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llvm-6502/lib/Target/X86/X86ISelPattern.cpp
Chris Lattner bf52d49f36 Fix a crash compiling 134.perl. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19711 91177308-0d34-0410-b5e6-96231b3b80d8
2005-01-20 16:50:16 +00:00

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//===-- X86ISelPattern.cpp - A pattern matching inst selector for X86 -----===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a pattern matching instruction selector for X86.
//
//===----------------------------------------------------------------------===//
#include "X86.h"
#include "X86InstrBuilder.h"
#include "X86RegisterInfo.h"
#include "llvm/Constants.h" // FIXME: REMOVE
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineConstantPool.h" // FIXME: REMOVE
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/ADT/Statistic.h"
#include <set>
#include <algorithm>
using namespace llvm;
//===----------------------------------------------------------------------===//
// X86TargetLowering - X86 Implementation of the TargetLowering interface
namespace {
class X86TargetLowering : public TargetLowering {
int VarArgsFrameIndex; // FrameIndex for start of varargs area.
int ReturnAddrIndex; // FrameIndex for return slot.
public:
X86TargetLowering(TargetMachine &TM) : TargetLowering(TM) {
// Set up the TargetLowering object.
// X86 is wierd, it always uses i8 for shift amounts and setcc results.
setShiftAmountType(MVT::i8);
setSetCCResultType(MVT::i8);
setShiftAmountFlavor(Mask); // shl X, 32 == shl X, 0
// Set up the register classes.
addRegisterClass(MVT::i8, X86::R8RegisterClass);
addRegisterClass(MVT::i16, X86::R16RegisterClass);
addRegisterClass(MVT::i32, X86::R32RegisterClass);
addRegisterClass(MVT::f64, X86::RFPRegisterClass);
// FIXME: Eliminate these two classes when legalize can handle promotions
// well.
/**/ addRegisterClass(MVT::i1, X86::R8RegisterClass);
setOperationAction(ISD::MEMMOVE , MVT::Other, Expand);
setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16 , Expand);
setOperationAction(ISD::ZERO_EXTEND_INREG, MVT::i16 , Expand);
setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1 , Expand);
setOperationAction(ISD::ZERO_EXTEND_INREG, MVT::i1 , Expand);
setOperationAction(ISD::FP_ROUND_INREG , MVT::f32 , Expand);
setOperationAction(ISD::SEXTLOAD , MVT::i1 , Expand);
setOperationAction(ISD::SREM , MVT::f64 , Expand);
// These should be promoted to a larger select which is supported.
/**/ setOperationAction(ISD::SELECT , MVT::i1 , Promote);
setOperationAction(ISD::SELECT , MVT::i8 , Promote);
computeRegisterProperties();
addLegalFPImmediate(+0.0); // FLD0
addLegalFPImmediate(+1.0); // FLD1
addLegalFPImmediate(-0.0); // FLD0/FCHS
addLegalFPImmediate(-1.0); // FLD1/FCHS
}
/// LowerArguments - This hook must be implemented to indicate how we should
/// lower the arguments for the specified function, into the specified DAG.
virtual std::vector<SDOperand>
LowerArguments(Function &F, SelectionDAG &DAG);
/// LowerCallTo - This hook lowers an abstract call to a function into an
/// actual call.
virtual std::pair<SDOperand, SDOperand>
LowerCallTo(SDOperand Chain, const Type *RetTy, SDOperand Callee,
ArgListTy &Args, SelectionDAG &DAG);
virtual std::pair<SDOperand, SDOperand>
LowerVAStart(SDOperand Chain, SelectionDAG &DAG);
virtual std::pair<SDOperand,SDOperand>
LowerVAArgNext(bool isVANext, SDOperand Chain, SDOperand VAList,
const Type *ArgTy, SelectionDAG &DAG);
virtual std::pair<SDOperand, SDOperand>
LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
SelectionDAG &DAG);
};
}
std::vector<SDOperand>
X86TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
std::vector<SDOperand> ArgValues;
// Add DAG nodes to load the arguments... On entry to a function on the X86,
// the stack frame looks like this:
//
// [ESP] -- return address
// [ESP + 4] -- first argument (leftmost lexically)
// [ESP + 8] -- second argument, if first argument is four bytes in size
// ...
//
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot
for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I) {
MVT::ValueType ObjectVT = getValueType(I->getType());
unsigned ArgIncrement = 4;
unsigned ObjSize;
switch (ObjectVT) {
default: assert(0 && "Unhandled argument type!");
case MVT::i1:
case MVT::i8: ObjSize = 1; break;
case MVT::i16: ObjSize = 2; break;
case MVT::i32: ObjSize = 4; break;
case MVT::i64: ObjSize = ArgIncrement = 8; break;
case MVT::f32: ObjSize = 4; break;
case MVT::f64: ObjSize = ArgIncrement = 8; break;
}
// Create the frame index object for this incoming parameter...
int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
// Create the SelectionDAG nodes corresponding to a load from this parameter
SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
// Don't codegen dead arguments. FIXME: remove this check when we can nuke
// dead loads.
SDOperand ArgValue;
if (!I->use_empty())
ArgValue = DAG.getLoad(ObjectVT, DAG.getEntryNode(), FIN);
else {
if (MVT::isInteger(ObjectVT))
ArgValue = DAG.getConstant(0, ObjectVT);
else
ArgValue = DAG.getConstantFP(0, ObjectVT);
}
ArgValues.push_back(ArgValue);
ArgOffset += ArgIncrement; // Move on to the next argument...
}
// If the function takes variable number of arguments, make a frame index for
// the start of the first vararg value... for expansion of llvm.va_start.
if (F.isVarArg())
VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
ReturnAddrIndex = 0; // No return address slot generated yet.
return ArgValues;
}
std::pair<SDOperand, SDOperand>
X86TargetLowering::LowerCallTo(SDOperand Chain,
const Type *RetTy, SDOperand Callee,
ArgListTy &Args, SelectionDAG &DAG) {
// Count how many bytes are to be pushed on the stack.
unsigned NumBytes = 0;
if (Args.empty()) {
// Save zero bytes.
Chain = DAG.getNode(ISD::ADJCALLSTACKDOWN, MVT::Other, Chain,
DAG.getConstant(0, getPointerTy()));
} else {
for (unsigned i = 0, e = Args.size(); i != e; ++i)
switch (getValueType(Args[i].second)) {
default: assert(0 && "Unknown value type!");
case MVT::i1:
case MVT::i8:
case MVT::i16:
case MVT::i32:
case MVT::f32:
NumBytes += 4;
break;
case MVT::i64:
case MVT::f64:
NumBytes += 8;
break;
}
Chain = DAG.getNode(ISD::ADJCALLSTACKDOWN, MVT::Other, Chain,
DAG.getConstant(NumBytes, getPointerTy()));
// Arguments go on the stack in reverse order, as specified by the ABI.
unsigned ArgOffset = 0;
SDOperand StackPtr = DAG.getCopyFromReg(X86::ESP, MVT::i32,
DAG.getEntryNode());
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
unsigned ArgReg;
SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
switch (getValueType(Args[i].second)) {
default: assert(0 && "Unexpected ValueType for argument!");
case MVT::i1:
case MVT::i8:
case MVT::i16:
// Promote the integer to 32 bits. If the input type is signed use a
// sign extend, otherwise use a zero extend.
if (Args[i].second->isSigned())
Args[i].first =DAG.getNode(ISD::SIGN_EXTEND, MVT::i32, Args[i].first);
else
Args[i].first =DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Args[i].first);
// FALL THROUGH
case MVT::i32:
case MVT::f32:
// FIXME: Note that all of these stores are independent of each other.
Chain = DAG.getNode(ISD::STORE, MVT::Other, Chain,
Args[i].first, PtrOff);
ArgOffset += 4;
break;
case MVT::i64:
case MVT::f64:
// FIXME: Note that all of these stores are independent of each other.
Chain = DAG.getNode(ISD::STORE, MVT::Other, Chain,
Args[i].first, PtrOff);
ArgOffset += 8;
break;
}
}
}
std::vector<MVT::ValueType> RetVals;
MVT::ValueType RetTyVT = getValueType(RetTy);
if (RetTyVT != MVT::isVoid)
RetVals.push_back(RetTyVT);
RetVals.push_back(MVT::Other);
SDOperand TheCall = SDOperand(DAG.getCall(RetVals, Chain, Callee), 0);
Chain = TheCall.getValue(RetTyVT != MVT::isVoid);
Chain = DAG.getNode(ISD::ADJCALLSTACKUP, MVT::Other, Chain,
DAG.getConstant(NumBytes, getPointerTy()));
return std::make_pair(TheCall, Chain);
}
std::pair<SDOperand, SDOperand>
X86TargetLowering::LowerVAStart(SDOperand Chain, SelectionDAG &DAG) {
// vastart just returns the address of the VarArgsFrameIndex slot.
return std::make_pair(DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32), Chain);
}
std::pair<SDOperand,SDOperand> X86TargetLowering::
LowerVAArgNext(bool isVANext, SDOperand Chain, SDOperand VAList,
const Type *ArgTy, SelectionDAG &DAG) {
MVT::ValueType ArgVT = getValueType(ArgTy);
SDOperand Result;
if (!isVANext) {
Result = DAG.getLoad(ArgVT, DAG.getEntryNode(), VAList);
} else {
unsigned Amt;
if (ArgVT == MVT::i32)
Amt = 4;
else {
assert((ArgVT == MVT::i64 || ArgVT == MVT::f64) &&
"Other types should have been promoted for varargs!");
Amt = 8;
}
Result = DAG.getNode(ISD::ADD, VAList.getValueType(), VAList,
DAG.getConstant(Amt, VAList.getValueType()));
}
return std::make_pair(Result, Chain);
}
std::pair<SDOperand, SDOperand> X86TargetLowering::
LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth,
SelectionDAG &DAG) {
SDOperand Result;
if (Depth) // Depths > 0 not supported yet!
Result = DAG.getConstant(0, getPointerTy());
else {
if (ReturnAddrIndex == 0) {
// Set up a frame object for the return address.
MachineFunction &MF = DAG.getMachineFunction();
ReturnAddrIndex = MF.getFrameInfo()->CreateFixedObject(4, -4);
}
SDOperand RetAddrFI = DAG.getFrameIndex(ReturnAddrIndex, MVT::i32);
if (!isFrameAddress)
// Just load the return address
Result = DAG.getLoad(MVT::i32, DAG.getEntryNode(), RetAddrFI);
else
Result = DAG.getNode(ISD::SUB, MVT::i32, RetAddrFI,
DAG.getConstant(4, MVT::i32));
}
return std::make_pair(Result, Chain);
}
namespace {
/// X86ISelAddressMode - This corresponds to X86AddressMode, but uses
/// SDOperand's instead of register numbers for the leaves of the matched
/// tree.
struct X86ISelAddressMode {
enum {
RegBase,
FrameIndexBase,
} BaseType;
struct { // This is really a union, discriminated by BaseType!
SDOperand Reg;
int FrameIndex;
} Base;
unsigned Scale;
SDOperand IndexReg;
unsigned Disp;
GlobalValue *GV;
X86ISelAddressMode()
: BaseType(RegBase), Scale(1), IndexReg(), Disp(), GV(0) {
}
};
}
namespace {
Statistic<>
NumFPKill("x86-codegen", "Number of FP_REG_KILL instructions added");
//===--------------------------------------------------------------------===//
/// ISel - X86 specific code to select X86 machine instructions for
/// SelectionDAG operations.
///
class ISel : public SelectionDAGISel {
/// ContainsFPCode - Every instruction we select that uses or defines a FP
/// register should set this to true.
bool ContainsFPCode;
/// X86Lowering - This object fully describes how to lower LLVM code to an
/// X86-specific SelectionDAG.
X86TargetLowering X86Lowering;
/// RegPressureMap - This keeps an approximate count of the number of
/// registers required to evaluate each node in the graph.
std::map<SDNode*, unsigned> RegPressureMap;
/// ExprMap - As shared expressions are codegen'd, we keep track of which
/// vreg the value is produced in, so we only emit one copy of each compiled
/// tree.
std::map<SDOperand, unsigned> ExprMap;
public:
ISel(TargetMachine &TM) : SelectionDAGISel(X86Lowering), X86Lowering(TM) {
}
unsigned getRegPressure(SDOperand O) {
return RegPressureMap[O.Val];
}
unsigned ComputeRegPressure(SDOperand O);
/// InstructionSelectBasicBlock - This callback is invoked by
/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
bool isFoldableLoad(SDOperand Op, SDOperand OtherOp);
void EmitFoldedLoad(SDOperand Op, X86AddressMode &AM);
bool TryToFoldLoadOpStore(SDNode *Node);
bool EmitOrOpOp(SDOperand Op1, SDOperand Op2, unsigned DestReg);
void EmitCMP(SDOperand LHS, SDOperand RHS, bool isOnlyUse);
bool EmitBranchCC(MachineBasicBlock *Dest, SDOperand Chain, SDOperand Cond);
void EmitSelectCC(SDOperand Cond, MVT::ValueType SVT,
unsigned RTrue, unsigned RFalse, unsigned RDest);
unsigned SelectExpr(SDOperand N);
X86AddressMode SelectAddrExprs(const X86ISelAddressMode &IAM);
bool MatchAddress(SDOperand N, X86ISelAddressMode &AM);
void SelectAddress(SDOperand N, X86AddressMode &AM);
void Select(SDOperand N);
};
}
/// InstructionSelectBasicBlock - This callback is invoked by SelectionDAGISel
/// when it has created a SelectionDAG for us to codegen.
void ISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
// While we're doing this, keep track of whether we see any FP code for
// FP_REG_KILL insertion.
ContainsFPCode = false;
// Scan the PHI nodes that already are inserted into this basic block. If any
// of them is a PHI of a floating point value, we need to insert an
// FP_REG_KILL.
SSARegMap *RegMap = BB->getParent()->getSSARegMap();
for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end();
I != E; ++I) {
assert(I->getOpcode() == X86::PHI &&
"Isn't just PHI nodes?");
if (RegMap->getRegClass(I->getOperand(0).getReg()) ==
X86::RFPRegisterClass) {
ContainsFPCode = true;
break;
}
}
// Compute the RegPressureMap, which is an approximation for the number of
// registers required to compute each node.
ComputeRegPressure(DAG.getRoot());
// Codegen the basic block.
Select(DAG.getRoot());
// Finally, look at all of the successors of this block. If any contain a PHI
// node of FP type, we need to insert an FP_REG_KILL in this block.
for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
E = BB->succ_end(); SI != E && !ContainsFPCode; ++SI)
for (MachineBasicBlock::iterator I = (*SI)->begin(), E = (*SI)->end();
I != E && I->getOpcode() == X86::PHI; ++I) {
if (RegMap->getRegClass(I->getOperand(0).getReg()) ==
X86::RFPRegisterClass) {
ContainsFPCode = true;
break;
}
}
// Insert FP_REG_KILL instructions into basic blocks that need them. This
// only occurs due to the floating point stackifier not being aggressive
// enough to handle arbitrary global stackification.
