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llvm-6502/lib/Target/X86/X86FastISel.cpp
Chad Rosier 425e951734 Fall back to the selection dag isel to select tail calls. 
This shouldn't affect codegen for -O0 compiles as tail call markers are not
emitted in unoptimized compiles.  Testing with the external/internal nightly
test suite reveals no change in compile time performance.  Testing with -O1,
-O2 and -O3 with fast-isel enabled did not cause any compile-time or
execution-time failures.  All tests were performed on my x86 machine.
I'll monitor our arm testers to ensure no regressions occur there.

In an upcoming clang patch I will be marking the objc_autoreleaseReturnValue
and objc_retainAutoreleaseReturnValue as tail calls unconditionally.  While
it's theoretically true that this is just an optimization, it's an
optimization that we very much want to happen even at -O0, or else ARC
applications become substantially harder to debug.

Part of rdar://12553082

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169796 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-11 00:18:02 +00:00

2231 lines
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//===-- X86FastISel.cpp - X86 FastISel implementation ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the X86-specific support for the FastISel class. Much
// of the target-specific code is generated by tablegen in the file
// X86GenFastISel.inc, which is #included here.
//
//===----------------------------------------------------------------------===//
#include "X86.h"
#include "X86ISelLowering.h"
#include "X86InstrBuilder.h"
#include "X86RegisterInfo.h"
#include "X86Subtarget.h"
#include "X86TargetMachine.h"
#include "llvm/CallingConv.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalAlias.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Operator.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
namespace {
class X86FastISel : public FastISel {
/// Subtarget - Keep a pointer to the X86Subtarget around so that we can
/// make the right decision when generating code for different targets.
const X86Subtarget *Subtarget;
/// RegInfo - X86 register info.
///
const X86RegisterInfo *RegInfo;
/// X86ScalarSSEf32, X86ScalarSSEf64 - Select between SSE or x87
/// floating point ops.
/// When SSE is available, use it for f32 operations.
/// When SSE2 is available, use it for f64 operations.
bool X86ScalarSSEf64;
bool X86ScalarSSEf32;
public:
explicit X86FastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo)
: FastISel(funcInfo, libInfo) {
Subtarget = &TM.getSubtarget<X86Subtarget>();
X86ScalarSSEf64 = Subtarget->hasSSE2();
X86ScalarSSEf32 = Subtarget->hasSSE1();
RegInfo = static_cast<const X86RegisterInfo*>(TM.getRegisterInfo());
}
virtual bool TargetSelectInstruction(const Instruction *I);
/// TryToFoldLoad - The specified machine instr operand is a vreg, and that
/// vreg is being provided by the specified load instruction. If possible,
/// try to fold the load as an operand to the instruction, returning true if
/// possible.
virtual bool TryToFoldLoad(MachineInstr *MI, unsigned OpNo,
const LoadInst *LI);
#include "X86GenFastISel.inc"
private:
bool X86FastEmitCompare(const Value *LHS, const Value *RHS, EVT VT);
bool X86FastEmitLoad(EVT VT, const X86AddressMode &AM, unsigned &RR);
bool X86FastEmitStore(EVT VT, const Value *Val, const X86AddressMode &AM);
bool X86FastEmitStore(EVT VT, unsigned Val, const X86AddressMode &AM);
bool X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT, unsigned Src, EVT SrcVT,
unsigned &ResultReg);
bool X86SelectAddress(const Value *V, X86AddressMode &AM);
bool X86SelectCallAddress(const Value *V, X86AddressMode &AM);
bool X86SelectLoad(const Instruction *I);
bool X86SelectStore(const Instruction *I);
bool X86SelectRet(const Instruction *I);
bool X86SelectCmp(const Instruction *I);
bool X86SelectZExt(const Instruction *I);
bool X86SelectBranch(const Instruction *I);
bool X86SelectShift(const Instruction *I);
bool X86SelectSelect(const Instruction *I);
bool X86SelectTrunc(const Instruction *I);
bool X86SelectFPExt(const Instruction *I);
bool X86SelectFPTrunc(const Instruction *I);
bool X86VisitIntrinsicCall(const IntrinsicInst &I);
bool X86SelectCall(const Instruction *I);
bool DoSelectCall(const Instruction *I, const char *MemIntName);
const X86InstrInfo *getInstrInfo() const {
return getTargetMachine()->getInstrInfo();
}
const X86TargetMachine *getTargetMachine() const {
return static_cast<const X86TargetMachine *>(&TM);
}
unsigned TargetMaterializeConstant(const Constant *C);
unsigned TargetMaterializeAlloca(const AllocaInst *C);
unsigned TargetMaterializeFloatZero(const ConstantFP *CF);
/// isScalarFPTypeInSSEReg - Return true if the specified scalar FP type is
/// computed in an SSE register, not on the X87 floating point stack.
bool isScalarFPTypeInSSEReg(EVT VT) const {
return (VT == MVT::f64 && X86ScalarSSEf64) || // f64 is when SSE2
(VT == MVT::f32 && X86ScalarSSEf32); // f32 is when SSE1
}
bool isTypeLegal(Type *Ty, MVT &VT, bool AllowI1 = false);
bool IsMemcpySmall(uint64_t Len);
bool TryEmitSmallMemcpy(X86AddressMode DestAM,
X86AddressMode SrcAM, uint64_t Len);
};
} // end anonymous namespace.
bool X86FastISel::isTypeLegal(Type *Ty, MVT &VT, bool AllowI1) {
EVT evt = TLI.getValueType(Ty, /*HandleUnknown=*/true);
if (evt == MVT::Other || !evt.isSimple())
// Unhandled type. Halt "fast" selection and bail.
return false;
VT = evt.getSimpleVT();
// For now, require SSE/SSE2 for performing floating-point operations,
// since x87 requires additional work.
if (VT == MVT::f64 && !X86ScalarSSEf64)
return false;
if (VT == MVT::f32 && !X86ScalarSSEf32)
return false;
// Similarly, no f80 support yet.
if (VT == MVT::f80)
return false;
// We only handle legal types. For example, on x86-32 the instruction
// selector contains all of the 64-bit instructions from x86-64,
// under the assumption that i64 won't be used if the target doesn't
// support it.
return (AllowI1 && VT == MVT::i1) || TLI.isTypeLegal(VT);
}
#include "X86GenCallingConv.inc"
/// X86FastEmitLoad - Emit a machine instruction to load a value of type VT.
/// The address is either pre-computed, i.e. Ptr, or a GlobalAddress, i.e. GV.
/// Return true and the result register by reference if it is possible.
bool X86FastISel::X86FastEmitLoad(EVT VT, const X86AddressMode &AM,
unsigned &ResultReg) {
// Get opcode and regclass of the output for the given load instruction.
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
switch (VT.getSimpleVT().SimpleTy) {
default: return false;
case MVT::i1:
case MVT::i8:
Opc = X86::MOV8rm;
RC = &X86::GR8RegClass;
break;
case MVT::i16:
Opc = X86::MOV16rm;
RC = &X86::GR16RegClass;
break;
case MVT::i32:
Opc = X86::MOV32rm;
RC = &X86::GR32RegClass;
break;
case MVT::i64:
// Must be in x86-64 mode.
Opc = X86::MOV64rm;
RC = &X86::GR64RegClass;
break;
case MVT::f32:
if (X86ScalarSSEf32) {
Opc = Subtarget->hasAVX() ? X86::VMOVSSrm : X86::MOVSSrm;
RC = &X86::FR32RegClass;
} else {
Opc = X86::LD_Fp32m;
RC = &X86::RFP32RegClass;
}
break;
case MVT::f64:
if (X86ScalarSSEf64) {
Opc = Subtarget->hasAVX() ? X86::VMOVSDrm : X86::MOVSDrm;
RC = &X86::FR64RegClass;
} else {
Opc = X86::LD_Fp64m;
RC = &X86::RFP64RegClass;
}
break;
case MVT::f80:
// No f80 support yet.
return false;
}
ResultReg = createResultReg(RC);
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt,
DL, TII.get(Opc), ResultReg), AM);
return true;
}
/// X86FastEmitStore - Emit a machine instruction to store a value Val of
/// type VT. The address is either pre-computed, consisted of a base ptr, Ptr
/// and a displacement offset, or a GlobalAddress,
/// i.e. V. Return true if it is possible.
bool
X86FastISel::X86FastEmitStore(EVT VT, unsigned Val, const X86AddressMode &AM) {
// Get opcode and regclass of the output for the given store instruction.
unsigned Opc = 0;
switch (VT.getSimpleVT().SimpleTy) {
case MVT::f80: // No f80 support yet.
default: return false;
case MVT::i1: {
// Mask out all but lowest bit.
unsigned AndResult = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(X86::AND8ri), AndResult).addReg(Val).addImm(1);
Val = AndResult;
}
// FALLTHROUGH, handling i1 as i8.
case MVT::i8: Opc = X86::MOV8mr; break;
case MVT::i16: Opc = X86::MOV16mr; break;
case MVT::i32: Opc = X86::MOV32mr; break;
case MVT::i64: Opc = X86::MOV64mr; break; // Must be in x86-64 mode.
case MVT::f32:
Opc = X86ScalarSSEf32 ?
(Subtarget->hasAVX() ? X86::VMOVSSmr : X86::MOVSSmr) : X86::ST_Fp32m;
break;
case MVT::f64:
Opc = X86ScalarSSEf64 ?
