode(ISD::FEXP2, dl, Op.getValueType(), Op);
}
/// visitPow - Lower a pow intrinsic. Handles the special sequences for
/// limited-precision mode with x == 10.0f.
static SDValue expandPow(SDLoc dl, SDValue LHS, SDValue RHS,
SelectionDAG &DAG, const TargetLowering &TLI) {
bool IsExp10 = false;
if (LHS.getValueType() == MVT::f32 && RHS.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
if (ConstantFPSDNode *LHSC = dyn_cast<ConstantFPSDNode>(LHS)) {
APFloat Ten(10.0f);
IsExp10 = LHSC->isExactlyValue(Ten);
}
}
if (IsExp10) {
// Put the exponent in the right bit position for later addition to the
// final result:
//
// #define LOG2OF10 3.3219281f
// t0 = Op * LOG2OF10;
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, RHS,
getF32Constant(DAG, 0x40549a78, dl));
return getLimitedPrecisionExp2(t0, dl, DAG);
}
// No special expansion.
return DAG.getNode(ISD::FPOW, dl, LHS.getValueType(), LHS, RHS);
}
/// ExpandPowI - Expand a llvm.powi intrinsic.
static SDValue ExpandPowI(SDLoc DL, SDValue LHS, SDValue RHS,
SelectionDAG &DAG) {
// If RHS is a constant, we can expand this out to a multiplication tree,
// otherwise we end up lowering to a call to __powidf2 (for example). When
// optimizing for size, we only want to do this if the expansion would produce
// a small number of multiplies, otherwise we do the full expansion.
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS)) {
// Get the exponent as a positive value.
unsigned Val = RHSC->getSExtValue();
if ((int)Val < 0) Val = -Val;
// powi(x, 0) -> 1.0
if (Val == 0)
return DAG.getConstantFP(1.0, DL, LHS.getValueType());
const Function *F = DAG.getMachineFunction().getFunction();
if (!F->hasFnAttribute(Attribute::OptimizeForSize) ||
// If optimizing for size, don't insert too many multiplies. This
// inserts up to 5 multiplies.
countPopulation(Val) + Log2_32(Val) < 7) {
// We use the simple binary decomposition method to generate the multiply
// sequence. There are more optimal ways to do this (for example,
// powi(x,15) generates one more multiply than it should), but this has
// the benefit of being both really simple and much better than a libcall.
SDValue Res; // Logically starts equal to 1.0
SDValue CurSquare = LHS;
while (Val) {
if (Val & 1) {
if (Res.getNode())
Res = DAG.getNode(ISD::FMUL, DL,Res.getValueType(), Res, CurSquare);
else
Res = CurSquare; // 1.0*CurSquare.
}
CurSquare = DAG.getNode(ISD::FMUL, DL, CurSquare.getValueType(),
CurSquare, CurSquare);
Val >>= 1;
}
// If the original was negative, invert the result, producing 1/(x*x*x).
if (RHSC->getSExtValue() < 0)
Res = DAG.getNode(ISD::FDIV, DL, LHS.getValueType(),
DAG.getConstantFP(1.0, DL, LHS.getValueType()), Res);
return Res;
}
}
// Otherwise, expand to a libcall.
return DAG.getNode(ISD::FPOWI, DL, LHS.getValueType(), LHS, RHS);
}
// getTruncatedArgReg - Find underlying register used for an truncated
// argument.
static unsigned getTruncatedArgReg(const SDValue &N) {
if (N.getOpcode() != ISD::TRUNCATE)
return 0;
const SDValue &Ext = N.getOperand(0);
if (Ext.getOpcode() == ISD::AssertZext ||
Ext.getOpcode() == ISD::AssertSext) {
const SDValue &CFR = Ext.getOperand(0);
if (CFR.getOpcode() == ISD::CopyFromReg)
return cast<RegisterSDNode>(CFR.getOperand(1))->getReg();
if (CFR.getOpcode() == ISD::TRUNCATE)
return getTruncatedArgReg(CFR);
}
return 0;
}
/// EmitFuncArgumentDbgValue - If the DbgValueInst is a dbg_value of a function
/// argument, create the corresponding DBG_VALUE machine instruction for it now.
/// At the end of instruction selection, they will be inserted to the entry BB.
bool SelectionDAGBuilder::EmitFuncArgumentDbgValue(
const Value *V, DILocalVariable *Variable, DIExpression *Expr,
DILocation *DL, int64_t Offset, bool IsIndirect, const SDValue &N) {
const Argument *Arg = dyn_cast<Argument>(V);
if (!Arg)
return false;
MachineFunction &MF = DAG.getMachineFunction();
const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo();
// Ignore inlined function arguments here.
//
// FIXME: Should we be checking DL->inlinedAt() to determine this?
if (!Variable->getScope()->getSubprogram()->describes(MF.getFunction()))
return false;
Optional<MachineOperand> Op;
// Some arguments' frame index is recorded during argument lowering.
if (int FI = FuncInfo.getArgumentFrameIndex(Arg))
Op = MachineOperand::CreateFI(FI);
if (!Op && N.getNode()) {
unsigned Reg;
if (N.getOpcode() == ISD::CopyFromReg)
Reg = cast<RegisterSDNode>(N.getOperand(1))->getReg();
else
Reg = getTruncatedArgReg(N);
if (Reg && TargetRegisterInfo::isVirtualRegister(Reg)) {
MachineRegisterInfo &RegInfo = MF.getRegInfo();
unsigned PR = RegInfo.getLiveInPhysReg(Reg);
if (PR)
Reg = PR;
}
if (Reg)
Op = MachineOperand::CreateReg(Reg, false);
}
if (!Op) {
// Check if ValueMap has reg number.
DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
if (VMI != FuncInfo.ValueMap.end())
Op = MachineOperand::CreateReg(VMI->second, false);
}
if (!Op && N.getNode())
// Check if frame index is available.
if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(N.getNode()))
if (FrameIndexSDNode *FINode =
dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()))
Op = MachineOperand::CreateFI(FINode->getIndex());
if (!Op)
return false;
assert(Variable->isValidLocationForIntrinsic(DL) &&
"Expected inlined-at fields to agree");
if (Op->isReg())
FuncInfo.ArgDbgValues.push_back(
BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsIndirect,
Op->getReg(), Offset, Variable, Expr));
else
FuncInfo.ArgDbgValues.push_back(
BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE))
.addOperand(*Op)
.addImm(Offset)
.addMetadata(Variable)
.addMetadata(Expr));
return true;
}
// VisualStudio defines setjmp as _setjmp
#if defined(_MSC_VER) && defined(setjmp) && \
!defined(setjmp_undefined_for_msvc)
# pragma push_macro("setjmp")
# undef setjmp
# define setjmp_undefined_for_msvc
#endif
/// visitIntrinsicCall - Lower the call to the specified intrinsic function. If
/// we want to emit this as a call to a named external function, return the name
/// otherwise lower it and return null.
const char *
SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDLoc sdl = getCurSDLoc();
DebugLoc dl = getCurDebugLoc();
SDValue Res;
switch (Intrinsic) {
default:
// By default, turn this into a target intrinsic node.
visitTargetIntrinsic(I, Intrinsic);
return nullptr;
case Intrinsic::vastart: visitVAStart(I); return nullptr;
case Intrinsic::vaend: visitVAEnd(I); return nullptr;
case Intrinsic::vacopy: visitVACopy(I); return nullptr;
case Intrinsic::returnaddress:
setValue(&I, DAG.getNode(ISD::RETURNADDR, sdl, TLI.getPointerTy(),
getValue(I.getArgOperand(0))));
return nullptr;
case Intrinsic::frameaddress:
setValue(&I, DAG.getNode(ISD::FRAMEADDR, sdl, TLI.getPointerTy(),
getValue(I.getArgOperand(0))));
return nullptr;
case Intrinsic::read_register: {
Value *Reg = I.getArgOperand(0);
SDValue RegName =
DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata()));
EVT VT = TLI.getValueType(I.getType());
setValue(&I, DAG.getNode(ISD::READ_REGISTER, sdl, VT, RegName));
return nullptr;
}
case Intrinsic::write_register: {
Value *Reg = I.getArgOperand(0);
Value *RegValue = I.getArgOperand(1);
SDValue Chain = getValue(RegValue).getOperand(0);
SDValue RegName =
DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata()));
DAG.setRoot(DAG.getNode(ISD::WRITE_REGISTER, sdl, MVT::Other, Chain,
RegName, getValue(RegValue)));
return nullptr;
}
case Intrinsic::setjmp:
return &"_setjmp"[!TLI.usesUnderscoreSetJmp()];
case Intrinsic::longjmp:
return &"_longjmp"[!TLI.usesUnderscoreLongJmp()];
case Intrinsic::memcpy: {
// FIXME: this definition of "user defined address space" is x86-specific
// Assert for address < 256 since we support only user defined address
// spaces.
assert(cast<PointerType>(I.getArgOperand(0)->getType())->getAddressSpace()
< 256 &&
cast<PointerType>(I.getArgOperand(1)->getType())->getAddressSpace()
< 256 &&
"Unknown address space");
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
if (!Align)
Align = 1; // @llvm.memcpy defines 0 and 1 to both mean no alignment.
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
SDValue MC = DAG.getMemcpy(getRoot(), sdl, Op1, Op2, Op3, Align, isVol,
false, isTC,
MachinePointerInfo(I.getArgOperand(0)),
MachinePointerInfo(I.getArgOperand(1)));
updateDAGForMaybeTailCall(MC);
return nullptr;
}
case Intrinsic::memset: {
// FIXME: this definition of "user defined address space" is x86-specific
// Assert for address < 256 since we support only user defined address
// spaces.
assert(cast<PointerType>(I.getArgOperand(0)->getType())->getAddressSpace()
< 256 &&
"Unknown address space");
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
if (!Align)
Align = 1; // @llvm.memset defines 0 and 1 to both mean no alignment.
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
SDValue MS = DAG.getMemset(getRoot(), sdl, Op1, Op2, Op3, Align, isVol,
isTC, MachinePointerInfo(I.getArgOperand(0)));
updateDAGForMaybeTailCall(MS);
return nullptr;
}
case Intrinsic::memmove: {
// FIXME: this definition of "user defined address space" is x86-specific
// Assert for address < 256 since we support only user defined address
// spaces.
assert(cast<PointerType>(I.getArgOperand(0)->getType())->getAddressSpace()
< 256 &&
cast<PointerType>(I.getArgOperand(1)->getType())->getAddressSpace()
< 256 &&
"Unknown address space");
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
if (!Align)
Align = 1; // @llvm.memmove defines 0 and 1 to both mean no alignment.
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
SDValue MM = DAG.getMemmove(getRoot(), sdl, Op1, Op2, Op3, Align, isVol,
isTC, MachinePointerInfo(I.getArgOperand(0)),
MachinePointerInfo(I.getArgOperand(1)));
updateDAGForMaybeTailCall(MM);
return nullptr;
}
case Intrinsic::dbg_declare: {
const DbgDeclareInst &DI = cast<DbgDeclareInst>(I);
DILocalVariable *Variable = DI.getVariable();
DIExpression *Expression = DI.getExpression();
const Value *Address = DI.getAddress();
assert(Variable && "Missing variable");
if (!Address) {
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
return nullptr;
}
// Check if address has undef value.
if (isa<UndefValue>(Address) ||
(Address->use_empty() && !isa<Argument>(Address))) {
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
return nullptr;
}
SDValue &N = NodeMap[Address];
if (!N.getNode() && isa<Argument>(Address))
// Check unused arguments map.
N = UnusedArgNodeMap[Address];
SDDbgValue *SDV;
if (N.getNode()) {
if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
Address = BCI->getOperand(0);
// Parameters are handled specially.
bool isParameter = Variable->getTag() == dwarf::DW_TAG_arg_variable ||
isa<Argument>(Address);
const AllocaInst *AI = dyn_cast<AllocaInst>(Address);
if (isParameter && !AI) {
FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(N.getNode());
if (FINode)
// Byval parameter. We have a frame index at this point.
SDV = DAG.getFrameIndexDbgValue(
Variable, Expression, FINode->getIndex(), 0, dl, SDNodeOrder);
else {
// Address is an argument, so try to emit its dbg value using
// virtual register info from the FuncInfo.ValueMap.
EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false,
N);
return nullptr;
}
} else if (AI)
SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
true, 0, dl, SDNodeOrder);
else {
// Can't do anything with other non-AI cases yet.
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
DEBUG(dbgs() << "non-AllocaInst issue for Address: \n\t");
DEBUG(Address->dump());
return nullptr;
}
DAG.AddDbgValue(SDV, N.getNode(), isParameter);
} else {
// If Address is an argument then try to emit its dbg value using
// virtual register info from the FuncInfo.ValueMap.
if (!EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false,
N)) {
// If variable is pinned by a alloca in dominating bb then
// use StaticAllocaMap.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
if (AI->getParent() != DI.getParent()) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
SDV = DAG.getFrameIndexDbgValue(Variable, Expression, SI->second,
0, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
return nullptr;
}
}
}
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
}
}
return nullptr;
}
case Intrinsic::dbg_value: {
const DbgValueInst &DI = cast<DbgValueInst>(I);
assert(DI.getVariable() && "Missing variable");
DILocalVariable *Variable = DI.getVariable();
DIExpression *Expression = DI.getExpression();
uint64_t Offset = DI.getOffset();
const Value *V = DI.getValue();
if (!V)
return nullptr;
SDDbgValue *SDV;
if (isa<ConstantInt>(V) || isa<ConstantFP>(V) || isa<UndefValue>(V)) {
SDV = DAG.getConstantDbgValue(Variable, Expression, V, Offset, dl,
SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
} else {
// Do not use getValue() in here; we don't want to generate code at
// this point if it hasn't been done yet.
SDValue N = NodeMap[V];
if (!N.getNode() && isa<Argument>(V))
// Check unused arguments map.
N = UnusedArgNodeMap[V];
if (N.getNode()) {
// A dbg.value for an alloca is always indirect.
bool IsIndirect = isa<AllocaInst>(V) || Offset != 0;
if (!EmitFuncArgumentDbgValue(V, Variable, Expression, dl, Offset,
IsIndirect, N)) {
SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
IsIndirect, Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, N.getNode(), false);
}
} else if (!V->use_empty() ) {
// Do not call getValue(V) yet, as we don't want to generate code.
// Remember it for later.
DanglingDebugInfo DDI(&DI, dl, SDNodeOrder);
DanglingDebugInfoMap[V] = DDI;
} else {
// We may expand this to cover more cases. One case where we have no
// data available is an unreferenced parameter.
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
}
}
// Build a debug info table entry.
if (const BitCastInst *BCI = dyn_cast<BitCastInst>(V))
V = BCI->getOperand(0);
const AllocaInst *AI = dyn_cast<AllocaInst>(V);
// Don't handle byval struct arguments or VLAs, for example.
if (!AI) {
DEBUG(dbgs() << "Dropping debug location info for:\n " << DI << "\n");
DEBUG(dbgs() << " Last seen at:\n " << *V << "\n");
return nullptr;
}
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI == FuncInfo.StaticAllocaMap.end())
return nullptr; // VLAs.
return nullptr;
}
case Intrinsic::eh_typeid_for: {
// Find the type id for the given typeinfo.
GlobalValue *GV = ExtractTypeInfo(I.getArgOperand(0));
unsigned TypeID = DAG.getMachineFunction().getMMI().getTypeIDFor(GV);
Res = DAG.getConstant(TypeID, sdl, MVT::i32);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::eh_return_i32:
case Intrinsic::eh_return_i64:
DAG.getMachineFunction().getMMI().setCallsEHReturn(true);
DAG.setRoot(DAG.getNode(ISD::EH_RETURN, sdl,
MVT::Other,
getControlRoot(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
case Intrinsic::eh_unwind_init:
DAG.getMachineFunction().getMMI().setCallsUnwindInit(true);
return nullptr;
case Intrinsic::eh_dwarf_cfa: {
SDValue CfaArg = DAG.getSExtOrTrunc(getValue(I.getArgOperand(0)), sdl,
TLI.getPointerTy());
SDValue Offset = DAG.getNode(ISD::ADD, sdl,
CfaArg.getValueType(),
DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, sdl,
CfaArg.getValueType()),
CfaArg);
SDValue FA = DAG.getNode(ISD::FRAMEADDR, sdl, TLI.getPointerTy(),
DAG.getConstant(0, sdl, TLI.getPointerTy()));
setValue(&I, DAG.getNode(ISD::ADD, sdl, FA.getValueType(),
FA, Offset));
return nullptr;
}
case Intrinsic::eh_sjlj_callsite: {
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(0));
assert(CI && "Non-constant call site value in eh.sjlj.callsite!");
assert(MMI.getCurrentCallSite() == 0 && "Overlapping call sites!");
MMI.setCurrentCallSite(CI->getZExtValue());
return nullptr;
}
case Intrinsic::eh_sjlj_functioncontext: {
// Get and store the index of the function context.
MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
AllocaInst *FnCtx =
cast<AllocaInst>(I.getArgOperand(0)->stripPointerCasts());
int FI = FuncInfo.StaticAllocaMap[FnCtx];
MFI->setFunctionContextIndex(FI);
return nullptr;
}
case Intrinsic::eh_sjlj_setjmp: {
SDValue Ops[2];
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
SDValue Op = DAG.getNode(ISD::EH_SJLJ_SETJMP, sdl,
DAG.getVTList(MVT::i32, MVT::Other), Ops);
setValue(&I, Op.getValue(0));
DAG.setRoot(Op.getValue(1));
return nullptr;
}
case Intrinsic::eh_sjlj_longjmp: {
DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_LONGJMP, sdl, MVT::Other,
getRoot(), getValue(I.getArgOperand(0))));
return nullptr;
}
case Intrinsic::masked_gather:
visitMaskedGather(I);
return nullptr;
case Intrinsic::masked_load:
visitMaskedLoad(I);
return nullptr;
case Intrinsic::masked_scatter:
visitMaskedScatter(I);
return nullptr;
case Intrinsic::masked_store:
visitMaskedStore(I);
return nullptr;
case Intrinsic::x86_mmx_pslli_w:
case Intrinsic::x86_mmx_pslli_d:
case Intrinsic::x86_mmx_pslli_q:
case Intrinsic::x86_mmx_psrli_w:
case Intrinsic::x86_mmx_psrli_d:
case Intrinsic::x86_mmx_psrli_q:
case Intrinsic::x86_mmx_psrai_w:
case Intrinsic::x86_mmx_psrai_d: {
SDValue ShAmt = getValue(I.getArgOperand(1));
if (isa<ConstantSDNode>(ShAmt)) {
visitTargetIntrinsic(I, Intrinsic);
return nullptr;
}
unsigned NewIntrinsic = 0;
EVT ShAmtVT = MVT::v2i32;
switch (Intrinsic) {
case Intrinsic::x86_mmx_pslli_w:
NewIntrinsic = Intrinsic::x86_mmx_psll_w;
break;
case Intrinsic::x86_mmx_pslli_d:
NewIntrinsic = Intrinsic::x86_mmx_psll_d;
break;
case Intrinsic::x86_mmx_pslli_q:
NewIntrinsic = Intrinsic::x86_mmx_psll_q;
break;
case Intrinsic::x86_mmx_psrli_w:
NewIntrinsic = Intrinsic::x86_mmx_psrl_w;
break;
case Intrinsic::x86_mmx_psrli_d:
NewIntrinsic = Intrinsic::x86_mmx_psrl_d;
break;
case Intrinsic::x86_mmx_psrli_q:
NewIntrinsic = Intrinsic::x86_mmx_psrl_q;
break;
case Intrinsic::x86_mmx_psrai_w:
NewIntrinsic = Intrinsic::x86_mmx_psra_w;
break;
case Intrinsic::x86_mmx_psrai_d:
NewIntrinsic = Intrinsic::x86_mmx_psra_d;
break;
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
}
// The vector shift intrinsics with scalars uses 32b shift amounts but
// the sse2/mmx shift instructions reads 64 bits. Set the upper 32 bits
// to be zero.
