maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/lib/Target/X86/X86FastISel.cpp

1771 lines
60 KiB
C++
Raw Blame History

//===-- X86FastISel.cpp - X86 FastISel implementation ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the X86-specific support for the FastISel class. Much
// of the target-specific code is generated by tablegen in the file
// X86GenFastISel.inc, which is #included here.
//
//===----------------------------------------------------------------------===//
#include "X86.h"
#include "X86InstrBuilder.h"
#include "X86RegisterInfo.h"
#include "X86Subtarget.h"
#include "X86TargetMachine.h"
#include "llvm/CallingConv.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
namespace {
class X86FastISel : public FastISel {
/// Subtarget - Keep a pointer to the X86Subtarget around so that we can
/// make the right decision when generating code for different targets.
const X86Subtarget *Subtarget;
/// StackPtr - Register used as the stack pointer.
///
unsigned StackPtr;
/// X86ScalarSSEf32, X86ScalarSSEf64 - Select between SSE or x87
/// floating point ops.
/// When SSE is available, use it for f32 operations.
/// When SSE2 is available, use it for f64 operations.
bool X86ScalarSSEf64;
bool X86ScalarSSEf32;
public:
explicit X86FastISel(MachineFunction &mf,
DenseMap<const Value *, unsigned> &vm,
DenseMap<const BasicBlock *, MachineBasicBlock *> &bm,
DenseMap<const AllocaInst *, int> &am,
std::vector<std::pair<MachineInstr*, unsigned> > &pn
#ifndef NDEBUG
, SmallSet<const Instruction *, 8> &cil
#endif
)
: FastISel(mf, vm, bm, am, pn
#ifndef NDEBUG
, cil
#endif
) {
Subtarget = &TM.getSubtarget<X86Subtarget>();
StackPtr = Subtarget->is64Bit() ? X86::RSP : X86::ESP;
X86ScalarSSEf64 = Subtarget->hasSSE2();
X86ScalarSSEf32 = Subtarget->hasSSE1();
}
virtual bool TargetSelectInstruction(const Instruction *I);
#include "X86GenFastISel.inc"
private:
bool X86FastEmitCompare(const Value *LHS, const Value *RHS, EVT VT);
bool X86FastEmitLoad(EVT VT, const X86AddressMode &AM, unsigned &RR);
bool X86FastEmitStore(EVT VT, const Value *Val,
const X86AddressMode &AM);
bool X86FastEmitStore(EVT VT, unsigned Val,
const X86AddressMode &AM);
bool X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT, unsigned Src, EVT SrcVT,
unsigned &ResultReg);
bool X86SelectAddress(const Value *V, X86AddressMode &AM);
bool X86SelectCallAddress(const Value *V, X86AddressMode &AM);
bool X86SelectLoad(const Instruction *I);
bool X86SelectStore(const Instruction *I);
bool X86SelectCmp(const Instruction *I);
bool X86SelectZExt(const Instruction *I);
bool X86SelectBranch(const Instruction *I);
bool X86SelectShift(const Instruction *I);
bool X86SelectSelect(const Instruction *I);
bool X86SelectTrunc(const Instruction *I);
bool X86SelectFPExt(const Instruction *I);
bool X86SelectFPTrunc(const Instruction *I);
bool X86SelectExtractValue(const Instruction *I);
bool X86VisitIntrinsicCall(const IntrinsicInst &I);
bool X86SelectCall(const Instruction *I);
CCAssignFn *CCAssignFnForCall(CallingConv::ID CC, bool isTailCall = false);
const X86InstrInfo *getInstrInfo() const {
return getTargetMachine()->getInstrInfo();
}
const X86TargetMachine *getTargetMachine() const {
return static_cast<const X86TargetMachine *>(&TM);
}
unsigned TargetMaterializeConstant(const Constant *C);
unsigned TargetMaterializeAlloca(const AllocaInst *C);
/// isScalarFPTypeInSSEReg - Return true if the specified scalar FP type is
/// computed in an SSE register, not on the X87 floating point stack.