(Subtarget->hasAVX() ? X86::VMOVSDmr : X86::MOVSDmr) : X86::ST_Fp64m;
break;
case MVT::v4f32:
Opc = X86::MOVAPSmr;
break;
case MVT::v2f64:
Opc = X86::MOVAPDmr;
break;
case MVT::v4i32:
case MVT::v2i64:
case MVT::v8i16:
case MVT::v16i8:
Opc = X86::MOVDQAmr;
break;
}
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt,
DL, TII.get(Opc)), AM).addReg(Val);
return true;
}
bool X86FastISel::X86FastEmitStore(EVT VT, const Value *Val,
const X86AddressMode &AM) {
// Handle 'null' like i32/i64 0.
if (isa<ConstantPointerNull>(Val))
Val = Constant::getNullValue(TD.getIntPtrType(Val->getContext()));
// If this is a store of a simple constant, fold the constant into the store.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
unsigned Opc = 0;
bool Signed = true;
switch (VT.getSimpleVT().SimpleTy) {
default: break;
case MVT::i1: Signed = false; // FALLTHROUGH to handle as i8.
case MVT::i8: Opc = X86::MOV8mi; break;
case MVT::i16: Opc = X86::MOV16mi; break;
case MVT::i32: Opc = X86::MOV32mi; break;
case MVT::i64:
// Must be a 32-bit sign extended value.
if (isInt<32>(CI->getSExtValue()))
Opc = X86::MOV64mi32;
break;
}
if (Opc) {
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt,
DL, TII.get(Opc)), AM)
.addImm(Signed ? (uint64_t) CI->getSExtValue() :
CI->getZExtValue());
return true;
}
}
unsigned ValReg = getRegForValue(Val);
if (ValReg == 0)
return false;
return X86FastEmitStore(VT, ValReg, AM);
}
/// X86FastEmitExtend - Emit a machine instruction to extend a value Src of
/// type SrcVT to type DstVT using the specified extension opcode Opc (e.g.
/// ISD::SIGN_EXTEND).
bool X86FastISel::X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT,
unsigned Src, EVT SrcVT,
unsigned &ResultReg) {
unsigned RR = FastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Opc,
Src, /*TODO: Kill=*/false);
if (RR != 0) {
ResultReg = RR;
return true;
} else
return false;
}
/// X86SelectAddress - Attempt to fill in an address from the given value.
///
bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
const User *U = NULL;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(V)) {
// Don't walk into other basic blocks; it's possible we haven't
// visited them yet, so the instructions may not yet be assigned
// virtual registers.
if (FuncInfo.StaticAllocaMap.count(static_cast<const AllocaInst *>(V)) ||
FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB) {
Opcode = I->getOpcode();
U = I;
}
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
Opcode = C->getOpcode();
U = C;
}
if (PointerType *Ty = dyn_cast<PointerType>(V->getType()))
if (Ty->getAddressSpace() > 255)
// Fast instruction selection doesn't support the special
// address spaces.
return false;
switch (Opcode) {
default: break;
case Instruction::BitCast:
// Look past bitcasts.
return X86SelectAddress(U->getOperand(0), AM);
case Instruction::IntToPtr:
// Look past no-op inttoptrs.
if (TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
return X86SelectAddress(U->getOperand(0), AM);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints.
if (TLI.getValueType(U->getType()) == TLI.getPointerTy())
return X86SelectAddress(U->getOperand(0), AM);
break;
case Instruction::Alloca: {
// Do static allocas.
const AllocaInst *A = cast<AllocaInst>(V);
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(A);
if (SI != FuncInfo.StaticAllocaMap.end()) {
AM.BaseType = X86AddressMode::FrameIndexBase;
AM.Base.FrameIndex = SI->second;
return true;
}
break;
}
case Instruction::Add: {
// Adds of constants are common and easy enough.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(U->getOperand(1))) {
uint64_t Disp = (int32_t)AM.Disp + (uint64_t)CI->getSExtValue();
// They have to fit in the 32-bit signed displacement field though.
if (isInt<32>(Disp)) {
AM.Disp = (uint32_t)Disp;
return X86SelectAddress(U->getOperand(0), AM);
}
}
break;
}
case Instruction::GetElementPtr: {
X86AddressMode SavedAM = AM;
// Pattern-match simple GEPs.
uint64_t Disp = (int32_t)AM.Disp;
unsigned IndexReg = AM.IndexReg;
unsigned Scale = AM.Scale;
gep_type_iterator GTI = gep_type_begin(U);
// Iterate through the indices, folding what we can. Constants can be
// folded, and one dynamic index can be handled, if the scale is supported.
for (User::const_op_iterator i = U->op_begin() + 1, e = U->op_end();
i != e; ++i, ++GTI) {
const Value *Op = *i;
if (StructType *STy = dyn_cast<StructType>(*GTI)) {
const StructLayout *SL = TD.getStructLayout(STy);
Disp += SL->getElementOffset(cast<ConstantInt>(Op)->getZExtValue());
continue;
}
// A array/variable index is always of the form i*S where S is the
// constant scale size. See if we can push the scale into immediates.
uint64_t S = TD.getTypeAllocSize(GTI.getIndexedType());
for (;;) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
// Constant-offset addressing.
Disp += CI->getSExtValue() * S;
break;
}
if (isa<AddOperator>(Op) &&
(!isa<Instruction>(Op) ||
FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
== FuncInfo.MBB) &&
isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
// An add (in the same block) with a constant operand. Fold the
// constant.
ConstantInt *CI =
cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
Disp += CI->getSExtValue() * S;
// Iterate on the other operand.
Op = cast<AddOperator>(Op)->getOperand(0);
continue;
}
if (IndexReg == 0 &&
(!AM.GV || !Subtarget->isPICStyleRIPRel()) &&
(S == 1 || S == 2 || S == 4 || S == 8)) {
// Scaled-index addressing.
Scale = S;
IndexReg = getRegForGEPIndex(Op).first;
if (IndexReg == 0)
return false;
break;
}
// Unsupported.
goto unsupported_gep;
}
}
// Check for displacement overflow.
if (!isInt<32>(Disp))
break;
// Ok, the GEP indices were covered by constant-offset and scaled-index
// addressing. Update the address state and move on to examining the base.
AM.IndexReg = IndexReg;
AM.Scale = Scale;
AM.Disp = (uint32_t)Disp;
if (X86SelectAddress(U->getOperand(0), AM))
return true;
// If we couldn't merge the gep value into this addr mode, revert back to
// our address and just match the value instead of completely failing.
AM = SavedAM;
break;
unsupported_gep:
// Ok, the GEP indices weren't all covered.
break;
}
}
// Handle constant address.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Can't handle alternate code models yet.
if (TM.getCodeModel() != CodeModel::Small)
return false;
// Can't handle TLS yet.
if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
if (GVar->isThreadLocal())
return false;
// Can't handle TLS yet, part 2 (this is slightly crazy, but this is how
// it works...).
if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
if (const GlobalVariable *GVar =
dyn_cast_or_null<GlobalVariable>(GA->resolveAliasedGlobal(false)))
if (GVar->isThreadLocal())
return false;
// RIP-relative addresses can't have additional register operands, so if
// we've already folded stuff into the addressing mode, just force the
// global value into its own register, which we can use as the basereg.
if (!Subtarget->isPICStyleRIPRel() ||
(AM.Base.Reg == 0 && AM.IndexReg == 0)) {
// Okay, we've committed to selecting this global. Set up the address.
AM.GV = GV;
// Allow the subtarget to classify the global.
unsigned char GVFlags = Subtarget->ClassifyGlobalReference(GV, TM);
// If this reference is relative to the pic base, set it now.
if (isGlobalRelativeToPICBase(GVFlags)) {
// FIXME: How do we know Base.Reg is free??
AM.Base.Reg = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
}
// Unless the ABI requires an extra load, return a direct reference to
// the global.
if (!isGlobalStubReference(GVFlags)) {
if (Subtarget->isPICStyleRIPRel()) {
// Use rip-relative addressing if we can. Above we verified that the
// base and index registers are unused.
assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
AM.Base.Reg = X86::RIP;
}
AM.GVOpFlags = GVFlags;
return true;
}
// Ok, we need to do a load from a stub. If we've already loaded from
// this stub, reuse the loaded pointer, otherwise emit the load now.
DenseMap<const Value*, unsigned>::iterator I = LocalValueMap.find(V);
unsigned LoadReg;
if (I != LocalValueMap.end() && I->second != 0) {
LoadReg = I->second;
} else {
// Issue load from stub.
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
X86AddressMode StubAM;
StubAM.Base.Reg = AM.Base.Reg;
StubAM.GV = GV;
StubAM.GVOpFlags = GVFlags;
// Prepare for inserting code in the local-value area.
SavePoint SaveInsertPt = enterLocalValueArea();
if (TLI.getPointerTy() == MVT::i64) {
Opc = X86::MOV64rm;
RC = &X86::GR64RegClass;
if (Subtarget->isPICStyleRIPRel())
StubAM.Base.Reg = X86::RIP;
} else {
Opc = X86::MOV32rm;
RC = &X86::GR32RegClass;
}
LoadReg = createResultReg(RC);
MachineInstrBuilder LoadMI =
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), LoadReg);
addFullAddress(LoadMI, StubAM);
// Ok, back to normal mode.
leaveLocalValueArea(SaveInsertPt);
// Prevent loading GV stub multiple times in same MBB.
LocalValueMap[V] = LoadReg;
}
// Now construct the final address. Note that the Disp, Scale,
// and Index values may already be set here.