// We must do this early because v2i32 is not a legal type.
SDValue ShOps[2];
ShOps[0] = ShAmt;
ShOps[1] = DAG.getConstant(0, sdl, MVT::i32);
ShAmt = DAG.getNode(ISD::BUILD_VECTOR, sdl, ShAmtVT, ShOps);
EVT DestVT = TLI.getValueType(I.getType());
ShAmt = DAG.getNode(ISD::BITCAST, sdl, DestVT, ShAmt);
Res = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, sdl, DestVT,
DAG.getConstant(NewIntrinsic, sdl, MVT::i32),
getValue(I.getArgOperand(0)), ShAmt);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::convertff:
case Intrinsic::convertfsi:
case Intrinsic::convertfui:
case Intrinsic::convertsif:
case Intrinsic::convertuif:
case Intrinsic::convertss:
case Intrinsic::convertsu:
case Intrinsic::convertus:
case Intrinsic::convertuu: {
ISD::CvtCode Code = ISD::CVT_INVALID;
switch (Intrinsic) {
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
case Intrinsic::convertff: Code = ISD::CVT_FF; break;
case Intrinsic::convertfsi: Code = ISD::CVT_FS; break;
case Intrinsic::convertfui: Code = ISD::CVT_FU; break;
case Intrinsic::convertsif: Code = ISD::CVT_SF; break;
case Intrinsic::convertuif: Code = ISD::CVT_UF; break;
case Intrinsic::convertss: Code = ISD::CVT_SS; break;
case Intrinsic::convertsu: Code = ISD::CVT_SU; break;
case Intrinsic::convertus: Code = ISD::CVT_US; break;
case Intrinsic::convertuu: Code = ISD::CVT_UU; break;
}
EVT DestVT = TLI.getValueType(I.getType());
const Value *Op1 = I.getArgOperand(0);
Res = DAG.getConvertRndSat(DestVT, sdl, getValue(Op1),
DAG.getValueType(DestVT),
DAG.getValueType(getValue(Op1).getValueType()),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2)),
Code);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::powi:
setValue(&I, ExpandPowI(sdl, getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)), DAG));
return nullptr;
case Intrinsic::log:
setValue(&I, expandLog(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::log2:
setValue(&I, expandLog2(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::log10:
setValue(&I, expandLog10(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::exp:
setValue(&I, expandExp(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::exp2:
setValue(&I, expandExp2(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::pow:
setValue(&I, expandPow(sdl, getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)), DAG, TLI));
return nullptr;
case Intrinsic::sqrt:
case Intrinsic::fabs:
case Intrinsic::sin:
case Intrinsic::cos:
case Intrinsic::floor:
case Intrinsic::ceil:
case Intrinsic::trunc:
case Intrinsic::rint:
case Intrinsic::nearbyint:
case Intrinsic::round: {
unsigned Opcode;
switch (Intrinsic) {
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
case Intrinsic::sqrt: Opcode = ISD::FSQRT; break;
case Intrinsic::fabs: Opcode = ISD::FABS; break;
case Intrinsic::sin: Opcode = ISD::FSIN; break;
case Intrinsic::cos: Opcode = ISD::FCOS; break;
case Intrinsic::floor: Opcode = ISD::FFLOOR; break;
case Intrinsic::ceil: Opcode = ISD::FCEIL; break;
case Intrinsic::trunc: Opcode = ISD::FTRUNC; break;
case Intrinsic::rint: Opcode = ISD::FRINT; break;
case Intrinsic::nearbyint: Opcode = ISD::FNEARBYINT; break;
case Intrinsic::round: Opcode = ISD::FROUND; break;
}
setValue(&I, DAG.getNode(Opcode, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return nullptr;
}
case Intrinsic::minnum:
setValue(&I, DAG.getNode(ISD::FMINNUM, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
case Intrinsic::maxnum:
setValue(&I, DAG.getNode(ISD::FMAXNUM, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
case Intrinsic::copysign:
setValue(&I, DAG.getNode(ISD::FCOPYSIGN, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
case Intrinsic::fma:
setValue(&I, DAG.getNode(ISD::FMA, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2))));
return nullptr;
case Intrinsic::fmuladd: {
EVT VT = TLI.getValueType(I.getType());
if (TM.Options.AllowFPOpFusion != FPOpFusion::Strict &&
TLI.isFMAFasterThanFMulAndFAdd(VT)) {
setValue(&I, DAG.getNode(ISD::FMA, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2))));
} else {
SDValue Mul = DAG.getNode(ISD::FMUL, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)));
SDValue Add = DAG.getNode(ISD::FADD, sdl,
getValue(I.getArgOperand(0)).getValueType(),
Mul,
getValue(I.getArgOperand(2)));
setValue(&I, Add);
}
return nullptr;
}
case Intrinsic::convert_to_fp16:
setValue(&I, DAG.getNode(ISD::BITCAST, sdl, MVT::i16,
DAG.getNode(ISD::FP_ROUND, sdl, MVT::f16,
getValue(I.getArgOperand(0)),
DAG.getTargetConstant(0, sdl,
MVT::i32))));
return nullptr;
case Intrinsic::convert_from_fp16:
setValue(&I,
DAG.getNode(ISD::FP_EXTEND, sdl, TLI.getValueType(I.getType()),
DAG.getNode(ISD::BITCAST, sdl, MVT::f16,
getValue(I.getArgOperand(0)))));
return nullptr;
case Intrinsic::pcmarker: {
SDValue Tmp = getValue(I.getArgOperand(0));
DAG.setRoot(DAG.getNode(ISD::PCMARKER, sdl, MVT::Other, getRoot(), Tmp));
return nullptr;
}
case Intrinsic::readcyclecounter: {
SDValue Op = getRoot();
Res = DAG.getNode(ISD::READCYCLECOUNTER, sdl,
DAG.getVTList(MVT::i64, MVT::Other), Op);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return nullptr;
}
case Intrinsic::bswap:
setValue(&I, DAG.getNode(ISD::BSWAP, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return nullptr;
case Intrinsic::cttz: {
SDValue Arg = getValue(I.getArgOperand(0));
ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTTZ : ISD::CTTZ_ZERO_UNDEF,
sdl, Ty, Arg));
return nullptr;
}
case Intrinsic::ctlz: {
SDValue Arg = getValue(I.getArgOperand(0));
ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTLZ : ISD::CTLZ_ZERO_UNDEF,
sdl, Ty, Arg));
return nullptr;
}
case Intrinsic::ctpop: {
SDValue Arg = getValue(I.getArgOperand(0));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(ISD::CTPOP, sdl, Ty, Arg));
return nullptr;
}
case Intrinsic::stacksave: {
SDValue Op = getRoot();
Res = DAG.getNode(ISD::STACKSAVE, sdl,
DAG.getVTList(TLI.getPointerTy(), MVT::Other), Op);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return nullptr;
}
case Intrinsic::stackrestore: {
Res = getValue(I.getArgOperand(0));
DAG.setRoot(DAG.getNode(ISD::STACKRESTORE, sdl, MVT::Other, getRoot(), Res));
return nullptr;
}
case Intrinsic::stackprotector: {
// Emit code into the DAG to store the stack guard onto the stack.
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
EVT PtrTy = TLI.getPointerTy();
SDValue Src, Chain = getRoot();
const Value *Ptr = cast<LoadInst>(I.getArgOperand(0))->getPointerOperand();
const GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr);
// See if Ptr is a bitcast. If it is, look through it and see if we can get
// global variable __stack_chk_guard.
if (!GV)
if (const Operator *BC = dyn_cast<Operator>(Ptr))
if (BC->getOpcode() == Instruction::BitCast)
GV = dyn_cast<GlobalVariable>(BC->getOperand(0));
if (GV && TLI.useLoadStackGuardNode()) {
// Emit a LOAD_STACK_GUARD node.
MachineSDNode *Node = DAG.getMachineNode(TargetOpcode::LOAD_STACK_GUARD,
sdl, PtrTy, Chain);
MachinePointerInfo MPInfo(GV);
MachineInstr::mmo_iterator MemRefs = MF.allocateMemRefsArray(1);
unsigned Flags = MachineMemOperand::MOLoad |
MachineMemOperand::MOInvariant;
*MemRefs = MF.getMachineMemOperand(MPInfo, Flags,
PtrTy.getSizeInBits() / 8,
DAG.getEVTAlignment(PtrTy));
Node->setMemRefs(MemRefs, MemRefs + 1);
// Copy the guard value to a virtual register so that it can be
// retrieved in the epilogue.
Src = SDValue(Node, 0);
const TargetRegisterClass *RC =
TLI.getRegClassFor(Src.getSimpleValueType());
unsigned Reg = MF.getRegInfo().createVirtualRegister(RC);
SPDescriptor.setGuardReg(Reg);
Chain = DAG.getCopyToReg(Chain, sdl, Reg, Src);
} else {
Src = getValue(I.getArgOperand(0)); // The guard's value.
}
AllocaInst *Slot = cast<AllocaInst>(I.getArgOperand(1));
int FI = FuncInfo.StaticAllocaMap[Slot];
MFI->setStackProtectorIndex(FI);
SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
// Store the stack protector onto the stack.
Res = DAG.getStore(Chain, sdl, Src, FIN,
MachinePointerInfo::getFixedStack(FI),
true, false, 0);
setValue(&I, Res);
DAG.setRoot(Res);
return nullptr;
}
case Intrinsic::objectsize: {
// If we don't know by now, we're never going to know.
ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(1));
assert(CI && "Non-constant type in __builtin_object_size?");
SDValue Arg = getValue(I.getCalledValue());
EVT Ty = Arg.getValueType();
if (CI->isZero())
Res = DAG.getConstant(-1ULL, sdl, Ty);
else
Res = DAG.getConstant(0, sdl, Ty);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::annotation:
case Intrinsic::ptr_annotation:
// Drop the intrinsic, but forward the value
setValue(&I, getValue(I.getOperand(0)));
return nullptr;
case Intrinsic::assume:
case Intrinsic::var_annotation:
// Discard annotate attributes and assumptions
return nullptr;
case Intrinsic::init_trampoline: {
const Function *F = cast<Function>(I.getArgOperand(1)->stripPointerCasts());
SDValue Ops[6];
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
Ops[2] = getValue(I.getArgOperand(1));
Ops[3] = getValue(I.getArgOperand(2));
Ops[4] = DAG.getSrcValue(I.getArgOperand(0));
Ops[5] = DAG.getSrcValue(F);
Res = DAG.getNode(ISD::INIT_TRAMPOLINE, sdl, MVT::Other, Ops);
DAG.setRoot(Res);
return nullptr;
}
case Intrinsic::adjust_trampoline: {
setValue(&I, DAG.getNode(ISD::ADJUST_TRAMPOLINE, sdl,
TLI.getPointerTy(),
getValue(I.getArgOperand(0))));
return nullptr;
}
case Intrinsic::gcroot:
if (GFI) {
const Value *Alloca = I.getArgOperand(0)->stripPointerCasts();
const Constant *TypeMap = cast<Constant>(I.getArgOperand(1));
FrameIndexSDNode *FI = cast<FrameIndexSDNode>(getValue(Alloca).getNode());
GFI->addStackRoot(FI->getIndex(), TypeMap);
}
return nullptr;
case Intrinsic::gcread:
case Intrinsic::gcwrite:
llvm_unreachable("GC failed to lower gcread/gcwrite intrinsics!");
case Intrinsic::flt_rounds:
setValue(&I, DAG.getNode(ISD::FLT_ROUNDS_, sdl, MVT::i32));
return nullptr;
case Intrinsic::expect: {
// Just replace __builtin_expect(exp, c) with EXP.
setValue(&I, getValue(I.getArgOperand(0)));
return nullptr;
}
case Intrinsic::debugtrap:
case Intrinsic::trap: {
StringRef TrapFuncName = TM.Options.getTrapFunctionName();
if (TrapFuncName.empty()) {
ISD::NodeType Op = (Intrinsic == Intrinsic::trap) ?
ISD::TRAP : ISD::DEBUGTRAP;
DAG.setRoot(DAG.getNode(Op, sdl,MVT::Other, getRoot()));
return nullptr;
}
TargetLowering::ArgListTy Args;
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(sdl).setChain(getRoot())
.setCallee(CallingConv::C, I.getType(),
DAG.getExternalSymbol(TrapFuncName.data(), TLI.getPointerTy()),
std::move(Args), 0);
std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI);
DAG.setRoot(Result.second);
return nullptr;
}
case Intrinsic::uadd_with_overflow:
case Intrinsic::sadd_with_overflow:
case Intrinsic::usub_with_overflow:
case Intrinsic::ssub_with_overflow:
case Intrinsic::umul_with_overflow:
case Intrinsic::smul_with_overflow: {
ISD::NodeType Op;
switch (Intrinsic) {
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
case Intrinsic::uadd_with_overflow: Op = ISD::UADDO; break;
case Intrinsic::sadd_with_overflow: Op = ISD::SADDO; break;
case Intrinsic::usub_with_overflow: Op = ISD::USUBO; break;
case Intrinsic::ssub_with_overflow: Op = ISD::SSUBO; break;
case Intrinsic::umul_with_overflow: Op = ISD::UMULO; break;
case Intrinsic::smul_with_overflow: Op = ISD::SMULO; break;
}
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDVTList VTs = DAG.getVTList(Op1.getValueType(), MVT::i1);
setValue(&I, DAG.getNode(Op, sdl, VTs, Op1, Op2));
return nullptr;
}
case Intrinsic::prefetch: {
SDValue Ops[5];
unsigned rw = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue();
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
Ops[2] = getValue(I.getArgOperand(1));
Ops[3] = getValue(I.getArgOperand(2));
Ops[4] = getValue(I.getArgOperand(3));
DAG.setRoot(DAG.getMemIntrinsicNode(ISD::PREFETCH, sdl,
DAG.getVTList(MVT::Other), Ops,
EVT::getIntegerVT(*Context, 8),
MachinePointerInfo(I.getArgOperand(0)),
0, /* align */
false, /* volatile */
rw==0, /* read */
rw==1)); /* write */
return nullptr;
}
case Intrinsic::lifetime_start:
case Intrinsic::lifetime_end: {
bool IsStart = (Intrinsic == Intrinsic::lifetime_start);
// Stack coloring is not enabled in O0, discard region information.
if (TM.getOptLevel() == CodeGenOpt::None)
return nullptr;
SmallVector<Value *, 4> Allocas;
GetUnderlyingObjects(I.getArgOperand(1), Allocas, *DL);
for (SmallVectorImpl<Value*>::iterator Object = Allocas.begin(),
E = Allocas.end(); Object != E; ++Object) {
AllocaInst *LifetimeObject = dyn_cast_or_null<AllocaInst>(*Object);
// Could not find an Alloca.
if (!LifetimeObject)
continue;
// First check that the Alloca is static, otherwise it won't have a
// valid frame index.
auto SI = FuncInfo.StaticAllocaMap.find(LifetimeObject);
if (SI == FuncInfo.StaticAllocaMap.end())
return nullptr;
int FI = SI->second;
SDValue Ops[2];
Ops[0] = getRoot();
Ops[1] = DAG.getFrameIndex(FI, TLI.getPointerTy(), true);
unsigned Opcode = (IsStart ? ISD::LIFETIME_START : ISD::LIFETIME_END);
Res = DAG.getNode(Opcode, sdl, MVT::Other, Ops);
DAG.setRoot(Res);
}
return nullptr;
}
case Intrinsic::invariant_start:
// Discard region information.
setValue(&I, DAG.getUNDEF(TLI.getPointerTy()));
return nullptr;
case Intrinsic::invariant_end:
// Discard region information.
return nullptr;
case Intrinsic::stackprotectorcheck: {
// Do not actually emit anything for this basic block. Instead we initialize
// the stack protector descriptor and export the guard variable so we can
// access it in FinishBasicBlock.
const BasicBlock *BB = I.getParent();
SPDescriptor.initialize(BB, FuncInfo.MBBMap[BB], I);
ExportFromCurrentBlock(SPDescriptor.getGuard());
// Flush our exports since we are going to process a terminator.
(void)getControlRoot();
return nullptr;
}
case Intrinsic::clear_cache:
return TLI.getClearCacheBuiltinName();
case Intrinsic::eh_actions:
setValue(&I, DAG.getUNDEF(TLI.getPointerTy()));
return nullptr;
case Intrinsic::donothing:
// ignore
return nullptr;
case Intrinsic::experimental_stackmap: {
visitStackmap(I);
return nullptr;
}
case Intrinsic::experimental_patchpoint_void:
case Intrinsic::experimental_patchpoint_i64: {
visitPatchpoint(&I);
return nullptr;
}
case Intrinsic::experimental_gc_statepoint: {
visitStatepoint(I);
return nullptr;
}
case Intrinsic::experimental_gc_result_int:
case Intrinsic::experimental_gc_result_float:
case Intrinsic::experimental_gc_result_ptr:
case Intrinsic::experimental_gc_result: {
visitGCResult(I);
return nullptr;
}
case Intrinsic::experimental_gc_relocate: {
visitGCRelocate(I);
return nullptr;
}
case Intrinsic::instrprof_increment:
llvm_unreachable("instrprof failed to lower an increment");
case Intrinsic::frameescape: {
MachineFunction &MF = DAG.getMachineFunction();
const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo();
// Directly emit some FRAME_ALLOC machine instrs. Label assignment emission
// is the same on all targets.
for (unsigned Idx = 0, E = I.getNumArgOperands(); Idx < E; ++Idx) {
Value *Arg = I.getArgOperand(Idx)->stripPointerCasts();
if (isa<ConstantPointerNull>(Arg))
continue; // Skip null pointers. They represent a hole in index space.
AllocaInst *Slot = cast<AllocaInst>(Arg);
assert(FuncInfo.StaticAllocaMap.count(Slot) &&
"can only escape static allocas");
int FI = FuncInfo.StaticAllocaMap[Slot];
MCSymbol *FrameAllocSym =
MF.getMMI().getContext().getOrCreateFrameAllocSymbol(
GlobalValue::getRealLinkageName(MF.getName()), Idx);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, dl,
TII->get(TargetOpcode::FRAME_ALLOC))
.addSym(FrameAllocSym)
.addFrameIndex(FI);
}
return nullptr;
}
case Intrinsic::framerecover: {
// i8* @llvm.framerecover(i8* %fn, i8* %fp, i32 %idx)
MachineFunction &MF = DAG.getMachineFunction();
MVT PtrVT = TLI.getPointerTy(0);
// Get the symbol that defines the frame offset.
auto *Fn = cast<Function>(I.getArgOperand(0)->stripPointerCasts());
auto *Idx = cast<ConstantInt>(I.getArgOperand(2));
unsigned IdxVal = unsigned(Idx->getLimitedValue(INT_MAX));
MCSymbol *FrameAllocSym =
MF.getMMI().getContext().getOrCreateFrameAllocSymbol(
GlobalValue::getRealLinkageName(Fn->getName()), IdxVal);
// Create a TargetExternalSymbol for the label to avoid any target lowering
// that would make this PC relative.