//
// Currently we insert an FP_REG_KILL instruction into each block that uses or
// defines a floating point virtual register.
//
// When the global register allocators (like linear scan) finally update live
// variable analysis, we can keep floating point values in registers across
// basic blocks. This will be a huge win, but we are waiting on the global
// allocators before we can do this.
//
if (ContainsFPCode && BB->succ_size()) {
BuildMI(*BB, BB->getFirstTerminator(), X86::FP_REG_KILL, 0);
++NumFPKill;
}
// Clear state used for selection.
ExprMap.clear();
RegPressureMap.clear();
}
// ComputeRegPressure - Compute the RegPressureMap, which is an approximation
// for the number of registers required to compute each node. This is basically
// computing a generalized form of the Sethi-Ullman number for each node.
unsigned ISel::ComputeRegPressure(SDOperand O) {
SDNode *N = O.Val;
unsigned &Result = RegPressureMap[N];
if (Result) return Result;
// FIXME: Should operations like CALL (which clobber lots o regs) have a
// higher fixed cost??
if (N->getNumOperands() == 0) {
Result = 1;
} else {
unsigned MaxRegUse = 0;
unsigned NumExtraMaxRegUsers = 0;
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
unsigned Regs;
if (N->getOperand(i).getOpcode() == ISD::Constant)
Regs = 0;
else
Regs = ComputeRegPressure(N->getOperand(i));
if (Regs > MaxRegUse) {
MaxRegUse = Regs;
NumExtraMaxRegUsers = 0;
} else if (Regs == MaxRegUse &&
N->getOperand(i).getValueType() != MVT::Other) {
++NumExtraMaxRegUsers;
}
}
if (O.getOpcode() != ISD::TokenFactor)
Result = MaxRegUse+NumExtraMaxRegUsers;
else
Result = MaxRegUse == 1 ? 0 : MaxRegUse-1;
}
//std::cerr << " WEIGHT: " << Result << " "; N->dump(); std::cerr << "\n";
return Result;
}
/// NodeTransitivelyUsesValue - Return true if N or any of its uses uses Op.
/// The DAG cannot have cycles in it, by definition, so the visited set is not
/// needed to prevent infinite loops. The DAG CAN, however, have unbounded
/// reuse, so it prevents exponential cases.
///
static bool NodeTransitivelyUsesValue(SDOperand N, SDOperand Op,
std::set<SDNode*> &Visited) {
if (N == Op) return true; // Found it.
SDNode *Node = N.Val;
if (Node->getNumOperands() == 0) return false; // Leaf?
if (!Visited.insert(Node).second) return false; // Already visited?
// Recurse for the first N-1 operands.
for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i)
if (NodeTransitivelyUsesValue(Node->getOperand(i), Op, Visited))
return true;
// Tail recurse for the last operand.
return NodeTransitivelyUsesValue(Node->getOperand(0), Op, Visited);
}
X86AddressMode ISel::SelectAddrExprs(const X86ISelAddressMode &IAM) {
X86AddressMode Result;
// If we need to emit two register operands, emit the one with the highest
// register pressure first.
if (IAM.BaseType == X86ISelAddressMode::RegBase &&
IAM.Base.Reg.Val && IAM.IndexReg.Val) {
bool EmitBaseThenIndex;
if (getRegPressure(IAM.Base.Reg) > getRegPressure(IAM.IndexReg)) {
std::set<SDNode*> Visited;
EmitBaseThenIndex = true;
// If Base ends up pointing to Index, we must emit index first. This is
// because of the way we fold loads, we may end up doing bad things with
// the folded add.
if (NodeTransitivelyUsesValue(IAM.Base.Reg, IAM.IndexReg, Visited))
EmitBaseThenIndex = false;
} else {
std::set<SDNode*> Visited;
EmitBaseThenIndex = false;
// If Base ends up pointing to Index, we must emit index first. This is
// because of the way we fold loads, we may end up doing bad things with
// the folded add.
if (NodeTransitivelyUsesValue(IAM.IndexReg, IAM.Base.Reg, Visited))
EmitBaseThenIndex = true;
}
if (EmitBaseThenIndex) {
Result.Base.Reg = SelectExpr(IAM.Base.Reg);
Result.IndexReg = SelectExpr(IAM.IndexReg);
} else {
Result.IndexReg = SelectExpr(IAM.IndexReg);
Result.Base.Reg = SelectExpr(IAM.Base.Reg);
}
} else if (IAM.BaseType == X86ISelAddressMode::RegBase && IAM.Base.Reg.Val) {
Result.Base.Reg = SelectExpr(IAM.Base.Reg);
} else if (IAM.IndexReg.Val) {
Result.IndexReg = SelectExpr(IAM.IndexReg);
}
switch (IAM.BaseType) {
case X86ISelAddressMode::RegBase:
Result.BaseType = X86AddressMode::RegBase;
break;
case X86ISelAddressMode::FrameIndexBase:
Result.BaseType = X86AddressMode::FrameIndexBase;
Result.Base.FrameIndex = IAM.Base.FrameIndex;
break;
default:
assert(0 && "Unknown base type!");
break;
}
Result.Scale = IAM.Scale;
Result.Disp = IAM.Disp;
Result.GV = IAM.GV;
return Result;
}
/// SelectAddress - Pattern match the maximal addressing mode for this node and
/// emit all of the leaf registers.
void ISel::SelectAddress(SDOperand N, X86AddressMode &AM) {
X86ISelAddressMode IAM;
MatchAddress(N, IAM);
AM = SelectAddrExprs(IAM);
}
/// MatchAddress - Add the specified node to the specified addressing mode,
/// returning true if it cannot be done. This just pattern matches for the
/// addressing mode, it does not cause any code to be emitted. For that, use
/// SelectAddress.
bool ISel::MatchAddress(SDOperand N, X86ISelAddressMode &AM) {
switch (N.getOpcode()) {
default: break;
case ISD::FrameIndex:
if (AM.BaseType == X86ISelAddressMode::RegBase && AM.Base.Reg.Val == 0) {
AM.BaseType = X86ISelAddressMode::FrameIndexBase;
AM.Base.FrameIndex = cast<FrameIndexSDNode>(N)->getIndex();
return false;
}
break;
case ISD::GlobalAddress:
if (AM.GV == 0) {
AM.GV = cast<GlobalAddressSDNode>(N)->getGlobal();
return false;
}
break;
case ISD::Constant:
AM.Disp += cast<ConstantSDNode>(N)->getValue();
return false;
case ISD::SHL:
// We might have folded the load into this shift, so don't regen the value
// if so.
if (ExprMap.count(N)) break;
if (AM.IndexReg.Val == 0 && AM.Scale == 1)
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1))) {
unsigned Val = CN->getValue();
if (Val == 1 || Val == 2 || Val == 3) {
AM.Scale = 1 << Val;
SDOperand ShVal = N.Val->getOperand(0);
// Okay, we know that we have a scale by now. However, if the scaled
// value is an add of something and a constant, we can fold the
// constant into the disp field here.
if (ShVal.Val->getOpcode() == ISD::ADD && ShVal.hasOneUse() &&
isa<ConstantSDNode>(ShVal.Val->getOperand(1))) {
AM.IndexReg = ShVal.Val->getOperand(0);
ConstantSDNode *AddVal =
cast<ConstantSDNode>(ShVal.Val->getOperand(1));
AM.Disp += AddVal->getValue() << Val;
} else {
AM.IndexReg = ShVal;
}
return false;
}
}
break;
case ISD::MUL:
// We might have folded the load into this mul, so don't regen the value if
// so.
if (ExprMap.count(N)) break;
// X*[3,5,9] -> X+X*[2,4,8]
if (AM.IndexReg.Val == 0 && AM.BaseType == X86ISelAddressMode::RegBase &&
AM.Base.Reg.Val == 0)
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.Val->getOperand(1)))
if (CN->getValue() == 3 || CN->getValue() == 5 || CN->getValue() == 9) {
AM.Scale = unsigned(CN->getValue())-1;
SDOperand MulVal = N.Val->getOperand(0);
SDOperand Reg;
// Okay, we know that we have a scale by now. However, if the scaled
// value is an add of something and a constant, we can fold the
// constant into the disp field here.
if (MulVal.Val->getOpcode() == ISD::ADD && MulVal.hasOneUse() &&
isa<ConstantSDNode>(MulVal.Val->getOperand(1))) {
Reg = MulVal.Val->getOperand(0);
ConstantSDNode *AddVal =
cast<ConstantSDNode>(MulVal.Val->getOperand(1));
AM.Disp += AddVal->getValue() * CN->getValue();
} else {
Reg = N.Val->getOperand(0);
}
AM.IndexReg = AM.Base.Reg = Reg;
return false;
}
break;
case ISD::ADD: {
// We might have folded the load into this mul, so don't regen the value if
// so.
if (ExprMap.count(N)) break;
X86ISelAddressMode Backup = AM;
if (!MatchAddress(N.Val->getOperand(0), AM) &&
!MatchAddress(N.Val->getOperand(1), AM))
return false;
AM = Backup;
if (!MatchAddress(N.Val->getOperand(1), AM) &&
!MatchAddress(N.Val->getOperand(0), AM))
return false;
AM = Backup;
break;
}
}
// Is the base register already occupied?
if (AM.BaseType != X86ISelAddressMode::RegBase || AM.Base.Reg.Val) {
// If so, check to see if the scale index register is set.
if (AM.IndexReg.Val == 0) {
AM.IndexReg = N;
AM.Scale = 1;
return false;
}
// Otherwise, we cannot select it.
return true;
}
// Default, generate it as a register.
AM.BaseType = X86ISelAddressMode::RegBase;
AM.Base.Reg = N;
return false;
}
/// Emit2SetCCsAndLogical - Emit the following sequence of instructions,
/// assuming that the temporary registers are in the 8-bit register class.
///
/// Tmp1 = setcc1
/// Tmp2 = setcc2
/// DestReg = logicalop Tmp1, Tmp2
///
static void Emit2SetCCsAndLogical(MachineBasicBlock *BB, unsigned SetCC1,
unsigned SetCC2, unsigned LogicalOp,
unsigned DestReg) {
SSARegMap *RegMap = BB->getParent()->getSSARegMap();
unsigned Tmp1 = RegMap->createVirtualRegister(X86::R8RegisterClass);
unsigned Tmp2 = RegMap->createVirtualRegister(X86::R8RegisterClass);
BuildMI(BB, SetCC1, 0, Tmp1);
BuildMI(BB, SetCC2, 0, Tmp2);
BuildMI(BB, LogicalOp, 2, DestReg).addReg(Tmp1).addReg(Tmp2);
}
/// EmitSetCC - Emit the code to set the specified 8-bit register to 1 if the
/// condition codes match the specified SetCCOpcode. Note that some conditions
/// require multiple instructions to generate the correct value.
static void EmitSetCC(MachineBasicBlock *BB, unsigned DestReg,
ISD::CondCode SetCCOpcode, bool isFP) {
unsigned Opc;
if (!isFP) {
switch (SetCCOpcode) {
default: assert(0 && "Illegal integer SetCC!");
case ISD::SETEQ: Opc = X86::SETEr; break;
case ISD::SETGT: Opc = X86::SETGr; break;
case ISD::SETGE: Opc = X86::SETGEr; break;
case ISD::SETLT: Opc = X86::SETLr; break;
case ISD::SETLE: Opc = X86::SETLEr; break;
case ISD::SETNE: Opc = X86::SETNEr; break;
case ISD::SETULT: Opc = X86::SETBr; break;
case ISD::SETUGT: Opc = X86::SETAr; break;
case ISD::SETULE: Opc = X86::SETBEr; break;
case ISD::SETUGE: Opc = X86::SETAEr; break;
}
} else {
// On a floating point condition, the flags are set as follows:
// ZF PF CF op
// 0 | 0 | 0 | X > Y
// 0 | 0 | 1 | X < Y
// 1 | 0 | 0 | X == Y
// 1 | 1 | 1 | unordered
//
switch (SetCCOpcode) {
default: assert(0 && "Invalid FP setcc!");
case ISD::SETUEQ:
case ISD::SETEQ:
Opc = X86::SETEr; // True if ZF = 1
break;
case ISD::SETOGT:
case ISD::SETGT:
Opc = X86::SETAr; // True if CF = 0 and ZF = 0
break;
case ISD::SETOGE:
case ISD::SETGE:
Opc = X86::SETAEr; // True if CF = 0
break;
case ISD::SETULT:
case ISD::SETLT:
Opc = X86::SETBr; // True if CF = 1
break;
case ISD::SETULE:
case ISD::SETLE:
Opc = X86::SETBEr; // True if CF = 1 or ZF = 1
break;
case ISD::SETONE:
case ISD::SETNE:
Opc = X86::SETNEr; // True if ZF = 0
break;
case ISD::SETUO:
Opc = X86::SETPr; // True if PF = 1
break;
case ISD::SETO:
Opc = X86::SETNPr; // True if PF = 0
break;
case ISD::SETOEQ: // !PF & ZF
Emit2SetCCsAndLogical(BB, X86::SETNPr, X86::SETEr, X86::AND8rr, DestReg);
return;
case ISD::SETOLT: // !PF & CF
Emit2SetCCsAndLogical(BB, X86::SETNPr, X86::SETBr, X86::AND8rr, DestReg);
return;
case ISD::SETOLE: // !PF & (CF || ZF)
Emit2SetCCsAndLogical(BB, X86::SETNPr, X86::SETBEr, X86::AND8rr, DestReg);
return;
case ISD::SETUGT: // PF | (!ZF & !CF)
Emit2SetCCsAndLogical(BB, X86::SETPr, X86::SETAr, X86::OR8rr, DestReg);
return;
case ISD::SETUGE: // PF | !CF
Emit2SetCCsAndLogical(BB, X86::SETPr, X86::SETAEr, X86::OR8rr, DestReg);
return;
case ISD::SETUNE: // PF | !ZF
Emit2SetCCsAndLogical(BB, X86::SETPr, X86::SETNEr, X86::OR8rr, DestReg);
return;
}
}
BuildMI(BB, Opc, 0, DestReg);
}
/// EmitBranchCC - Emit code into BB that arranges for control to transfer to
/// the Dest block if the Cond condition is true. If we cannot fold this
/// condition into the branch, return true.