AM.Base.Reg = LoadReg;
AM.GV = 0;
return true;
}
}
// If all else fails, try to materialize the value in a register.
if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
if (AM.Base.Reg == 0) {
AM.Base.Reg = getRegForValue(V);
return AM.Base.Reg != 0;
}
if (AM.IndexReg == 0) {
assert(AM.Scale == 1 && "Scale with no index!");
AM.IndexReg = getRegForValue(V);
return AM.IndexReg != 0;
}
}
return false;
}
/// X86SelectCallAddress - Attempt to fill in an address from the given value.
///
bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) {
const User *U = NULL;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(V)) {
Opcode = I->getOpcode();
U = I;
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default: break;
case Instruction::BitCast:
// Look past bitcasts.
return X86SelectCallAddress(U->getOperand(0), AM);
case Instruction::IntToPtr:
// Look past no-op inttoptrs.
if (TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
return X86SelectCallAddress(U->getOperand(0), AM);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints.
if (TLI.getValueType(U->getType()) == TLI.getPointerTy())
return X86SelectCallAddress(U->getOperand(0), AM);
break;
}
// Handle constant address.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Can't handle alternate code models yet.
if (TM.getCodeModel() != CodeModel::Small)
return false;
// RIP-relative addresses can't have additional register operands.
if (Subtarget->isPICStyleRIPRel() &&
(AM.Base.Reg != 0 || AM.IndexReg != 0))
return false;
// Can't handle DLLImport.
if (GV->hasDLLImportLinkage())
return false;
// Can't handle TLS.
if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
if (GVar->isThreadLocal())
return false;
// Okay, we've committed to selecting this global. Set up the basic address.
AM.GV = GV;
// No ABI requires an extra load for anything other than DLLImport, which
// we rejected above. Return a direct reference to the global.
if (Subtarget->isPICStyleRIPRel()) {
// Use rip-relative addressing if we can. Above we verified that the
// base and index registers are unused.
assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
AM.Base.Reg = X86::RIP;
} else if (Subtarget->isPICStyleStubPIC()) {
AM.GVOpFlags = X86II::MO_PIC_BASE_OFFSET;
} else if (Subtarget->isPICStyleGOT()) {
AM.GVOpFlags = X86II::MO_GOTOFF;
}
return true;
}
// If all else fails, try to materialize the value in a register.
if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
if (AM.Base.Reg == 0) {
AM.Base.Reg = getRegForValue(V);
return AM.Base.Reg != 0;
}
if (AM.IndexReg == 0) {
assert(AM.Scale == 1 && "Scale with no index!");
AM.IndexReg = getRegForValue(V);
return AM.IndexReg != 0;
}
}
return false;
}
/// X86SelectStore - Select and emit code to implement store instructions.
bool X86FastISel::X86SelectStore(const Instruction *I) {
// Atomic stores need special handling.
const StoreInst *S = cast<StoreInst>(I);
if (S->isAtomic())
return false;
unsigned SABIAlignment =
TD.getABITypeAlignment(S->getValueOperand()->getType());
if (S->getAlignment() != 0 && S->getAlignment() < SABIAlignment)
return false;
MVT VT;
if (!isTypeLegal(I->getOperand(0)->getType(), VT, /*AllowI1=*/true))
return false;
X86AddressMode AM;
if (!X86SelectAddress(I->getOperand(1), AM))
return false;
return X86FastEmitStore(VT, I->getOperand(0), AM);
}
/// X86SelectRet - Select and emit code to implement ret instructions.
bool X86FastISel::X86SelectRet(const Instruction *I) {
const ReturnInst *Ret = cast<ReturnInst>(I);
const Function &F = *I->getParent()->getParent();
const X86MachineFunctionInfo *X86MFInfo =
FuncInfo.MF->getInfo<X86MachineFunctionInfo>();
if (!FuncInfo.CanLowerReturn)
return false;
CallingConv::ID CC = F.getCallingConv();
if (CC != CallingConv::C &&
CC != CallingConv::Fast &&
CC != CallingConv::X86_FastCall)
return false;
if (Subtarget->isTargetWin64())
return false;
// Don't handle popping bytes on return for now.
if (X86MFInfo->getBytesToPopOnReturn() != 0)
return 0;
// fastcc with -tailcallopt is intended to provide a guaranteed
// tail call optimization. Fastisel doesn't know how to do that.
if (CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt)
return false;
// Let SDISel handle vararg functions.
if (F.isVarArg())
return false;
if (Ret->getNumOperands() > 0) {
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(F.getReturnType(), F.getAttributes().getRetAttributes(),
Outs, TLI);
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ValLocs;
CCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, TM, ValLocs,
I->getContext());
CCInfo.AnalyzeReturn(Outs, RetCC_X86);
const Value *RV = Ret->getOperand(0);
unsigned Reg = getRegForValue(RV);
if (Reg == 0)
return false;
// Only handle a single return value for now.
if (ValLocs.size() != 1)
return false;
CCValAssign &VA = ValLocs[0];
// Don't bother handling odd stuff for now.
if (VA.getLocInfo() != CCValAssign::Full)
return false;
// Only handle register returns for now.
if (!VA.isRegLoc())
return false;
// The calling-convention tables for x87 returns don't tell
// the whole story.
if (VA.getLocReg() == X86::ST0 || VA.getLocReg() == X86::ST1)
return false;
unsigned SrcReg = Reg + VA.getValNo();
EVT SrcVT = TLI.getValueType(RV->getType());
EVT DstVT = VA.getValVT();
// Special handling for extended integers.
if (SrcVT != DstVT) {
if (SrcVT != MVT::i1 && SrcVT != MVT::i8 && SrcVT != MVT::i16)
return false;
if (!Outs[0].Flags.isZExt() && !Outs[0].Flags.isSExt())
return false;
assert(DstVT == MVT::i32 && "X86 should always ext to i32");
if (SrcVT == MVT::i1) {
if (Outs[0].Flags.isSExt())
return false;
SrcReg = FastEmitZExtFromI1(MVT::i8, SrcReg, /*TODO: Kill=*/false);
SrcVT = MVT::i8;
}
unsigned Op = Outs[0].Flags.isZExt() ? ISD::ZERO_EXTEND :
ISD::SIGN_EXTEND;
SrcReg = FastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Op,
SrcReg, /*TODO: Kill=*/false);
}
// Make the copy.
unsigned DstReg = VA.getLocReg();
const TargetRegisterClass* SrcRC = MRI.getRegClass(SrcReg);
// Avoid a cross-class copy. This is very unlikely.
if (!SrcRC->contains(DstReg))
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
DstReg).addReg(SrcReg);
// Mark the register as live out of the function.
MRI.addLiveOut(VA.getLocReg());
}
// The x86-64 ABI for returning structs by value requires that we copy
// the sret argument into %rax for the return. We saved the argument into
// a virtual register in the entry block, so now we copy the value out
// and into %rax.
if (Subtarget->is64Bit() && F.hasStructRetAttr()) {
unsigned Reg = X86MFInfo->getSRetReturnReg();
assert(Reg &&
"SRetReturnReg should have been set in LowerFormalArguments()!");
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
X86::RAX).addReg(Reg);
MRI.addLiveOut(X86::RAX);
}
// Now emit the RET.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::RET));
return true;
}
/// X86SelectLoad - Select and emit code to implement load instructions.
///
bool X86FastISel::X86SelectLoad(const Instruction *I) {
// Atomic loads need special handling.
if (cast<LoadInst>(I)->isAtomic())
return false;
MVT VT;
if (!isTypeLegal(I->getType(), VT, /*AllowI1=*/true))
return false;
X86AddressMode AM;
if (!X86SelectAddress(I->getOperand(0), AM))
return false;
unsigned ResultReg = 0;
if (X86FastEmitLoad(VT, AM, ResultReg)) {
UpdateValueMap(I, ResultReg);
return true;
}
return false;
}
static unsigned X86ChooseCmpOpcode(EVT VT, const X86Subtarget *Subtarget) {
bool HasAVX = Subtarget->hasAVX();
bool X86ScalarSSEf32 = Subtarget->hasSSE1();
bool X86ScalarSSEf64 = Subtarget->hasSSE2();
switch (VT.getSimpleVT().SimpleTy) {
default: return 0;
case MVT::i8: return X86::CMP8rr;
case MVT::i16: return X86::CMP16rr;
case MVT::i32: return X86::CMP32rr;
case MVT::i64: return X86::CMP64rr;
case MVT::f32:
return X86ScalarSSEf32 ? (HasAVX ? X86::VUCOMISSrr : X86::UCOMISSrr) : 0;
case MVT::f64:
return X86ScalarSSEf64 ? (HasAVX ? X86::VUCOMISDrr : X86::UCOMISDrr) : 0;
}
}
/// X86ChooseCmpImmediateOpcode - If we have a comparison with RHS as the RHS
/// of the comparison, return an opcode that works for the compare (e.g.