bool isScalarFPTypeInSSEReg(EVT VT) const {
return (VT == MVT::f64 && X86ScalarSSEf64) || // f64 is when SSE2
(VT == MVT::f32 && X86ScalarSSEf32); // f32 is when SSE1
}
bool isTypeLegal(const Type *Ty, EVT &VT, bool AllowI1 = false);
};
} // end anonymous namespace.
bool X86FastISel::isTypeLegal(const Type *Ty, EVT &VT, bool AllowI1) {
VT = TLI.getValueType(Ty, /*HandleUnknown=*/true);
if (VT == MVT::Other || !VT.isSimple())
// Unhandled type. Halt "fast" selection and bail.
return false;
// For now, require SSE/SSE2 for performing floating-point operations,
// since x87 requires additional work.
if (VT == MVT::f64 && !X86ScalarSSEf64)
return false;
if (VT == MVT::f32 && !X86ScalarSSEf32)
return false;
// Similarly, no f80 support yet.
if (VT == MVT::f80)
return false;
// We only handle legal types. For example, on x86-32 the instruction
// selector contains all of the 64-bit instructions from x86-64,
// under the assumption that i64 won't be used if the target doesn't
// support it.
return (AllowI1 && VT == MVT::i1) || TLI.isTypeLegal(VT);
}
#include "X86GenCallingConv.inc"
/// CCAssignFnForCall - Selects the correct CCAssignFn for a given calling
/// convention.
CCAssignFn *X86FastISel::CCAssignFnForCall(CallingConv::ID CC,
bool isTaillCall) {
if (Subtarget->is64Bit()) {
if (CC == CallingConv::GHC)
return CC_X86_64_GHC;
else if (Subtarget->isTargetWin64())
return CC_X86_Win64_C;
else
return CC_X86_64_C;
}
if (CC == CallingConv::X86_FastCall)
return CC_X86_32_FastCall;
else if (CC == CallingConv::Fast)
return CC_X86_32_FastCC;
else if (CC == CallingConv::GHC)
return CC_X86_32_GHC;
else
return CC_X86_32_C;
}
/// X86FastEmitLoad - Emit a machine instruction to load a value of type VT.
/// The address is either pre-computed, i.e. Ptr, or a GlobalAddress, i.e. GV.
/// Return true and the result register by reference if it is possible.
bool X86FastISel::X86FastEmitLoad(EVT VT, const X86AddressMode &AM,
unsigned &ResultReg) {
// Get opcode and regclass of the output for the given load instruction.
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
switch (VT.getSimpleVT().SimpleTy) {
default: return false;
case MVT::i1:
case MVT::i8:
Opc = X86::MOV8rm;
RC = X86::GR8RegisterClass;
break;
case MVT::i16:
Opc = X86::MOV16rm;
RC = X86::GR16RegisterClass;
break;
case MVT::i32:
Opc = X86::MOV32rm;
RC = X86::GR32RegisterClass;
break;
case MVT::i64:
// Must be in x86-64 mode.
Opc = X86::MOV64rm;
RC = X86::GR64RegisterClass;
break;
case MVT::f32:
if (Subtarget->hasSSE1()) {
Opc = X86::MOVSSrm;
RC = X86::FR32RegisterClass;
} else {
Opc = X86::LD_Fp32m;
RC = X86::RFP32RegisterClass;
}
break;
case MVT::f64:
if (Subtarget->hasSSE2()) {
Opc = X86::MOVSDrm;
RC = X86::FR64RegisterClass;
} else {
Opc = X86::LD_Fp64m;
RC = X86::RFP64RegisterClass;
}
break;
case MVT::f80:
// No f80 support yet.
return false;
}
ResultReg = createResultReg(RC);
addFullAddress(BuildMI(MBB, DL, TII.get(Opc), ResultReg), AM);
return true;
}
/// X86FastEmitStore - Emit a machine instruction to store a value Val of
/// type VT. The address is either pre-computed, consisted of a base ptr, Ptr
/// and a displacement offset, or a GlobalAddress,
/// i.e. V. Return true if it is possible.