StringRef Name = FrameAllocSym->getName();
assert(Name.data()[Name.size()] == '\0' && "not null terminated");
SDValue OffsetSym = DAG.getTargetExternalSymbol(Name.data(), PtrVT);
SDValue OffsetVal =
DAG.getNode(ISD::FRAME_ALLOC_RECOVER, sdl, PtrVT, OffsetSym);
// Add the offset to the FP.
Value *FP = I.getArgOperand(1);
SDValue FPVal = getValue(FP);
SDValue Add = DAG.getNode(ISD::ADD, sdl, PtrVT, FPVal, OffsetVal);
setValue(&I, Add);
return nullptr;
}
case Intrinsic::eh_begincatch:
case Intrinsic::eh_endcatch:
llvm_unreachable("begin/end catch intrinsics not lowered in codegen");
case Intrinsic::eh_exceptioncode: {
unsigned Reg = TLI.getExceptionPointerRegister();
assert(Reg && "cannot get exception code on this platform");
MVT PtrVT = TLI.getPointerTy();
const TargetRegisterClass *PtrRC = TLI.getRegClassFor(PtrVT);
unsigned VReg = FuncInfo.MBB->addLiveIn(Reg, PtrRC);
SDValue N =
DAG.getCopyFromReg(DAG.getEntryNode(), getCurSDLoc(), VReg, PtrVT);
N = DAG.getZExtOrTrunc(N, getCurSDLoc(), MVT::i32);
setValue(&I, N);
return nullptr;
}
}
}
std::pair<SDValue, SDValue>
SelectionDAGBuilder::lowerInvokable(TargetLowering::CallLoweringInfo &CLI,
MachineBasicBlock *LandingPad) {
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
MCSymbol *BeginLabel = nullptr;
if (LandingPad) {
// Insert a label before the invoke call to mark the try range. This can be
// used to detect deletion of the invoke via the MachineModuleInfo.
BeginLabel = MMI.getContext().CreateTempSymbol();
// For SjLj, keep track of which landing pads go with which invokes
// so as to maintain the ordering of pads in the LSDA.
unsigned CallSiteIndex = MMI.getCurrentCallSite();
if (CallSiteIndex) {
MMI.setCallSiteBeginLabel(BeginLabel, CallSiteIndex);
LPadToCallSiteMap[LandingPad].push_back(CallSiteIndex);
// Now that the call site is handled, stop tracking it.
MMI.setCurrentCallSite(0);
}
// Both PendingLoads and PendingExports must be flushed here;
// this call might not return.
(void)getRoot();
DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getControlRoot(), BeginLabel));
CLI.setChain(getRoot());
}
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI);
assert((CLI.IsTailCall || Result.second.getNode()) &&
"Non-null chain expected with non-tail call!");
assert((Result.second.getNode() || !Result.first.getNode()) &&
"Null value expected with tail call!");
if (!Result.second.getNode()) {
// As a special case, a null chain means that a tail call has been emitted
// and the DAG root is already updated.
HasTailCall = true;
// Since there's no actual continuation from this block, nothing can be
// relying on us setting vregs for them.
PendingExports.clear();
} else {
DAG.setRoot(Result.second);
}
if (LandingPad) {
// Insert a label at the end of the invoke call to mark the try range. This
// can be used to detect deletion of the invoke via the MachineModuleInfo.
MCSymbol *EndLabel = MMI.getContext().CreateTempSymbol();
DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getRoot(), EndLabel));
// Inform MachineModuleInfo of range.
MMI.addInvoke(LandingPad, BeginLabel, EndLabel);
}
return Result;
}
void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee,
bool isTailCall,
MachineBasicBlock *LandingPad) {
PointerType *PT = cast<PointerType>(CS.getCalledValue()->getType());
FunctionType *FTy = cast<FunctionType>(PT->getElementType());
Type *RetTy = FTy->getReturnType();
TargetLowering::ArgListTy Args;
TargetLowering::ArgListEntry Entry;
Args.reserve(CS.arg_size());
for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
i != e; ++i) {
const Value *V = *i;
// Skip empty types
if (V->getType()->isEmptyTy())
continue;
SDValue ArgNode = getValue(V);
Entry.Node = ArgNode; Entry.Ty = V->getType();
// Skip the first return-type Attribute to get to params.
Entry.setAttributes(&CS, i - CS.arg_begin() + 1);
Args.push_back(Entry);
// If we have an explicit sret argument that is an Instruction, (i.e., it
// might point to function-local memory), we can't meaningfully tail-call.
if (Entry.isSRet && isa<Instruction>(V))
isTailCall = false;
}
// Check if target-independent constraints permit a tail call here.
// Target-dependent constraints are checked within TLI->LowerCallTo.
if (isTailCall && !isInTailCallPosition(CS, DAG.getTarget()))
isTailCall = false;
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(getCurSDLoc()).setChain(getRoot())
.setCallee(RetTy, FTy, Callee, std::move(Args), CS)
.setTailCall(isTailCall);
std::pair<SDValue,SDValue> Result = lowerInvokable(CLI, LandingPad);
if (Result.first.getNode())
setValue(CS.getInstruction(), Result.first);
}
/// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
/// value is equal or not-equal to zero.
static bool IsOnlyUsedInZeroEqualityComparison(const Value *V) {
for (const User *U : V->users()) {
if (const ICmpInst *IC = dyn_cast<ICmpInst>(U))
if (IC->isEquality())
if (const Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
if (C->isNullValue())
continue;
// Unknown instruction.
return false;
}
return true;
}
static SDValue getMemCmpLoad(const Value *PtrVal, MVT LoadVT,
Type *LoadTy,
SelectionDAGBuilder &Builder) {
// Check to see if this load can be trivially constant folded, e.g. if the
// input is from a string literal.
if (const Constant *LoadInput = dyn_cast<Constant>(PtrVal)) {
// Cast pointer to the type we really want to load.
LoadInput = ConstantExpr::getBitCast(const_cast<Constant *>(LoadInput),
PointerType::getUnqual(LoadTy));
if (const Constant *LoadCst = ConstantFoldLoadFromConstPtr(
const_cast<Constant *>(LoadInput), *Builder.DL))
return Builder.getValue(LoadCst);
}
// Otherwise, we have to emit the load. If the pointer is to unfoldable but
// still constant memory, the input chain can be the entry node.
SDValue Root;
bool ConstantMemory = false;
// Do not serialize (non-volatile) loads of constant memory with anything.
if (Builder.AA->pointsToConstantMemory(PtrVal)) {
Root = Builder.DAG.getEntryNode();
ConstantMemory = true;
} else {
// Do not serialize non-volatile loads against each other.
Root = Builder.DAG.getRoot();
}
SDValue Ptr = Builder.getValue(PtrVal);
SDValue LoadVal = Builder.DAG.getLoad(LoadVT, Builder.getCurSDLoc(), Root,
Ptr, MachinePointerInfo(PtrVal),
false /*volatile*/,
false /*nontemporal*/,
false /*isinvariant*/, 1 /* align=1 */);
if (!ConstantMemory)
Builder.PendingLoads.push_back(LoadVal.getValue(1));
return LoadVal;
}
/// processIntegerCallValue - Record the value for an instruction that
/// produces an integer result, converting the type where necessary.
void SelectionDAGBuilder::processIntegerCallValue(const Instruction &I,
SDValue Value,
bool IsSigned) {
EVT VT = DAG.getTargetLoweringInfo().getValueType(I.getType(), true);
if (IsSigned)
Value = DAG.getSExtOrTrunc(Value, getCurSDLoc(), VT);
else
Value = DAG.getZExtOrTrunc(Value, getCurSDLoc(), VT);
setValue(&I, Value);
}
/// visitMemCmpCall - See if we can lower a call to memcmp in an optimized form.
/// If so, return true and lower it, otherwise return false and it will be
/// lowered like a normal call.
bool SelectionDAGBuilder::visitMemCmpCall(const CallInst &I) {
// Verify that the prototype makes sense. int memcmp(void*,void*,size_t)
if (I.getNumArgOperands() != 3)
return false;
const Value *LHS = I.getArgOperand(0), *RHS = I.getArgOperand(1);
if (!LHS->getType()->isPointerTy() || !RHS->getType()->isPointerTy() ||
!I.getArgOperand(2)->getType()->isIntegerTy() ||
!I.getType()->isIntegerTy())
return false;
const Value *Size = I.getArgOperand(2);
const ConstantInt *CSize = dyn_cast<ConstantInt>(Size);
if (CSize && CSize->getZExtValue() == 0) {
EVT CallVT = DAG.getTargetLoweringInfo().getValueType(I.getType(), true);
setValue(&I, DAG.getConstant(0, getCurSDLoc(), CallVT));
return true;
}
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForMemcmp(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(LHS), getValue(RHS), getValue(Size),
MachinePointerInfo(LHS),
MachinePointerInfo(RHS));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, true);
PendingLoads.push_back(Res.second);
return true;
}
// memcmp(S1,S2,2) != 0 -> (*(short*)LHS != *(short*)RHS) != 0
// memcmp(S1,S2,4) != 0 -> (*(int*)LHS != *(int*)RHS) != 0
if (CSize && IsOnlyUsedInZeroEqualityComparison(&I)) {
bool ActuallyDoIt = true;
MVT LoadVT;
Type *LoadTy;
switch (CSize->getZExtValue()) {
default:
LoadVT = MVT::Other;
LoadTy = nullptr;
ActuallyDoIt = false;
break;
case 2:
LoadVT = MVT::i16;
LoadTy = Type::getInt16Ty(CSize->getContext());
break;
case 4:
LoadVT = MVT::i32;
LoadTy = Type::getInt32Ty(CSize->getContext());
break;
case 8:
LoadVT = MVT::i64;
LoadTy = Type::getInt64Ty(CSize->getContext());
break;
/*
case 16:
LoadVT = MVT::v4i32;
LoadTy = Type::getInt32Ty(CSize->getContext());
LoadTy = VectorType::get(LoadTy, 4);
break;
*/
}
// This turns into unaligned loads. We only do this if the target natively
// supports the MVT we'll be loading or if it is small enough (<= 4) that
// we'll only produce a small number of byte loads.
// Require that we can find a legal MVT, and only do this if the target
// supports unaligned loads of that type. Expanding into byte loads would
// bloat the code.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (ActuallyDoIt && CSize->getZExtValue() > 4) {
unsigned DstAS = LHS->getType()->getPointerAddressSpace();
unsigned SrcAS = RHS->getType()->getPointerAddressSpace();
// TODO: Handle 5 byte compare as 4-byte + 1 byte.
// TODO: Handle 8 byte compare on x86-32 as two 32-bit loads.
// TODO: Check alignment of src and dest ptrs.
if (!TLI.isTypeLegal(LoadVT) ||
!TLI.allowsMisalignedMemoryAccesses(LoadVT, SrcAS) ||
!TLI.allowsMisalignedMemoryAccesses(LoadVT, DstAS))
ActuallyDoIt = false;
}
if (ActuallyDoIt) {
SDValue LHSVal = getMemCmpLoad(LHS, LoadVT, LoadTy, *this);
SDValue RHSVal = getMemCmpLoad(RHS, LoadVT, LoadTy, *this);
SDValue Res = DAG.getSetCC(getCurSDLoc(), MVT::i1, LHSVal, RHSVal,
ISD::SETNE);
processIntegerCallValue(I, Res, false);
return true;
}
}
return false;
}
/// visitMemChrCall -- See if we can lower a memchr call into an optimized
/// form. If so, return true and lower it, otherwise return false and it
/// will be lowered like a normal call.
bool SelectionDAGBuilder::visitMemChrCall(const CallInst &I) {
// Verify that the prototype makes sense. void *memchr(void *, int, size_t)
if (I.getNumArgOperands() != 3)
return false;
const Value *Src = I.getArgOperand(0);
const Value *Char = I.getArgOperand(1);
const Value *Length = I.getArgOperand(2);
if (!Src->getType()->isPointerTy() ||
!Char->getType()->isIntegerTy() ||
!Length->getType()->isIntegerTy() ||
!I.getType()->isPointerTy())
return false;
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForMemchr(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Src), getValue(Char), getValue(Length),
MachinePointerInfo(Src));
if (Res.first.getNode()) {
setValue(&I, Res.first);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
/// visitStrCpyCall -- See if we can lower a strcpy or stpcpy call into an
/// optimized form. If so, return true and lower it, otherwise return false
/// and it will be lowered like a normal call.
bool SelectionDAGBuilder::visitStrCpyCall(const CallInst &I, bool isStpcpy) {
// Verify that the prototype makes sense. char *strcpy(char *, char *)
if (I.getNumArgOperands() != 2)
return false;
const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
if (!Arg0->getType()->isPointerTy() ||
!Arg1->getType()->isPointerTy() ||
!I.getType()->isPointerTy())
return false;
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrcpy(DAG, getCurSDLoc(), getRoot(),
getValue(Arg0), getValue(Arg1),
MachinePointerInfo(Arg0),
MachinePointerInfo(Arg1), isStpcpy);
if (Res.first.getNode()) {
setValue(&I, Res.first);
DAG.setRoot(Res.second);
return true;
}
return false;
}
/// visitStrCmpCall - See if we can lower a call to strcmp in an optimized form.
/// If so, return true and lower it, otherwise return false and it will be
/// lowered like a normal call.
bool SelectionDAGBuilder::visitStrCmpCall(const CallInst &I) {
// Verify that the prototype makes sense. int strcmp(void*,void*)
if (I.getNumArgOperands() != 2)
return false;
const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
if (!Arg0->getType()->isPointerTy() ||
!Arg1->getType()->isPointerTy() ||
!I.getType()->isIntegerTy())
return false;
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrcmp(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Arg0), getValue(Arg1),
MachinePointerInfo(Arg0),
MachinePointerInfo(Arg1));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, true);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
/// visitStrLenCall -- See if we can lower a strlen call into an optimized
/// form. If so, return true and lower it, otherwise return false and it
/// will be lowered like a normal call.
bool SelectionDAGBuilder::visitStrLenCall(const CallInst &I) {
// Verify that the prototype makes sense. size_t strlen(char *)
if (I.getNumArgOperands() != 1)
return false;
const Value *Arg0 = I.getArgOperand(0);
if (!Arg0->getType()->isPointerTy() || !I.getType()->isIntegerTy())
return false;
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrlen(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Arg0), MachinePointerInfo(Arg0));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, false);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
/// visitStrNLenCall -- See if we can lower a strnlen call into an optimized
/// form. If so, return true and lower it, otherwise return false and it
/// will be lowered like a normal call.
bool SelectionDAGBuilder::visitStrNLenCall(const CallInst &I) {
// Verify that the prototype makes sense. size_t strnlen(char *, size_t)
if (I.getNumArgOperands() != 2)
return false;
const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
if (!Arg0->getType()->isPointerTy() ||
!Arg1->getType()->isIntegerTy() ||
!I.getType()->isIntegerTy())
return false;
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrnlen(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Arg0), getValue(Arg1),
MachinePointerInfo(Arg0));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, false);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
/// visitUnaryFloatCall - If a call instruction is a unary floating-point
/// operation (as expected), translate it to an SDNode with the specified opcode
/// and return true.
bool SelectionDAGBuilder::visitUnaryFloatCall(const CallInst &I,
unsigned Opcode) {
// Sanity check that it really is a unary floating-point call.
if (I.getNumArgOperands() != 1 ||
!I.getArgOperand(0)->getType()->isFloatingPointTy() ||
I.getType() != I.getArgOperand(0)->getType() ||
!I.onlyReadsMemory())
return false;
SDValue Tmp = getValue(I.getArgOperand(0));
setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), Tmp.getValueType(), Tmp));
return true;
}
/// visitBinaryFloatCall - If a call instruction is a binary floating-point
/// operation (as expected), translate it to an SDNode with the specified opcode
/// and return true.
bool SelectionDAGBuilder::visitBinaryFloatCall(const CallInst &I,
unsigned Opcode) {
// Sanity check that it really is a binary floating-point call.
if (I.getNumArgOperands() != 2 ||
!I.getArgOperand(0)->getType()->isFloatingPointTy() ||
I.getType() != I.getArgOperand(0)->getType() ||
I.getType() != I.getArgOperand(1)->getType() ||
!I.onlyReadsMemory())
return false;
SDValue Tmp0 = getValue(I.getArgOperand(0));
SDValue Tmp1 = getValue(I.getArgOperand(1));
EVT VT = Tmp0.getValueType();
setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), VT, Tmp0, Tmp1));
return true;
}
void SelectionDAGBuilder::visitCall(const CallInst &I) {
// Handle inline assembly differently.
if (isa<InlineAsm>(I.getCalledValue())) {
visitInlineAsm(&I);
return;
}
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
ComputeUsesVAFloatArgument(I, &MMI);
const char *RenameFn = nullptr;
if (Function *F = I.getCalledFunction()) {
if (F->isDeclaration()) {
if (const TargetIntrinsicInfo *II = TM.getIntrinsicInfo()) {
if (unsigned IID = II->getIntrinsicID(F)) {
RenameFn = visitIntrinsicCall(I, IID);
if (!RenameFn)
return;
}
}
if (unsigned IID = F->getIntrinsicID()) {
RenameFn = visitIntrinsicCall(I, IID);
if (!RenameFn)
return;
}
}
// Check for well-known libc/libm calls. If the function is internal, it
// can't be a library call.
LibFunc::Func Func;
if (!F->hasLocalLinkage() && F->hasName() &&
LibInfo->getLibFunc(F->getName(), Func) &&
LibInfo->hasOptimizedCodeGen(Func)) {
switch (Func) {
default: break;
case LibFunc::copysign:
case LibFunc::copysignf:
case LibFunc::copysignl:
if (I.getNumArgOperands() == 2 && // Basic sanity checks.
I.getArgOperand(0)->getType()->isFloatingPointTy() &&
I.getType() == I.getArgOperand(0)->getType() &&
I.getType() == I.getArgOperand(1)->getType() &&
I.onlyReadsMemory()) {
SDValue LHS = getValue(I.getArgOperand(0));
SDValue RHS = getValue(I.getArgOperand(1));
setValue(&I, DAG.getNode(ISD::FCOPYSIGN, getCurSDLoc(),
LHS.getValueType(), LHS, RHS));
return;
}
break;
case LibFunc::fabs:
case LibFunc::fabsf:
case LibFunc::fabsl:
if (visitUnaryFloatCall(I, ISD::FABS))
return;
break;
case LibFunc::fmin:
case LibFunc::fminf:
case LibFunc::fminl:
if (visitBinaryFloatCall(I, ISD::FMINNUM))
return;
break;
case LibFunc::fmax:
case LibFunc::fmaxf:
case LibFunc::fmaxl:
if (visitBinaryFloatCall(I, ISD::FMAXNUM))
return;
break;
case LibFunc::sin:
case LibFunc::sinf:
case LibFunc::sinl:
if (visitUnaryFloatCall(I, ISD::FSIN))
return;
break;
case LibFunc::cos:
case LibFunc::cosf:
case LibFunc::cosl:
if (visitUnaryFloatCall(I, ISD::FCOS))
return;
break;
case LibFunc::sqrt:
case LibFunc::sqrtf:
case LibFunc::sqrtl:
case LibFunc::sqrt_finite:
case LibFunc::sqrtf_finite:
case LibFunc::sqrtl_finite:
if (visitUnaryFloatCall(I, ISD::FSQRT))
return;
break;
case LibFunc::floor:
case LibFunc::floorf:
case LibFunc::floorl:
if (visitUnaryFloatCall(I, ISD::FFLOOR))
return;
break;
case LibFunc::nearbyint:
case LibFunc::nearbyintf:
case LibFunc::nearbyintl:
if (visitUnaryFloatCall(I, ISD::FNEARBYINT))
return;
break;
case LibFunc::ceil:
case LibFunc::ceilf:
case LibFunc::ceill:
if (visitUnaryFloatCall(I, ISD::FCEIL))
return;
break;
case LibFunc::rint:
case LibFunc::rintf:
case LibFunc::rintl:
if (visitUnaryFloatCall(I, ISD::FRINT))
return;
break;
case LibFunc::round:
case LibFunc::roundf:
case LibFunc::roundl:
if (visitUnaryFloatCall(I, ISD::FROUND))
return;
break;
case LibFunc::trunc:
case LibFunc::truncf:
case LibFunc::truncl:
if (visitUnaryFloatCall(I, ISD::FTRUNC))
return;
break;
case LibFunc::log2:
case LibFunc::log2f:
case LibFunc::log2l:
if (visitUnaryFloatCall(I, ISD::FLOG2))
return;
break;
case LibFunc::exp2:
case LibFunc::exp2f:
case LibFunc::exp2l:
if (visitUnaryFloatCall(I, ISD::FEXP2))
return;
break;
case LibFunc::memcmp:
if (visitMemCmpCall(I))
return;
break;
case LibFunc::memchr:
if (visitMemChrCall(I))
return;
break;
case LibFunc::strcpy:
if (visitStrCpyCall(I, false))
return;
break;
case LibFunc::stpcpy:
if (visitStrCpyCall(I, true))
return;
break;
case LibFunc::strcmp:
if (visitStrCmpCall(I))
return;
break;
case LibFunc::strlen:
if (visitStrLenCall(I))
return;
break;
case LibFunc::strnlen:
if (visitStrNLenCall(I))
return;
break;
}
}
}
SDValue Callee;
if (!RenameFn)
Callee = getValue(I.getCalledValue());
else
Callee = DAG.getExternalSymbol(RenameFn,
DAG.getTargetLoweringInfo().getPointerTy());
// Check if we can potentially perform a tail call. More detailed checking is
// be done within LowerCallTo, after more information about the call is known.