///
bool ISel::EmitBranchCC(MachineBasicBlock *Dest, SDOperand Chain,
SDOperand Cond) {
// FIXME: Evaluate whether it would be good to emit code like (X < Y) | (A >
// B) using two conditional branches instead of one condbr, two setcc's, and
// an or.
if ((Cond.getOpcode() == ISD::OR ||
Cond.getOpcode() == ISD::AND) && Cond.Val->hasOneUse()) {
// And and or set the flags for us, so there is no need to emit a TST of the
// result. It is only safe to do this if there is only a single use of the
// AND/OR though, otherwise we don't know it will be emitted here.
Select(Chain);
SelectExpr(Cond);
BuildMI(BB, X86::JNE, 1).addMBB(Dest);
return false;
}
// Codegen br not C -> JE.
if (Cond.getOpcode() == ISD::XOR)
if (ConstantSDNode *NC = dyn_cast<ConstantSDNode>(Cond.Val->getOperand(1)))
if (NC->isAllOnesValue()) {
unsigned CondR;
if (getRegPressure(Chain) > getRegPressure(Cond)) {
Select(Chain);
CondR = SelectExpr(Cond.Val->getOperand(0));
} else {
CondR = SelectExpr(Cond.Val->getOperand(0));
Select(Chain);
}
BuildMI(BB, X86::TEST8rr, 2).addReg(CondR).addReg(CondR);
BuildMI(BB, X86::JE, 1).addMBB(Dest);
return false;
}
SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(Cond);
if (SetCC == 0)
return true; // Can only handle simple setcc's so far.
unsigned Opc;
// Handle integer conditions first.
if (MVT::isInteger(SetCC->getOperand(0).getValueType())) {
switch (SetCC->getCondition()) {
default: assert(0 && "Illegal integer SetCC!");
case ISD::SETEQ: Opc = X86::JE; break;
case ISD::SETGT: Opc = X86::JG; break;
case ISD::SETGE: Opc = X86::JGE; break;
case ISD::SETLT: Opc = X86::JL; break;
case ISD::SETLE: Opc = X86::JLE; break;
case ISD::SETNE: Opc = X86::JNE; break;
case ISD::SETULT: Opc = X86::JB; break;
case ISD::SETUGT: Opc = X86::JA; break;
case ISD::SETULE: Opc = X86::JBE; break;
case ISD::SETUGE: Opc = X86::JAE; break;
}
Select(Chain);
EmitCMP(SetCC->getOperand(0), SetCC->getOperand(1), SetCC->hasOneUse());
BuildMI(BB, Opc, 1).addMBB(Dest);
return false;
}
unsigned Opc2 = 0; // Second branch if needed.
// On a floating point condition, the flags are set as follows:
// ZF PF CF op
// 0 | 0 | 0 | X > Y
// 0 | 0 | 1 | X < Y
// 1 | 0 | 0 | X == Y
// 1 | 1 | 1 | unordered
//
switch (SetCC->getCondition()) {
default: assert(0 && "Invalid FP setcc!");
case ISD::SETUEQ:
case ISD::SETEQ: Opc = X86::JE; break; // True if ZF = 1
case ISD::SETOGT:
case ISD::SETGT: Opc = X86::JA; break; // True if CF = 0 and ZF = 0
case ISD::SETOGE:
case ISD::SETGE: Opc = X86::JAE; break; // True if CF = 0
case ISD::SETULT:
case ISD::SETLT: Opc = X86::JB; break; // True if CF = 1
case ISD::SETULE:
case ISD::SETLE: Opc = X86::JBE; break; // True if CF = 1 or ZF = 1
case ISD::SETONE:
case ISD::SETNE: Opc = X86::JNE; break; // True if ZF = 0
case ISD::SETUO: Opc = X86::JP; break; // True if PF = 1
case ISD::SETO: Opc = X86::JNP; break; // True if PF = 0
case ISD::SETUGT: // PF = 1 | (ZF = 0 & CF = 0)
Opc = X86::JA; // ZF = 0 & CF = 0
Opc2 = X86::JP; // PF = 1
break;
case ISD::SETUGE: // PF = 1 | CF = 0
Opc = X86::JAE; // CF = 0
Opc2 = X86::JP; // PF = 1
break;
case ISD::SETUNE: // PF = 1 | ZF = 0
Opc = X86::JNE; // ZF = 0
Opc2 = X86::JP; // PF = 1
break;
case ISD::SETOEQ: // PF = 0 & ZF = 1
//X86::JNP, X86::JE
//X86::AND8rr
return true; // FIXME: Emit more efficient code for this branch.
case ISD::SETOLT: // PF = 0 & CF = 1
//X86::JNP, X86::JB
//X86::AND8rr
return true; // FIXME: Emit more efficient code for this branch.
case ISD::SETOLE: // PF = 0 & (CF = 1 || ZF = 1)
//X86::JNP, X86::JBE
//X86::AND8rr
return true; // FIXME: Emit more efficient code for this branch.
}
Select(Chain);
EmitCMP(SetCC->getOperand(0), SetCC->getOperand(1), SetCC->hasOneUse());
BuildMI(BB, Opc, 1).addMBB(Dest);
if (Opc2)
BuildMI(BB, Opc2, 1).addMBB(Dest);
return false;
}
/// EmitSelectCC - Emit code into BB that performs a select operation between
/// the two registers RTrue and RFalse, generating a result into RDest. Return
/// true if the fold cannot be performed.
///
void ISel::EmitSelectCC(SDOperand Cond, MVT::ValueType SVT,
unsigned RTrue, unsigned RFalse, unsigned RDest) {
enum Condition {
EQ, NE, LT, LE, GT, GE, B, BE, A, AE, P, NP,
NOT_SET
} CondCode = NOT_SET;
static const unsigned CMOVTAB16[] = {
X86::CMOVE16rr, X86::CMOVNE16rr, X86::CMOVL16rr, X86::CMOVLE16rr,
X86::CMOVG16rr, X86::CMOVGE16rr, X86::CMOVB16rr, X86::CMOVBE16rr,
X86::CMOVA16rr, X86::CMOVAE16rr, X86::CMOVP16rr, X86::CMOVNP16rr,
};
static const unsigned CMOVTAB32[] = {
X86::CMOVE32rr, X86::CMOVNE32rr, X86::CMOVL32rr, X86::CMOVLE32rr,
X86::CMOVG32rr, X86::CMOVGE32rr, X86::CMOVB32rr, X86::CMOVBE32rr,
X86::CMOVA32rr, X86::CMOVAE32rr, X86::CMOVP32rr, X86::CMOVNP32rr,
};
static const unsigned CMOVTABFP[] = {
X86::FCMOVE , X86::FCMOVNE, /*missing*/0, /*missing*/0,
/*missing*/0, /*missing*/0, X86::FCMOVB , X86::FCMOVBE,
X86::FCMOVA , X86::FCMOVAE, X86::FCMOVP , X86::FCMOVNP
};
if (SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(Cond)) {
if (MVT::isInteger(SetCC->getOperand(0).getValueType())) {
switch (SetCC->getCondition()) {
default: assert(0 && "Unknown integer comparison!");
case ISD::SETEQ: CondCode = EQ; break;
case ISD::SETGT: CondCode = GT; break;
case ISD::SETGE: CondCode = GE; break;
case ISD::SETLT: CondCode = LT; break;
case ISD::SETLE: CondCode = LE; break;
case ISD::SETNE: CondCode = NE; break;
case ISD::SETULT: CondCode = B; break;
case ISD::SETUGT: CondCode = A; break;
case ISD::SETULE: CondCode = BE; break;
case ISD::SETUGE: CondCode = AE; break;
}
} else {
// On a floating point condition, the flags are set as follows:
// ZF PF CF op
// 0 | 0 | 0 | X > Y
// 0 | 0 | 1 | X < Y
// 1 | 0 | 0 | X == Y
// 1 | 1 | 1 | unordered
//
switch (SetCC->getCondition()) {
default: assert(0 && "Unknown FP comparison!");
case ISD::SETUEQ:
case ISD::SETEQ: CondCode = EQ; break; // True if ZF = 1
case ISD::SETOGT:
case ISD::SETGT: CondCode = A; break; // True if CF = 0 and ZF = 0
case ISD::SETOGE:
case ISD::SETGE: CondCode = AE; break; // True if CF = 0
case ISD::SETULT:
case ISD::SETLT: CondCode = B; break; // True if CF = 1
case ISD::SETULE:
case ISD::SETLE: CondCode = BE; break; // True if CF = 1 or ZF = 1
case ISD::SETONE:
case ISD::SETNE: CondCode = NE; break; // True if ZF = 0
case ISD::SETUO: CondCode = P; break; // True if PF = 1
case ISD::SETO: CondCode = NP; break; // True if PF = 0
case ISD::SETUGT: // PF = 1 | (ZF = 0 & CF = 0)
case ISD::SETUGE: // PF = 1 | CF = 0
case ISD::SETUNE: // PF = 1 | ZF = 0
case ISD::SETOEQ: // PF = 0 & ZF = 1
case ISD::SETOLT: // PF = 0 & CF = 1
case ISD::SETOLE: // PF = 0 & (CF = 1 || ZF = 1)
// We cannot emit this comparison as a single cmov.
break;
}
}
}
unsigned Opc = 0;
if (CondCode != NOT_SET) {
switch (SVT) {
default: assert(0 && "Cannot select this type!");
case MVT::i16: Opc = CMOVTAB16[CondCode]; break;
case MVT::i32: Opc = CMOVTAB32[CondCode]; break;
case MVT::f64: Opc = CMOVTABFP[CondCode]; break;
}
}
// Finally, if we weren't able to fold this, just emit the condition and test
// it.
if (CondCode == NOT_SET || Opc == 0) {
// Get the condition into the zero flag.
unsigned CondReg = SelectExpr(Cond);
BuildMI(BB, X86::TEST8rr, 2).addReg(CondReg).addReg(CondReg);
switch (SVT) {
default: assert(0 && "Cannot select this type!");
case MVT::i16: Opc = X86::CMOVE16rr; break;
case MVT::i32: Opc = X86::CMOVE32rr; break;
case MVT::f64: Opc = X86::FCMOVE; break;
}
} else {
// FIXME: CMP R, 0 -> TEST R, R
EmitCMP(Cond.getOperand(0), Cond.getOperand(1), Cond.Val->hasOneUse());
std::swap(RTrue, RFalse);
}
BuildMI(BB, Opc, 2, RDest).addReg(RTrue).addReg(RFalse);
}
void ISel::EmitCMP(SDOperand LHS, SDOperand RHS, bool HasOneUse) {
unsigned Opc;
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(RHS)) {
Opc = 0;
if (HasOneUse && isFoldableLoad(LHS, RHS)) {
switch (RHS.getValueType()) {
default: break;
case MVT::i1:
case MVT::i8: Opc = X86::CMP8mi; break;
case MVT::i16: Opc = X86::CMP16mi; break;
case MVT::i32: Opc = X86::CMP32mi; break;
}
if (Opc) {
X86AddressMode AM;
EmitFoldedLoad(LHS, AM);
addFullAddress(BuildMI(BB, Opc, 5), AM).addImm(CN->getValue());
return;
}
}
switch (RHS.getValueType()) {
default: break;
case MVT::i1:
case MVT::i8: Opc = X86::CMP8ri; break;
case MVT::i16: Opc = X86::CMP16ri; break;
case MVT::i32: Opc = X86::CMP32ri; break;
}
if (Opc) {
unsigned Tmp1 = SelectExpr(LHS);
BuildMI(BB, Opc, 2).addReg(Tmp1).addImm(CN->getValue());
return;
}
} else if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(RHS)) {
if (CN->isExactlyValue(+0.0) ||
CN->isExactlyValue(-0.0)) {
unsigned Reg = SelectExpr(LHS);
BuildMI(BB, X86::FTST, 1).addReg(Reg);
BuildMI(BB, X86::FNSTSW8r, 0);
BuildMI(BB, X86::SAHF, 1);
}
}
Opc = 0;
if (HasOneUse && isFoldableLoad(LHS, RHS)) {
switch (RHS.getValueType()) {
default: break;
case MVT::i1:
case MVT::i8: Opc = X86::CMP8mr; break;
case MVT::i16: Opc = X86::CMP16mr; break;
case MVT::i32: Opc = X86::CMP32mr; break;
}
if (Opc) {
X86AddressMode AM;
EmitFoldedLoad(LHS, AM);
unsigned Reg = SelectExpr(RHS);
addFullAddress(BuildMI(BB, Opc, 5), AM).addReg(Reg);
return;
}
}
switch (LHS.getValueType()) {
default: assert(0 && "Cannot compare this value!");
case MVT::i1:
case MVT::i8: Opc = X86::CMP8rr; break;
case MVT::i16: Opc = X86::CMP16rr; break;
case MVT::i32: Opc = X86::CMP32rr; break;
case MVT::f64: Opc = X86::FUCOMIr; break;
}
unsigned Tmp1, Tmp2;
if (getRegPressure(LHS) > getRegPressure(RHS)) {
Tmp1 = SelectExpr(LHS);
Tmp2 = SelectExpr(RHS);
} else {
Tmp2 = SelectExpr(RHS);
Tmp1 = SelectExpr(LHS);
}
BuildMI(BB, Opc, 2).addReg(Tmp1).addReg(Tmp2);
}
/// isFoldableLoad - Return true if this is a load instruction that can safely
/// be folded into an operation that uses it.
bool ISel::isFoldableLoad(SDOperand Op, SDOperand OtherOp) {
if (Op.getOpcode() != ISD::LOAD ||
// FIXME: currently can't fold constant pool indexes.
isa<ConstantPoolSDNode>(Op.getOperand(1)))
return false;
// If this load has already been emitted, we clearly can't fold it.
assert(Op.ResNo == 0 && "Not a use of the value of the load?");
if (ExprMap.count(Op.getValue(1))) return false;
assert(!ExprMap.count(Op.getValue(0)) && "Value in map but not token chain?");
assert(!ExprMap.count(Op.getValue(1))&&"Token lowered but value not in map?");
// If there is not just one use of its value, we cannot fold.
if (!Op.Val->hasNUsesOfValue(1, 0)) return false;
// Finally, we cannot fold the load into the operation if this would induce a
// cycle into the resultant dag. To check for this, see if OtherOp (the other
// operand of the operation we are folding the load into) can possible use the
// chain node defined by the load.
if (OtherOp.Val && !Op.Val->hasNUsesOfValue(0, 1)) { // Has uses of chain?
std::set<SDNode*> Visited;
if (NodeTransitivelyUsesValue(OtherOp, Op.getValue(1), Visited))
return false;
}
return true;
}
/// EmitFoldedLoad - Ensure that the arguments of the load are code generated,
/// and compute the address being loaded into AM.
void ISel::EmitFoldedLoad(SDOperand Op, X86AddressMode &AM) {
SDOperand Chain = Op.getOperand(0);
SDOperand Address = Op.getOperand(1);
if (getRegPressure(Chain) > getRegPressure(Address)) {
Select(Chain);
SelectAddress(Address, AM);
} else {
SelectAddress(Address, AM);
Select(Chain);
}
// The chain for this load is now lowered.
assert(ExprMap.count(SDOperand(Op.Val, 1)) == 0 &&
"Load emitted more than once?");
if (!ExprMap.insert(std::make_pair(Op.getValue(1), 1)).second)
assert(0 && "Load emitted more than once!");
}
// EmitOrOpOp - Pattern match the expression (Op1|Op2), where we know that op1
// and op2 are i8/i16/i32 values with one use each (the or). If we can form a
// SHLD or SHRD, emit the instruction (generating the value into DestReg) and
// return true.
bool ISel::EmitOrOpOp(SDOperand Op1, SDOperand Op2, unsigned DestReg) {
if (Op1.getOpcode() == ISD::SHL && Op2.getOpcode() == ISD::SRL) {
// good!