bool
X86FastISel::X86FastEmitStore(EVT VT, unsigned Val,
const X86AddressMode &AM) {
// Get opcode and regclass of the output for the given store instruction.
unsigned Opc = 0;
switch (VT.getSimpleVT().SimpleTy) {
case MVT::f80: // No f80 support yet.
default: return false;
case MVT::i1: {
// Mask out all but lowest bit.
unsigned AndResult = createResultReg(X86::GR8RegisterClass);
BuildMI(MBB, DL,
TII.get(X86::AND8ri), AndResult).addReg(Val).addImm(1);
Val = AndResult;
}
// FALLTHROUGH, handling i1 as i8.
case MVT::i8: Opc = X86::MOV8mr; break;
case MVT::i16: Opc = X86::MOV16mr; break;
case MVT::i32: Opc = X86::MOV32mr; break;
case MVT::i64: Opc = X86::MOV64mr; break; // Must be in x86-64 mode.
case MVT::f32:
Opc = Subtarget->hasSSE1() ? X86::MOVSSmr : X86::ST_Fp32m;
break;
case MVT::f64:
Opc = Subtarget->hasSSE2() ? X86::MOVSDmr : X86::ST_Fp64m;
break;
}
addFullAddress(BuildMI(MBB, DL, TII.get(Opc)), AM).addReg(Val);
return true;
}
bool X86FastISel::X86FastEmitStore(EVT VT, const Value *Val,
const X86AddressMode &AM) {
// Handle 'null' like i32/i64 0.
if (isa<ConstantPointerNull>(Val))
Val = Constant::getNullValue(TD.getIntPtrType(Val->getContext()));
// If this is a store of a simple constant, fold the constant into the store.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
unsigned Opc = 0;
bool Signed = true;
switch (VT.getSimpleVT().SimpleTy) {
default: break;
case MVT::i1: Signed = false; // FALLTHROUGH to handle as i8.
case MVT::i8: Opc = X86::MOV8mi; break;
case MVT::i16: Opc = X86::MOV16mi; break;
case MVT::i32: Opc = X86::MOV32mi; break;
case MVT::i64:
// Must be a 32-bit sign extended value.
if ((int)CI->getSExtValue() == CI->getSExtValue())
Opc = X86::MOV64mi32;
break;
}
if (Opc) {
addFullAddress(BuildMI(MBB, DL, TII.get(Opc)), AM)
.addImm(Signed ? (uint64_t) CI->getSExtValue() :
CI->getZExtValue());
return true;
}
}
unsigned ValReg = getRegForValue(Val);
if (ValReg == 0)
return false;
return X86FastEmitStore(VT, ValReg, AM);
}
/// X86FastEmitExtend - Emit a machine instruction to extend a value Src of
/// type SrcVT to type DstVT using the specified extension opcode Opc (e.g.
/// ISD::SIGN_EXTEND).
bool X86FastISel::X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT,
unsigned Src, EVT SrcVT,
unsigned &ResultReg) {
unsigned RR = FastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Opc, Src);
if (RR != 0) {
ResultReg = RR;
return true;
} else
return false;
}
/// X86SelectAddress - Attempt to fill in an address from the given value.
///
bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
const User *U = NULL;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(V)) {
Opcode = I->getOpcode();
U = I;
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default: break;
case Instruction::BitCast:
// Look past bitcasts.
return X86SelectAddress(U->getOperand(0), AM);
case Instruction::IntToPtr:
// Look past no-op inttoptrs.
if (TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
return X86SelectAddress(U->getOperand(0), AM);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints.
if (TLI.getValueType(U->getType()) == TLI.getPointerTy())
return X86SelectAddress(U->getOperand(0), AM);
break;
case Instruction::Alloca: {
// Do static allocas.
const AllocaInst *A = cast<AllocaInst>(V);
DenseMap<const AllocaInst*, int>::iterator SI = StaticAllocaMap.find(A);
if (SI != StaticAllocaMap.end()) {
AM.BaseType = X86AddressMode::FrameIndexBase;
AM.Base.FrameIndex = SI->second;
return true;
}
break;
}
case Instruction::Add: {
// Adds of constants are common and easy enough.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(U->getOperand(1))) {
uint64_t Disp = (int32_t)AM.Disp + (uint64_t)CI->getSExtValue();
// They have to fit in the 32-bit signed displacement field though.