/// CMP32ri) otherwise return 0.
static unsigned X86ChooseCmpImmediateOpcode(EVT VT, const ConstantInt *RHSC) {
switch (VT.getSimpleVT().SimpleTy) {
// Otherwise, we can't fold the immediate into this comparison.
default: return 0;
case MVT::i8: return X86::CMP8ri;
case MVT::i16: return X86::CMP16ri;
case MVT::i32: return X86::CMP32ri;
case MVT::i64:
// 64-bit comparisons are only valid if the immediate fits in a 32-bit sext
// field.
if ((int)RHSC->getSExtValue() == RHSC->getSExtValue())
return X86::CMP64ri32;
return 0;
}
}
bool X86FastISel::X86FastEmitCompare(const Value *Op0, const Value *Op1,
EVT VT) {
unsigned Op0Reg = getRegForValue(Op0);
if (Op0Reg == 0) return false;
// Handle 'null' like i32/i64 0.
if (isa<ConstantPointerNull>(Op1))
Op1 = Constant::getNullValue(TD.getIntPtrType(Op0->getContext()));
// We have two options: compare with register or immediate. If the RHS of
// the compare is an immediate that we can fold into this compare, use
// CMPri, otherwise use CMPrr.
if (const ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
if (unsigned CompareImmOpc = X86ChooseCmpImmediateOpcode(VT, Op1C)) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CompareImmOpc))
.addReg(Op0Reg)
.addImm(Op1C->getSExtValue());
return true;
}
}
unsigned CompareOpc = X86ChooseCmpOpcode(VT, Subtarget);
if (CompareOpc == 0) return false;
unsigned Op1Reg = getRegForValue(Op1);
if (Op1Reg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CompareOpc))
.addReg(Op0Reg)
.addReg(Op1Reg);
return true;
}
bool X86FastISel::X86SelectCmp(const Instruction *I) {
const CmpInst *CI = cast<CmpInst>(I);
MVT VT;
if (!isTypeLegal(I->getOperand(0)->getType(), VT))
return false;
unsigned ResultReg = createResultReg(&X86::GR8RegClass);
unsigned SetCCOpc;
bool SwapArgs; // false -> compare Op0, Op1. true -> compare Op1, Op0.
switch (CI->getPredicate()) {
case CmpInst::FCMP_OEQ: {
if (!X86FastEmitCompare(CI->getOperand(0), CI->getOperand(1), VT))
return false;
unsigned EReg = createResultReg(&X86::GR8RegClass);
unsigned NPReg = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::SETEr), EReg);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(X86::SETNPr), NPReg);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(X86::AND8rr), ResultReg).addReg(NPReg).addReg(EReg);
UpdateValueMap(I, ResultReg);
return true;
}
case CmpInst::FCMP_UNE: {
if (!X86FastEmitCompare(CI->getOperand(0), CI->getOperand(1), VT))
return false;
unsigned NEReg = createResultReg(&X86::GR8RegClass);
unsigned PReg = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::SETNEr), NEReg);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::SETPr), PReg);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::OR8rr),ResultReg)
.addReg(PReg).addReg(NEReg);
UpdateValueMap(I, ResultReg);
return true;
}
case CmpInst::FCMP_OGT: SwapArgs = false; SetCCOpc = X86::SETAr; break;
case CmpInst::FCMP_OGE: SwapArgs = false; SetCCOpc = X86::SETAEr; break;
case CmpInst::FCMP_OLT: SwapArgs = true; SetCCOpc = X86::SETAr; break;
case CmpInst::FCMP_OLE: SwapArgs = true; SetCCOpc = X86::SETAEr; break;
case CmpInst::FCMP_ONE: SwapArgs = false; SetCCOpc = X86::SETNEr; break;
case CmpInst::FCMP_ORD: SwapArgs = false; SetCCOpc = X86::SETNPr; break;
case CmpInst::FCMP_UNO: SwapArgs = false; SetCCOpc = X86::SETPr; break;
case CmpInst::FCMP_UEQ: SwapArgs = false; SetCCOpc = X86::SETEr; break;
case CmpInst::FCMP_UGT: SwapArgs = true; SetCCOpc = X86::SETBr; break;
case CmpInst::FCMP_UGE: SwapArgs = true; SetCCOpc = X86::SETBEr; break;
case CmpInst::FCMP_ULT: SwapArgs = false; SetCCOpc = X86::SETBr; break;
case CmpInst::FCMP_ULE: SwapArgs = false; SetCCOpc = X86::SETBEr; break;
case CmpInst::ICMP_EQ: SwapArgs = false; SetCCOpc = X86::SETEr; break;
case CmpInst::ICMP_NE: SwapArgs = false; SetCCOpc = X86::SETNEr; break;
case CmpInst::ICMP_UGT: SwapArgs = false; SetCCOpc = X86::SETAr; break;
case CmpInst::ICMP_UGE: SwapArgs = false; SetCCOpc = X86::SETAEr; break;
case CmpInst::ICMP_ULT: SwapArgs = false; SetCCOpc = X86::SETBr; break;
case CmpInst::ICMP_ULE: SwapArgs = false; SetCCOpc = X86::SETBEr; break;
case CmpInst::ICMP_SGT: SwapArgs = false; SetCCOpc = X86::SETGr; break;
case CmpInst::ICMP_SGE: SwapArgs = false; SetCCOpc = X86::SETGEr; break;
case CmpInst::ICMP_SLT: SwapArgs = false; SetCCOpc = X86::SETLr; break;
case CmpInst::ICMP_SLE: SwapArgs = false; SetCCOpc = X86::SETLEr; break;
default:
return false;
}
const Value *Op0 = CI->getOperand(0), *Op1 = CI->getOperand(1);
if (SwapArgs)
std::swap(Op0, Op1);
// Emit a compare of Op0/Op1.
if (!X86FastEmitCompare(Op0, Op1, VT))
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(SetCCOpc), ResultReg);
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectZExt(const Instruction *I) {
// Handle zero-extension from i1 to i8, which is common.
if (!I->getOperand(0)->getType()->isIntegerTy(1))
return false;
EVT DstVT = TLI.getValueType(I->getType());
if (!TLI.isTypeLegal(DstVT))
return false;
unsigned ResultReg = getRegForValue(I->getOperand(0));
if (ResultReg == 0)
return false;
// Set the high bits to zero.
ResultReg = FastEmitZExtFromI1(MVT::i8, ResultReg, /*TODO: Kill=*/false);
if (ResultReg == 0)
return false;
if (DstVT != MVT::i8) {
ResultReg = FastEmit_r(MVT::i8, DstVT.getSimpleVT(), ISD::ZERO_EXTEND,
ResultReg, /*Kill=*/true);
if (ResultReg == 0)
return false;
}
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectBranch(const Instruction *I) {
// Unconditional branches are selected by tablegen-generated code.
// Handle a conditional branch.
const BranchInst *BI = cast<BranchInst>(I);
MachineBasicBlock *TrueMBB = FuncInfo.MBBMap[BI->getSuccessor(0)];
MachineBasicBlock *FalseMBB = FuncInfo.MBBMap[BI->getSuccessor(1)];
// Fold the common case of a conditional branch with a comparison
// in the same block (values defined on other blocks may not have
// initialized registers).
if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) {
if (CI->hasOneUse() && CI->getParent() == I->getParent()) {
EVT VT = TLI.getValueType(CI->getOperand(0)->getType());
// Try to take advantage of fallthrough opportunities.
CmpInst::Predicate Predicate = CI->getPredicate();
if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) {
std::swap(TrueMBB, FalseMBB);
Predicate = CmpInst::getInversePredicate(Predicate);
}
bool SwapArgs; // false -> compare Op0, Op1. true -> compare Op1, Op0.
unsigned BranchOpc; // Opcode to jump on, e.g. "X86::JA"
switch (Predicate) {
case CmpInst::FCMP_OEQ:
std::swap(TrueMBB, FalseMBB);
Predicate = CmpInst::FCMP_UNE;
// FALL THROUGH
case CmpInst::FCMP_UNE: SwapArgs = false; BranchOpc = X86::JNE_4; break;
case CmpInst::FCMP_OGT: SwapArgs = false; BranchOpc = X86::JA_4; break;
case CmpInst::FCMP_OGE: SwapArgs = false; BranchOpc = X86::JAE_4; break;
case CmpInst::FCMP_OLT: SwapArgs = true; BranchOpc = X86::JA_4; break;
case CmpInst::FCMP_OLE: SwapArgs = true; BranchOpc = X86::JAE_4; break;
case CmpInst::FCMP_ONE: SwapArgs = false; BranchOpc = X86::JNE_4; break;
case CmpInst::FCMP_ORD: SwapArgs = false; BranchOpc = X86::JNP_4; break;
case CmpInst::FCMP_UNO: SwapArgs = false; BranchOpc = X86::JP_4; break;
case CmpInst::FCMP_UEQ: SwapArgs = false; BranchOpc = X86::JE_4; break;
case CmpInst::FCMP_UGT: SwapArgs = true; BranchOpc = X86::JB_4; break;
case CmpInst::FCMP_UGE: SwapArgs = true; BranchOpc = X86::JBE_4; break;
case CmpInst::FCMP_ULT: SwapArgs = false; BranchOpc = X86::JB_4; break;
case CmpInst::FCMP_ULE: SwapArgs = false; BranchOpc = X86::JBE_4; break;
case CmpInst::ICMP_EQ: SwapArgs = false; BranchOpc = X86::JE_4; break;
case CmpInst::ICMP_NE: SwapArgs = false; BranchOpc = X86::JNE_4; break;
case CmpInst::ICMP_UGT: SwapArgs = false; BranchOpc = X86::JA_4; break;
case CmpInst::ICMP_UGE: SwapArgs = false; BranchOpc = X86::JAE_4; break;
case CmpInst::ICMP_ULT: SwapArgs = false; BranchOpc = X86::JB_4; break;
case CmpInst::ICMP_ULE: SwapArgs = false; BranchOpc = X86::JBE_4; break;
case CmpInst::ICMP_SGT: SwapArgs = false; BranchOpc = X86::JG_4; break;
case CmpInst::ICMP_SGE: SwapArgs = false; BranchOpc = X86::JGE_4; break;
case CmpInst::ICMP_SLT: SwapArgs = false; BranchOpc = X86::JL_4; break;
case CmpInst::ICMP_SLE: SwapArgs = false; BranchOpc = X86::JLE_4; break;
default:
return false;
}
const Value *Op0 = CI->getOperand(0), *Op1 = CI->getOperand(1);
if (SwapArgs)
std::swap(Op0, Op1);
// Emit a compare of the LHS and RHS, setting the flags.
if (!X86FastEmitCompare(Op0, Op1, VT))
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(BranchOpc))
.addMBB(TrueMBB);
if (Predicate == CmpInst::FCMP_UNE) {
// X86 requires a second branch to handle UNE (and OEQ,
// which is mapped to UNE above).