} else if (Op2.getOpcode() == ISD::SHL && Op1.getOpcode() == ISD::SRL) {
std::swap(Op1, Op2); // Op1 is the SHL now.
} else {
return false; // No match
}
SDOperand ShlVal = Op1.getOperand(0);
SDOperand ShlAmt = Op1.getOperand(1);
SDOperand ShrVal = Op2.getOperand(0);
SDOperand ShrAmt = Op2.getOperand(1);
unsigned RegSize = MVT::getSizeInBits(Op1.getValueType());
// Find out if ShrAmt = 32-ShlAmt or ShlAmt = 32-ShrAmt.
if (ShlAmt.getOpcode() == ISD::SUB && ShlAmt.getOperand(1) == ShrAmt)
if (ConstantSDNode *SubCST = dyn_cast<ConstantSDNode>(ShlAmt.getOperand(0)))
if (SubCST->getValue() == RegSize) {
// (A >> ShrAmt) | (A << (32-ShrAmt)) ==> ROR A, ShrAmt
// (A >> ShrAmt) | (B << (32-ShrAmt)) ==> SHRD A, B, ShrAmt
if (ShrVal == ShlVal) {
unsigned Reg, ShAmt;
if (getRegPressure(ShrVal) > getRegPressure(ShrAmt)) {
Reg = SelectExpr(ShrVal);
ShAmt = SelectExpr(ShrAmt);
} else {
ShAmt = SelectExpr(ShrAmt);
Reg = SelectExpr(ShrVal);
}
BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt);
unsigned Opc = RegSize == 8 ? X86::ROR8rCL :
(RegSize == 16 ? X86::ROR16rCL : X86::ROR32rCL);
BuildMI(BB, Opc, 1, DestReg).addReg(Reg);
return true;
} else if (RegSize != 8) {
unsigned AReg, BReg;
if (getRegPressure(ShlVal) > getRegPressure(ShrVal)) {
BReg = SelectExpr(ShlVal);
AReg = SelectExpr(ShrVal);
} else {
AReg = SelectExpr(ShrVal);
BReg = SelectExpr(ShlVal);
}
unsigned ShAmt = SelectExpr(ShrAmt);
BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt);
unsigned Opc = RegSize == 16 ? X86::SHRD16rrCL : X86::SHRD32rrCL;
BuildMI(BB, Opc, 2, DestReg).addReg(AReg).addReg(BReg);
return true;
}
}
if (ShrAmt.getOpcode() == ISD::SUB && ShrAmt.getOperand(1) == ShlAmt)
if (ConstantSDNode *SubCST = dyn_cast<ConstantSDNode>(ShrAmt.getOperand(0)))
if (SubCST->getValue() == RegSize) {
// (A << ShlAmt) | (A >> (32-ShlAmt)) ==> ROL A, ShrAmt
// (A << ShlAmt) | (B >> (32-ShlAmt)) ==> SHLD A, B, ShrAmt
if (ShrVal == ShlVal) {
unsigned Reg, ShAmt;
if (getRegPressure(ShrVal) > getRegPressure(ShlAmt)) {
Reg = SelectExpr(ShrVal);
ShAmt = SelectExpr(ShlAmt);
} else {
ShAmt = SelectExpr(ShlAmt);
Reg = SelectExpr(ShrVal);
}
BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt);
unsigned Opc = RegSize == 8 ? X86::ROL8rCL :
(RegSize == 16 ? X86::ROL16rCL : X86::ROL32rCL);
BuildMI(BB, Opc, 1, DestReg).addReg(Reg);
return true;
} else if (RegSize != 8) {
unsigned AReg, BReg;
if (getRegPressure(ShlVal) > getRegPressure(ShrVal)) {
AReg = SelectExpr(ShlVal);
BReg = SelectExpr(ShrVal);
} else {
BReg = SelectExpr(ShrVal);
AReg = SelectExpr(ShlVal);
}
unsigned ShAmt = SelectExpr(ShlAmt);
BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(ShAmt);
unsigned Opc = RegSize == 16 ? X86::SHLD16rrCL : X86::SHLD32rrCL;
BuildMI(BB, Opc, 2, DestReg).addReg(AReg).addReg(BReg);
return true;
}
}
if (ConstantSDNode *ShrCst = dyn_cast<ConstantSDNode>(ShrAmt))
if (ConstantSDNode *ShlCst = dyn_cast<ConstantSDNode>(ShlAmt))
if (ShrCst->getValue() < RegSize && ShlCst->getValue() < RegSize)
if (ShrCst->getValue() == RegSize-ShlCst->getValue()) {
// (A >> 5) | (A << 27) --> ROR A, 5
// (A >> 5) | (B << 27) --> SHRD A, B, 5
if (ShrVal == ShlVal) {
unsigned Reg = SelectExpr(ShrVal);
unsigned Opc = RegSize == 8 ? X86::ROR8ri :
(RegSize == 16 ? X86::ROR16ri : X86::ROR32ri);
BuildMI(BB, Opc, 2, DestReg).addReg(Reg).addImm(ShrCst->getValue());
return true;
} else if (RegSize != 8) {
unsigned AReg, BReg;
if (getRegPressure(ShlVal) > getRegPressure(ShrVal)) {
BReg = SelectExpr(ShlVal);
AReg = SelectExpr(ShrVal);
} else {
AReg = SelectExpr(ShrVal);
BReg = SelectExpr(ShlVal);
}
unsigned Opc = RegSize == 16 ? X86::SHRD16rri8 : X86::SHRD32rri8;
BuildMI(BB, Opc, 3, DestReg).addReg(AReg).addReg(BReg)
.addImm(ShrCst->getValue());
return true;
}
}
return false;
}
unsigned ISel::SelectExpr(SDOperand N) {
unsigned Result;
unsigned Tmp1, Tmp2, Tmp3;
unsigned Opc = 0;
SDNode *Node = N.Val;
SDOperand Op0, Op1;
if (Node->getOpcode() == ISD::CopyFromReg) {
// FIXME: Handle copy from physregs!
// Just use the specified register as our input.
return dyn_cast<RegSDNode>(Node)->getReg();
}
unsigned &Reg = ExprMap[N];
if (Reg) return Reg;
if (N.getOpcode() != ISD::CALL)
Reg = Result = (N.getValueType() != MVT::Other) ?
MakeReg(N.getValueType()) : 1;
else {
// If this is a call instruction, make sure to prepare ALL of the result
// values as well as the chain.
if (Node->getNumValues() == 1)
Reg = Result = 1; // Void call, just a chain.
else {
Result = MakeReg(Node->getValueType(0));
ExprMap[N.getValue(0)] = Result;
for (unsigned i = 1, e = N.Val->getNumValues()-1; i != e; ++i)
ExprMap[N.getValue(i)] = MakeReg(Node->getValueType(i));
ExprMap[SDOperand(Node, Node->getNumValues()-1)] = 1;
}
}
switch (N.getOpcode()) {
default:
Node->dump();
assert(0 && "Node not handled!\n");
case ISD::FrameIndex:
Tmp1 = cast<FrameIndexSDNode>(N)->getIndex();
addFrameReference(BuildMI(BB, X86::LEA32r, 4, Result), (int)Tmp1);
return Result;
case ISD::ConstantPool:
Tmp1 = cast<ConstantPoolSDNode>(N)->getIndex();
addConstantPoolReference(BuildMI(BB, X86::LEA32r, 4, Result), Tmp1);
return Result;
case ISD::ConstantFP:
ContainsFPCode = true;
Tmp1 = Result; // Intermediate Register
if (cast<ConstantFPSDNode>(N)->getValue() < 0.0 ||
cast<ConstantFPSDNode>(N)->isExactlyValue(-0.0))
Tmp1 = MakeReg(MVT::f64);
if (cast<ConstantFPSDNode>(N)->isExactlyValue(+0.0) ||
cast<ConstantFPSDNode>(N)->isExactlyValue(-0.0))
BuildMI(BB, X86::FLD0, 0, Tmp1);
else if (cast<ConstantFPSDNode>(N)->isExactlyValue(+1.0) ||
cast<ConstantFPSDNode>(N)->isExactlyValue(-1.0))
BuildMI(BB, X86::FLD1, 0, Tmp1);
else
assert(0 && "Unexpected constant!");
if (Tmp1 != Result)
BuildMI(BB, X86::FCHS, 1, Result).addReg(Tmp1);
return Result;
case ISD::Constant:
switch (N.getValueType()) {
default: assert(0 && "Cannot use constants of this type!");
case MVT::i1:
case MVT::i8: Opc = X86::MOV8ri; break;
case MVT::i16: Opc = X86::MOV16ri; break;
case MVT::i32: Opc = X86::MOV32ri; break;
}
BuildMI(BB, Opc, 1,Result).addImm(cast<ConstantSDNode>(N)->getValue());
return Result;
case ISD::GlobalAddress: {
GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
BuildMI(BB, X86::MOV32ri, 1, Result).addGlobalAddress(GV);
return Result;
}
case ISD::ExternalSymbol: {
const char *Sym = cast<ExternalSymbolSDNode>(N)->getSymbol();
BuildMI(BB, X86::MOV32ri, 1, Result).addExternalSymbol(Sym);
return Result;
}
case ISD::ZERO_EXTEND: {
int DestIs16 = N.getValueType() == MVT::i16;
int SrcIs16 = N.getOperand(0).getValueType() == MVT::i16;
// FIXME: This hack is here for zero extension casts from bool to i8. This
// would not be needed if bools were promoted by Legalize.
if (N.getValueType() == MVT::i8) {
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, X86::MOV8rr, 1, Result).addReg(Tmp1);
return Result;
}
if (isFoldableLoad(N.getOperand(0), SDOperand())) {
static const unsigned Opc[3] = {
X86::MOVZX32rm8, X86::MOVZX32rm16, X86::MOVZX16rm8
};
X86AddressMode AM;
EmitFoldedLoad(N.getOperand(0), AM);
addFullAddress(BuildMI(BB, Opc[SrcIs16+DestIs16*2], 4, Result), AM);
return Result;
}
static const unsigned Opc[3] = {
X86::MOVZX32rr8, X86::MOVZX32rr16, X86::MOVZX16rr8
};
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, Opc[SrcIs16+DestIs16*2], 1, Result).addReg(Tmp1);
return Result;
}
case ISD::SIGN_EXTEND: {
int DestIs16 = N.getValueType() == MVT::i16;
int SrcIs16 = N.getOperand(0).getValueType() == MVT::i16;
// FIXME: Legalize should promote bools to i8!
assert(N.getOperand(0).getValueType() != MVT::i1 &&
"Sign extend from bool not implemented!");
if (isFoldableLoad(N.getOperand(0), SDOperand())) {
static const unsigned Opc[3] = {
X86::MOVSX32rm8, X86::MOVSX32rm16, X86::MOVSX16rm8
};
X86AddressMode AM;
EmitFoldedLoad(N.getOperand(0), AM);
addFullAddress(BuildMI(BB, Opc[SrcIs16+DestIs16*2], 4, Result), AM);
return Result;
}
static const unsigned Opc[3] = {
X86::MOVSX32rr8, X86::MOVSX32rr16, X86::MOVSX16rr8
};
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, Opc[SrcIs16+DestIs16*2], 1, Result).addReg(Tmp1);
return Result;
}
case ISD::TRUNCATE:
// Fold TRUNCATE (LOAD P) into a smaller load from P.
// FIXME: This should be performed by the DAGCombiner.
if (isFoldableLoad(N.getOperand(0), SDOperand())) {
switch (N.getValueType()) {
default: assert(0 && "Unknown truncate!");
case MVT::i1:
case MVT::i8: Opc = X86::MOV8rm; break;
case MVT::i16: Opc = X86::MOV16rm; break;
}
X86AddressMode AM;
EmitFoldedLoad(N.getOperand(0), AM);
addFullAddress(BuildMI(BB, Opc, 4, Result), AM);
return Result;
}
// Handle cast of LARGER int to SMALLER int using a move to EAX followed by
// a move out of AX or AL.
switch (N.getOperand(0).getValueType()) {
default: assert(0 && "Unknown truncate!");
case MVT::i8: Tmp2 = X86::AL; Opc = X86::MOV8rr; break;
case MVT::i16: Tmp2 = X86::AX; Opc = X86::MOV16rr; break;
case MVT::i32: Tmp2 = X86::EAX; Opc = X86::MOV32rr; break;
}
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, Opc, 1, Tmp2).addReg(Tmp1);
switch (N.getValueType()) {
default: assert(0 && "Unknown truncate!");
case MVT::i1:
case MVT::i8: Tmp2 = X86::AL; Opc = X86::MOV8rr; break;
case MVT::i16: Tmp2 = X86::AX; Opc = X86::MOV16rr; break;
}
BuildMI(BB, Opc, 1, Result).addReg(Tmp2);
return Result;
case ISD::SINT_TO_FP:
case ISD::UINT_TO_FP: {
// FIXME: Most of this grunt work should be done by legalize!
ContainsFPCode = true;
// Promote the integer to a type supported by FLD. We do this because there
// are no unsigned FLD instructions, so we must promote an unsigned value to
// a larger signed value, then use FLD on the larger value.
//
MVT::ValueType PromoteType = MVT::Other;
MVT::ValueType SrcTy = N.getOperand(0).getValueType();
unsigned PromoteOpcode = 0;
unsigned RealDestReg = Result;
switch (SrcTy) {
case MVT::i1:
case MVT::i8:
// We don't have the facilities for directly loading byte sized data from
// memory (even signed). Promote it to 16 bits.
PromoteType = MVT::i16;
PromoteOpcode = Node->getOpcode() == ISD::SINT_TO_FP ?