LowerCallTo(&I, Callee, I.isTailCall());
}
namespace {
/// AsmOperandInfo - This contains information for each constraint that we are
/// lowering.
class SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo {
public:
/// CallOperand - If this is the result output operand or a clobber
/// this is null, otherwise it is the incoming operand to the CallInst.
/// This gets modified as the asm is processed.
SDValue CallOperand;
/// AssignedRegs - If this is a register or register class operand, this
/// contains the set of register corresponding to the operand.
RegsForValue AssignedRegs;
explicit SDISelAsmOperandInfo(const TargetLowering::AsmOperandInfo &info)
: TargetLowering::AsmOperandInfo(info), CallOperand(nullptr,0) {
}
/// getCallOperandValEVT - Return the EVT of the Value* that this operand
/// corresponds to. If there is no Value* for this operand, it returns
/// MVT::Other.
EVT getCallOperandValEVT(LLVMContext &Context,
const TargetLowering &TLI,
const DataLayout *DL) const {
if (!CallOperandVal) return MVT::Other;
if (isa<BasicBlock>(CallOperandVal))
return TLI.getPointerTy();
llvm::Type *OpTy = CallOperandVal->getType();
// FIXME: code duplicated from TargetLowering::ParseConstraints().
// If this is an indirect operand, the operand is a pointer to the
// accessed type.
if (isIndirect) {
llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy);
if (!PtrTy)
report_fatal_error("Indirect operand for inline asm not a pointer!");
OpTy = PtrTy->getElementType();
}
// Look for vector wrapped in a struct. e.g. { <16 x i8> }.
if (StructType *STy = dyn_cast<StructType>(OpTy))
if (STy->getNumElements() == 1)
OpTy = STy->getElementType(0);
// If OpTy is not a single value, it may be a struct/union that we
// can tile with integers.
if (!OpTy->isSingleValueType() && OpTy->isSized()) {
unsigned BitSize = DL->getTypeSizeInBits(OpTy);
switch (BitSize) {
default: break;
case 1:
case 8:
case 16:
case 32:
case 64:
case 128:
OpTy = IntegerType::get(Context, BitSize);
break;
}
}
return TLI.getValueType(OpTy, true);
}
};
typedef SmallVector<SDISelAsmOperandInfo,16> SDISelAsmOperandInfoVector;
} // end anonymous namespace
/// GetRegistersForValue - Assign registers (virtual or physical) for the
/// specified operand. We prefer to assign virtual registers, to allow the
/// register allocator to handle the assignment process. However, if the asm
/// uses features that we can't model on machineinstrs, we have SDISel do the
/// allocation. This produces generally horrible, but correct, code.
///
/// OpInfo describes the operand.
///
static void GetRegistersForValue(SelectionDAG &DAG,
const TargetLowering &TLI,
SDLoc DL,
SDISelAsmOperandInfo &OpInfo) {
LLVMContext &Context = *DAG.getContext();
MachineFunction &MF = DAG.getMachineFunction();
SmallVector<unsigned, 4> Regs;
// If this is a constraint for a single physreg, or a constraint for a
// register class, find it.
std::pair<unsigned, const TargetRegisterClass *> PhysReg =
TLI.getRegForInlineAsmConstraint(MF.getSubtarget().getRegisterInfo(),
OpInfo.ConstraintCode,
OpInfo.ConstraintVT);
unsigned NumRegs = 1;
if (OpInfo.ConstraintVT != MVT::Other) {
// If this is a FP input in an integer register (or visa versa) insert a bit
// cast of the input value. More generally, handle any case where the input
// value disagrees with the register class we plan to stick this in.
if (OpInfo.Type == InlineAsm::isInput &&
PhysReg.second && !PhysReg.second->hasType(OpInfo.ConstraintVT)) {
// Try to convert to the first EVT that the reg class contains. If the
// types are identical size, use a bitcast to convert (e.g. two differing
// vector types).
MVT RegVT = *PhysReg.second->vt_begin();
if (RegVT.getSizeInBits() == OpInfo.CallOperand.getValueSizeInBits()) {
OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL,
RegVT, OpInfo.CallOperand);
OpInfo.ConstraintVT = RegVT;
} else if (RegVT.isInteger() && OpInfo.ConstraintVT.isFloatingPoint()) {
// If the input is a FP value and we want it in FP registers, do a
// bitcast to the corresponding integer type. This turns an f64 value
// into i64, which can be passed with two i32 values on a 32-bit
// machine.
RegVT = MVT::getIntegerVT(OpInfo.ConstraintVT.getSizeInBits());
OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL,
RegVT, OpInfo.CallOperand);
OpInfo.ConstraintVT = RegVT;
}
}
NumRegs = TLI.getNumRegisters(Context, OpInfo.ConstraintVT);
}
MVT RegVT;
EVT ValueVT = OpInfo.ConstraintVT;
// If this is a constraint for a specific physical register, like {r17},
// assign it now.
if (unsigned AssignedReg = PhysReg.first) {
const TargetRegisterClass *RC = PhysReg.second;
if (OpInfo.ConstraintVT == MVT::Other)
ValueVT = *RC->vt_begin();
// Get the actual register value type. This is important, because the user
// may have asked for (e.g.) the AX register in i32 type. We need to
// remember that AX is actually i16 to get the right extension.
RegVT = *RC->vt_begin();
// This is a explicit reference to a physical register.
Regs.push_back(AssignedReg);
// If this is an expanded reference, add the rest of the regs to Regs.
if (NumRegs != 1) {
TargetRegisterClass::iterator I = RC->begin();
for (; *I != AssignedReg; ++I)
assert(I != RC->end() && "Didn't find reg!");
// Already added the first reg.
--NumRegs; ++I;
for (; NumRegs; --NumRegs, ++I) {
assert(I != RC->end() && "Ran out of registers to allocate!");
Regs.push_back(*I);
}
}
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
return;
}
// Otherwise, if this was a reference to an LLVM register class, create vregs
// for this reference.
if (const TargetRegisterClass *RC = PhysReg.second) {
RegVT = *RC->vt_begin();
if (OpInfo.ConstraintVT == MVT::Other)
ValueVT = RegVT;
// Create the appropriate number of virtual registers.
MachineRegisterInfo &RegInfo = MF.getRegInfo();
for (; NumRegs; --NumRegs)
Regs.push_back(RegInfo.createVirtualRegister(RC));
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
return;
}
// Otherwise, we couldn't allocate enough registers for this.
}
/// visitInlineAsm - Handle a call to an InlineAsm object.
///
void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
/// ConstraintOperands - Information about all of the constraints.
SDISelAsmOperandInfoVector ConstraintOperands;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
TargetLowering::AsmOperandInfoVector TargetConstraints =
TLI.ParseConstraints(DAG.getSubtarget().getRegisterInfo(), CS);
bool hasMemory = false;
unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
unsigned ResNo = 0; // ResNo - The result number of the next output.
for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
ConstraintOperands.push_back(SDISelAsmOperandInfo(TargetConstraints[i]));
SDISelAsmOperandInfo &OpInfo = ConstraintOperands.back();
MVT OpVT = MVT::Other;
// Compute the value type for each operand.
switch (OpInfo.Type) {
case InlineAsm::isOutput:
// Indirect outputs just consume an argument.
if (OpInfo.isIndirect) {
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
break;
}
// The return value of the call is this value. As such, there is no
// corresponding argument.
assert(!CS.getType()->isVoidTy() && "Bad inline asm!");
if (StructType *STy = dyn_cast<StructType>(CS.getType())) {
OpVT = TLI.getSimpleValueType(STy->getElementType(ResNo));
} else {
assert(ResNo == 0 && "Asm only has one result!");
OpVT = TLI.getSimpleValueType(CS.getType());
}
++ResNo;
break;
case InlineAsm::isInput:
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
break;
case InlineAsm::isClobber:
// Nothing to do.
break;
}
// If this is an input or an indirect output, process the call argument.
// BasicBlocks are labels, currently appearing only in asm's.
if (OpInfo.CallOperandVal) {
if (const BasicBlock *BB = dyn_cast<BasicBlock>(OpInfo.CallOperandVal)) {
OpInfo.CallOperand = DAG.getBasicBlock(FuncInfo.MBBMap[BB]);
} else {
OpInfo.CallOperand = getValue(OpInfo.CallOperandVal);
}
OpVT =
OpInfo.getCallOperandValEVT(*DAG.getContext(), TLI, DL).getSimpleVT();
}
OpInfo.ConstraintVT = OpVT;
// Indirect operand accesses access memory.
if (OpInfo.isIndirect)
hasMemory = true;
else {
for (unsigned j = 0, ee = OpInfo.Codes.size(); j != ee; ++j) {
TargetLowering::ConstraintType
CType = TLI.getConstraintType(OpInfo.Codes[j]);
if (CType == TargetLowering::C_Memory) {
hasMemory = true;
break;
}
}
}
}
SDValue Chain, Flag;
// We won't need to flush pending loads if this asm doesn't touch
// memory and is nonvolatile.
if (hasMemory || IA->hasSideEffects())
Chain = getRoot();
else
Chain = DAG.getRoot();
// Second pass over the constraints: compute which constraint option to use
// and assign registers to constraints that want a specific physreg.
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
// If this is an output operand with a matching input operand, look up the
// matching input. If their types mismatch, e.g. one is an integer, the
// other is floating point, or their sizes are different, flag it as an
// error.
if (OpInfo.hasMatchingInput()) {
SDISelAsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
if (OpInfo.ConstraintVT != Input.ConstraintVT) {
const TargetRegisterInfo *TRI = DAG.getSubtarget().getRegisterInfo();
std::pair<unsigned, const TargetRegisterClass *> MatchRC =
TLI.getRegForInlineAsmConstraint(TRI, OpInfo.ConstraintCode,
OpInfo.ConstraintVT);
std::pair<unsigned, const TargetRegisterClass *> InputRC =
TLI.getRegForInlineAsmConstraint(TRI, Input.ConstraintCode,
Input.ConstraintVT);
if ((OpInfo.ConstraintVT.isInteger() !=
Input.ConstraintVT.isInteger()) ||
(MatchRC.second != InputRC.second)) {
report_fatal_error("Unsupported asm: input constraint"
" with a matching output constraint of"
" incompatible type!");
}
Input.ConstraintVT = OpInfo.ConstraintVT;
}
}
// Compute the constraint code and ConstraintType to use.
TLI.ComputeConstraintToUse(OpInfo, OpInfo.CallOperand, &DAG);
if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
OpInfo.Type == InlineAsm::isClobber)
continue;
// If this is a memory input, and if the operand is not indirect, do what we
// need to to provide an address for the memory input.
if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
!OpInfo.isIndirect) {
assert((OpInfo.isMultipleAlternative ||
(OpInfo.Type == InlineAsm::isInput)) &&
"Can only indirectify direct input operands!");
// Memory operands really want the address of the value. If we don't have
// an indirect input, put it in the constpool if we can, otherwise spill
// it to a stack slot.
// TODO: This isn't quite right. We need to handle these according to
// the addressing mode that the constraint wants. Also, this may take
// an additional register for the computation and we don't want that
// either.
// If the operand is a float, integer, or vector constant, spill to a
// constant pool entry to get its address.
const Value *OpVal = OpInfo.CallOperandVal;
if (isa<ConstantFP>(OpVal) || isa<ConstantInt>(OpVal) ||
isa<ConstantVector>(OpVal) || isa<ConstantDataVector>(OpVal)) {
OpInfo.CallOperand = DAG.getConstantPool(cast<Constant>(OpVal),
TLI.getPointerTy());
} else {
// Otherwise, create a stack slot and emit a store to it before the
// asm.
Type *Ty = OpVal->getType();
uint64_t TySize = TLI.getDataLayout()->getTypeAllocSize(Ty);
unsigned Align = TLI.getDataLayout()->getPrefTypeAlignment(Ty);
MachineFunction &MF = DAG.getMachineFunction();
int SSFI = MF.getFrameInfo()->CreateStackObject(TySize, Align, false);
SDValue StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy());
Chain = DAG.getStore(Chain, getCurSDLoc(),
OpInfo.CallOperand, StackSlot,
MachinePointerInfo::getFixedStack(SSFI),
false, false, 0);
OpInfo.CallOperand = StackSlot;
}
// There is no longer a Value* corresponding to this operand.
OpInfo.CallOperandVal = nullptr;
// It is now an indirect operand.
OpInfo.isIndirect = true;
}
// If this constraint is for a specific register, allocate it before
// anything else.
if (OpInfo.ConstraintType == TargetLowering::C_Register)
GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo);
}
// Second pass - Loop over all of the operands, assigning virtual or physregs
// to register class operands.
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
// C_Register operands have already been allocated, Other/Memory don't need
// to be.
if (OpInfo.ConstraintType == TargetLowering::C_RegisterClass)
GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo);
}
// AsmNodeOperands - The operands for the ISD::INLINEASM node.
std::vector<SDValue> AsmNodeOperands;
AsmNodeOperands.push_back(SDValue()); // reserve space for input chain
AsmNodeOperands.push_back(
DAG.getTargetExternalSymbol(IA->getAsmString().c_str(),
TLI.getPointerTy()));
// If we have a !srcloc metadata node associated with it, we want to attach
// this to the ultimately generated inline asm machineinstr. To do this, we
// pass in the third operand as this (potentially null) inline asm MDNode.
const MDNode *SrcLoc = CS.getInstruction()->getMetadata("srcloc");
AsmNodeOperands.push_back(DAG.getMDNode(SrcLoc));
// Remember the HasSideEffect, AlignStack, AsmDialect, MayLoad and MayStore
// bits as operand 3.
unsigned ExtraInfo = 0;
if (IA->hasSideEffects())
ExtraInfo |= InlineAsm::Extra_HasSideEffects;
if (IA->isAlignStack())
ExtraInfo |= InlineAsm::Extra_IsAlignStack;
// Set the asm dialect.
ExtraInfo |= IA->getDialect() * InlineAsm::Extra_AsmDialect;
// Determine if this InlineAsm MayLoad or MayStore based on the constraints.
for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i];
// Compute the constraint code and ConstraintType to use.
TLI.ComputeConstraintToUse(OpInfo, SDValue());
// Ideally, we would only check against memory constraints. However, the
// meaning of an other constraint can be target-specific and we can't easily
// reason about it. Therefore, be conservative and set MayLoad/MayStore
// for other constriants as well.
if (OpInfo.ConstraintType == TargetLowering::C_Memory ||
OpInfo.ConstraintType == TargetLowering::C_Other) {
if (OpInfo.Type == InlineAsm::isInput)
ExtraInfo |= InlineAsm::Extra_MayLoad;
else if (OpInfo.Type == InlineAsm::isOutput)
ExtraInfo |= InlineAsm::Extra_MayStore;
else if (OpInfo.Type == InlineAsm::isClobber)
ExtraInfo |= (InlineAsm::Extra_MayLoad | InlineAsm::Extra_MayStore);
}
}
AsmNodeOperands.push_back(DAG.getTargetConstant(ExtraInfo, getCurSDLoc(),
TLI.getPointerTy()));
// Loop over all of the inputs, copying the operand values into the
// appropriate registers and processing the output regs.
RegsForValue RetValRegs;
// IndirectStoresToEmit - The set of stores to emit after the inline asm node.
std::vector<std::pair<RegsForValue, Value*> > IndirectStoresToEmit;
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
switch (OpInfo.Type) {
case InlineAsm::isOutput: {
if (OpInfo.ConstraintType != TargetLowering::C_RegisterClass &&
OpInfo.ConstraintType != TargetLowering::C_Register) {
// Memory output, or 'other' output (e.g. 'X' constraint).
assert(OpInfo.isIndirect && "Memory output must be indirect operand");
unsigned ConstraintID =
TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode);
assert(ConstraintID != InlineAsm::Constraint_Unknown &&
"Failed to convert memory constraint code to constraint id.");
// Add information to the INLINEASM node to know about this output.
unsigned OpFlags = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
OpFlags = InlineAsm::getFlagWordForMem(OpFlags, ConstraintID);
AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlags, getCurSDLoc(),
MVT::i32));
AsmNodeOperands.push_back(OpInfo.CallOperand);
break;
}
// Otherwise, this is a register or register class output.
// Copy the output from the appropriate register. Find a register that
// we can use.
if (OpInfo.AssignedRegs.Regs.empty()) {
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(),
"couldn't allocate output register for constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
// If this is an indirect operand, store through the pointer after the
// asm.
if (OpInfo.isIndirect) {
IndirectStoresToEmit.push_back(std::make_pair(OpInfo.AssignedRegs,
OpInfo.CallOperandVal));
} else {
// This is the result value of the call.
assert(!CS.getType()->isVoidTy() && "Bad inline asm!");
// Concatenate this output onto the outputs list.
RetValRegs.append(OpInfo.AssignedRegs);
}
// Add information to the INLINEASM node to know that this register is
// set.
OpInfo.AssignedRegs
.AddInlineAsmOperands(OpInfo.isEarlyClobber
? InlineAsm::Kind_RegDefEarlyClobber
: InlineAsm::Kind_RegDef,
false, 0, getCurSDLoc(), DAG, AsmNodeOperands);
break;
}
case InlineAsm::isInput: {
SDValue InOperandVal = OpInfo.CallOperand;
if (OpInfo.isMatchingInputConstraint()) { // Matching constraint?
// If this is required to match an output register we have already set,
// just use its register.
unsigned OperandNo = OpInfo.getMatchedOperand();
// Scan until we find the definition we already emitted of this operand.