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::JP_4))
.addMBB(TrueMBB);
}
FastEmitBranch(FalseMBB, DL);
FuncInfo.MBB->addSuccessor(TrueMBB);
return true;
}
} else if (TruncInst *TI = dyn_cast<TruncInst>(BI->getCondition())) {
// Handle things like "%cond = trunc i32 %X to i1 / br i1 %cond", which
// typically happen for _Bool and C++ bools.
MVT SourceVT;
if (TI->hasOneUse() && TI->getParent() == I->getParent() &&
isTypeLegal(TI->getOperand(0)->getType(), SourceVT)) {
unsigned TestOpc = 0;
switch (SourceVT.SimpleTy) {
default: break;
case MVT::i8: TestOpc = X86::TEST8ri; break;
case MVT::i16: TestOpc = X86::TEST16ri; break;
case MVT::i32: TestOpc = X86::TEST32ri; break;
case MVT::i64: TestOpc = X86::TEST64ri32; break;
}
if (TestOpc) {
unsigned OpReg = getRegForValue(TI->getOperand(0));
if (OpReg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TestOpc))
.addReg(OpReg).addImm(1);
unsigned JmpOpc = X86::JNE_4;
if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) {
std::swap(TrueMBB, FalseMBB);
JmpOpc = X86::JE_4;
}
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(JmpOpc))
.addMBB(TrueMBB);
FastEmitBranch(FalseMBB, DL);
FuncInfo.MBB->addSuccessor(TrueMBB);
return true;
}
}
}
// Otherwise do a clumsy setcc and re-test it.
// Note that i1 essentially gets ANY_EXTEND'ed to i8 where it isn't used
// in an explicit cast, so make sure to handle that correctly.
unsigned OpReg = getRegForValue(BI->getCondition());
if (OpReg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::TEST8ri))
.addReg(OpReg).addImm(1);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::JNE_4))
.addMBB(TrueMBB);
FastEmitBranch(FalseMBB, DL);
FuncInfo.MBB->addSuccessor(TrueMBB);
return true;
}
bool X86FastISel::X86SelectShift(const Instruction *I) {
unsigned CReg = 0, OpReg = 0;
const TargetRegisterClass *RC = NULL;
if (I->getType()->isIntegerTy(8)) {
CReg = X86::CL;
RC = &X86::GR8RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR8rCL; break;
case Instruction::AShr: OpReg = X86::SAR8rCL; break;
case Instruction::Shl: OpReg = X86::SHL8rCL; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(16)) {
CReg = X86::CX;
RC = &X86::GR16RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR16rCL; break;
case Instruction::AShr: OpReg = X86::SAR16rCL; break;
case Instruction::Shl: OpReg = X86::SHL16rCL; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(32)) {
CReg = X86::ECX;
RC = &X86::GR32RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR32rCL; break;
case Instruction::AShr: OpReg = X86::SAR32rCL; break;
case Instruction::Shl: OpReg = X86::SHL32rCL; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(64)) {
CReg = X86::RCX;
RC = &X86::GR64RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR64rCL; break;
case Instruction::AShr: OpReg = X86::SAR64rCL; break;
case Instruction::Shl: OpReg = X86::SHL64rCL; break;
default: return false;
}
} else {
return false;
}
MVT VT;
if (!isTypeLegal(I->getType(), VT))
return false;
unsigned Op0Reg = getRegForValue(I->getOperand(0));
if (Op0Reg == 0) return false;
unsigned Op1Reg = getRegForValue(I->getOperand(1));
if (Op1Reg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
CReg).addReg(Op1Reg);
// The shift instruction uses X86::CL. If we defined a super-register
// of X86::CL, emit a subreg KILL to precisely describe what we're doing here.
if (CReg != X86::CL)
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(TargetOpcode::KILL), X86::CL)
.addReg(CReg, RegState::Kill);
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(OpReg), ResultReg)
.addReg(Op0Reg);
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectSelect(const Instruction *I) {
MVT VT;
if (!isTypeLegal(I->getType(), VT))
return false;
// We only use cmov here, if we don't have a cmov instruction bail.
if (!Subtarget->hasCMov()) return false;
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
if (VT == MVT::i16) {
Opc = X86::CMOVE16rr;
RC = &X86::GR16RegClass;
} else if (VT == MVT::i32) {
Opc = X86::CMOVE32rr;
RC = &X86::GR32RegClass;
} else if (VT == MVT::i64) {
Opc = X86::CMOVE64rr;
RC = &X86::GR64RegClass;
} else {
return false;
}
unsigned Op0Reg = getRegForValue(I->getOperand(0));
if (Op0Reg == 0) return false;
unsigned Op1Reg = getRegForValue(I->getOperand(1));
if (Op1Reg == 0) return false;
unsigned Op2Reg = getRegForValue(I->getOperand(2));
if (Op2Reg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::TEST8rr))
.addReg(Op0Reg).addReg(Op0Reg);
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), ResultReg)
.addReg(Op1Reg).addReg(Op2Reg);
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectFPExt(const Instruction *I) {
// fpext from float to double.
if (X86ScalarSSEf64 &&
I->getType()->isDoubleTy()) {
const Value *V = I->getOperand(0);
if (V->getType()->isFloatTy()) {
unsigned OpReg = getRegForValue(V);
if (OpReg == 0) return false;
unsigned ResultReg = createResultReg(&X86::FR64RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(X86::CVTSS2SDrr), ResultReg)
.addReg(OpReg);
UpdateValueMap(I, ResultReg);
return true;
}
}
return false;
}
bool X86FastISel::X86SelectFPTrunc(const Instruction *I) {
if (X86ScalarSSEf64) {
if (I->getType()->isFloatTy()) {
const Value *V = I->getOperand(0);
if (V->getType()->isDoubleTy()) {
unsigned OpReg = getRegForValue(V);
if (OpReg == 0) return false;
unsigned ResultReg = createResultReg(&X86::FR32RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(X86::CVTSD2SSrr), ResultReg)
.addReg(OpReg);
UpdateValueMap(I, ResultReg);
return true;
}
}
}
return false;
}
bool X86FastISel::X86SelectTrunc(const Instruction *I) {
EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
EVT DstVT = TLI.getValueType(I->getType());
// This code only handles truncation to byte.
if (DstVT != MVT::i8 && DstVT != MVT::i1)
return false;
if (!TLI.isTypeLegal(SrcVT))
return false;
unsigned InputReg = getRegForValue(I->getOperand(0));
if (!InputReg)
// Unhandled operand. Halt "fast" selection and bail.
return false;
if (SrcVT == MVT::i8) {
// Truncate from i8 to i1; no code needed.
UpdateValueMap(I, InputReg);
return true;
}
if (!Subtarget->is64Bit()) {
// If we're on x86-32; we can't extract an i8 from a general register.
// First issue a copy to GR16_ABCD or GR32_ABCD.
const TargetRegisterClass *CopyRC = (SrcVT == MVT::i16) ?
(const TargetRegisterClass*)&X86::GR16_ABCDRegClass :
(const TargetRegisterClass*)&X86::GR32_ABCDRegClass;
unsigned CopyReg = createResultReg(CopyRC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
CopyReg).addReg(InputReg);
InputReg = CopyReg;
}
// Issue an extract_subreg.
unsigned ResultReg = FastEmitInst_extractsubreg(MVT::i8,
InputReg, /*Kill=*/true,
X86::sub_8bit);
if (!ResultReg)
return false;
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::IsMemcpySmall(uint64_t Len) {
return Len <= (Subtarget->is64Bit() ? 32 : 16);
}
bool X86FastISel::TryEmitSmallMemcpy(X86AddressMode DestAM,
X86AddressMode SrcAM, uint64_t Len) {
// Make sure we don't bloat code by inlining very large memcpy's.
if (!IsMemcpySmall(Len))
return false;
bool i64Legal = Subtarget->is64Bit();
// We don't care about alignment here since we just emit integer accesses.
while (Len) {
MVT VT;
if (Len >= 8 && i64Legal)
VT = MVT::i64;
else if (Len >= 4)
VT = MVT::i32;
else if (Len >= 2)
VT = MVT::i16;
else {
assert(Len == 1);
VT = MVT::i8;
}
unsigned Reg;
bool RV = X86FastEmitLoad(VT, SrcAM, Reg);
RV &= X86FastEmitStore(VT, Reg, DestAM);
assert(RV && "Failed to emit load or store??");
unsigned Size = VT.getSizeInBits()/8;
Len -= Size;
DestAM.Disp += Size;
SrcAM.Disp += Size;
}
return true;
}
bool X86FastISel::X86VisitIntrinsicCall(const IntrinsicInst &I) {
// FIXME: Handle more intrinsics.