X86::MOVSX16rr8 : X86::MOVZX16rr8;
break;
case MVT::i16:
if (Node->getOpcode() == ISD::UINT_TO_FP) {
PromoteType = MVT::i32;
PromoteOpcode = X86::MOVZX32rr16;
}
break;
default:
// Don't fild into the real destination.
if (Node->getOpcode() == ISD::UINT_TO_FP)
Result = MakeReg(Node->getValueType(0));
break;
}
Tmp1 = SelectExpr(N.getOperand(0)); // Get the operand register
if (PromoteType != MVT::Other) {
Tmp2 = MakeReg(PromoteType);
BuildMI(BB, PromoteOpcode, 1, Tmp2).addReg(Tmp1);
SrcTy = PromoteType;
Tmp1 = Tmp2;
}
// Spill the integer to memory and reload it from there.
unsigned Size = MVT::getSizeInBits(SrcTy)/8;
MachineFunction *F = BB->getParent();
int FrameIdx = F->getFrameInfo()->CreateStackObject(Size, Size);
switch (SrcTy) {
case MVT::i64:
assert(0 && "Cast ulong to FP not implemented yet!");
// FIXME: this won't work for cast [u]long to FP
addFrameReference(BuildMI(BB, X86::MOV32mr, 5),
FrameIdx).addReg(Tmp1);
addFrameReference(BuildMI(BB, X86::MOV32mr, 5),
FrameIdx, 4).addReg(Tmp1+1);
addFrameReference(BuildMI(BB, X86::FILD64m, 5, Result), FrameIdx);
break;
case MVT::i32:
addFrameReference(BuildMI(BB, X86::MOV32mr, 5),
FrameIdx).addReg(Tmp1);
addFrameReference(BuildMI(BB, X86::FILD32m, 5, Result), FrameIdx);
break;
case MVT::i16:
addFrameReference(BuildMI(BB, X86::MOV16mr, 5),
FrameIdx).addReg(Tmp1);
addFrameReference(BuildMI(BB, X86::FILD16m, 5, Result), FrameIdx);
break;
default: break; // No promotion required.
}
if (Node->getOpcode() == ISD::UINT_TO_FP && Result != RealDestReg) {
// If this is a cast from uint -> double, we need to be careful when if
// the "sign" bit is set. If so, we don't want to make a negative number,
// we want to make a positive number. Emit code to add an offset if the
// sign bit is set.
// Compute whether the sign bit is set by shifting the reg right 31 bits.
unsigned IsNeg = MakeReg(MVT::i32);
BuildMI(BB, X86::SHR32ri, 2, IsNeg).addReg(Tmp1).addImm(31);
// Create a CP value that has the offset in one word and 0 in the other.
static ConstantInt *TheOffset = ConstantUInt::get(Type::ULongTy,
0x4f80000000000000ULL);
unsigned CPI = F->getConstantPool()->getConstantPoolIndex(TheOffset);
BuildMI(BB, X86::FADD32m, 5, RealDestReg).addReg(Result)
.addConstantPoolIndex(CPI).addZImm(4).addReg(IsNeg).addSImm(0);
} else if (Node->getOpcode() == ISD::UINT_TO_FP && SrcTy == MVT::i64) {
// We need special handling for unsigned 64-bit integer sources. If the
// input number has the "sign bit" set, then we loaded it incorrectly as a
// negative 64-bit number. In this case, add an offset value.
// Emit a test instruction to see if the dynamic input value was signed.
BuildMI(BB, X86::TEST32rr, 2).addReg(Tmp1+1).addReg(Tmp1+1);
// If the sign bit is set, get a pointer to an offset, otherwise get a
// pointer to a zero.
MachineConstantPool *CP = F->getConstantPool();
unsigned Zero = MakeReg(MVT::i32);
Constant *Null = Constant::getNullValue(Type::UIntTy);
addConstantPoolReference(BuildMI(BB, X86::LEA32r, 5, Zero),
CP->getConstantPoolIndex(Null));
unsigned Offset = MakeReg(MVT::i32);
Constant *OffsetCst = ConstantUInt::get(Type::UIntTy, 0x5f800000);
addConstantPoolReference(BuildMI(BB, X86::LEA32r, 5, Offset),
CP->getConstantPoolIndex(OffsetCst));
unsigned Addr = MakeReg(MVT::i32);
BuildMI(BB, X86::CMOVS32rr, 2, Addr).addReg(Zero).addReg(Offset);
// Load the constant for an add. FIXME: this could make an 'fadd' that
// reads directly from memory, but we don't support these yet.
unsigned ConstReg = MakeReg(MVT::f64);
addDirectMem(BuildMI(BB, X86::FLD32m, 4, ConstReg), Addr);
BuildMI(BB, X86::FpADD, 2, RealDestReg).addReg(ConstReg).addReg(Result);
}
return RealDestReg;
}
case ISD::FP_TO_SINT:
case ISD::FP_TO_UINT: {
// FIXME: Most of this grunt work should be done by legalize!
Tmp1 = SelectExpr(N.getOperand(0)); // Get the operand register
// Change the floating point control register to use "round towards zero"
// mode when truncating to an integer value.
//
MachineFunction *F = BB->getParent();
int CWFrameIdx = F->getFrameInfo()->CreateStackObject(2, 2);
addFrameReference(BuildMI(BB, X86::FNSTCW16m, 4), CWFrameIdx);
// Load the old value of the high byte of the control word...
unsigned HighPartOfCW = MakeReg(MVT::i8);
addFrameReference(BuildMI(BB, X86::MOV8rm, 4, HighPartOfCW),
CWFrameIdx, 1);
// Set the high part to be round to zero...
addFrameReference(BuildMI(BB, X86::MOV8mi, 5),
CWFrameIdx, 1).addImm(12);
// Reload the modified control word now...
addFrameReference(BuildMI(BB, X86::FLDCW16m, 4), CWFrameIdx);
// Restore the memory image of control word to original value
addFrameReference(BuildMI(BB, X86::MOV8mr, 5),
CWFrameIdx, 1).addReg(HighPartOfCW);
// We don't have the facilities for directly storing byte sized data to
// memory. Promote it to 16 bits. We also must promote unsigned values to
// larger classes because we only have signed FP stores.
MVT::ValueType StoreClass = Node->getValueType(0);
if (StoreClass == MVT::i8 || Node->getOpcode() == ISD::FP_TO_UINT)
switch (StoreClass) {
case MVT::i8: StoreClass = MVT::i16; break;
case MVT::i16: StoreClass = MVT::i32; break;
case MVT::i32: StoreClass = MVT::i64; break;
// The following treatment of cLong may not be perfectly right,
// but it survives chains of casts of the form
// double->ulong->double.
case MVT::i64: StoreClass = MVT::i64; break;
default: assert(0 && "Unknown store class!");
}
// Spill the integer to memory and reload it from there.
unsigned Size = MVT::getSizeInBits(StoreClass)/8;
int FrameIdx = F->getFrameInfo()->CreateStackObject(Size, Size);
switch (StoreClass) {
default: assert(0 && "Unknown store class!");
case MVT::i16:
addFrameReference(BuildMI(BB, X86::FIST16m, 5), FrameIdx).addReg(Tmp1);
break;
case MVT::i32:
addFrameReference(BuildMI(BB, X86::FIST32m, 5), FrameIdx).addReg(Tmp1);
break;
case MVT::i64:
addFrameReference(BuildMI(BB, X86::FISTP64m, 5), FrameIdx).addReg(Tmp1);
break;
}
switch (Node->getValueType(0)) {
default:
assert(0 && "Unknown integer type!");
case MVT::i64:
// FIXME: this isn't gunna work.
assert(0 && "Cast FP to long not implemented yet!");
addFrameReference(BuildMI(BB, X86::MOV32rm, 4, Result), FrameIdx);
addFrameReference(BuildMI(BB, X86::MOV32rm, 4, Result+1), FrameIdx, 4);
case MVT::i32:
addFrameReference(BuildMI(BB, X86::MOV32rm, 4, Result), FrameIdx);
break;
case MVT::i16:
addFrameReference(BuildMI(BB, X86::MOV16rm, 4, Result), FrameIdx);
break;
case MVT::i8:
addFrameReference(BuildMI(BB, X86::MOV8rm, 4, Result), FrameIdx);
break;
}
// Reload the original control word now.
addFrameReference(BuildMI(BB, X86::FLDCW16m, 4), CWFrameIdx);
return Result;
}
case ISD::ADD:
Op0 = N.getOperand(0);
Op1 = N.getOperand(1);
if (isFoldableLoad(Op0, Op1)) {
std::swap(Op0, Op1);
goto FoldAdd;
}
if (isFoldableLoad(Op1, Op0)) {
FoldAdd:
switch (N.getValueType()) {
default: assert(0 && "Cannot add this type!");
case MVT::i1:
case MVT::i8: Opc = X86::ADD8rm; break;
case MVT::i16: Opc = X86::ADD16rm; break;
case MVT::i32: Opc = X86::ADD32rm; break;
case MVT::f32: Opc = X86::FADD32m; break;
case MVT::f64: Opc = X86::FADD64m; break;
}
X86AddressMode AM;
EmitFoldedLoad(Op1, AM);
Tmp1 = SelectExpr(Op0);
addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM);
return Result;
}
// See if we can codegen this as an LEA to fold operations together.
if (N.getValueType() == MVT::i32) {
ExprMap.erase(N);
X86ISelAddressMode AM;
MatchAddress(N, AM);
ExprMap[N] = Result;
// If this is not just an add, emit the LEA. For a simple add (like
// reg+reg or reg+imm), we just emit an add. It might be a good idea to
// leave this as LEA, then peephole it to 'ADD' after two address elim
// happens.
if (AM.Scale != 1 || AM.BaseType == X86ISelAddressMode::FrameIndexBase||
AM.GV || (AM.Base.Reg.Val && AM.IndexReg.Val && AM.Disp)) {
X86AddressMode XAM = SelectAddrExprs(AM);
addFullAddress(BuildMI(BB, X86::LEA32r, 4, Result), XAM);
return Result;
}
}
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) {
Opc = 0;
if (CN->getValue() == 1) { // add X, 1 -> inc X
switch (N.getValueType()) {
default: assert(0 && "Cannot integer add this type!");
case MVT::i8: Opc = X86::INC8r; break;
case MVT::i16: Opc = X86::INC16r; break;
case MVT::i32: Opc = X86::INC32r; break;
}
} else if (CN->isAllOnesValue()) { // add X, -1 -> dec X
switch (N.getValueType()) {
default: assert(0 && "Cannot integer add this type!");
case MVT::i8: Opc = X86::DEC8r; break;
case MVT::i16: Opc = X86::DEC16r; break;
case MVT::i32: Opc = X86::DEC32r; break;
}
}
if (Opc) {
Tmp1 = SelectExpr(Op0);
BuildMI(BB, Opc, 1, Result).addReg(Tmp1);
return Result;
}
switch (N.getValueType()) {
default: assert(0 && "Cannot add this type!");
case MVT::i8: Opc = X86::ADD8ri; break;
case MVT::i16: Opc = X86::ADD16ri; break;
case MVT::i32: Opc = X86::ADD32ri; break;
}
if (Opc) {
Tmp1 = SelectExpr(Op0);
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue());
return Result;
}
}
switch (N.getValueType()) {
default: assert(0 && "Cannot add this type!");
case MVT::i8: Opc = X86::ADD8rr; break;
case MVT::i16: Opc = X86::ADD16rr; break;
case MVT::i32: Opc = X86::ADD32rr; break;
case MVT::f64: Opc = X86::FpADD; break;
}
if (getRegPressure(Op0) > getRegPressure(Op1)) {
Tmp1 = SelectExpr(Op0);
Tmp2 = SelectExpr(Op1);
} else {
Tmp2 = SelectExpr(Op1);
Tmp1 = SelectExpr(Op0);
}
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
return Result;
case ISD::SUB:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR: {
static const unsigned SUBTab[] = {
X86::SUB8ri, X86::SUB16ri, X86::SUB32ri, 0, 0,
X86::SUB8rm, X86::SUB16rm, X86::SUB32rm, X86::FSUB32m, X86::FSUB64m,
X86::SUB8rr, X86::SUB16rr, X86::SUB32rr, X86::FpSUB , X86::FpSUB,
};
static const unsigned MULTab[] = {
0, X86::IMUL16rri, X86::IMUL32rri, 0, 0,
0, X86::IMUL16rm , X86::IMUL32rm, X86::FMUL32m, X86::FMUL64m,
0, X86::IMUL16rr , X86::IMUL32rr, X86::FpMUL , X86::FpMUL,
};
static const unsigned ANDTab[] = {
X86::AND8ri, X86::AND16ri, X86::AND32ri, 0, 0,
X86::AND8rm, X86::AND16rm, X86::AND32rm, 0, 0,
X86::AND8rr, X86::AND16rr, X86::AND32rr, 0, 0,
};
static const unsigned ORTab[] = {
X86::OR8ri, X86::OR16ri, X86::OR32ri, 0, 0,
X86::OR8rm, X86::OR16rm, X86::OR32rm, 0, 0,
X86::OR8rr, X86::OR16rr, X86::OR32rr, 0, 0,
};
static const unsigned XORTab[] = {
X86::XOR8ri, X86::XOR16ri, X86::XOR32ri, 0, 0,
X86::XOR8rm, X86::XOR16rm, X86::XOR32rm, 0, 0,
X86::XOR8rr, X86::XOR16rr, X86::XOR32rr, 0, 0,
};
Op0 = Node->getOperand(0);
Op1 = Node->getOperand(1);
if (Node->getOpcode() == ISD::OR && Op0.hasOneUse() && Op1.hasOneUse())
if (EmitOrOpOp(Op0, Op1, Result)) // Match SHLD, SHRD, and rotates.
return Result;
if (Node->getOpcode() == ISD::SUB)
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(0)))
if (CN->isNullValue()) { // 0 - N -> neg N
switch (N.getValueType()) {
default: assert(0 && "Cannot sub this type!");
case MVT::i1:
case MVT::i8: Opc = X86::NEG8r; break;
case MVT::i16: Opc = X86::NEG16r; break;
case MVT::i32: Opc = X86::NEG32r; break;
}
Tmp1 = SelectExpr(N.getOperand(1));
BuildMI(BB, Opc, 1, Result).addReg(Tmp1);
return Result;
}
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) {
if (CN->isAllOnesValue() && Node->getOpcode() == ISD::XOR) {
Opc = 0;
switch (N.getValueType()) {
default: assert(0 && "Cannot add this type!");
case MVT::i1: break; // Not supported, don't invert upper bits!
case MVT::i8: Opc = X86::NOT8r; break;
case MVT::i16: Opc = X86::NOT16r; break;
case MVT::i32: Opc = X86::NOT32r; break;
}
if (Opc) {
Tmp1 = SelectExpr(Op0);
BuildMI(BB, Opc, 1, Result).addReg(Tmp1);
return Result;
}
}
// Fold common multiplies into LEA instructions.
if (Node->getOpcode() == ISD::MUL && N.getValueType() == MVT::i32) {
switch ((int)CN->getValue()) {
default: break;
case 3:
case 5:
case 9:
// Remove N from exprmap so SelectAddress doesn't get confused.