// When we find it, create a RegsForValue operand.
unsigned CurOp = InlineAsm::Op_FirstOperand;
for (; OperandNo; --OperandNo) {
// Advance to the next operand.
unsigned OpFlag =
cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue();
assert((InlineAsm::isRegDefKind(OpFlag) ||
InlineAsm::isRegDefEarlyClobberKind(OpFlag) ||
InlineAsm::isMemKind(OpFlag)) && "Skipped past definitions?");
CurOp += InlineAsm::getNumOperandRegisters(OpFlag)+1;
}
unsigned OpFlag =
cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue();
if (InlineAsm::isRegDefKind(OpFlag) ||
InlineAsm::isRegDefEarlyClobberKind(OpFlag)) {
// Add (OpFlag&0xffff)>>3 registers to MatchedRegs.
if (OpInfo.isIndirect) {
// This happens on gcc/testsuite/gcc.dg/pr8788-1.c
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(), "inline asm not supported yet:"
" don't know how to handle tied "
"indirect register inputs");
return;
}
RegsForValue MatchedRegs;
MatchedRegs.ValueVTs.push_back(InOperandVal.getValueType());
MVT RegVT = AsmNodeOperands[CurOp+1].getSimpleValueType();
MatchedRegs.RegVTs.push_back(RegVT);
MachineRegisterInfo &RegInfo = DAG.getMachineFunction().getRegInfo();
for (unsigned i = 0, e = InlineAsm::getNumOperandRegisters(OpFlag);
i != e; ++i) {
if (const TargetRegisterClass *RC = TLI.getRegClassFor(RegVT))
MatchedRegs.Regs.push_back(RegInfo.createVirtualRegister(RC));
else {
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(),
"inline asm error: This value"
" type register class is not natively supported!");
return;
}
}
SDLoc dl = getCurSDLoc();
// Use the produced MatchedRegs object to
MatchedRegs.getCopyToRegs(InOperandVal, DAG, dl,
Chain, &Flag, CS.getInstruction());
MatchedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse,
true, OpInfo.getMatchedOperand(), dl,
DAG, AsmNodeOperands);
break;
}
assert(InlineAsm::isMemKind(OpFlag) && "Unknown matching constraint!");
assert(InlineAsm::getNumOperandRegisters(OpFlag) == 1 &&
"Unexpected number of operands");
// Add information to the INLINEASM node to know about this input.
// See InlineAsm.h isUseOperandTiedToDef.
OpFlag = InlineAsm::convertMemFlagWordToMatchingFlagWord(OpFlag);
OpFlag = InlineAsm::getFlagWordForMatchingOp(OpFlag,
OpInfo.getMatchedOperand());
AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlag, getCurSDLoc(),
TLI.getPointerTy()));
AsmNodeOperands.push_back(AsmNodeOperands[CurOp+1]);
break;
}
// Treat indirect 'X' constraint as memory.
if (OpInfo.ConstraintType == TargetLowering::C_Other &&
OpInfo.isIndirect)
OpInfo.ConstraintType = TargetLowering::C_Memory;
if (OpInfo.ConstraintType == TargetLowering::C_Other) {
std::vector<SDValue> Ops;
TLI.LowerAsmOperandForConstraint(InOperandVal, OpInfo.ConstraintCode,
Ops, DAG);
if (Ops.empty()) {
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(),
"invalid operand for inline asm constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
// Add information to the INLINEASM node to know about this input.
unsigned ResOpType =
InlineAsm::getFlagWord(InlineAsm::Kind_Imm, Ops.size());
AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType,
getCurSDLoc(),
TLI.getPointerTy()));
AsmNodeOperands.insert(AsmNodeOperands.end(), Ops.begin(), Ops.end());
break;
}
if (OpInfo.ConstraintType == TargetLowering::C_Memory) {
assert(OpInfo.isIndirect && "Operand must be indirect to be a mem!");
assert(InOperandVal.getValueType() == TLI.getPointerTy() &&
"Memory operands expect pointer values");
unsigned ConstraintID =
TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode);
assert(ConstraintID != InlineAsm::Constraint_Unknown &&
"Failed to convert memory constraint code to constraint id.");
// Add information to the INLINEASM node to know about this input.
unsigned ResOpType = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
ResOpType = InlineAsm::getFlagWordForMem(ResOpType, ConstraintID);
AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType,
getCurSDLoc(),
MVT::i32));
AsmNodeOperands.push_back(InOperandVal);
break;
}
assert((OpInfo.ConstraintType == TargetLowering::C_RegisterClass ||
OpInfo.ConstraintType == TargetLowering::C_Register) &&
"Unknown constraint type!");
// TODO: Support this.
if (OpInfo.isIndirect) {
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(),
"Don't know how to handle indirect register inputs yet "
"for constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
// Copy the input into the appropriate registers.
if (OpInfo.AssignedRegs.Regs.empty()) {
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(),
"couldn't allocate input reg for constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
SDLoc dl = getCurSDLoc();
OpInfo.AssignedRegs.getCopyToRegs(InOperandVal, DAG, dl,
Chain, &Flag, CS.getInstruction());
OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse, false, 0,
dl, DAG, AsmNodeOperands);
break;
}
case InlineAsm::isClobber: {
// Add the clobbered value to the operand list, so that the register
// allocator is aware that the physreg got clobbered.
if (!OpInfo.AssignedRegs.Regs.empty())
OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_Clobber,
false, 0, getCurSDLoc(), DAG,
AsmNodeOperands);
break;
}
}
}
// Finish up input operands. Set the input chain and add the flag last.
AsmNodeOperands[InlineAsm::Op_InputChain] = Chain;
if (Flag.getNode()) AsmNodeOperands.push_back(Flag);
Chain = DAG.getNode(ISD::INLINEASM, getCurSDLoc(),
DAG.getVTList(MVT::Other, MVT::Glue), AsmNodeOperands);
Flag = Chain.getValue(1);
// If this asm returns a register value, copy the result from that register
// and set it as the value of the call.
if (!RetValRegs.Regs.empty()) {
SDValue Val = RetValRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(),
Chain, &Flag, CS.getInstruction());
// FIXME: Why don't we do this for inline asms with MRVs?
if (CS.getType()->isSingleValueType() && CS.getType()->isSized()) {
EVT ResultType = TLI.getValueType(CS.getType());
// If any of the results of the inline asm is a vector, it may have the
// wrong width/num elts. This can happen for register classes that can
// contain multiple different value types. The preg or vreg allocated may
// not have the same VT as was expected. Convert it to the right type
// with bit_convert.
if (ResultType != Val.getValueType() && Val.getValueType().isVector()) {
Val = DAG.getNode(ISD::BITCAST, getCurSDLoc(),
ResultType, Val);
} else if (ResultType != Val.getValueType() &&
ResultType.isInteger() && Val.getValueType().isInteger()) {
// If a result value was tied to an input value, the computed result may
// have a wider width than the expected result. Extract the relevant
// portion.
Val = DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), ResultType, Val);
}
assert(ResultType == Val.getValueType() && "Asm result value mismatch!");
}
setValue(CS.getInstruction(), Val);
// Don't need to use this as a chain in this case.
if (!IA->hasSideEffects() && !hasMemory && IndirectStoresToEmit.empty())
return;
}
std::vector<std::pair<SDValue, const Value *> > StoresToEmit;
// Process indirect outputs, first output all of the flagged copies out of
// physregs.
for (unsigned i = 0, e = IndirectStoresToEmit.size(); i != e; ++i) {
RegsForValue &OutRegs = IndirectStoresToEmit[i].first;
const Value *Ptr = IndirectStoresToEmit[i].second;
SDValue OutVal = OutRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(),
Chain, &Flag, IA);
StoresToEmit.push_back(std::make_pair(OutVal, Ptr));
}
// Emit the non-flagged stores from the physregs.
SmallVector<SDValue, 8> OutChains;
for (unsigned i = 0, e = StoresToEmit.size(); i != e; ++i) {
SDValue Val = DAG.getStore(Chain, getCurSDLoc(),
StoresToEmit[i].first,
getValue(StoresToEmit[i].second),
MachinePointerInfo(StoresToEmit[i].second),
false, false, 0);
OutChains.push_back(Val);
}
if (!OutChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, OutChains);
DAG.setRoot(Chain);
}
void SelectionDAGBuilder::visitVAStart(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VASTART, getCurSDLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(0))));
}
void SelectionDAGBuilder::visitVAArg(const VAArgInst &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
const DataLayout &DL = *TLI.getDataLayout();
SDValue V = DAG.getVAArg(TLI.getValueType(I.getType()), getCurSDLoc(),
getRoot(), getValue(I.getOperand(0)),
DAG.getSrcValue(I.getOperand(0)),
DL.getABITypeAlignment(I.getType()));
setValue(&I, V);
DAG.setRoot(V.getValue(1));
}
void SelectionDAGBuilder::visitVAEnd(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VAEND, getCurSDLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(0))));
}
void SelectionDAGBuilder::visitVACopy(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VACOPY, getCurSDLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
DAG.getSrcValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(1))));
}
/// \brief Lower an argument list according to the target calling convention.
///
/// \return A tuple of <return-value, token-chain>
///
/// This is a helper for lowering intrinsics that follow a target calling
/// convention or require stack pointer adjustment. Only a subset of the
/// intrinsic's operands need to participate in the calling convention.
std::pair<SDValue, SDValue>
SelectionDAGBuilder::lowerCallOperands(ImmutableCallSite CS, unsigned ArgIdx,
unsigned NumArgs, SDValue Callee,
bool UseVoidTy,
MachineBasicBlock *LandingPad,
bool IsPatchPoint) {
TargetLowering::ArgListTy Args;
Args.reserve(NumArgs);
// Populate the argument list.
// Attributes for args start at offset 1, after the return attribute.
for (unsigned ArgI = ArgIdx, ArgE = ArgIdx + NumArgs, AttrI = ArgIdx + 1;
ArgI != ArgE; ++ArgI) {
const Value *V = CS->getOperand(ArgI);
assert(!V->getType()->isEmptyTy() && "Empty type passed to intrinsic.");
TargetLowering::ArgListEntry Entry;
Entry.Node = getValue(V);
Entry.Ty = V->getType();
Entry.setAttributes(&CS, AttrI);
Args.push_back(Entry);
}
Type *retTy = UseVoidTy ? Type::getVoidTy(*DAG.getContext()) : CS->getType();
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(getCurSDLoc()).setChain(getRoot())
.setCallee(CS.getCallingConv(), retTy, Callee, std::move(Args), NumArgs)
.setDiscardResult(CS->use_empty()).setIsPatchPoint(IsPatchPoint);
return lowerInvokable(CLI, LandingPad);
}
/// \brief Add a stack map intrinsic call's live variable operands to a stackmap
/// or patchpoint target node's operand list.
///
/// Constants are converted to TargetConstants purely as an optimization to
/// avoid constant materialization and register allocation.
///
/// FrameIndex operands are converted to TargetFrameIndex so that ISEL does not
/// generate addess computation nodes, and so ExpandISelPseudo can convert the
/// TargetFrameIndex into a DirectMemRefOp StackMap location. This avoids
/// address materialization and register allocation, but may also be required
/// for correctness. If a StackMap (or PatchPoint) intrinsic directly uses an
/// alloca in the entry block, then the runtime may assume that the alloca's
/// StackMap location can be read immediately after compilation and that the
/// location is valid at any point during execution (this is similar to the
/// assumption made by the llvm.gcroot intrinsic). If the alloca's location were
/// only available in a register, then the runtime would need to trap when
/// execution reaches the StackMap in order to read the alloca's location.
static void addStackMapLiveVars(ImmutableCallSite CS, unsigned StartIdx,
SDLoc DL, SmallVectorImpl<SDValue> &Ops,
SelectionDAGBuilder &Builder) {
for (unsigned i = StartIdx, e = CS.arg_size(); i != e; ++i) {
SDValue OpVal = Builder.getValue(CS.getArgument(i));
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(OpVal)) {
Ops.push_back(
Builder.DAG.getTargetConstant(StackMaps::ConstantOp, DL, MVT::i64));
Ops.push_back(
Builder.DAG.getTargetConstant(C->getSExtValue(), DL, MVT::i64));
} else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(OpVal)) {
const TargetLowering &TLI = Builder.DAG.getTargetLoweringInfo();
Ops.push_back(
Builder.DAG.getTargetFrameIndex(FI->getIndex(), TLI.getPointerTy()));
} else
Ops.push_back(OpVal);
}
}
/// \brief Lower llvm.experimental.stackmap directly to its target opcode.
void SelectionDAGBuilder::visitStackmap(const CallInst &CI) {
// void @llvm.experimental.stackmap(i32 <id>, i32 <numShadowBytes>,
// [live variables...])
assert(CI.getType()->isVoidTy() && "Stackmap cannot return a value.");
SDValue Chain, InFlag, Callee, NullPtr;
SmallVector<SDValue, 32> Ops;
SDLoc DL = getCurSDLoc();
Callee = getValue(CI.getCalledValue());
NullPtr = DAG.getIntPtrConstant(0, DL, true);
// The stackmap intrinsic only records the live variables (the arguemnts
// passed to it) and emits NOPS (if requested). Unlike the patchpoint
// intrinsic, this won't be lowered to a function call. This means we don't
// have to worry about calling conventions and target specific lowering code.
// Instead we perform the call lowering right here.
//
// chain, flag = CALLSEQ_START(chain, 0)
// chain, flag = STACKMAP(id, nbytes, ..., chain, flag)
// chain, flag = CALLSEQ_END(chain, 0, 0, flag)
//
Chain = DAG.getCALLSEQ_START(getRoot(), NullPtr, DL);
InFlag = Chain.getValue(1);
// Add the <id> and <numBytes> constants.
SDValue IDVal = getValue(CI.getOperand(PatchPointOpers::IDPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(IDVal)->getZExtValue(), DL, MVT::i64));
SDValue NBytesVal = getValue(CI.getOperand(PatchPointOpers::NBytesPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(NBytesVal)->getZExtValue(), DL,
MVT::i32));
// Push live variables for the stack map.
addStackMapLiveVars(&CI, 2, DL, Ops, *this);
// We are not pushing any register mask info here on the operands list,
// because the stackmap doesn't clobber anything.
// Push the chain and the glue flag.
Ops.push_back(Chain);
Ops.push_back(InFlag);
// Create the STACKMAP node.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
SDNode *SM = DAG.getMachineNode(TargetOpcode::STACKMAP, DL, NodeTys, Ops);
Chain = SDValue(SM, 0);
InFlag = Chain.getValue(1);
Chain = DAG.getCALLSEQ_END(Chain, NullPtr, NullPtr, InFlag, DL);
// Stackmaps don't generate values, so nothing goes into the NodeMap.
// Set the root to the target-lowered call chain.
DAG.setRoot(Chain);
// Inform the Frame Information that we have a stackmap in this function.
FuncInfo.MF->getFrameInfo()->setHasStackMap();
}
/// \brief Lower llvm.experimental.patchpoint directly to its target opcode.
void SelectionDAGBuilder::visitPatchpoint(ImmutableCallSite CS,
MachineBasicBlock *LandingPad) {
// void|i64 @llvm.experimental.patchpoint.void|i64(i64 <id>,
// i32 <numBytes>,
// i8* <target>,
// i32 <numArgs>,
// [Args...],
// [live variables...])
CallingConv::ID CC = CS.getCallingConv();
bool IsAnyRegCC = CC == CallingConv::AnyReg;
bool HasDef = !CS->getType()->isVoidTy();
SDLoc dl = getCurSDLoc();
SDValue Callee = getValue(CS->getOperand(PatchPointOpers::TargetPos));
// Handle immediate and symbolic callees.
if (auto* ConstCallee = dyn_cast<ConstantSDNode>(Callee))
Callee = DAG.getIntPtrConstant(ConstCallee->getZExtValue(), dl,
/*isTarget=*/true);
else if (auto* SymbolicCallee = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(SymbolicCallee->getGlobal(),
SDLoc(SymbolicCallee),
SymbolicCallee->getValueType(0));
// Get the real number of arguments participating in the call <numArgs>
SDValue NArgVal = getValue(CS.getArgument(PatchPointOpers::NArgPos));
unsigned NumArgs = cast<ConstantSDNode>(NArgVal)->getZExtValue();
// Skip the four meta args: <id>, <numNopBytes>, <target>, <numArgs>
// Intrinsics include all meta-operands up to but not including CC.
unsigned NumMetaOpers = PatchPointOpers::CCPos;
assert(CS.arg_size() >= NumMetaOpers + NumArgs &&
"Not enough arguments provided to the patchpoint intrinsic");
// For AnyRegCC the arguments are lowered later on manually.
unsigned NumCallArgs = IsAnyRegCC ? 0 : NumArgs;
std::pair<SDValue, SDValue> Result =
lowerCallOperands(CS, NumMetaOpers, NumCallArgs, Callee, IsAnyRegCC,
LandingPad, true);
SDNode *CallEnd = Result.second.getNode();
if (HasDef && (CallEnd->getOpcode() == ISD::CopyFromReg))
CallEnd = CallEnd->getOperand(0).getNode();
/// Get a call instruction from the call sequence chain.
/// Tail calls are not allowed.
assert(CallEnd->getOpcode() == ISD::CALLSEQ_END &&
"Expected a callseq node.");
SDNode *Call = CallEnd->getOperand(0).getNode();
bool HasGlue = Call->getGluedNode();
// Replace the target specific call node with the patchable intrinsic.
SmallVector<SDValue, 8> Ops;
// Add the <id> and <numBytes> constants.
SDValue IDVal = getValue(CS->getOperand(PatchPointOpers::IDPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(IDVal)->getZExtValue(), dl, MVT::i64));
SDValue NBytesVal = getValue(CS->getOperand(PatchPointOpers::NBytesPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(NBytesVal)->getZExtValue(), dl,
MVT::i32));
// Add the callee.
Ops.push_back(Callee);
// Adjust <numArgs> to account for any arguments that have been passed on the
// stack instead.
// Call Node: Chain, Target, {Args}, RegMask, [Glue]
unsigned NumCallRegArgs = Call->getNumOperands() - (HasGlue ? 4 : 3);
NumCallRegArgs = IsAnyRegCC ? NumArgs : NumCallRegArgs;
Ops.push_back(DAG.getTargetConstant(NumCallRegArgs, dl, MVT::i32));
// Add the calling convention
Ops.push_back(DAG.getTargetConstant((unsigned)CC, dl, MVT::i32));
// Add the arguments we omitted previously. The register allocator should
// place these in any free register.
if (IsAnyRegCC)
for (unsigned i = NumMetaOpers, e = NumMetaOpers + NumArgs; i != e; ++i)
Ops.push_back(getValue(CS.getArgument(i)));
// Push the arguments from the call instruction up to the register mask.
SDNode::op_iterator e = HasGlue ? Call->op_end()-2 : Call->op_end()-1;
Ops.append(Call->op_begin() + 2, e);
// Push live variables for the stack map.
addStackMapLiveVars(CS, NumMetaOpers + NumArgs, dl, Ops, *this);
// Push the register mask info.
if (HasGlue)
Ops.push_back(*(Call->op_end()-2));
else
Ops.push_back(*(Call->op_end()-1));
// Push the chain (this is originally the first operand of the call, but
// becomes now the last or second to last operand).
Ops.push_back(*(Call->op_begin()));
// Push the glue flag (last operand).
if (HasGlue)
Ops.push_back(*(Call->op_end()-1));
SDVTList NodeTys;
if (IsAnyRegCC && HasDef) {
// Create the return types based on the intrinsic definition
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SmallVector<EVT, 3> ValueVTs;
ComputeValueVTs(TLI, CS->getType(), ValueVTs);
assert(ValueVTs.size() == 1 && "Expected only one return value type.");
// There is always a chain and a glue type at the end
ValueVTs.push_back(MVT::Other);
ValueVTs.push_back(MVT::Glue);
NodeTys = DAG.getVTList(ValueVTs);
} else
NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
// Replace the target specific call node with a PATCHPOINT node.