switch (I.getIntrinsicID()) {
default: return false;
case Intrinsic::memcpy: {
const MemCpyInst &MCI = cast<MemCpyInst>(I);
// Don't handle volatile or variable length memcpys.
if (MCI.isVolatile())
return false;
if (isa<ConstantInt>(MCI.getLength())) {
// Small memcpy's are common enough that we want to do them
// without a call if possible.
uint64_t Len = cast<ConstantInt>(MCI.getLength())->getZExtValue();
if (IsMemcpySmall(Len)) {
X86AddressMode DestAM, SrcAM;
if (!X86SelectAddress(MCI.getRawDest(), DestAM) ||
!X86SelectAddress(MCI.getRawSource(), SrcAM))
return false;
TryEmitSmallMemcpy(DestAM, SrcAM, Len);
return true;
}
}
unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
if (!MCI.getLength()->getType()->isIntegerTy(SizeWidth))
return false;
if (MCI.getSourceAddressSpace() > 255 || MCI.getDestAddressSpace() > 255)
return false;
return DoSelectCall(&I, "memcpy");
}
case Intrinsic::memset: {
const MemSetInst &MSI = cast<MemSetInst>(I);
if (MSI.isVolatile())
return false;
unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
if (!MSI.getLength()->getType()->isIntegerTy(SizeWidth))
return false;
if (MSI.getDestAddressSpace() > 255)
return false;
return DoSelectCall(&I, "memset");
}
case Intrinsic::stackprotector: {
// Emit code to store the stack guard onto the stack.
EVT PtrTy = TLI.getPointerTy();
const Value *Op1 = I.getArgOperand(0); // The guard's value.
const AllocaInst *Slot = cast<AllocaInst>(I.getArgOperand(1));
// Grab the frame index.
X86AddressMode AM;
if (!X86SelectAddress(Slot, AM)) return false;
if (!X86FastEmitStore(PtrTy, Op1, AM)) return false;
return true;
}
case Intrinsic::dbg_declare: {
const DbgDeclareInst *DI = cast<DbgDeclareInst>(&I);
X86AddressMode AM;
assert(DI->getAddress() && "Null address should be checked earlier!");
if (!X86SelectAddress(DI->getAddress(), AM))
return false;
const MCInstrDesc &II = TII.get(TargetOpcode::DBG_VALUE);
// FIXME may need to add RegState::Debug to any registers produced,
// although ESP/EBP should be the only ones at the moment.
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II), AM).
addImm(0).addMetadata(DI->getVariable());
return true;
}
case Intrinsic::trap: {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::TRAP));
return true;
}
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow: {
// FIXME: Should fold immediates.
// Replace "add with overflow" intrinsics with an "add" instruction followed
// by a seto/setc instruction.
const Function *Callee = I.getCalledFunction();
Type *RetTy =
cast<StructType>(Callee->getReturnType())->getTypeAtIndex(unsigned(0));
MVT VT;
if (!isTypeLegal(RetTy, VT))
return false;
const Value *Op1 = I.getArgOperand(0);
const Value *Op2 = I.getArgOperand(1);
unsigned Reg1 = getRegForValue(Op1);
unsigned Reg2 = getRegForValue(Op2);
if (Reg1 == 0 || Reg2 == 0)
// FIXME: Handle values *not* in registers.
return false;
unsigned OpC = 0;
if (VT == MVT::i32)
OpC = X86::ADD32rr;
else if (VT == MVT::i64)
OpC = X86::ADD64rr;
else
return false;
// The call to CreateRegs builds two sequential registers, to store the
// both the returned values.
unsigned ResultReg = FuncInfo.CreateRegs(I.getType());
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(OpC), ResultReg)
.addReg(Reg1).addReg(Reg2);
unsigned Opc = X86::SETBr;
if (I.getIntrinsicID() == Intrinsic::sadd_with_overflow)
Opc = X86::SETOr;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), ResultReg+1);
UpdateValueMap(&I, ResultReg, 2);
return true;
}
}
}
bool X86FastISel::X86SelectCall(const Instruction *I) {
const CallInst *CI = cast<CallInst>(I);
const Value *Callee = CI->getCalledValue();
// Can't handle inline asm yet.
if (isa<InlineAsm>(Callee))
return false;
// Handle intrinsic calls.
if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI))
return X86VisitIntrinsicCall(*II);
// Allow SelectionDAG isel to handle tail calls.
if (cast<CallInst>(I)->isTailCall())
return false;
return DoSelectCall(I, 0);
}
static unsigned computeBytesPoppedByCallee(const X86Subtarget &Subtarget,
const ImmutableCallSite &CS) {
if (Subtarget.is64Bit())
return 0;
if (Subtarget.isTargetWindows())
return 0;
CallingConv::ID CC = CS.getCallingConv();
if (CC == CallingConv::Fast || CC == CallingConv::GHC)
return 0;
if (!CS.paramHasAttr(1, Attributes::StructRet))
return 0;
if (CS.paramHasAttr(1, Attributes::InReg))
return 0;
return 4;
}
// Select either a call, or an llvm.memcpy/memmove/memset intrinsic
bool X86FastISel::DoSelectCall(const Instruction *I, const char *MemIntName) {
const CallInst *CI = cast<CallInst>(I);
const Value *Callee = CI->getCalledValue();
// Handle only C and fastcc calling conventions for now.
ImmutableCallSite CS(CI);
CallingConv::ID CC = CS.getCallingConv();
if (CC != CallingConv::C && CC != CallingConv::Fast &&
CC != CallingConv::X86_FastCall)
return false;
// fastcc with -tailcallopt is intended to provide a guaranteed
// tail call optimization. Fastisel doesn't know how to do that.
if (CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt)
return false;
PointerType *PT = cast<PointerType>(CS.getCalledValue()->getType());
FunctionType *FTy = cast<FunctionType>(PT->getElementType());
bool isVarArg = FTy->isVarArg();
// Don't know how to handle Win64 varargs yet. Nothing special needed for
// x86-32. Special handling for x86-64 is implemented.
if (isVarArg && Subtarget->isTargetWin64())
return false;
// Fast-isel doesn't know about callee-pop yet.
if (X86::isCalleePop(CC, Subtarget->is64Bit(), isVarArg,
TM.Options.GuaranteedTailCallOpt))
return false;
// Check whether the function can return without sret-demotion.
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(I->getType(), CS.getAttributes().getRetAttributes(),
Outs, TLI);
bool CanLowerReturn = TLI.CanLowerReturn(CS.getCallingConv(),
*FuncInfo.MF, FTy->isVarArg(),
Outs, FTy->getContext());
if (!CanLowerReturn)
return false;
// Materialize callee address in a register. FIXME: GV address can be
// handled with a CALLpcrel32 instead.
X86AddressMode CalleeAM;
if (!X86SelectCallAddress(Callee, CalleeAM))
return false;
unsigned CalleeOp = 0;
const GlobalValue *GV = 0;
if (CalleeAM.GV != 0) {
GV = CalleeAM.GV;
} else if (CalleeAM.Base.Reg != 0) {
CalleeOp = CalleeAM.Base.Reg;
} else
return false;
// Deal with call operands first.
SmallVector<const Value *, 8> ArgVals;
SmallVector<unsigned, 8> Args;
SmallVector<MVT, 8> ArgVTs;
SmallVector<ISD::ArgFlagsTy, 8> ArgFlags;
unsigned arg_size = CS.arg_size();
Args.reserve(arg_size);
ArgVals.reserve(arg_size);
ArgVTs.reserve(arg_size);
ArgFlags.reserve(arg_size);
for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
i != e; ++i) {
// If we're lowering a mem intrinsic instead of a regular call, skip the
// last two arguments, which should not passed to the underlying functions.
if (MemIntName && e-i <= 2)
break;
Value *ArgVal = *i;
ISD::ArgFlagsTy Flags;
unsigned AttrInd = i - CS.arg_begin() + 1;
if (CS.paramHasAttr(AttrInd, Attributes::SExt))
Flags.setSExt();
if (CS.paramHasAttr(AttrInd, Attributes::ZExt))
Flags.setZExt();
if (CS.paramHasAttr(AttrInd, Attributes::ByVal)) {
PointerType *Ty = cast<PointerType>(ArgVal->getType());
Type *ElementTy = Ty->getElementType();
unsigned FrameSize = TD.getTypeAllocSize(ElementTy);
unsigned FrameAlign = CS.getParamAlignment(AttrInd);
if (!FrameAlign)
FrameAlign = TLI.getByValTypeAlignment(ElementTy);
Flags.setByVal();
Flags.setByValSize(FrameSize);
Flags.setByValAlign(FrameAlign);
if (!IsMemcpySmall(FrameSize))
return false;
}
if (CS.paramHasAttr(AttrInd, Attributes::InReg))
Flags.setInReg();
if (CS.paramHasAttr(AttrInd, Attributes::Nest))
Flags.setNest();
// If this is an i1/i8/i16 argument, promote to i32 to avoid an extra
// instruction. This is safe because it is common to all fastisel supported
// calling conventions on x86.
if (ConstantInt *CI = dyn_cast<ConstantInt>(ArgVal)) {
if (CI->getBitWidth() == 1 || CI->getBitWidth() == 8 ||
CI->getBitWidth() == 16) {
if (Flags.isSExt())
ArgVal = ConstantExpr::getSExt(CI,Type::getInt32Ty(CI->getContext()));
else
ArgVal = ConstantExpr::getZExt(CI,Type::getInt32Ty(CI->getContext()));
}
}
unsigned ArgReg;
// Passing bools around ends up doing a trunc to i1 and passing it.