ExprMap.erase(N);
X86AddressMode AM;
SelectAddress(N, AM);
// Restore it to the map.
ExprMap[N] = Result;
addFullAddress(BuildMI(BB, X86::LEA32r, 4, Result), AM);
return Result;
}
}
switch (N.getValueType()) {
default: assert(0 && "Cannot xor this type!");
case MVT::i1:
case MVT::i8: Opc = 0; break;
case MVT::i16: Opc = 1; break;
case MVT::i32: Opc = 2; break;
}
switch (Node->getOpcode()) {
default: assert(0 && "Unreachable!");
case ISD::SUB: Opc = SUBTab[Opc]; break;
case ISD::MUL: Opc = MULTab[Opc]; break;
case ISD::AND: Opc = ANDTab[Opc]; break;
case ISD::OR: Opc = ORTab[Opc]; break;
case ISD::XOR: Opc = XORTab[Opc]; break;
}
if (Opc) { // Can't fold MUL:i8 R, imm
Tmp1 = SelectExpr(Op0);
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue());
return Result;
}
}
if (isFoldableLoad(Op0, Op1))
if (Node->getOpcode() != ISD::SUB) {
std::swap(Op0, Op1);
goto FoldOps;
} else {
// Emit 'reverse' subract, with a memory operand.
switch (N.getValueType()) {
default: Opc = 0; break;
case MVT::f32: Opc = X86::FSUBR32m; break;
case MVT::f64: Opc = X86::FSUBR64m; break;
}
if (Opc) {
X86AddressMode AM;
EmitFoldedLoad(Op0, AM);
Tmp1 = SelectExpr(Op1);
addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM);
return Result;
}
}
if (isFoldableLoad(Op1, Op0)) {
FoldOps:
switch (N.getValueType()) {
default: assert(0 && "Cannot operate on this type!");
case MVT::i1:
case MVT::i8: Opc = 5; break;
case MVT::i16: Opc = 6; break;
case MVT::i32: Opc = 7; break;
case MVT::f32: Opc = 8; break;
case MVT::f64: Opc = 9; break;
}
switch (Node->getOpcode()) {
default: assert(0 && "Unreachable!");
case ISD::SUB: Opc = SUBTab[Opc]; break;
case ISD::MUL: Opc = MULTab[Opc]; break;
case ISD::AND: Opc = ANDTab[Opc]; break;
case ISD::OR: Opc = ORTab[Opc]; break;
case ISD::XOR: Opc = XORTab[Opc]; break;
}
X86AddressMode AM;
EmitFoldedLoad(Op1, AM);
Tmp1 = SelectExpr(Op0);
if (Opc) {
addFullAddress(BuildMI(BB, Opc, 5, Result).addReg(Tmp1), AM);
} else {
assert(Node->getOpcode() == ISD::MUL &&
N.getValueType() == MVT::i8 && "Unexpected situation!");
// Must use the MUL instruction, which forces use of AL.
BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(Tmp1);
addFullAddress(BuildMI(BB, X86::MUL8m, 1), AM);
BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL);
}
return Result;
}
if (getRegPressure(Op0) > getRegPressure(Op1)) {
Tmp1 = SelectExpr(Op0);
Tmp2 = SelectExpr(Op1);
} else {
Tmp2 = SelectExpr(Op1);
Tmp1 = SelectExpr(Op0);
}
switch (N.getValueType()) {
default: assert(0 && "Cannot add this type!");
case MVT::i1:
case MVT::i8: Opc = 10; break;
case MVT::i16: Opc = 11; break;
case MVT::i32: Opc = 12; break;
case MVT::f32: Opc = 13; break;
case MVT::f64: Opc = 14; break;
}
switch (Node->getOpcode()) {
default: assert(0 && "Unreachable!");
case ISD::SUB: Opc = SUBTab[Opc]; break;
case ISD::MUL: Opc = MULTab[Opc]; break;
case ISD::AND: Opc = ANDTab[Opc]; break;
case ISD::OR: Opc = ORTab[Opc]; break;
case ISD::XOR: Opc = XORTab[Opc]; break;
}
if (Opc) {
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
} else {
assert(Node->getOpcode() == ISD::MUL &&
N.getValueType() == MVT::i8 && "Unexpected situation!");
// Must use the MUL instruction, which forces use of AL.
BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(Tmp1);
BuildMI(BB, X86::MUL8r, 1).addReg(Tmp2);
BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL);
}
return Result;
}
case ISD::SELECT:
if (getRegPressure(N.getOperand(1)) > getRegPressure(N.getOperand(2))) {
Tmp2 = SelectExpr(N.getOperand(1));
Tmp3 = SelectExpr(N.getOperand(2));
} else {
Tmp3 = SelectExpr(N.getOperand(2));
Tmp2 = SelectExpr(N.getOperand(1));
}
EmitSelectCC(N.getOperand(0), N.getValueType(), Tmp2, Tmp3, Result);
return Result;
case ISD::SDIV:
case ISD::UDIV:
case ISD::SREM:
case ISD::UREM: {
assert((N.getOpcode() != ISD::SREM || MVT::isInteger(N.getValueType())) &&
"We don't support this operator!");
if (N.getOpcode() == ISD::SDIV)
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
// FIXME: These special cases should be handled by the lowering impl!
unsigned RHS = CN->getValue();
bool isNeg = false;
if ((int)RHS < 0) {
isNeg = true;
RHS = -RHS;
}
if (RHS && (RHS & (RHS-1)) == 0) { // Signed division by power of 2?
unsigned Log = log2(RHS);
unsigned TmpReg = MakeReg(N.getValueType());
unsigned SAROpc, SHROpc, ADDOpc, NEGOpc;
switch (N.getValueType()) {
default: assert("Unknown type to signed divide!");
case MVT::i8:
SAROpc = X86::SAR8ri;
SHROpc = X86::SHR8ri;
ADDOpc = X86::ADD8rr;
NEGOpc = X86::NEG8r;
break;
case MVT::i16:
SAROpc = X86::SAR16ri;
SHROpc = X86::SHR16ri;
ADDOpc = X86::ADD16rr;
NEGOpc = X86::NEG16r;
break;
case MVT::i32:
SAROpc = X86::SAR32ri;
SHROpc = X86::SHR32ri;
ADDOpc = X86::ADD32rr;
NEGOpc = X86::NEG32r;
break;
}
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, SAROpc, 2, TmpReg).addReg(Tmp1).addImm(Log-1);
unsigned TmpReg2 = MakeReg(N.getValueType());
BuildMI(BB, SHROpc, 2, TmpReg2).addReg(TmpReg).addImm(32-Log);
unsigned TmpReg3 = MakeReg(N.getValueType());
BuildMI(BB, ADDOpc, 2, TmpReg3).addReg(Tmp1).addReg(TmpReg2);
unsigned TmpReg4 = isNeg ? MakeReg(N.getValueType()) : Result;
BuildMI(BB, SAROpc, 2, TmpReg4).addReg(TmpReg3).addImm(Log);
if (isNeg)
BuildMI(BB, NEGOpc, 1, Result).addReg(TmpReg4);
return Result;
}
}
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Tmp1 = SelectExpr(N.getOperand(0));
Tmp2 = SelectExpr(N.getOperand(1));
} else {
Tmp2 = SelectExpr(N.getOperand(1));
Tmp1 = SelectExpr(N.getOperand(0));
}
bool isSigned = N.getOpcode() == ISD::SDIV || N.getOpcode() == ISD::SREM;
bool isDiv = N.getOpcode() == ISD::SDIV || N.getOpcode() == ISD::UDIV;
unsigned LoReg, HiReg, DivOpcode, MovOpcode, ClrOpcode, SExtOpcode;
switch (N.getValueType()) {
default: assert(0 && "Cannot sdiv this type!");
case MVT::i8:
DivOpcode = isSigned ? X86::IDIV8r : X86::DIV8r;
LoReg = X86::AL;
HiReg = X86::AH;
MovOpcode = X86::MOV8rr;
ClrOpcode = X86::MOV8ri;
SExtOpcode = X86::CBW;
break;
case MVT::i16:
DivOpcode = isSigned ? X86::IDIV16r : X86::DIV16r;
LoReg = X86::AX;
HiReg = X86::DX;
MovOpcode = X86::MOV16rr;
ClrOpcode = X86::MOV16ri;
SExtOpcode = X86::CWD;
break;
case MVT::i32:
DivOpcode = isSigned ? X86::IDIV32r : X86::DIV32r;
LoReg = X86::EAX;
HiReg = X86::EDX;
MovOpcode = X86::MOV32rr;
ClrOpcode = X86::MOV32ri;
SExtOpcode = X86::CDQ;
break;
case MVT::f64:
BuildMI(BB, X86::FpDIV, 2, Result).addReg(Tmp1).addReg(Tmp2);
return Result;
}
// Set up the low part.
BuildMI(BB, MovOpcode, 1, LoReg).addReg(Tmp1);
if (isSigned) {
// Sign extend the low part into the high part.
BuildMI(BB, SExtOpcode, 0);
} else {
// Zero out the high part, effectively zero extending the input.
BuildMI(BB, ClrOpcode, 1, HiReg).addImm(0);
}
// Emit the DIV/IDIV instruction.
BuildMI(BB, DivOpcode, 1).addReg(Tmp2);
// Get the result of the divide or rem.
BuildMI(BB, MovOpcode, 1, Result).addReg(isDiv ? LoReg : HiReg);
return Result;
}
case ISD::SHL:
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
if (CN->getValue() == 1) { // X = SHL Y, 1 -> X = ADD Y, Y
switch (N.getValueType()) {
default: assert(0 && "Cannot shift this type!");
case MVT::i8: Opc = X86::ADD8rr; break;
case MVT::i16: Opc = X86::ADD16rr; break;
case MVT::i32: Opc = X86::ADD32rr; break;
}
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp1);
return Result;
}
switch (N.getValueType()) {
default: assert(0 && "Cannot shift this type!");
case MVT::i8: Opc = X86::SHL8ri; break;
case MVT::i16: Opc = X86::SHL16ri; break;
case MVT::i32: Opc = X86::SHL32ri; break;
}
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue());
return Result;
}
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Tmp1 = SelectExpr(N.getOperand(0));
Tmp2 = SelectExpr(N.getOperand(1));
} else {
Tmp2 = SelectExpr(N.getOperand(1));
Tmp1 = SelectExpr(N.getOperand(0));
}
switch (N.getValueType()) {
default: assert(0 && "Cannot shift this type!");
case MVT::i8 : Opc = X86::SHL8rCL; break;
case MVT::i16: Opc = X86::SHL16rCL; break;
case MVT::i32: Opc = X86::SHL32rCL; break;
}
BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(Tmp2);
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
return Result;
case ISD::SRL:
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
switch (N.getValueType()) {
default: assert(0 && "Cannot shift this type!");
case MVT::i8: Opc = X86::SHR8ri; break;
case MVT::i16: Opc = X86::SHR16ri; break;
case MVT::i32: Opc = X86::SHR32ri; break;
}
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue());
return Result;
}
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Tmp1 = SelectExpr(N.getOperand(0));
Tmp2 = SelectExpr(N.getOperand(1));
} else {
Tmp2 = SelectExpr(N.getOperand(1));
Tmp1 = SelectExpr(N.getOperand(0));
}
switch (N.getValueType()) {
default: assert(0 && "Cannot shift this type!");
case MVT::i8 : Opc = X86::SHR8rCL; break;
case MVT::i16: Opc = X86::SHR16rCL; break;
case MVT::i32: Opc = X86::SHR32rCL; break;
}
BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(Tmp2);
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
return Result;
case ISD::SRA:
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
switch (N.getValueType()) {
default: assert(0 && "Cannot shift this type!");
case MVT::i8: Opc = X86::SAR8ri; break;
case MVT::i16: Opc = X86::SAR16ri; break;
case MVT::i32: Opc = X86::SAR32ri; break;
}
Tmp1 = SelectExpr(N.getOperand(0));
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(CN->getValue());
return Result;
}
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Tmp1 = SelectExpr(N.getOperand(0));
Tmp2 = SelectExpr(N.getOperand(1));
} else {
Tmp2 = SelectExpr(N.getOperand(1));
Tmp1 = SelectExpr(N.getOperand(0));
}
switch (N.getValueType()) {
default: assert(0 && "Cannot shift this type!");
case MVT::i8 : Opc = X86::SAR8rCL; break;
case MVT::i16: Opc = X86::SAR16rCL; break;
case MVT::i32: Opc = X86::SAR32rCL; break;
}
BuildMI(BB, X86::MOV8rr, 1, X86::CL).addReg(Tmp2);
BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
return Result;
case ISD::SETCC:
EmitCMP(N.getOperand(0), N.getOperand(1), Node->hasOneUse());
EmitSetCC(BB, Result, cast<SetCCSDNode>(N)->getCondition(),
MVT::isFloatingPoint(N.getOperand(1).getValueType()));
return Result;
case ISD::LOAD:
// Make sure we generate both values.
if (Result != 1) { // Generate the token
if (!ExprMap.insert(std::make_pair(N.getValue(1), 1)).second)
assert(0 && "Load already emitted!?");
} else
Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
switch (Node->getValueType(0)) {
default: assert(0 && "Cannot load this type!");
case MVT::i1:
case MVT::i8: Opc = X86::MOV8rm; break;
case MVT::i16: Opc = X86::MOV16rm; break;
case MVT::i32: Opc = X86::MOV32rm; break;
case MVT::f64: Opc = X86::FLD64m; ContainsFPCode = true; break;
}
if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(N.getOperand(1))){
Select(N.getOperand(0));
addConstantPoolReference(BuildMI(BB, Opc, 4, Result), CP->getIndex());
} else {
X86AddressMode AM;
SDOperand Chain = N.getOperand(0);
SDOperand Address = N.getOperand(1);
if (getRegPressure(Chain) > getRegPressure(Address)) {
Select(Chain);
SelectAddress(Address, AM);
} else {
SelectAddress(Address, AM);
Select(Chain);
}
addFullAddress(BuildMI(BB, Opc, 4, Result), AM);
}
return Result;
case ISD::EXTLOAD: // Arbitrarily codegen extloads as MOVZX*
case ISD::ZEXTLOAD: {
// Make sure we generate both values.