MachineSDNode *MN = DAG.getMachineNode(TargetOpcode::PATCHPOINT,
dl, NodeTys, Ops);
// Update the NodeMap.
if (HasDef) {
if (IsAnyRegCC)
setValue(CS.getInstruction(), SDValue(MN, 0));
else
setValue(CS.getInstruction(), Result.first);
}
// Fixup the consumers of the intrinsic. The chain and glue may be used in the
// call sequence. Furthermore the location of the chain and glue can change
// when the AnyReg calling convention is used and the intrinsic returns a
// value.
if (IsAnyRegCC && HasDef) {
SDValue From[] = {SDValue(Call, 0), SDValue(Call, 1)};
SDValue To[] = {SDValue(MN, 1), SDValue(MN, 2)};
DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
} else
DAG.ReplaceAllUsesWith(Call, MN);
DAG.DeleteNode(Call);
// Inform the Frame Information that we have a patchpoint in this function.
FuncInfo.MF->getFrameInfo()->setHasPatchPoint();
}
/// Returns an AttributeSet representing the attributes applied to the return
/// value of the given call.
static AttributeSet getReturnAttrs(TargetLowering::CallLoweringInfo &CLI) {
SmallVector<Attribute::AttrKind, 2> Attrs;
if (CLI.RetSExt)
Attrs.push_back(Attribute::SExt);
if (CLI.RetZExt)
Attrs.push_back(Attribute::ZExt);
if (CLI.IsInReg)
Attrs.push_back(Attribute::InReg);
return AttributeSet::get(CLI.RetTy->getContext(), AttributeSet::ReturnIndex,
Attrs);
}
/// TargetLowering::LowerCallTo - This is the default LowerCallTo
/// implementation, which just calls LowerCall.
/// FIXME: When all targets are
/// migrated to using LowerCall, this hook should be integrated into SDISel.
std::pair<SDValue, SDValue>
TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
// Handle the incoming return values from the call.
CLI.Ins.clear();
Type *OrigRetTy = CLI.RetTy;
SmallVector<EVT, 4> RetTys;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(*this, CLI.RetTy, RetTys, &Offsets);
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(CLI.RetTy, getReturnAttrs(CLI), Outs, *this);
bool CanLowerReturn =
this->CanLowerReturn(CLI.CallConv, CLI.DAG.getMachineFunction(),
CLI.IsVarArg, Outs, CLI.RetTy->getContext());
SDValue DemoteStackSlot;
int DemoteStackIdx = -100;
if (!CanLowerReturn) {
// FIXME: equivalent assert?
// assert(!CS.hasInAllocaArgument() &&
// "sret demotion is incompatible with inalloca");
uint64_t TySize = getDataLayout()->getTypeAllocSize(CLI.RetTy);
unsigned Align = getDataLayout()->getPrefTypeAlignment(CLI.RetTy);
MachineFunction &MF = CLI.DAG.getMachineFunction();
DemoteStackIdx = MF.getFrameInfo()->CreateStackObject(TySize, Align, false);
Type *StackSlotPtrType = PointerType::getUnqual(CLI.RetTy);
DemoteStackSlot = CLI.DAG.getFrameIndex(DemoteStackIdx, getPointerTy());
ArgListEntry Entry;
Entry.Node = DemoteStackSlot;
Entry.Ty = StackSlotPtrType;
Entry.isSExt = false;
Entry.isZExt = false;
Entry.isInReg = false;
Entry.isSRet = true;
Entry.isNest = false;
Entry.isByVal = false;
Entry.isReturned = false;
Entry.Alignment = Align;
CLI.getArgs().insert(CLI.getArgs().begin(), Entry);
CLI.RetTy = Type::getVoidTy(CLI.RetTy->getContext());
// sret demotion isn't compatible with tail-calls, since the sret argument
// points into the callers stack frame.
CLI.IsTailCall = false;
} else {
for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
EVT VT = RetTys[I];
MVT RegisterVT = getRegisterType(CLI.RetTy->getContext(), VT);
unsigned NumRegs = getNumRegisters(CLI.RetTy->getContext(), VT);
for (unsigned i = 0; i != NumRegs; ++i) {
ISD::InputArg MyFlags;
MyFlags.VT = RegisterVT;
MyFlags.ArgVT = VT;
MyFlags.Used = CLI.IsReturnValueUsed;
if (CLI.RetSExt)
MyFlags.Flags.setSExt();
if (CLI.RetZExt)
MyFlags.Flags.setZExt();
if (CLI.IsInReg)
MyFlags.Flags.setInReg();
CLI.Ins.push_back(MyFlags);
}
}
}
// Handle all of the outgoing arguments.
CLI.Outs.clear();
CLI.OutVals.clear();
ArgListTy &Args = CLI.getArgs();
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*this, Args[i].Ty, ValueVTs);
Type *FinalType = Args[i].Ty;
if (Args[i].isByVal)
FinalType = cast<PointerType>(Args[i].Ty)->getElementType();
bool NeedsRegBlock = functionArgumentNeedsConsecutiveRegisters(
FinalType, CLI.CallConv, CLI.IsVarArg);
for (unsigned Value = 0, NumValues = ValueVTs.size(); Value != NumValues;
++Value) {
EVT VT = ValueVTs[Value];
Type *ArgTy = VT.getTypeForEVT(CLI.RetTy->getContext());
SDValue Op = SDValue(Args[i].Node.getNode(),
Args[i].Node.getResNo() + Value);
ISD::ArgFlagsTy Flags;
unsigned OriginalAlignment = getDataLayout()->getABITypeAlignment(ArgTy);
if (Args[i].isZExt)
Flags.setZExt();
if (Args[i].isSExt)
Flags.setSExt();
if (Args[i].isInReg)
Flags.setInReg();
if (Args[i].isSRet)
Flags.setSRet();
if (Args[i].isByVal)
Flags.setByVal();
if (Args[i].isInAlloca) {
Flags.setInAlloca();
// Set the byval flag for CCAssignFn callbacks that don't know about
// inalloca. This way we can know how many bytes we should've allocated
// and how many bytes a callee cleanup function will pop. If we port
// inalloca to more targets, we'll have to add custom inalloca handling
// in the various CC lowering callbacks.
Flags.setByVal();
}
if (Args[i].isByVal || Args[i].isInAlloca) {
PointerType *Ty = cast<PointerType>(Args[i].Ty);
Type *ElementTy = Ty->getElementType();
Flags.setByValSize(getDataLayout()->getTypeAllocSize(ElementTy));
// For ByVal, alignment should come from FE. BE will guess if this
// info is not there but there are cases it cannot get right.
unsigned FrameAlign;
if (Args[i].Alignment)
FrameAlign = Args[i].Alignment;
else
FrameAlign = getByValTypeAlignment(ElementTy);
Flags.setByValAlign(FrameAlign);
}
if (Args[i].isNest)
Flags.setNest();
if (NeedsRegBlock)
Flags.setInConsecutiveRegs();
Flags.setOrigAlign(OriginalAlignment);
MVT PartVT = getRegisterType(CLI.RetTy->getContext(), VT);
unsigned NumParts = getNumRegisters(CLI.RetTy->getContext(), VT);
SmallVector<SDValue, 4> Parts(NumParts);
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (Args[i].isSExt)
ExtendKind = ISD::SIGN_EXTEND;
else if (Args[i].isZExt)
ExtendKind = ISD::ZERO_EXTEND;
// Conservatively only handle 'returned' on non-vectors for now
if (Args[i].isReturned && !Op.getValueType().isVector()) {
assert(CLI.RetTy == Args[i].Ty && RetTys.size() == NumValues &&
"unexpected use of 'returned'");
// Before passing 'returned' to the target lowering code, ensure that
// either the register MVT and the actual EVT are the same size or that
// the return value and argument are extended in the same way; in these
// cases it's safe to pass the argument register value unchanged as the
// return register value (although it's at the target's option whether
// to do so)
// TODO: allow code generation to take advantage of partially preserved
// registers rather than clobbering the entire register when the
// parameter extension method is not compatible with the return
// extension method
if ((NumParts * PartVT.getSizeInBits() == VT.getSizeInBits()) ||
(ExtendKind != ISD::ANY_EXTEND &&
CLI.RetSExt == Args[i].isSExt && CLI.RetZExt == Args[i].isZExt))
Flags.setReturned();
}
getCopyToParts(CLI.DAG, CLI.DL, Op, &Parts[0], NumParts, PartVT,
CLI.CS ? CLI.CS->getInstruction() : nullptr, ExtendKind);
for (unsigned j = 0; j != NumParts; ++j) {
// if it isn't first piece, alignment must be 1
ISD::OutputArg MyFlags(Flags, Parts[j].getValueType(), VT,
i < CLI.NumFixedArgs,
i, j*Parts[j].getValueType().getStoreSize());
if (NumParts > 1 && j == 0)
MyFlags.Flags.setSplit();
else if (j != 0)
MyFlags.Flags.setOrigAlign(1);
CLI.Outs.push_back(MyFlags);
CLI.OutVals.push_back(Parts[j]);
}
if (NeedsRegBlock && Value == NumValues - 1)
CLI.Outs[CLI.Outs.size() - 1].Flags.setInConsecutiveRegsLast();
}
}
SmallVector<SDValue, 4> InVals;
CLI.Chain = LowerCall(CLI, InVals);
// Verify that the target's LowerCall behaved as expected.
assert(CLI.Chain.getNode() && CLI.Chain.getValueType() == MVT::Other &&
"LowerCall didn't return a valid chain!");
assert((!CLI.IsTailCall || InVals.empty()) &&
"LowerCall emitted a return value for a tail call!");
assert((CLI.IsTailCall || InVals.size() == CLI.Ins.size()) &&
"LowerCall didn't emit the correct number of values!");
// For a tail call, the return value is merely live-out and there aren't
// any nodes in the DAG representing it. Return a special value to
// indicate that a tail call has been emitted and no more Instructions
// should be processed in the current block.
if (CLI.IsTailCall) {
CLI.DAG.setRoot(CLI.Chain);
return std::make_pair(SDValue(), SDValue());
}
DEBUG(for (unsigned i = 0, e = CLI.Ins.size(); i != e; ++i) {
assert(InVals[i].getNode() &&
"LowerCall emitted a null value!");
assert(EVT(CLI.Ins[i].VT) == InVals[i].getValueType() &&
"LowerCall emitted a value with the wrong type!");
});
SmallVector<SDValue, 4> ReturnValues;
if (!CanLowerReturn) {
// The instruction result is the result of loading from the
// hidden sret parameter.
SmallVector<EVT, 1> PVTs;
Type *PtrRetTy = PointerType::getUnqual(OrigRetTy);
ComputeValueVTs(*this, PtrRetTy, PVTs);
assert(PVTs.size() == 1 && "Pointers should fit in one register");
EVT PtrVT = PVTs[0];
unsigned NumValues = RetTys.size();
ReturnValues.resize(NumValues);
SmallVector<SDValue, 4> Chains(NumValues);
for (unsigned i = 0; i < NumValues; ++i) {
SDValue Add = CLI.DAG.getNode(ISD::ADD, CLI.DL, PtrVT, DemoteStackSlot,
CLI.DAG.getConstant(Offsets[i], CLI.DL,
PtrVT));
SDValue L = CLI.DAG.getLoad(
RetTys[i], CLI.DL, CLI.Chain, Add,
MachinePointerInfo::getFixedStack(DemoteStackIdx, Offsets[i]), false,
false, false, 1);
ReturnValues[i] = L;
Chains[i] = L.getValue(1);
}
CLI.Chain = CLI.DAG.getNode(ISD::TokenFactor, CLI.DL, MVT::Other, Chains);
} else {
// Collect the legal value parts into potentially illegal values
// that correspond to the original function's return values.
ISD::NodeType AssertOp = ISD::DELETED_NODE;
if (CLI.RetSExt)
AssertOp = ISD::AssertSext;
else if (CLI.RetZExt)
AssertOp = ISD::AssertZext;
unsigned CurReg = 0;
for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
EVT VT = RetTys[I];
MVT RegisterVT = getRegisterType(CLI.RetTy->getContext(), VT);
unsigned NumRegs = getNumRegisters(CLI.RetTy->getContext(), VT);
ReturnValues.push_back(getCopyFromParts(CLI.DAG, CLI.DL, &InVals[CurReg],
NumRegs, RegisterVT, VT, nullptr,
AssertOp));
CurReg += NumRegs;
}
// For a function returning void, there is no return value. We can't create
// such a node, so we just return a null return value in that case. In
// that case, nothing will actually look at the value.
if (ReturnValues.empty())
return std::make_pair(SDValue(), CLI.Chain);
}
SDValue Res = CLI.DAG.getNode(ISD::MERGE_VALUES, CLI.DL,
CLI.DAG.getVTList(RetTys), ReturnValues);
return std::make_pair(Res, CLI.Chain);
}
void TargetLowering::LowerOperationWrapper(SDNode *N,
SmallVectorImpl<SDValue> &Results,
SelectionDAG &DAG) const {
SDValue Res = LowerOperation(SDValue(N, 0), DAG);
if (Res.getNode())
Results.push_back(Res);
}
SDValue TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
llvm_unreachable("LowerOperation not implemented for this target!");
}
void
SelectionDAGBuilder::CopyValueToVirtualRegister(const Value *V, unsigned Reg) {
SDValue Op = getNonRegisterValue(V);
assert((Op.getOpcode() != ISD::CopyFromReg ||
cast<RegisterSDNode>(Op.getOperand(1))->getReg() != Reg) &&
"Copy from a reg to the same reg!");
assert(!TargetRegisterInfo::isPhysicalRegister(Reg) && "Is a physreg");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
RegsForValue RFV(V->getContext(), TLI, Reg, V->getType());
SDValue Chain = DAG.getEntryNode();
ISD::NodeType ExtendType = (FuncInfo.PreferredExtendType.find(V) ==
FuncInfo.PreferredExtendType.end())
? ISD::ANY_EXTEND
: FuncInfo.PreferredExtendType[V];
RFV.getCopyToRegs(Op, DAG, getCurSDLoc(), Chain, nullptr, V, ExtendType);
PendingExports.push_back(Chain);
}
#include "llvm/CodeGen/SelectionDAGISel.h"
/// isOnlyUsedInEntryBlock - If the specified argument is only used in the
/// entry block, return true. This includes arguments used by switches, since
/// the switch may expand into multiple basic blocks.
static bool isOnlyUsedInEntryBlock(const Argument *A, bool FastISel) {
// With FastISel active, we may be splitting blocks, so force creation
// of virtual registers for all non-dead arguments.
if (FastISel)
return A->use_empty();
const BasicBlock *Entry = A->getParent()->begin();
for (const User *U : A->users())
if (cast<Instruction>(U)->getParent() != Entry || isa<SwitchInst>(U))
return false; // Use not in entry block.
return true;
}
void SelectionDAGISel::LowerArguments(const Function &F) {
SelectionDAG &DAG = SDB->DAG;
SDLoc dl = SDB->getCurSDLoc();
const DataLayout *DL = TLI->getDataLayout();
SmallVector<ISD::InputArg, 16> Ins;
if (!FuncInfo->CanLowerReturn) {
// Put in an sret pointer parameter before all the other parameters.
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(*TLI, PointerType::getUnqual(F.getReturnType()), ValueVTs);
// NOTE: Assuming that a pointer will never break down to more than one VT
// or one register.
ISD::ArgFlagsTy Flags;
Flags.setSRet();
MVT RegisterVT = TLI->getRegisterType(*DAG.getContext(), ValueVTs[0]);
ISD::InputArg RetArg(Flags, RegisterVT, ValueVTs[0], true,
ISD::InputArg::NoArgIndex, 0);
Ins.push_back(RetArg);
}
// Set up the incoming argument description vector.
unsigned Idx = 1;
for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end();
I != E; ++I, ++Idx) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*TLI, I->getType(), ValueVTs);
bool isArgValueUsed = !I->use_empty();
unsigned PartBase = 0;
Type *FinalType = I->getType();
if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal))
FinalType = cast<PointerType>(FinalType)->getElementType();
bool NeedsRegBlock = TLI->functionArgumentNeedsConsecutiveRegisters(
FinalType, F.getCallingConv(), F.isVarArg());
for (unsigned Value = 0, NumValues = ValueVTs.size();
Value != NumValues; ++Value) {
EVT VT = ValueVTs[Value];
Type *ArgTy = VT.getTypeForEVT(*DAG.getContext());
ISD::ArgFlagsTy Flags;
unsigned OriginalAlignment = DL->getABITypeAlignment(ArgTy);
if (F.getAttributes().hasAttribute(Idx, Attribute::ZExt))
Flags.setZExt();
if (F.getAttributes().hasAttribute(Idx, Attribute::SExt))
Flags.setSExt();
if (F.getAttributes().hasAttribute(Idx, Attribute::InReg))
Flags.setInReg();
if (F.getAttributes().hasAttribute(Idx, Attribute::StructRet))
Flags.setSRet();
if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal))
Flags.setByVal();
if (F.getAttributes().hasAttribute(Idx, Attribute::InAlloca)) {
Flags.setInAlloca();
// Set the byval flag for CCAssignFn callbacks that don't know about
// inalloca. This way we can know how many bytes we should've allocated
// and how many bytes a callee cleanup function will pop. If we port
// inalloca to more targets, we'll have to add custom inalloca handling
// in the various CC lowering callbacks.
Flags.setByVal();
}
if (Flags.isByVal() || Flags.isInAlloca()) {
PointerType *Ty = cast<PointerType>(I->getType());
Type *ElementTy = Ty->getElementType();
Flags.setByValSize(DL->getTypeAllocSize(ElementTy));
// For ByVal, alignment should be passed from FE. BE will guess if
// this info is not there but there are cases it cannot get right.
unsigned FrameAlign;
if (F.getParamAlignment(Idx))
FrameAlign = F.getParamAlignment(Idx);
else
FrameAlign = TLI->getByValTypeAlignment(ElementTy);
Flags.setByValAlign(FrameAlign);
}
if (F.getAttributes().hasAttribute(Idx, Attribute::Nest))
Flags.setNest();
if (NeedsRegBlock)
Flags.setInConsecutiveRegs();
Flags.setOrigAlign(OriginalAlignment);
MVT RegisterVT = TLI->getRegisterType(*CurDAG->getContext(), VT);
unsigned NumRegs = TLI->getNumRegisters(*CurDAG->getContext(), VT);
for (unsigned i = 0; i != NumRegs; ++i) {
ISD::InputArg MyFlags(Flags, RegisterVT, VT, isArgValueUsed,
Idx-1, PartBase+i*RegisterVT.getStoreSize());
if (NumRegs > 1 && i == 0)
MyFlags.Flags.setSplit();
// if it isn't first piece, alignment must be 1
else if (i > 0)
MyFlags.Flags.setOrigAlign(1);
Ins.push_back(MyFlags);
}
if (NeedsRegBlock && Value == NumValues - 1)
Ins[Ins.size() - 1].Flags.setInConsecutiveRegsLast();
PartBase += VT.getStoreSize();
}
}
// Call the target to set up the argument values.