// Codegen this as an argument + "and 1".
if (ArgVal->getType()->isIntegerTy(1) && isa<TruncInst>(ArgVal) &&
cast<TruncInst>(ArgVal)->getParent() == I->getParent() &&
ArgVal->hasOneUse()) {
ArgVal = cast<TruncInst>(ArgVal)->getOperand(0);
ArgReg = getRegForValue(ArgVal);
if (ArgReg == 0) return false;
MVT ArgVT;
if (!isTypeLegal(ArgVal->getType(), ArgVT)) return false;
ArgReg = FastEmit_ri(ArgVT, ArgVT, ISD::AND, ArgReg,
ArgVal->hasOneUse(), 1);
} else {
ArgReg = getRegForValue(ArgVal);
}
if (ArgReg == 0) return false;
Type *ArgTy = ArgVal->getType();
MVT ArgVT;
if (!isTypeLegal(ArgTy, ArgVT))
return false;
if (ArgVT == MVT::x86mmx)
return false;
unsigned OriginalAlignment = TD.getABITypeAlignment(ArgTy);
Flags.setOrigAlign(OriginalAlignment);
Args.push_back(ArgReg);
ArgVals.push_back(ArgVal);
ArgVTs.push_back(ArgVT);
ArgFlags.push_back(Flags);
}
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, isVarArg, *FuncInfo.MF, TM, ArgLocs,
I->getParent()->getContext());
// Allocate shadow area for Win64
if (Subtarget->isTargetWin64())
CCInfo.AllocateStack(32, 8);
CCInfo.AnalyzeCallOperands(ArgVTs, ArgFlags, CC_X86);
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = CCInfo.getNextStackOffset();
// Issue CALLSEQ_START
unsigned AdjStackDown = TII.getCallFrameSetupOpcode();
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(AdjStackDown))
.addImm(NumBytes);
// Process argument: walk the register/memloc assignments, inserting
// copies / loads.
SmallVector<unsigned, 4> RegArgs;
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
unsigned Arg = Args[VA.getValNo()];
EVT ArgVT = ArgVTs[VA.getValNo()];
// Promote the value if needed.
switch (VA.getLocInfo()) {
case CCValAssign::Full: break;
case CCValAssign::SExt: {
assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
"Unexpected extend");
bool Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
assert(Emitted && "Failed to emit a sext!"); (void)Emitted;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::ZExt: {
assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
"Unexpected extend");
bool Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
assert(Emitted && "Failed to emit a zext!"); (void)Emitted;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::AExt: {
assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
"Unexpected extend");
bool Emitted = X86FastEmitExtend(ISD::ANY_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
if (!Emitted)
Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
if (!Emitted)
Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
assert(Emitted && "Failed to emit a aext!"); (void)Emitted;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::BCvt: {
unsigned BC = FastEmit_r(ArgVT.getSimpleVT(), VA.getLocVT(),
ISD::BITCAST, Arg, /*TODO: Kill=*/false);
assert(BC != 0 && "Failed to emit a bitcast!");
Arg = BC;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::VExt:
// VExt has not been implemented, so this should be impossible to reach
// for now. However, fallback to Selection DAG isel once implemented.
return false;
case CCValAssign::Indirect:
// FIXME: Indirect doesn't need extending, but fast-isel doesn't fully
// support this.
return false;
}
if (VA.isRegLoc()) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
VA.getLocReg()).addReg(Arg);
RegArgs.push_back(VA.getLocReg());
} else {
unsigned LocMemOffset = VA.getLocMemOffset();
X86AddressMode AM;
AM.Base.Reg = RegInfo->getStackRegister();
AM.Disp = LocMemOffset;
const Value *ArgVal = ArgVals[VA.getValNo()];
ISD::ArgFlagsTy Flags = ArgFlags[VA.getValNo()];
if (Flags.isByVal()) {
X86AddressMode SrcAM;
SrcAM.Base.Reg = Arg;
bool Res = TryEmitSmallMemcpy(AM, SrcAM, Flags.getByValSize());
assert(Res && "memcpy length already checked!"); (void)Res;
} else if (isa<ConstantInt>(ArgVal) || isa<ConstantPointerNull>(ArgVal)) {
// If this is a really simple value, emit this with the Value* version
// of X86FastEmitStore. If it isn't simple, we don't want to do this,
// as it can cause us to reevaluate the argument.
if (!X86FastEmitStore(ArgVT, ArgVal, AM))
return false;
} else {
if (!X86FastEmitStore(ArgVT, Arg, AM))
return false;
}
}
}
// ELF / PIC requires GOT in the EBX register before function calls via PLT
// GOT pointer.
if (Subtarget->isPICStyleGOT()) {
unsigned Base = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
X86::EBX).addReg(Base);
}
if (Subtarget->is64Bit() && isVarArg && !Subtarget->isTargetWin64()) {
// Count the number of XMM registers allocated.
static const uint16_t XMMArgRegs[] = {
X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3,
X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7
};
unsigned NumXMMRegs = CCInfo.getFirstUnallocated(XMMArgRegs, 8);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::MOV8ri),
X86::AL).addImm(NumXMMRegs);
}
// Issue the call.
MachineInstrBuilder MIB;
if (CalleeOp) {
// Register-indirect call.
unsigned CallOpc;
if (Subtarget->is64Bit())
CallOpc = X86::CALL64r;
else
CallOpc = X86::CALL32r;
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CallOpc))
.addReg(CalleeOp);
} else {
// Direct call.
assert(GV && "Not a direct call");
unsigned CallOpc;
if (Subtarget->is64Bit())
CallOpc = X86::CALL64pcrel32;
else
CallOpc = X86::CALLpcrel32;
// See if we need any target-specific flags on the GV operand.
unsigned char OpFlags = 0;
// On ELF targets, in both X86-64 and X86-32 mode, direct calls to
// external symbols most go through the PLT in PIC mode. If the symbol
// has hidden or protected visibility, or if it is static or local, then
// we don't need to use the PLT - we can directly call it.
if (Subtarget->isTargetELF() &&
TM.getRelocationModel() == Reloc::PIC_ &&
GV->hasDefaultVisibility() && !GV->hasLocalLinkage()) {
OpFlags = X86II::MO_PLT;
} else if (Subtarget->isPICStyleStubAny() &&
(GV->isDeclaration() || GV->isWeakForLinker()) &&
(!Subtarget->getTargetTriple().isMacOSX() ||
Subtarget->getTargetTriple().isMacOSXVersionLT(10, 5))) {
// PC-relative references to external symbols should go through $stub,
// unless we're building with the leopard linker or later, which
// automatically synthesizes these stubs.
OpFlags = X86II::MO_DARWIN_STUB;
}
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CallOpc));
if (MemIntName)
MIB.addExternalSymbol(MemIntName, OpFlags);
else
MIB.addGlobalAddress(GV, 0, OpFlags);
}
// Add a register mask with the call-preserved registers.
// Proper defs for return values will be added by setPhysRegsDeadExcept().
MIB.addRegMask(TRI.getCallPreservedMask(CS.getCallingConv()));
// Add an implicit use GOT pointer in EBX.
if (Subtarget->isPICStyleGOT())
MIB.addReg(X86::EBX, RegState::Implicit);
if (Subtarget->is64Bit() && isVarArg && !Subtarget->isTargetWin64())
MIB.addReg(X86::AL, RegState::Implicit);
// Add implicit physical register uses to the call.
for (unsigned i = 0, e = RegArgs.size(); i != e; ++i)
MIB.addReg(RegArgs[i], RegState::Implicit);
// Issue CALLSEQ_END
unsigned AdjStackUp = TII.getCallFrameDestroyOpcode();
const unsigned NumBytesCallee = computeBytesPoppedByCallee(*Subtarget, CS);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(AdjStackUp))
.addImm(NumBytes).addImm(NumBytesCallee);
// Build info for return calling conv lowering code.
// FIXME: This is practically a copy-paste from TargetLowering::LowerCallTo.
SmallVector<ISD::InputArg, 32> Ins;
SmallVector<EVT, 4> RetTys;
ComputeValueVTs(TLI, I->getType(), RetTys);
for (unsigned i = 0, e = RetTys.size(); i != e; ++i) {
EVT VT = RetTys[i];
EVT RegisterVT = TLI.getRegisterType(I->getParent()->getContext(), VT);
unsigned NumRegs = TLI.getNumRegisters(I->getParent()->getContext(), VT);
for (unsigned j = 0; j != NumRegs; ++j) {
ISD::InputArg MyFlags;
MyFlags.VT = RegisterVT.getSimpleVT();
MyFlags.Used = !CS.getInstruction()->use_empty();
if (CS.paramHasAttr(0, Attributes::SExt))
MyFlags.Flags.setSExt();
if (CS.paramHasAttr(0, Attributes::ZExt))
MyFlags.Flags.setZExt();
if (CS.paramHasAttr(0, Attributes::InReg))
MyFlags.Flags.setInReg();
Ins.push_back(MyFlags);
}
}
// Now handle call return values.