if (Result != 1)
ExprMap[N.getValue(1)] = 1; // Generate the token
else
Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(N.getOperand(1)))
if (Node->getValueType(0) == MVT::f64) {
assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::f32 &&
"Bad EXTLOAD!");
addConstantPoolReference(BuildMI(BB, X86::FLD32m, 4, Result),
CP->getIndex());
return Result;
}
X86AddressMode AM;
if (getRegPressure(Node->getOperand(0)) >
getRegPressure(Node->getOperand(1))) {
Select(Node->getOperand(0)); // chain
SelectAddress(Node->getOperand(1), AM);
} else {
SelectAddress(Node->getOperand(1), AM);
Select(Node->getOperand(0)); // chain
}
switch (Node->getValueType(0)) {
default: assert(0 && "Unknown type to sign extend to.");
case MVT::f64:
assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::f32 &&
"Bad EXTLOAD!");
addFullAddress(BuildMI(BB, X86::FLD32m, 5, Result), AM);
break;
case MVT::i32:
switch (cast<MVTSDNode>(Node)->getExtraValueType()) {
default:
assert(0 && "Bad zero extend!");
case MVT::i1:
case MVT::i8:
addFullAddress(BuildMI(BB, X86::MOVZX32rm8, 5, Result), AM);
break;
case MVT::i16:
addFullAddress(BuildMI(BB, X86::MOVZX32rm16, 5, Result), AM);
break;
}
break;
case MVT::i16:
assert(cast<MVTSDNode>(Node)->getExtraValueType() <= MVT::i8 &&
"Bad zero extend!");
addFullAddress(BuildMI(BB, X86::MOVSX16rm8, 5, Result), AM);
break;
case MVT::i8:
assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::i1 &&
"Bad zero extend!");
addFullAddress(BuildMI(BB, X86::MOV8rm, 5, Result), AM);
break;
}
return Result;
}
case ISD::SEXTLOAD: {
// Make sure we generate both values.
if (Result != 1)
ExprMap[N.getValue(1)] = 1; // Generate the token
else
Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
X86AddressMode AM;
if (getRegPressure(Node->getOperand(0)) >
getRegPressure(Node->getOperand(1))) {
Select(Node->getOperand(0)); // chain
SelectAddress(Node->getOperand(1), AM);
} else {
SelectAddress(Node->getOperand(1), AM);
Select(Node->getOperand(0)); // chain
}
switch (Node->getValueType(0)) {
case MVT::i8: assert(0 && "Cannot sign extend from bool!");
default: assert(0 && "Unknown type to sign extend to.");
case MVT::i32:
switch (cast<MVTSDNode>(Node)->getExtraValueType()) {
default:
case MVT::i1: assert(0 && "Cannot sign extend from bool!");
case MVT::i8:
addFullAddress(BuildMI(BB, X86::MOVSX32rm8, 5, Result), AM);
break;
case MVT::i16:
addFullAddress(BuildMI(BB, X86::MOVSX32rm16, 5, Result), AM);
break;
}
break;
case MVT::i16:
assert(cast<MVTSDNode>(Node)->getExtraValueType() == MVT::i8 &&
"Cannot sign extend from bool!");
addFullAddress(BuildMI(BB, X86::MOVSX16rm8, 5, Result), AM);
break;
}
return Result;
}
case ISD::DYNAMIC_STACKALLOC:
// Generate both result values.
if (Result != 1)
ExprMap[N.getValue(1)] = 1; // Generate the token
else
Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
// FIXME: We are currently ignoring the requested alignment for handling
// greater than the stack alignment. This will need to be revisited at some
// point. Align = N.getOperand(2);
if (!isa<ConstantSDNode>(N.getOperand(2)) ||
cast<ConstantSDNode>(N.getOperand(2))->getValue() != 0) {
std::cerr << "Cannot allocate stack object with greater alignment than"
<< " the stack alignment yet!";
abort();
}
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
Select(N.getOperand(0));
BuildMI(BB, X86::SUB32ri, 2, X86::ESP).addReg(X86::ESP)
.addImm(CN->getValue());
} else {
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Select(N.getOperand(0));
Tmp1 = SelectExpr(N.getOperand(1));
} else {
Tmp1 = SelectExpr(N.getOperand(1));
Select(N.getOperand(0));
}
// Subtract size from stack pointer, thereby allocating some space.
BuildMI(BB, X86::SUB32rr, 2, X86::ESP).addReg(X86::ESP).addReg(Tmp1);
}
// Put a pointer to the space into the result register, by copying the stack
// pointer.
BuildMI(BB, X86::MOV32rr, 1, Result).addReg(X86::ESP);
return Result;
case ISD::CALL:
// The chain for this call is now lowered.
ExprMap.insert(std::make_pair(N.getValue(Node->getNumValues()-1), 1));
if (GlobalAddressSDNode *GASD =
dyn_cast<GlobalAddressSDNode>(N.getOperand(1))) {
Select(N.getOperand(0));
BuildMI(BB, X86::CALLpcrel32, 1).addGlobalAddress(GASD->getGlobal(),true);
} else if (ExternalSymbolSDNode *ESSDN =
dyn_cast<ExternalSymbolSDNode>(N.getOperand(1))) {
Select(N.getOperand(0));
BuildMI(BB, X86::CALLpcrel32,
1).addExternalSymbol(ESSDN->getSymbol(), true);
} else {
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Select(N.getOperand(0));
Tmp1 = SelectExpr(N.getOperand(1));
} else {
Tmp1 = SelectExpr(N.getOperand(1));
Select(N.getOperand(0));
}
BuildMI(BB, X86::CALL32r, 1).addReg(Tmp1);
}
switch (Node->getValueType(0)) {
default: assert(0 && "Unknown value type for call result!");
case MVT::Other: return 1;
case MVT::i1:
case MVT::i8:
BuildMI(BB, X86::MOV8rr, 1, Result).addReg(X86::AL);
break;
case MVT::i16:
BuildMI(BB, X86::MOV16rr, 1, Result).addReg(X86::AX);
break;
case MVT::i32:
BuildMI(BB, X86::MOV32rr, 1, Result).addReg(X86::EAX);
if (Node->getValueType(1) == MVT::i32)
BuildMI(BB, X86::MOV32rr, 1, Result+1).addReg(X86::EDX);
break;
case MVT::f64: // Floating-point return values live in %ST(0)
ContainsFPCode = true;
BuildMI(BB, X86::FpGETRESULT, 1, Result);
break;
}
return Result+N.ResNo;
}
return 0;
}
/// TryToFoldLoadOpStore - Given a store node, try to fold together a
/// load/op/store instruction. If successful return true.
bool ISel::TryToFoldLoadOpStore(SDNode *Node) {
assert(Node->getOpcode() == ISD::STORE && "Can only do this for stores!");
SDOperand Chain = Node->getOperand(0);
SDOperand StVal = Node->getOperand(1);
SDOperand StPtr = Node->getOperand(2);
// The chain has to be a load, the stored value must be an integer binary
// operation with one use.
if (!StVal.Val->hasOneUse() || StVal.Val->getNumOperands() != 2 ||
MVT::isFloatingPoint(StVal.getValueType()))
return false;
// Token chain must either be a factor node or the load to fold.
if (Chain.getOpcode() != ISD::LOAD && Chain.getOpcode() != ISD::TokenFactor)
return false;
SDOperand TheLoad;
// Check to see if there is a load from the same pointer that we're storing
// to in either operand of the binop.
if (StVal.getOperand(0).getOpcode() == ISD::LOAD &&
StVal.getOperand(0).getOperand(1) == StPtr)
TheLoad = StVal.getOperand(0);
else if (StVal.getOperand(1).getOpcode() == ISD::LOAD &&
StVal.getOperand(1).getOperand(1) == StPtr)
TheLoad = StVal.getOperand(1);
else
return false; // No matching load operand.
// We can only fold the load if there are no intervening side-effecting
// operations. This means that the store uses the load as its token chain, or
// there are only token factor nodes in between the store and load.
if (Chain != TheLoad.getValue(1)) {
// Okay, the other option is that we have a store referring to (possibly
// nested) token factor nodes. For now, just try peeking through one level
// of token factors to see if this is the case.
bool ChainOk = false;
if (Chain.getOpcode() == ISD::TokenFactor) {
for (unsigned i = 0, e = Chain.getNumOperands(); i != e; ++i)
if (Chain.getOperand(i) == TheLoad.getValue(1)) {
ChainOk = true;
break;
}
}
if (!ChainOk) return false;
}
if (TheLoad.getOperand(1) != StPtr)
return false;
// Make sure that one of the operands of the binop is the load, and that the
// load folds into the binop.
if (((StVal.getOperand(0) != TheLoad ||
!isFoldableLoad(TheLoad, StVal.getOperand(1))) &&
(StVal.getOperand(1) != TheLoad ||
!isFoldableLoad(TheLoad, StVal.getOperand(0)))))
return false;
// Finally, check to see if this is one of the ops we can handle!
static const unsigned ADDTAB[] = {
X86::ADD8mi, X86::ADD16mi, X86::ADD32mi,
X86::ADD8mr, X86::ADD16mr, X86::ADD32mr,
};
static const unsigned SUBTAB[] = {
X86::SUB8mi, X86::SUB16mi, X86::SUB32mi,
X86::SUB8mr, X86::SUB16mr, X86::SUB32mr,
};
static const unsigned ANDTAB[] = {
X86::AND8mi, X86::AND16mi, X86::AND32mi,
X86::AND8mr, X86::AND16mr, X86::AND32mr,
};
static const unsigned ORTAB[] = {
X86::OR8mi, X86::OR16mi, X86::OR32mi,
X86::OR8mr, X86::OR16mr, X86::OR32mr,
};
static const unsigned XORTAB[] = {
X86::XOR8mi, X86::XOR16mi, X86::XOR32mi,
X86::XOR8mr, X86::XOR16mr, X86::XOR32mr,
};
static const unsigned SHLTAB[] = {
X86::SHL8mi, X86::SHL16mi, X86::SHL32mi,
/*Have to put the reg in CL*/0, 0, 0,
};
static const unsigned SARTAB[] = {
X86::SAR8mi, X86::SAR16mi, X86::SAR32mi,
/*Have to put the reg in CL*/0, 0, 0,
};
static const unsigned SHRTAB[] = {
X86::SHR8mi, X86::SHR16mi, X86::SHR32mi,
/*Have to put the reg in CL*/0, 0, 0,
};
const unsigned *TabPtr = 0;
switch (StVal.getOpcode()) {
default:
std::cerr << "CANNOT [mem] op= val: ";
StVal.Val->dump(); std::cerr << "\n";
case ISD::MUL:
case ISD::SDIV:
case ISD::UDIV:
case ISD::SREM:
case ISD::UREM: return false;
case ISD::ADD: TabPtr = ADDTAB; break;
case ISD::SUB: TabPtr = SUBTAB; break;
case ISD::AND: TabPtr = ANDTAB; break;
case ISD:: OR: TabPtr = ORTAB; break;
case ISD::XOR: TabPtr = XORTAB; break;
case ISD::SHL: TabPtr = SHLTAB; break;
case ISD::SRA: TabPtr = SARTAB; break;
case ISD::SRL: TabPtr = SHRTAB; break;
}
// Handle: [mem] op= CST
SDOperand Op0 = StVal.getOperand(0);
SDOperand Op1 = StVal.getOperand(1);
unsigned Opc;
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) {
switch (Op0.getValueType()) { // Use Op0's type because of shifts.
default: break;
case MVT::i1:
case MVT::i8: Opc = TabPtr[0]; break;
case MVT::i16: Opc = TabPtr[1]; break;
case MVT::i32: Opc = TabPtr[2]; break;
}
if (Opc) {
if (!ExprMap.insert(std::make_pair(TheLoad.getValue(1), 1)).second)
assert(0 && "Already emitted?");
Select(Chain);
X86AddressMode AM;
if (getRegPressure(TheLoad.getOperand(0)) >
getRegPressure(TheLoad.getOperand(1))) {
Select(TheLoad.getOperand(0));
SelectAddress(TheLoad.getOperand(1), AM);
} else {
SelectAddress(TheLoad.getOperand(1), AM);
Select(TheLoad.getOperand(0));
}
if (StVal.getOpcode() == ISD::ADD) {
if (CN->getValue() == 1) {
switch (Op0.getValueType()) {
default: break;
case MVT::i8:
addFullAddress(BuildMI(BB, X86::INC8m, 4), AM);
return true;
case MVT::i16: Opc = TabPtr[1];
addFullAddress(BuildMI(BB, X86::INC16m, 4), AM);
return true;
case MVT::i32: Opc = TabPtr[2];
addFullAddress(BuildMI(BB, X86::INC32m, 4), AM);
return true;
}
} else if (CN->getValue()+1 == 0) { // [X] += -1 -> DEC [X]
switch (Op0.getValueType()) {
default: break;
case MVT::i8:
addFullAddress(BuildMI(BB, X86::DEC8m, 4), AM);
return true;
case MVT::i16: Opc = TabPtr[1];
addFullAddress(BuildMI(BB, X86::DEC16m, 4), AM);
return true;
case MVT::i32: Opc = TabPtr[2];
addFullAddress(BuildMI(BB, X86::DEC32m, 4), AM);
return true;
}
}
}
addFullAddress(BuildMI(BB, Opc, 4+1),AM).addImm(CN->getValue());
return true;
}
}
// If we have [mem] = V op [mem], try to turn it into:
// [mem] = [mem] op V.
if (Op1 == TheLoad && StVal.getOpcode() != ISD::SUB &&
StVal.getOpcode() != ISD::SHL && StVal.getOpcode() != ISD::SRA &&
StVal.getOpcode() != ISD::SRL)
std::swap(Op0, Op1);
if (Op0 != TheLoad) return false;
switch (Op0.getValueType()) {
default: return false;
case MVT::i1:
case MVT::i8: Opc = TabPtr[3]; break;
case MVT::i16: Opc = TabPtr[4]; break;
case MVT::i32: Opc = TabPtr[5]; break;
}
// Table entry doesn't exist?
if (Opc == 0) return false;
if (!ExprMap.insert(std::make_pair(TheLoad.getValue(1), 1)).second)
assert(0 && "Already emitted?");
Select(Chain);
Select(TheLoad.getOperand(0));
X86AddressMode AM;
SelectAddress(TheLoad.getOperand(1), AM);
unsigned Reg = SelectExpr(Op1);
addFullAddress(BuildMI(BB, Opc, 4+1), AM).addReg(Reg);
return true;
}
void ISel::Select(SDOperand N) {
unsigned Tmp1, Tmp2, Opc;
// FIXME: Disable for our current expansion model!
if (/*!N->hasOneUse() &&*/ !ExprMap.insert(std::make_pair(N, 1)).second)
return; // Already selected.