SmallVector<SDValue, 8> InVals;
SDValue NewRoot = TLI->LowerFormalArguments(
DAG.getRoot(), F.getCallingConv(), F.isVarArg(), Ins, dl, DAG, InVals);
// Verify that the target's LowerFormalArguments behaved as expected.
assert(NewRoot.getNode() && NewRoot.getValueType() == MVT::Other &&
"LowerFormalArguments didn't return a valid chain!");
assert(InVals.size() == Ins.size() &&
"LowerFormalArguments didn't emit the correct number of values!");
DEBUG({
for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
assert(InVals[i].getNode() &&
"LowerFormalArguments emitted a null value!");
assert(EVT(Ins[i].VT) == InVals[i].getValueType() &&
"LowerFormalArguments emitted a value with the wrong type!");
}
});
// Update the DAG with the new chain value resulting from argument lowering.
DAG.setRoot(NewRoot);
// Set up the argument values.
unsigned i = 0;
Idx = 1;
if (!FuncInfo->CanLowerReturn) {
// Create a virtual register for the sret pointer, and put in a copy
// from the sret argument into it.
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(*TLI, PointerType::getUnqual(F.getReturnType()), ValueVTs);
MVT VT = ValueVTs[0].getSimpleVT();
MVT RegVT = TLI->getRegisterType(*CurDAG->getContext(), VT);
ISD::NodeType AssertOp = ISD::DELETED_NODE;
SDValue ArgValue = getCopyFromParts(DAG, dl, &InVals[0], 1,
RegVT, VT, nullptr, AssertOp);
MachineFunction& MF = SDB->DAG.getMachineFunction();
MachineRegisterInfo& RegInfo = MF.getRegInfo();
unsigned SRetReg = RegInfo.createVirtualRegister(TLI->getRegClassFor(RegVT));
FuncInfo->DemoteRegister = SRetReg;
NewRoot =
SDB->DAG.getCopyToReg(NewRoot, SDB->getCurSDLoc(), SRetReg, ArgValue);
DAG.setRoot(NewRoot);
// i indexes lowered arguments. Bump it past the hidden sret argument.
// Idx indexes LLVM arguments. Don't touch it.
++i;
}
for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E;
++I, ++Idx) {
SmallVector<SDValue, 4> ArgValues;
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*TLI, I->getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
// If this argument is unused then remember its value. It is used to generate
// debugging information.
if (I->use_empty() && NumValues) {
SDB->setUnusedArgValue(I, InVals[i]);
// Also remember any frame index for use in FastISel.
if (FrameIndexSDNode *FI =
dyn_cast<FrameIndexSDNode>(InVals[i].getNode()))
FuncInfo->setArgumentFrameIndex(I, FI->getIndex());
}
for (unsigned Val = 0; Val != NumValues; ++Val) {
EVT VT = ValueVTs[Val];
MVT PartVT = TLI->getRegisterType(*CurDAG->getContext(), VT);
unsigned NumParts = TLI->getNumRegisters(*CurDAG->getContext(), VT);
if (!I->use_empty()) {
ISD::NodeType AssertOp = ISD::DELETED_NODE;
if (F.getAttributes().hasAttribute(Idx, Attribute::SExt))
AssertOp = ISD::AssertSext;
else if (F.getAttributes().hasAttribute(Idx, Attribute::ZExt))
AssertOp = ISD::AssertZext;
ArgValues.push_back(getCopyFromParts(DAG, dl, &InVals[i],
NumParts, PartVT, VT,
nullptr, AssertOp));
}
i += NumParts;
}
// We don't need to do anything else for unused arguments.
if (ArgValues.empty())
continue;
// Note down frame index.
if (FrameIndexSDNode *FI =
dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode()))
FuncInfo->setArgumentFrameIndex(I, FI->getIndex());
SDValue Res = DAG.getMergeValues(makeArrayRef(ArgValues.data(), NumValues),
SDB->getCurSDLoc());
SDB->setValue(I, Res);
if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::BUILD_PAIR) {
if (LoadSDNode *LNode =
dyn_cast<LoadSDNode>(Res.getOperand(0).getNode()))
if (FrameIndexSDNode *FI =
dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()))
FuncInfo->setArgumentFrameIndex(I, FI->getIndex());
}
// If this argument is live outside of the entry block, insert a copy from
// wherever we got it to the vreg that other BB's will reference it as.
if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::CopyFromReg) {
// If we can, though, try to skip creating an unnecessary vreg.
// FIXME: This isn't very clean... it would be nice to make this more
// general. It's also subtly incompatible with the hacks FastISel
// uses with vregs.
unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg();
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
FuncInfo->ValueMap[I] = Reg;
continue;
}
}
if (!isOnlyUsedInEntryBlock(I, TM.Options.EnableFastISel)) {
FuncInfo->InitializeRegForValue(I);
SDB->CopyToExportRegsIfNeeded(I);
}
}
assert(i == InVals.size() && "Argument register count mismatch!");
// Finally, if the target has anything special to do, allow it to do so.
EmitFunctionEntryCode();
}
/// Handle PHI nodes in successor blocks. Emit code into the SelectionDAG to
/// ensure constants are generated when needed. Remember the virtual registers
/// that need to be added to the Machine PHI nodes as input. We cannot just
/// directly add them, because expansion might result in multiple MBB's for one
/// BB. As such, the start of the BB might correspond to a different MBB than
/// the end.
///
void
SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) {
const TerminatorInst *TI = LLVMBB->getTerminator();
SmallPtrSet<MachineBasicBlock *, 4> SuccsHandled;
// Check PHI nodes in successors that expect a value to be available from this
// block.
for (unsigned succ = 0, e = TI->getNumSuccessors(); succ != e; ++succ) {
const BasicBlock *SuccBB = TI->getSuccessor(succ);
if (!isa<PHINode>(SuccBB->begin())) continue;
MachineBasicBlock *SuccMBB = FuncInfo.MBBMap[SuccBB];
// If this terminator has multiple identical successors (common for
// switches), only handle each succ once.
if (!SuccsHandled.insert(SuccMBB).second)
continue;
MachineBasicBlock::iterator MBBI = SuccMBB->begin();
// At this point we know that there is a 1-1 correspondence between LLVM PHI
// nodes and Machine PHI nodes, but the incoming operands have not been
// emitted yet.
for (BasicBlock::const_iterator I = SuccBB->begin();
const PHINode *PN = dyn_cast<PHINode>(I); ++I) {
// Ignore dead phi's.
if (PN->use_empty()) continue;
// Skip empty types
if (PN->getType()->isEmptyTy())
continue;
unsigned Reg;
const Value *PHIOp = PN->getIncomingValueForBlock(LLVMBB);
if (const Constant *C = dyn_cast<Constant>(PHIOp)) {
unsigned &RegOut = ConstantsOut[C];
if (RegOut == 0) {
RegOut = FuncInfo.CreateRegs(C->getType());
CopyValueToVirtualRegister(C, RegOut);
}
Reg = RegOut;
} else {
DenseMap<const Value *, unsigned>::iterator I =
FuncInfo.ValueMap.find(PHIOp);
if (I != FuncInfo.ValueMap.end())
Reg = I->second;
else {
assert(isa<AllocaInst>(PHIOp) &&
FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(PHIOp)) &&
"Didn't codegen value into a register!??");
Reg = FuncInfo.CreateRegs(PHIOp->getType());
CopyValueToVirtualRegister(PHIOp, Reg);
}
}
// Remember that this register needs to added to the machine PHI node as
// the input for this MBB.
SmallVector<EVT, 4> ValueVTs;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
ComputeValueVTs(TLI, PN->getType(), ValueVTs);
for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
EVT VT = ValueVTs[vti];
unsigned NumRegisters = TLI.getNumRegisters(*DAG.getContext(), VT);
for (unsigned i = 0, e = NumRegisters; i != e; ++i)
FuncInfo.PHINodesToUpdate.push_back(std::make_pair(MBBI++, Reg+i));
Reg += NumRegisters;
}
}
}
ConstantsOut.clear();
}
/// Add a successor MBB to ParentMBB< creating a new MachineBB for BB if SuccMBB
/// is 0.
MachineBasicBlock *
SelectionDAGBuilder::StackProtectorDescriptor::
AddSuccessorMBB(const BasicBlock *BB,
MachineBasicBlock *ParentMBB,
bool IsLikely,
MachineBasicBlock *SuccMBB) {
// If SuccBB has not been created yet, create it.
if (!SuccMBB) {
MachineFunction *MF = ParentMBB->getParent();
MachineFunction::iterator BBI = ParentMBB;
SuccMBB = MF->CreateMachineBasicBlock(BB);
MF->insert(++BBI, SuccMBB);
}
// Add it as a successor of ParentMBB.
ParentMBB->addSuccessor(
SuccMBB, BranchProbabilityInfo::getBranchWeightStackProtector(IsLikely));
return SuccMBB;
}
MachineBasicBlock *SelectionDAGBuilder::NextBlock(MachineBasicBlock *MBB) {
MachineFunction::iterator I = MBB;
if (++I == FuncInfo.MF->end())
return nullptr;
return I;
}
/// During lowering new call nodes can be created (such as memset, etc.).
/// Those will become new roots of the current DAG, but complications arise
/// when they are tail calls. In such cases, the call lowering will update
/// the root, but the builder still needs to know that a tail call has been
/// lowered in order to avoid generating an additional return.
void SelectionDAGBuilder::updateDAGForMaybeTailCall(SDValue MaybeTC) {
// If the node is null, we do have a tail call.
if (MaybeTC.getNode() != nullptr)
DAG.setRoot(MaybeTC);
else
HasTailCall = true;
}
bool SelectionDAGBuilder::isDense(const CaseClusterVector &Clusters,
unsigned *TotalCases, unsigned First,
unsigned Last) {
assert(Last >= First);
assert(TotalCases[Last] >= TotalCases[First]);
APInt LowCase = Clusters[First].Low->getValue();
APInt HighCase = Clusters[Last].High->getValue();
assert(LowCase.getBitWidth() == HighCase.getBitWidth());
// FIXME: A range of consecutive cases has 100% density, but only requires one
// comparison to lower. We should discriminate against such consecutive ranges
// in jump tables.
uint64_t Diff = (HighCase - LowCase).getLimitedValue((UINT64_MAX - 1) / 100);
uint64_t Range = Diff + 1;
uint64_t NumCases =
TotalCases[Last] - (First == 0 ? 0 : TotalCases[First - 1]);
assert(NumCases < UINT64_MAX / 100);
assert(Range >= NumCases);
return NumCases * 100 >= Range * MinJumpTableDensity;
}
static inline bool areJTsAllowed(const TargetLowering &TLI) {
return TLI.isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
TLI.isOperationLegalOrCustom(ISD::BRIND, MVT::Other);
}
bool SelectionDAGBuilder::buildJumpTable(CaseClusterVector &Clusters,
unsigned First, unsigned Last,
const SwitchInst *SI,
MachineBasicBlock *DefaultMBB,
CaseCluster &JTCluster) {
assert(First <= Last);
uint32_t Weight = 0;
unsigned NumCmps = 0;
std::vector<MachineBasicBlock*> Table;
DenseMap<MachineBasicBlock*, uint32_t> JTWeights;
for (unsigned I = First; I <= Last; ++I) {
assert(Clusters[I].Kind == CC_Range);
Weight += Clusters[I].Weight;
assert(Weight >= Clusters[I].Weight && "Weight overflow!");
APInt Low = Clusters[I].Low->getValue();
APInt High = Clusters[I].High->getValue();
NumCmps += (Low == High) ? 1 : 2;
if (I != First) {
// Fill the gap between this and the previous cluster.
APInt PreviousHigh = Clusters[I - 1].High->getValue();
assert(PreviousHigh.slt(Low));
uint64_t Gap = (Low - PreviousHigh).getLimitedValue() - 1;
for (uint64_t J = 0; J < Gap; J++)
Table.push_back(DefaultMBB);
}
uint64_t ClusterSize = (High - Low).getLimitedValue() + 1;
for (uint64_t J = 0; J < ClusterSize; ++J)
Table.push_back(Clusters[I].MBB);
JTWeights[Clusters[I].MBB] += Clusters[I].Weight;
}
unsigned NumDests = JTWeights.size();
if (isSuitableForBitTests(NumDests, NumCmps,
Clusters[First].Low->getValue(),
Clusters[Last].High->getValue())) {
// Clusters[First..Last] should be lowered as bit tests instead.
return false;
}
// Create the MBB that will load from and jump through the table.
// Note: We create it here, but it's not inserted into the function yet.
MachineFunction *CurMF = FuncInfo.MF;
MachineBasicBlock *JumpTableMBB =
CurMF->CreateMachineBasicBlock(SI->getParent());
// Add successors. Note: use table order for determinism.
SmallPtrSet<MachineBasicBlock *, 8> Done;
for (MachineBasicBlock *Succ : Table) {
if (Done.count(Succ))
continue;
addSuccessorWithWeight(JumpTableMBB, Succ, JTWeights[Succ]);
Done.insert(Succ);
}
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned JTI = CurMF->getOrCreateJumpTableInfo(TLI.getJumpTableEncoding())
->createJumpTableIndex(Table);
// Set up the jump table info.
JumpTable JT(-1U, JTI, JumpTableMBB, nullptr);
JumpTableHeader JTH(Clusters[First].Low->getValue(),
Clusters[Last].High->getValue(), SI->getCondition(),
nullptr, false);
JTCases.push_back(JumpTableBlock(JTH, JT));
JTCluster = CaseCluster::jumpTable(Clusters[First].Low, Clusters[Last].High,
JTCases.size() - 1, Weight);
return true;
}
void SelectionDAGBuilder::findJumpTables(CaseClusterVector &Clusters,
const SwitchInst *SI,
MachineBasicBlock *DefaultMBB) {
#ifndef NDEBUG
// Clusters must be non-empty, sorted, and only contain Range clusters.
assert(!Clusters.empty());
for (CaseCluster &C : Clusters)
assert(C.Kind == CC_Range);
for (unsigned i = 1, e = Clusters.size(); i < e; ++i)
assert(Clusters[i - 1].High->getValue().slt(Clusters[i].Low->getValue()));
#endif
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (!areJTsAllowed(TLI))
return;
const int64_t N = Clusters.size();
const unsigned MinJumpTableSize = TLI.getMinimumJumpTableEntries();
// Split Clusters into minimum number of dense partitions. The algorithm uses
// the same idea as Kannan & Proebsting "Correction to 'Producing Good Code
// for the Case Statement'" (1994), but builds the MinPartitions array in
// reverse order to make it easier to reconstruct the partitions in ascending
// order. In the choice between two optimal partitionings, it picks the one
// which yields more jump tables.
// MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1].
SmallVector<unsigned, 8> MinPartitions(N);
// LastElement[i] is the last element of the partition starting at i.
SmallVector<unsigned, 8> LastElement(N);
// NumTables[i]: nbr of >= MinJumpTableSize partitions from Clusters[i..N-1].
SmallVector<unsigned, 8> NumTables(N);
// TotalCases[i]: Total nbr of cases in Clusters[0..i].
SmallVector<unsigned, 8> TotalCases(N);
for (unsigned i = 0; i < N; ++i) {
APInt Hi = Clusters[i].High->getValue();
APInt Lo = Clusters[i].Low->getValue();
TotalCases[i] = (Hi - Lo).getLimitedValue() + 1;
if (i != 0)
TotalCases[i] += TotalCases[i - 1];
}
// Base case: There is only one way to partition Clusters[N-1].
MinPartitions[N - 1] = 1;
LastElement[N - 1] = N - 1;
assert(MinJumpTableSize > 1);
NumTables[N - 1] = 0;
// Note: loop indexes are signed to avoid underflow.
for (int64_t i = N - 2; i >= 0; i--) {
// Find optimal partitioning of Clusters[i..N-1].
// Baseline: Put Clusters[i] into a partition on its own.
MinPartitions[i] = MinPartitions[i + 1] + 1;
LastElement[i] = i;
NumTables[i] = NumTables[i + 1];
// Search for a solution that results in fewer partitions.
for (int64_t j = N - 1; j > i; j--) {
// Try building a partition from Clusters[i..j].
if (isDense(Clusters, &TotalCases[0], i, j)) {
unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]);
bool IsTable = j - i + 1 >= MinJumpTableSize;
unsigned Tables = IsTable + (j == N - 1 ? 0 : NumTables[j + 1]);
// If this j leads to fewer partitions, or same number of partitions
// with more lookup tables, it is a better partitioning.
if (NumPartitions < MinPartitions[i] ||
(NumPartitions == MinPartitions[i] && Tables > NumTables[i])) {
MinPartitions[i] = NumPartitions;
LastElement[i] = j;
NumTables[i] = Tables;
}
}
}
}
// Iterate over the partitions, replacing some with jump tables in-place.
unsigned DstIndex = 0;
for (unsigned First = 0, Last; First < N; First = Last + 1) {
Last = LastElement[First];
assert(Last >= First);
assert(DstIndex <= First);
unsigned NumClusters = Last - First + 1;
CaseCluster JTCluster;
if (NumClusters >= MinJumpTableSize &&
buildJumpTable(Clusters, First, Last, SI, DefaultMBB, JTCluster)) {
Clusters[DstIndex++] = JTCluster;
} else {
for (unsigned I = First; I <= Last; ++I)
std::memmove(&Clusters[DstIndex++], &Clusters[I], sizeof(Clusters[I]));
}
}
Clusters.resize(DstIndex);
}
bool SelectionDAGBuilder::rangeFitsInWord(const APInt &Low, const APInt &High) {
// FIXME: Using the pointer type doesn't seem ideal.
uint64_t BW = DAG.getTargetLoweringInfo().getPointerTy().getSizeInBits();
uint64_t Range = (High - Low).getLimitedValue(UINT64_MAX - 1) + 1;
return Range <= BW;
}
bool SelectionDAGBuilder::isSuitableForBitTests(unsigned NumDests,
unsigned NumCmps,
const APInt &Low,
const APInt &High) {
// FIXME: I don't think NumCmps is the correct metric: a single case and a
// range of cases both require only one branch to lower. Just looking at the
// number of clusters and destinations should be enough to decide whether to
// build bit tests.
// To lower a range with bit tests, the range must fit the bitwidth of a
// machine word.
if (!rangeFitsInWord(Low, High))
return false;
// Decide whether it's profitable to lower this range with bit tests. Each
// destination requires a bit test and branch, and there is an overall range
// check branch. For a small number of clusters, separate comparisons might be
// cheaper, and for many destinations, splitting the range might be better.
return (NumDests == 1 && NumCmps >= 3) ||
(NumDests == 2 && NumCmps >= 5) ||
(NumDests == 3 && NumCmps >= 6);
}
bool SelectionDAGBuilder::buildBitTests(CaseClusterVector &Clusters,
unsigned First, unsigned Last,
const SwitchInst *SI,
CaseCluster &BTCluster) {
assert(First <= Last);
if (First == Last)
return false;
BitVector Dests(FuncInfo.MF->getNumBlockIDs());
unsigned NumCmps = 0;
for (int64_t I = First; I <= Last; ++I) {
assert(Clusters[I].Kind == CC_Range);
Dests.set(Clusters[I].MBB->getNumber());
NumCmps += (Clusters[I].Low == Clusters[I].High) ? 1 : 2;
}
unsigned NumDests = Dests.count();
APInt Low = Clusters[First].Low->getValue();
APInt High = Clusters[Last].High->getValue();
assert(Low.slt(High));
if (!isSuitableForBitTests(NumDests, NumCmps, Low, High))
return false;
APInt LowBound;
APInt CmpRange;
const int BitWidth =
DAG.getTargetLoweringInfo().getPointerTy().getSizeInBits();
assert((High - Low + 1).sle(BitWidth) && "Case range must fit in bit mask!");
if (Low.isNonNegative() && High.slt(BitWidth)) {
// Optimize the case where all the case values fit in a
// word without having to subtract minValue. In this case,
// we can optimize away the subtraction.