SmallVector<unsigned, 4> UsedRegs;
SmallVector<CCValAssign, 16> RVLocs;
CCState CCRetInfo(CC, false, *FuncInfo.MF, TM, RVLocs,
I->getParent()->getContext());
unsigned ResultReg = FuncInfo.CreateRegs(I->getType());
CCRetInfo.AnalyzeCallResult(Ins, RetCC_X86);
for (unsigned i = 0; i != RVLocs.size(); ++i) {
EVT CopyVT = RVLocs[i].getValVT();
unsigned CopyReg = ResultReg + i;
// If this is a call to a function that returns an fp value on the x87 fp
// stack, but where we prefer to use the value in xmm registers, copy it
// out as F80 and use a truncate to move it from fp stack reg to xmm reg.
if ((RVLocs[i].getLocReg() == X86::ST0 ||
RVLocs[i].getLocReg() == X86::ST1)) {
if (isScalarFPTypeInSSEReg(RVLocs[i].getValVT())) {
CopyVT = MVT::f80;
CopyReg = createResultReg(&X86::RFP80RegClass);
}
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::FpPOP_RETVAL),
CopyReg);
} else {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
CopyReg).addReg(RVLocs[i].getLocReg());
UsedRegs.push_back(RVLocs[i].getLocReg());
}
if (CopyVT != RVLocs[i].getValVT()) {
// Round the F80 the right size, which also moves to the appropriate xmm
// register. This is accomplished by storing the F80 value in memory and
// then loading it back. Ewww...
EVT ResVT = RVLocs[i].getValVT();
unsigned Opc = ResVT == MVT::f32 ? X86::ST_Fp80m32 : X86::ST_Fp80m64;
unsigned MemSize = ResVT.getSizeInBits()/8;
int FI = MFI.CreateStackObject(MemSize, MemSize, false);
addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(Opc)), FI)
.addReg(CopyReg);
Opc = ResVT == MVT::f32 ? X86::MOVSSrm : X86::MOVSDrm;
addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(Opc), ResultReg + i), FI);
}
}
if (RVLocs.size())
UpdateValueMap(I, ResultReg, RVLocs.size());
// Set all unused physreg defs as dead.
static_cast<MachineInstr *>(MIB)->setPhysRegsDeadExcept(UsedRegs, TRI);
return true;
}
bool
X86FastISel::TargetSelectInstruction(const Instruction *I) {
switch (I->getOpcode()) {
default: break;
case Instruction::Load:
return X86SelectLoad(I);
case Instruction::Store:
return X86SelectStore(I);
case Instruction::Ret:
return X86SelectRet(I);
case Instruction::ICmp:
case Instruction::FCmp:
return X86SelectCmp(I);
case Instruction::ZExt:
return X86SelectZExt(I);
case Instruction::Br:
return X86SelectBranch(I);
case Instruction::Call:
return X86SelectCall(I);
case Instruction::LShr:
case Instruction::AShr:
case Instruction::Shl:
return X86SelectShift(I);
case Instruction::Select:
return X86SelectSelect(I);
case Instruction::Trunc:
return X86SelectTrunc(I);
case Instruction::FPExt:
return X86SelectFPExt(I);
case Instruction::FPTrunc:
return X86SelectFPTrunc(I);
case Instruction::IntToPtr: // Deliberate fall-through.
case Instruction::PtrToInt: {
EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
EVT DstVT = TLI.getValueType(I->getType());
if (DstVT.bitsGT(SrcVT))
return X86SelectZExt(I);
if (DstVT.bitsLT(SrcVT))
return X86SelectTrunc(I);
unsigned Reg = getRegForValue(I->getOperand(0));
if (Reg == 0) return false;
UpdateValueMap(I, Reg);
return true;
}
}
return false;
}
unsigned X86FastISel::TargetMaterializeConstant(const Constant *C) {
MVT VT;
if (!isTypeLegal(C->getType(), VT))
return 0;
// Can't handle alternate code models yet.
if (TM.getCodeModel() != CodeModel::Small)
return 0;
// Get opcode and regclass of the output for the given load instruction.
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
switch (VT.SimpleTy) {
default: return 0;
case MVT::i8:
Opc = X86::MOV8rm;
RC = &X86::GR8RegClass;
break;
case MVT::i16:
Opc = X86::MOV16rm;
RC = &X86::GR16RegClass;
break;
case MVT::i32:
Opc = X86::MOV32rm;
RC = &X86::GR32RegClass;
break;
case MVT::i64:
// Must be in x86-64 mode.
Opc = X86::MOV64rm;
RC = &X86::GR64RegClass;
break;
case MVT::f32:
if (X86ScalarSSEf32) {
Opc = Subtarget->hasAVX() ? X86::VMOVSSrm : X86::MOVSSrm;
RC = &X86::FR32RegClass;
} else {
Opc = X86::LD_Fp32m;
RC = &X86::RFP32RegClass;
}
break;
case MVT::f64:
if (X86ScalarSSEf64) {
Opc = Subtarget->hasAVX() ? X86::VMOVSDrm : X86::MOVSDrm;
RC = &X86::FR64RegClass;
} else {
Opc = X86::LD_Fp64m;
RC = &X86::RFP64RegClass;
}
break;
case MVT::f80:
// No f80 support yet.
return 0;
}
// Materialize addresses with LEA instructions.
if (isa<GlobalValue>(C)) {
X86AddressMode AM;
if (X86SelectAddress(C, AM)) {
// If the expression is just a basereg, then we're done, otherwise we need
// to emit an LEA.
if (AM.BaseType == X86AddressMode::RegBase &&
AM.IndexReg == 0 && AM.Disp == 0 && AM.GV == 0)
return AM.Base.Reg;
Opc = TLI.getPointerTy() == MVT::i32 ? X86::LEA32r : X86::LEA64r;
unsigned ResultReg = createResultReg(RC);
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(Opc), ResultReg), AM);
return ResultReg;
}
return 0;
}
// MachineConstantPool wants an explicit alignment.
unsigned Align = TD.getPrefTypeAlignment(C->getType());
if (Align == 0) {
// Alignment of vector types. FIXME!
Align = TD.getTypeAllocSize(C->getType());
}
// x86-32 PIC requires a PIC base register for constant pools.
unsigned PICBase = 0;
unsigned char OpFlag = 0;
if (Subtarget->isPICStyleStubPIC()) { // Not dynamic-no-pic
OpFlag = X86II::MO_PIC_BASE_OFFSET;
PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
} else if (Subtarget->isPICStyleGOT()) {
OpFlag = X86II::MO_GOTOFF;
PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
} else if (Subtarget->isPICStyleRIPRel() &&
TM.getCodeModel() == CodeModel::Small) {
PICBase = X86::RIP;
}
// Create the load from the constant pool.
unsigned MCPOffset = MCP.getConstantPoolIndex(C, Align);
unsigned ResultReg = createResultReg(RC);
addConstantPoolReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(Opc), ResultReg),
MCPOffset, PICBase, OpFlag);
return ResultReg;
}
unsigned X86FastISel::TargetMaterializeAlloca(const AllocaInst *C) {
// Fail on dynamic allocas. At this point, getRegForValue has already
// checked its CSE maps, so if we're here trying to handle a dynamic
// alloca, we're not going to succeed. X86SelectAddress has a
// check for dynamic allocas, because it's called directly from
// various places, but TargetMaterializeAlloca also needs a check
// in order to avoid recursion between getRegForValue,
// X86SelectAddrss, and TargetMaterializeAlloca.
if (!FuncInfo.StaticAllocaMap.count(C))
return 0;
X86AddressMode AM;
if (!X86SelectAddress(C, AM))
return 0;
unsigned Opc = Subtarget->is64Bit() ? X86::LEA64r : X86::LEA32r;
const TargetRegisterClass* RC = TLI.getRegClassFor(TLI.getPointerTy());
unsigned ResultReg = createResultReg(RC);
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(Opc), ResultReg), AM);
return ResultReg;
}
unsigned X86FastISel::TargetMaterializeFloatZero(const ConstantFP *CF) {
MVT VT;
if (!isTypeLegal(CF->getType(), VT))
return 0;
// Get opcode and regclass for the given zero.
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
switch (VT.SimpleTy) {
default: return 0;
case MVT::f32:
if (X86ScalarSSEf32) {
Opc = X86::FsFLD0SS;
RC = &X86::FR32RegClass;
} else {
Opc = X86::LD_Fp032;
RC = &X86::RFP32RegClass;
}
break;
case MVT::f64:
if (X86ScalarSSEf64) {
Opc = X86::FsFLD0SD;
RC = &X86::FR64RegClass;
} else {
Opc = X86::LD_Fp064;
RC = &X86::RFP64RegClass;
}
break;
case MVT::f80:
// No f80 support yet.
return 0;
}
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc), ResultReg);
return ResultReg;
}
/// TryToFoldLoad - The specified machine instr operand is a vreg, and that
/// vreg is being provided by the specified load instruction. If possible,
/// try to fold the load as an operand to the instruction, returning true if
/// possible.
bool X86FastISel::TryToFoldLoad(MachineInstr *MI, unsigned OpNo,
const LoadInst *LI) {
X86AddressMode AM;
if (!X86SelectAddress(LI->getOperand(0), AM))
return false;
const X86InstrInfo &XII = (const X86InstrInfo&)TII;
unsigned Size = TD.getTypeAllocSize(LI->getType());
unsigned Alignment = LI->getAlignment();
SmallVector<MachineOperand, 8> AddrOps;
AM.getFullAddress(AddrOps);
MachineInstr *Result =
XII.foldMemoryOperandImpl(*FuncInfo.MF, MI, OpNo, AddrOps, Size, Alignment);
if (Result == 0) return false;
FuncInfo.MBB->insert(FuncInfo.InsertPt, Result);
MI->eraseFromParent();
return true;
}
namespace llvm {
FastISel *X86::createFastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo) {
return new X86FastISel(funcInfo, libInfo);
}
}
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