SDNode *Node = N.Val;
switch (Node->getOpcode()) {
default:
Node->dump(); std::cerr << "\n";
assert(0 && "Node not handled yet!");
case ISD::EntryToken: return; // Noop
case ISD::TokenFactor:
if (Node->getNumOperands() == 2) {
bool OneFirst =
getRegPressure(Node->getOperand(1))>getRegPressure(Node->getOperand(0));
Select(Node->getOperand(OneFirst));
Select(Node->getOperand(!OneFirst));
} else {
std::vector<std::pair<unsigned, unsigned> > OpsP;
for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i)
OpsP.push_back(std::make_pair(getRegPressure(Node->getOperand(i)), i));
std::sort(OpsP.begin(), OpsP.end());
std::reverse(OpsP.begin(), OpsP.end());
for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i)
Select(Node->getOperand(OpsP[i].second));
}
return;
case ISD::CopyToReg:
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Select(N.getOperand(0));
Tmp1 = SelectExpr(N.getOperand(1));
} else {
Tmp1 = SelectExpr(N.getOperand(1));
Select(N.getOperand(0));
}
Tmp2 = cast<RegSDNode>(N)->getReg();
if (Tmp1 != Tmp2) {
switch (N.getOperand(1).getValueType()) {
default: assert(0 && "Invalid type for operation!");
case MVT::i1:
case MVT::i8: Opc = X86::MOV8rr; break;
case MVT::i16: Opc = X86::MOV16rr; break;
case MVT::i32: Opc = X86::MOV32rr; break;
case MVT::f64: Opc = X86::FpMOV; ContainsFPCode = true; break;
}
BuildMI(BB, Opc, 1, Tmp2).addReg(Tmp1);
}
return;
case ISD::RET:
switch (N.getNumOperands()) {
default:
assert(0 && "Unknown return instruction!");
case 3:
assert(N.getOperand(1).getValueType() == MVT::i32 &&
N.getOperand(2).getValueType() == MVT::i32 &&
"Unknown two-register value!");
if (getRegPressure(N.getOperand(1)) > getRegPressure(N.getOperand(2))) {
Tmp1 = SelectExpr(N.getOperand(1));
Tmp2 = SelectExpr(N.getOperand(2));
} else {
Tmp2 = SelectExpr(N.getOperand(2));
Tmp1 = SelectExpr(N.getOperand(1));
}
Select(N.getOperand(0));
BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Tmp1);
BuildMI(BB, X86::MOV32rr, 1, X86::EDX).addReg(Tmp2);
// Declare that EAX & EDX are live on exit.
BuildMI(BB, X86::IMPLICIT_USE, 3).addReg(X86::EAX).addReg(X86::EDX)
.addReg(X86::ESP);
break;
case 2:
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Select(N.getOperand(0));
Tmp1 = SelectExpr(N.getOperand(1));
} else {
Tmp1 = SelectExpr(N.getOperand(1));
Select(N.getOperand(0));
}
switch (N.getOperand(1).getValueType()) {
default: assert(0 && "All other types should have been promoted!!");
case MVT::f64:
BuildMI(BB, X86::FpSETRESULT, 1).addReg(Tmp1);
// Declare that top-of-stack is live on exit
BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::ST0).addReg(X86::ESP);
break;
case MVT::i32:
BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Tmp1);
BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::EAX).addReg(X86::ESP);
break;
}
break;
case 1:
Select(N.getOperand(0));
break;
}
BuildMI(BB, X86::RET, 0); // Just emit a 'ret' instruction
return;
case ISD::BR: {
Select(N.getOperand(0));
MachineBasicBlock *Dest =
cast<BasicBlockSDNode>(N.getOperand(1))->getBasicBlock();
BuildMI(BB, X86::JMP, 1).addMBB(Dest);
return;
}
case ISD::BRCOND: {
MachineBasicBlock *Dest =
cast<BasicBlockSDNode>(N.getOperand(2))->getBasicBlock();
// Try to fold a setcc into the branch. If this fails, emit a test/jne
// pair.
if (EmitBranchCC(Dest, N.getOperand(0), N.getOperand(1))) {
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(1))) {
Select(N.getOperand(0));
Tmp1 = SelectExpr(N.getOperand(1));
} else {
Tmp1 = SelectExpr(N.getOperand(1));
Select(N.getOperand(0));
}
BuildMI(BB, X86::TEST8rr, 2).addReg(Tmp1).addReg(Tmp1);
BuildMI(BB, X86::JNE, 1).addMBB(Dest);
}
return;
}
case ISD::LOAD:
// If this load could be folded into the only using instruction, and if it
// is safe to emit the instruction here, try to do so now.
if (Node->hasNUsesOfValue(1, 0)) {
SDOperand TheVal = N.getValue(0);
SDNode *User = 0;
for (SDNode::use_iterator UI = Node->use_begin(); ; ++UI) {
assert(UI != Node->use_end() && "Didn't find use!");
SDNode *UN = *UI;
for (unsigned i = 0, e = UN->getNumOperands(); i != e; ++i)
if (UN->getOperand(i) == TheVal) {
User = UN;
goto FoundIt;
}
}
FoundIt:
// Only handle unary operators right now.
if (User->getNumOperands() == 1) {
ExprMap.erase(N);
SelectExpr(SDOperand(User, 0));
return;
}
}
ExprMap.erase(N);
SelectExpr(N);
return;
case ISD::EXTLOAD:
case ISD::SEXTLOAD:
case ISD::ZEXTLOAD:
case ISD::CALL:
case ISD::DYNAMIC_STACKALLOC:
ExprMap.erase(N);
SelectExpr(N);
return;
case ISD::TRUNCSTORE: { // truncstore chain, val, ptr :storety
// On X86, we can represent all types except for Bool and Float natively.
X86AddressMode AM;
MVT::ValueType StoredTy = cast<MVTSDNode>(Node)->getExtraValueType();
assert((StoredTy == MVT::i1 || StoredTy == MVT::f32 ||
StoredTy == MVT::i16 /*FIXME: THIS IS JUST FOR TESTING!*/)
&& "Unsupported TRUNCSTORE for this target!");
if (StoredTy == MVT::i16) {
// FIXME: This is here just to allow testing. X86 doesn't really have a
// TRUNCSTORE i16 operation, but this is required for targets that do not
// have 16-bit integer registers. We occasionally disable 16-bit integer
// registers to test the promotion code.
Select(N.getOperand(0));
Tmp1 = SelectExpr(N.getOperand(1));
SelectAddress(N.getOperand(2), AM);
BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(Tmp1);
addFullAddress(BuildMI(BB, X86::MOV16mr, 5), AM).addReg(X86::AX);
return;
}
// Store of constant bool?
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(2))) {
Select(N.getOperand(0));
SelectAddress(N.getOperand(2), AM);
} else {
SelectAddress(N.getOperand(2), AM);
Select(N.getOperand(0));
}
addFullAddress(BuildMI(BB, X86::MOV8mi, 5), AM).addImm(CN->getValue());
return;
}
switch (StoredTy) {
default: assert(0 && "Cannot truncstore this type!");
case MVT::i1: Opc = X86::MOV8mr; break;
case MVT::f32: Opc = X86::FST32m; break;
}
std::vector<std::pair<unsigned, unsigned> > RP;
RP.push_back(std::make_pair(getRegPressure(N.getOperand(0)), 0));
RP.push_back(std::make_pair(getRegPressure(N.getOperand(1)), 1));
RP.push_back(std::make_pair(getRegPressure(N.getOperand(2)), 2));
std::sort(RP.begin(), RP.end());
for (unsigned i = 0; i != 3; ++i)
switch (RP[2-i].second) {
default: assert(0 && "Unknown operand number!");
case 0: Select(N.getOperand(0)); break;
case 1: Tmp1 = SelectExpr(N.getOperand(1)); break;
case 2: SelectAddress(N.getOperand(2), AM); break;
}
addFullAddress(BuildMI(BB, Opc, 4+1), AM).addReg(Tmp1);
return;
}
case ISD::STORE: {
X86AddressMode AM;
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
Opc = 0;
switch (CN->getValueType(0)) {
default: assert(0 && "Invalid type for operation!");
case MVT::i1:
case MVT::i8: Opc = X86::MOV8mi; break;
case MVT::i16: Opc = X86::MOV16mi; break;
case MVT::i32: Opc = X86::MOV32mi; break;
case MVT::f64: break;
}
if (Opc) {
if (getRegPressure(N.getOperand(0)) > getRegPressure(N.getOperand(2))) {
Select(N.getOperand(0));
SelectAddress(N.getOperand(2), AM);
} else {
SelectAddress(N.getOperand(2), AM);
Select(N.getOperand(0));
}
addFullAddress(BuildMI(BB, Opc, 4+1), AM).addImm(CN->getValue());
return;
}
}
// Check to see if this is a load/op/store combination.
if (TryToFoldLoadOpStore(Node))
return;
switch (N.getOperand(1).getValueType()) {
default: assert(0 && "Cannot store this type!");
case MVT::i1:
case MVT::i8: Opc = X86::MOV8mr; break;
case MVT::i16: Opc = X86::MOV16mr; break;
case MVT::i32: Opc = X86::MOV32mr; break;
case MVT::f64: Opc = X86::FST64m; break;
}
std::vector<std::pair<unsigned, unsigned> > RP;
RP.push_back(std::make_pair(getRegPressure(N.getOperand(0)), 0));
RP.push_back(std::make_pair(getRegPressure(N.getOperand(1)), 1));
RP.push_back(std::make_pair(getRegPressure(N.getOperand(2)), 2));
std::sort(RP.begin(), RP.end());
for (unsigned i = 0; i != 3; ++i)
switch (RP[2-i].second) {
default: assert(0 && "Unknown operand number!");
case 0: Select(N.getOperand(0)); break;
case 1: Tmp1 = SelectExpr(N.getOperand(1)); break;
case 2: SelectAddress(N.getOperand(2), AM); break;
}
addFullAddress(BuildMI(BB, Opc, 4+1), AM).addReg(Tmp1);
return;
}
case ISD::ADJCALLSTACKDOWN:
case ISD::ADJCALLSTACKUP:
Select(N.getOperand(0));
Tmp1 = cast<ConstantSDNode>(N.getOperand(1))->getValue();
Opc = N.getOpcode() == ISD::ADJCALLSTACKDOWN ? X86::ADJCALLSTACKDOWN :
X86::ADJCALLSTACKUP;
BuildMI(BB, Opc, 1).addImm(Tmp1);
return;
case ISD::MEMSET: {
Select(N.getOperand(0)); // Select the chain.
unsigned Align =
(unsigned)cast<ConstantSDNode>(Node->getOperand(4))->getValue();
if (Align == 0) Align = 1;
// Turn the byte code into # iterations
unsigned CountReg;
unsigned Opcode;
if (ConstantSDNode *ValC = dyn_cast<ConstantSDNode>(Node->getOperand(2))) {
unsigned Val = ValC->getValue() & 255;
// If the value is a constant, then we can potentially use larger sets.
switch (Align & 3) {
case 2: // WORD aligned
CountReg = MakeReg(MVT::i32);
if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) {
BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/2);
} else {
unsigned ByteReg = SelectExpr(Node->getOperand(3));
BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(1);
}
BuildMI(BB, X86::MOV16ri, 1, X86::AX).addImm((Val << 8) | Val);
Opcode = X86::REP_STOSW;
break;
case 0: // DWORD aligned
CountReg = MakeReg(MVT::i32);
if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) {
BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/4);
} else {
unsigned ByteReg = SelectExpr(Node->getOperand(3));
BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(2);
}
Val = (Val << 8) | Val;
BuildMI(BB, X86::MOV32ri, 1, X86::EAX).addImm((Val << 16) | Val);
Opcode = X86::REP_STOSD;
break;
default: // BYTE aligned
CountReg = SelectExpr(Node->getOperand(3));
BuildMI(BB, X86::MOV8ri, 1, X86::AL).addImm(Val);
Opcode = X86::REP_STOSB;
break;
}
} else {
// If it's not a constant value we are storing, just fall back. We could
// try to be clever to form 16 bit and 32 bit values, but we don't yet.
unsigned ValReg = SelectExpr(Node->getOperand(2));
BuildMI(BB, X86::MOV8rr, 1, X86::AL).addReg(ValReg);
CountReg = SelectExpr(Node->getOperand(3));
Opcode = X86::REP_STOSB;
}
// No matter what the alignment is, we put the source in ESI, the
// destination in EDI, and the count in ECX.
unsigned TmpReg1 = SelectExpr(Node->getOperand(1));
BuildMI(BB, X86::MOV32rr, 1, X86::ECX).addReg(CountReg);
BuildMI(BB, X86::MOV32rr, 1, X86::EDI).addReg(TmpReg1);
BuildMI(BB, Opcode, 0);
return;
}
case ISD::MEMCPY:
Select(N.getOperand(0)); // Select the chain.
unsigned Align =
(unsigned)cast<ConstantSDNode>(Node->getOperand(4))->getValue();
if (Align == 0) Align = 1;
// Turn the byte code into # iterations
unsigned CountReg;
unsigned Opcode;
switch (Align & 3) {
case 2: // WORD aligned
CountReg = MakeReg(MVT::i32);
if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) {
BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/2);
} else {
unsigned ByteReg = SelectExpr(Node->getOperand(3));
BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(1);
}
Opcode = X86::REP_MOVSW;
break;
case 0: // DWORD aligned
CountReg = MakeReg(MVT::i32);
if (ConstantSDNode *I = dyn_cast<ConstantSDNode>(Node->getOperand(3))) {
BuildMI(BB, X86::MOV32ri, 1, CountReg).addImm(I->getValue()/4);
} else {
unsigned ByteReg = SelectExpr(Node->getOperand(3));
BuildMI(BB, X86::SHR32ri, 2, CountReg).addReg(ByteReg).addImm(2);
}
Opcode = X86::REP_MOVSD;
break;
default: // BYTE aligned
CountReg = SelectExpr(Node->getOperand(3));
Opcode = X86::REP_MOVSB;
break;
}
// No matter what the alignment is, we put the source in ESI, the
// destination in EDI, and the count in ECX.
unsigned TmpReg1 = SelectExpr(Node->getOperand(1));
unsigned TmpReg2 = SelectExpr(Node->getOperand(2));
BuildMI(BB, X86::MOV32rr, 1, X86::ECX).addReg(CountReg);
BuildMI(BB, X86::MOV32rr, 1, X86::EDI).addReg(TmpReg1);
BuildMI(BB, X86::MOV32rr, 1, X86::ESI).addReg(TmpReg2);
BuildMI(BB, Opcode, 0);
return;
}
assert(0 && "Should not be reached!");
}
/// createX86PatternInstructionSelector - This pass converts an LLVM function
/// into a machine code representation using pattern matching and a machine
/// description file.
///
FunctionPass *llvm::createX86PatternInstructionSelector(TargetMachine &TM) {
return new ISel(TM);
}
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