LowBound = APInt::getNullValue(Low.getBitWidth());
CmpRange = High;
} else {
LowBound = Low;
CmpRange = High - Low;
}
CaseBitsVector CBV;
uint32_t TotalWeight = 0;
for (unsigned i = First; i <= Last; ++i) {
// Find the CaseBits for this destination.
unsigned j;
for (j = 0; j < CBV.size(); ++j)
if (CBV[j].BB == Clusters[i].MBB)
break;
if (j == CBV.size())
CBV.push_back(CaseBits(0, Clusters[i].MBB, 0, 0));
CaseBits *CB = &CBV[j];
// Update Mask, Bits and ExtraWeight.
uint64_t Lo = (Clusters[i].Low->getValue() - LowBound).getZExtValue();
uint64_t Hi = (Clusters[i].High->getValue() - LowBound).getZExtValue();
for (uint64_t j = Lo; j <= Hi; ++j) {
CB->Mask |= 1ULL << j;
CB->Bits++;
}
CB->ExtraWeight += Clusters[i].Weight;
TotalWeight += Clusters[i].Weight;
assert(TotalWeight >= Clusters[i].Weight && "Weight overflow!");
}
BitTestInfo BTI;
std::sort(CBV.begin(), CBV.end(), [](const CaseBits &a, const CaseBits &b) {
// Sort by weight first, number of bits second.
if (a.ExtraWeight != b.ExtraWeight)
return a.ExtraWeight > b.ExtraWeight;
return a.Bits > b.Bits;
});
for (auto &CB : CBV) {
MachineBasicBlock *BitTestBB =
FuncInfo.MF->CreateMachineBasicBlock(SI->getParent());
BTI.push_back(BitTestCase(CB.Mask, BitTestBB, CB.BB, CB.ExtraWeight));
}
BitTestCases.push_back(BitTestBlock(LowBound, CmpRange, SI->getCondition(),
-1U, MVT::Other, false, nullptr,
nullptr, std::move(BTI)));
BTCluster = CaseCluster::bitTests(Clusters[First].Low, Clusters[Last].High,
BitTestCases.size() - 1, TotalWeight);
return true;
}
void SelectionDAGBuilder::findBitTestClusters(CaseClusterVector &Clusters,
const SwitchInst *SI) {
// Partition Clusters into as few subsets as possible, where each subset has a
// range that fits in a machine word and has <= 3 unique destinations.
#ifndef NDEBUG
// Clusters must be sorted and contain Range or JumpTable clusters.
assert(!Clusters.empty());
assert(Clusters[0].Kind == CC_Range || Clusters[0].Kind == CC_JumpTable);
for (const CaseCluster &C : Clusters)
assert(C.Kind == CC_Range || C.Kind == CC_JumpTable);
for (unsigned i = 1; i < Clusters.size(); ++i)
assert(Clusters[i-1].High->getValue().slt(Clusters[i].Low->getValue()));
#endif
// If target does not have legal shift left, do not emit bit tests at all.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT PTy = TLI.getPointerTy();
if (!TLI.isOperationLegal(ISD::SHL, PTy))
return;
int BitWidth = PTy.getSizeInBits();
const int64_t N = Clusters.size();
// MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1].
SmallVector<unsigned, 8> MinPartitions(N);
// LastElement[i] is the last element of the partition starting at i.
SmallVector<unsigned, 8> LastElement(N);
// FIXME: This might not be the best algorithm for finding bit test clusters.
// Base case: There is only one way to partition Clusters[N-1].
MinPartitions[N - 1] = 1;
LastElement[N - 1] = N - 1;
// Note: loop indexes are signed to avoid underflow.
for (int64_t i = N - 2; i >= 0; --i) {
// Find optimal partitioning of Clusters[i..N-1].
// Baseline: Put Clusters[i] into a partition on its own.
MinPartitions[i] = MinPartitions[i + 1] + 1;
LastElement[i] = i;
// Search for a solution that results in fewer partitions.
// Note: the search is limited by BitWidth, reducing time complexity.
for (int64_t j = std::min(N - 1, i + BitWidth - 1); j > i; --j) {
// Try building a partition from Clusters[i..j].
// Check the range.
if (!rangeFitsInWord(Clusters[i].Low->getValue(),
Clusters[j].High->getValue()))
continue;
// Check nbr of destinations and cluster types.
// FIXME: This works, but doesn't seem very efficient.
bool RangesOnly = true;
BitVector Dests(FuncInfo.MF->getNumBlockIDs());
for (int64_t k = i; k <= j; k++) {
if (Clusters[k].Kind != CC_Range) {
RangesOnly = false;
break;
}
Dests.set(Clusters[k].MBB->getNumber());
}
if (!RangesOnly || Dests.count() > 3)
break;
// Check if it's a better partition.
unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]);
if (NumPartitions < MinPartitions[i]) {
// Found a better partition.
MinPartitions[i] = NumPartitions;
LastElement[i] = j;
}
}
}
// Iterate over the partitions, replacing with bit-test clusters in-place.
unsigned DstIndex = 0;
for (unsigned First = 0, Last; First < N; First = Last + 1) {
Last = LastElement[First];
assert(First <= Last);
assert(DstIndex <= First);
CaseCluster BitTestCluster;
if (buildBitTests(Clusters, First, Last, SI, BitTestCluster)) {
Clusters[DstIndex++] = BitTestCluster;
} else {
for (unsigned I = First; I <= Last; ++I)
std::memmove(&Clusters[DstIndex++], &Clusters[I], sizeof(Clusters[I]));
}
}
Clusters.resize(DstIndex);
}
void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
MachineBasicBlock *SwitchMBB,
MachineBasicBlock *DefaultMBB) {
MachineFunction *CurMF = FuncInfo.MF;
MachineBasicBlock *NextMBB = nullptr;
MachineFunction::iterator BBI = W.MBB;
if (++BBI != FuncInfo.MF->end())
NextMBB = BBI;
unsigned Size = W.LastCluster - W.FirstCluster + 1;
BranchProbabilityInfo *BPI = FuncInfo.BPI;
if (Size == 2 && W.MBB == SwitchMBB) {
// If any two of the cases has the same destination, and if one value
// is the same as the other, but has one bit unset that the other has set,
// use bit manipulation to do two compares at once. For example:
// "if (X == 6 || X == 4)" -> "if ((X|2) == 6)"
// TODO: This could be extended to merge any 2 cases in switches with 3
// cases.
// TODO: Handle cases where W.CaseBB != SwitchBB.
CaseCluster &Small = *W.FirstCluster;
CaseCluster &Big = *W.LastCluster;
if (Small.Low == Small.High && Big.Low == Big.High &&
Small.MBB == Big.MBB) {
const APInt &SmallValue = Small.Low->getValue();
const APInt &BigValue = Big.Low->getValue();
// Check that there is only one bit different.
if (BigValue.countPopulation() == SmallValue.countPopulation() + 1 &&
(SmallValue | BigValue) == BigValue) {
// Isolate the common bit.
APInt CommonBit = BigValue & ~SmallValue;
assert((SmallValue | CommonBit) == BigValue &&
CommonBit.countPopulation() == 1 && "Not a common bit?");
SDValue CondLHS = getValue(Cond);
EVT VT = CondLHS.getValueType();
SDLoc DL = getCurSDLoc();
SDValue Or = DAG.getNode(ISD::OR, DL, VT, CondLHS,
DAG.getConstant(CommonBit, DL, VT));
SDValue Cond = DAG.getSetCC(DL, MVT::i1, Or,
DAG.getConstant(BigValue, DL, VT),
ISD::SETEQ);
// Update successor info.
// Both Small and Big will jump to Small.BB, so we sum up the weights.
addSuccessorWithWeight(SwitchMBB, Small.MBB, Small.Weight + Big.Weight);
addSuccessorWithWeight(
SwitchMBB, DefaultMBB,
// The default destination is the first successor in IR.
BPI ? BPI->getEdgeWeight(SwitchMBB->getBasicBlock(), (unsigned)0)
: 0);
// Insert the true branch.
SDValue BrCond =
DAG.getNode(ISD::BRCOND, DL, MVT::Other, getControlRoot(), Cond,
DAG.getBasicBlock(Small.MBB));
// Insert the false branch.
BrCond = DAG.getNode(ISD::BR, DL, MVT::Other, BrCond,
DAG.getBasicBlock(DefaultMBB));
DAG.setRoot(BrCond);
return;
}
}
}
if (TM.getOptLevel() != CodeGenOpt::None) {
// Order cases by weight so the most likely case will be checked first.
std::sort(W.FirstCluster, W.LastCluster + 1,
[](const CaseCluster &a, const CaseCluster &b) {
return a.Weight > b.Weight;
});
// Rearrange the case blocks so that the last one falls through if possible
// without without changing the order of weights.
for (CaseClusterIt I = W.LastCluster; I > W.FirstCluster; ) {
--I;
if (I->Weight > W.LastCluster->Weight)
break;
if (I->Kind == CC_Range && I->MBB == NextMBB) {
std::swap(*I, *W.LastCluster);
break;
}
}
}
// Compute total weight.
uint32_t UnhandledWeights = 0;
for (CaseClusterIt I = W.FirstCluster; I <= W.LastCluster; ++I) {
UnhandledWeights += I->Weight;
assert(UnhandledWeights >= I->Weight && "Weight overflow!");
}
MachineBasicBlock *CurMBB = W.MBB;
for (CaseClusterIt I = W.FirstCluster, E = W.LastCluster; I <= E; ++I) {
MachineBasicBlock *Fallthrough;
if (I == W.LastCluster) {
// For the last cluster, fall through to the default destination.
Fallthrough = DefaultMBB;
} else {
Fallthrough = CurMF->CreateMachineBasicBlock(CurMBB->getBasicBlock());
CurMF->insert(BBI, Fallthrough);
// Put Cond in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(Cond);
}
switch (I->Kind) {
case CC_JumpTable: {
// FIXME: Optimize away range check based on pivot comparisons.
JumpTableHeader *JTH = &JTCases[I->JTCasesIndex].first;
JumpTable *JT = &JTCases[I->JTCasesIndex].second;
// The jump block hasn't been inserted yet; insert it here.
MachineBasicBlock *JumpMBB = JT->MBB;
CurMF->insert(BBI, JumpMBB);
addSuccessorWithWeight(CurMBB, Fallthrough);
addSuccessorWithWeight(CurMBB, JumpMBB);
// The jump table header will be inserted in our current block, do the
// range check, and fall through to our fallthrough block.
JTH->HeaderBB = CurMBB;
JT->Default = Fallthrough; // FIXME: Move Default to JumpTableHeader.
// If we're in the right place, emit the jump table header right now.
if (CurMBB == SwitchMBB) {
visitJumpTableHeader(*JT, *JTH, SwitchMBB);
JTH->Emitted = true;
}
break;
}
case CC_BitTests: {
// FIXME: Optimize away range check based on pivot comparisons.
BitTestBlock *BTB = &BitTestCases[I->BTCasesIndex];
// The bit test blocks haven't been inserted yet; insert them here.
for (BitTestCase &BTC : BTB->Cases)
CurMF->insert(BBI, BTC.ThisBB);
// Fill in fields of the BitTestBlock.
BTB->Parent = CurMBB;
BTB->Default = Fallthrough;
// If we're in the right place, emit the bit test header header right now.
if (CurMBB ==SwitchMBB) {
visitBitTestHeader(*BTB, SwitchMBB);
BTB->Emitted = true;
}
break;
}
case CC_Range: {
const Value *RHS, *LHS, *MHS;
ISD::CondCode CC;
if (I->Low == I->High) {
// Check Cond == I->Low.
CC = ISD::SETEQ;
LHS = Cond;
RHS=I->Low;
MHS = nullptr;
} else {
// Check I->Low <= Cond <= I->High.
CC = ISD::SETLE;
LHS = I->Low;
MHS = Cond;
RHS = I->High;
}
// The false weight is the sum of all unhandled cases.
UnhandledWeights -= I->Weight;
CaseBlock CB(CC, LHS, RHS, MHS, I->MBB, Fallthrough, CurMBB, I->Weight,
UnhandledWeights);
if (CurMBB == SwitchMBB)
visitSwitchCase(CB, SwitchMBB);
else
SwitchCases.push_back(CB);
break;
}
}
CurMBB = Fallthrough;
}
}
void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList,
const SwitchWorkListItem &W,
Value *Cond,
MachineBasicBlock *SwitchMBB) {
assert(W.FirstCluster->Low->getValue().slt(W.LastCluster->Low->getValue()) &&
"Clusters not sorted?");
assert(W.LastCluster - W.FirstCluster + 1 >= 2 && "Too small to split!");
// Balance the tree based on branch weights to create a near-optimal (in terms
// of search time given key frequency) binary search tree. See e.g. Kurt
// Mehlhorn "Nearly Optimal Binary Search Trees" (1975).
CaseClusterIt LastLeft = W.FirstCluster;
CaseClusterIt FirstRight = W.LastCluster;
uint32_t LeftWeight = LastLeft->Weight;
uint32_t RightWeight = FirstRight->Weight;
// Move LastLeft and FirstRight towards each other from opposite directions to
// find a partitioning of the clusters which balances the weight on both
// sides.
while (LastLeft + 1 < FirstRight) {
// Zero-weight nodes would cause skewed trees since they don't affect
// LeftWeight or RightWeight.
assert(LastLeft->Weight != 0);
assert(FirstRight->Weight != 0);
if (LeftWeight < RightWeight)
LeftWeight += (++LastLeft)->Weight;
else
RightWeight += (--FirstRight)->Weight;
}
assert(LastLeft + 1 == FirstRight);
assert(LastLeft >= W.FirstCluster);
assert(FirstRight <= W.LastCluster);
// Use the first element on the right as pivot since we will make less-than
// comparisons against it.
CaseClusterIt PivotCluster = FirstRight;
assert(PivotCluster > W.FirstCluster);
assert(PivotCluster <= W.LastCluster);
CaseClusterIt FirstLeft = W.FirstCluster;
CaseClusterIt LastRight = W.LastCluster;
const ConstantInt *Pivot = PivotCluster->Low;
// New blocks will be inserted immediately after the current one.
MachineFunction::iterator BBI = W.MBB;
++BBI;
// We will branch to the LHS if Value < Pivot. If LHS is a single cluster,
// we can branch to its destination directly if it's squeezed exactly in
// between the known lower bound and Pivot - 1.
MachineBasicBlock *LeftMBB;
if (FirstLeft == LastLeft && FirstLeft->Kind == CC_Range &&
FirstLeft->Low == W.GE &&
(FirstLeft->High->getValue() + 1LL) == Pivot->getValue()) {
LeftMBB = FirstLeft->MBB;
} else {
LeftMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock());
FuncInfo.MF->insert(BBI, LeftMBB);
WorkList.push_back({LeftMBB, FirstLeft, LastLeft, W.GE, Pivot});
// Put Cond in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(Cond);
}
// Similarly, we will branch to the RHS if Value >= Pivot. If RHS is a
// single cluster, RHS.Low == Pivot, and we can branch to its destination
// directly if RHS.High equals the current upper bound.
MachineBasicBlock *RightMBB;
if (FirstRight == LastRight && FirstRight->Kind == CC_Range &&
W.LT && (FirstRight->High->getValue() + 1ULL) == W.LT->getValue()) {
RightMBB = FirstRight->MBB;
} else {
RightMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock());
FuncInfo.MF->insert(BBI, RightMBB);
WorkList.push_back({RightMBB, FirstRight, LastRight, Pivot, W.LT});
// Put Cond in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(Cond);
}
// Create the CaseBlock record that will be used to lower the branch.
CaseBlock CB(ISD::SETLT, Cond, Pivot, nullptr, LeftMBB, RightMBB, W.MBB,
LeftWeight, RightWeight);
if (W.MBB == SwitchMBB)
visitSwitchCase(CB, SwitchMBB);
else
SwitchCases.push_back(CB);
}
void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) {
// Extract cases from the switch.
BranchProbabilityInfo *BPI = FuncInfo.BPI;
CaseClusterVector Clusters;
Clusters.reserve(SI.getNumCases());
for (auto I : SI.cases()) {
MachineBasicBlock *Succ = FuncInfo.MBBMap[I.getCaseSuccessor()];
const ConstantInt *CaseVal = I.getCaseValue();
uint32_t Weight = 1;
if (BPI) {
Weight = BPI->getEdgeWeight(SI.getParent(), I.getSuccessorIndex());
assert(Weight <= UINT32_MAX / SI.getNumSuccessors());
}
Clusters.push_back(CaseCluster::range(CaseVal, CaseVal, Succ, Weight));
}
MachineBasicBlock *DefaultMBB = FuncInfo.MBBMap[SI.getDefaultDest()];
if (TM.getOptLevel() != CodeGenOpt::None) {
// Cluster adjacent cases with the same destination.
sortAndRangeify(Clusters);
// Replace an unreachable default with the most popular destination.
// FIXME: Exploit unreachable default more aggressively.
bool UnreachableDefault =
isa<UnreachableInst>(SI.getDefaultDest()->getFirstNonPHIOrDbg());
if (UnreachableDefault && !Clusters.empty()) {
DenseMap<const BasicBlock *, unsigned> Popularity;
unsigned MaxPop = 0;
const BasicBlock *MaxBB = nullptr;
for (auto I : SI.cases()) {
const BasicBlock *BB = I.getCaseSuccessor();
if (++Popularity[BB] > MaxPop) {
MaxPop = Popularity[BB];
MaxBB = BB;
}
}
// Set new default.
assert(MaxPop > 0 && MaxBB);
DefaultMBB = FuncInfo.MBBMap[MaxBB];
// Remove cases that were pointing to the destination that is now the
// default.
CaseClusterVector New;
New.reserve(Clusters.size());
for (CaseCluster &CC : Clusters) {
if (CC.MBB != DefaultMBB)
New.push_back(CC);
}
Clusters = std::move(New);
}
}
// If there is only the default destination, jump there directly.
MachineBasicBlock *SwitchMBB = FuncInfo.MBB;
if (Clusters.empty()) {
SwitchMBB->addSuccessor(DefaultMBB);
if (DefaultMBB != NextBlock(SwitchMBB)) {
DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other,
getControlRoot(), DAG.getBasicBlock(DefaultMBB)));
}
return;
}
if (TM.getOptLevel() != CodeGenOpt::None) {
findJumpTables(Clusters, &SI, DefaultMBB);
findBitTestClusters(Clusters, &SI);
}
DEBUG({
dbgs() << "Case clusters: ";
for (const CaseCluster &C : Clusters) {
if (C.Kind == CC_JumpTable) dbgs() << "JT:";
if (C.Kind == CC_BitTests) dbgs() << "BT:";
C.Low->getValue().print(dbgs(), true);
if (C.Low != C.High) {
dbgs() << '-';
C.High->getValue().print(dbgs(), true);
}
dbgs() << ' ';
}
dbgs() << '\n';
});
assert(!Clusters.empty());
SwitchWorkList WorkList;
CaseClusterIt First = Clusters.begin();
CaseClusterIt Last = Clusters.end() - 1;
WorkList.push_back({SwitchMBB, First, Last, nullptr, nullptr});
while (!WorkList.empty()) {
SwitchWorkListItem W = WorkList.back();
WorkList.pop_back();
unsigned NumClusters = W.LastCluster - W.FirstCluster + 1;
if (NumClusters > 3 && TM.getOptLevel() != CodeGenOpt::None) {
// For optimized builds, lower large range as a balanced binary tree.
splitWorkItem(WorkList, W, SI.getCondition(), SwitchMBB);
continue;
}
lowerWorkItem(W, SI.getCondition(), SwitchMBB, DefaultMBB);
}
}
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