if (isInt<32>(Disp)) {
AM.Disp = (uint32_t)Disp;
return X86SelectAddress(U->getOperand(0), AM);
}
}
break;
}
case Instruction::GetElementPtr: {
X86AddressMode SavedAM = AM;
// Pattern-match simple GEPs.
uint64_t Disp = (int32_t)AM.Disp;
unsigned IndexReg = AM.IndexReg;
unsigned Scale = AM.Scale;
gep_type_iterator GTI = gep_type_begin(U);
// Iterate through the indices, folding what we can. Constants can be
// folded, and one dynamic index can be handled, if the scale is supported.
for (User::const_op_iterator i = U->op_begin() + 1, e = U->op_end();
i != e; ++i, ++GTI) {
const Value *Op = *i;
if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
const StructLayout *SL = TD.getStructLayout(STy);
unsigned Idx = cast<ConstantInt>(Op)->getZExtValue();
Disp += SL->getElementOffset(Idx);
} else {
uint64_t S = TD.getTypeAllocSize(GTI.getIndexedType());
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
// Constant-offset addressing.
Disp += CI->getSExtValue() * S;
} else if (IndexReg == 0 &&
(!AM.GV || !Subtarget->isPICStyleRIPRel()) &&
(S == 1 || S == 2 || S == 4 || S == 8)) {
// Scaled-index addressing.
Scale = S;
IndexReg = getRegForGEPIndex(Op);
if (IndexReg == 0)
return false;
} else
// Unsupported.
goto unsupported_gep;
}
}
// Check for displacement overflow.
if (!isInt<32>(Disp))
break;
// Ok, the GEP indices were covered by constant-offset and scaled-index
// addressing. Update the address state and move on to examining the base.
AM.IndexReg = IndexReg;
AM.Scale = Scale;
AM.Disp = (uint32_t)Disp;
if (X86SelectAddress(U->getOperand(0), AM))
return true;
// If we couldn't merge the sub value into this addr mode, revert back to
// our address and just match the value instead of completely failing.
AM = SavedAM;
break;
unsupported_gep:
// Ok, the GEP indices weren't all covered.
break;
}
}
// Handle constant address.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Can't handle alternate code models yet.
if (TM.getCodeModel() != CodeModel::Small)
return false;
// RIP-relative addresses can't have additional register operands.
if (Subtarget->isPICStyleRIPRel() &&
(AM.Base.Reg != 0 || AM.IndexReg != 0))
return false;
// Can't handle TLS yet.
if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
if (GVar->isThreadLocal())
return false;
// Okay, we've committed to selecting this global. Set up the basic address.
AM.GV = GV;
// Allow the subtarget to classify the global.
unsigned char GVFlags = Subtarget->ClassifyGlobalReference(GV, TM);
// If this reference is relative to the pic base, set it now.
if (isGlobalRelativeToPICBase(GVFlags)) {
// FIXME: How do we know Base.Reg is free??
AM.Base.Reg = getInstrInfo()->getGlobalBaseReg(&MF);
}
// Unless the ABI requires an extra load, return a direct reference to
// the global.
if (!isGlobalStubReference(GVFlags)) {
if (Subtarget->isPICStyleRIPRel()) {
// Use rip-relative addressing if we can. Above we verified that the
// base and index registers are unused.
assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
AM.Base.Reg = X86::RIP;
}
AM.GVOpFlags = GVFlags;
return true;
}
// Ok, we need to do a load from a stub. If we've already loaded from this
// stub, reuse the loaded pointer, otherwise emit the load now.
DenseMap<const Value*, unsigned>::iterator I = LocalValueMap.find(V);
unsigned LoadReg;
if (I != LocalValueMap.end() && I->second != 0) {
LoadReg = I->second;
} else {
// Issue load from stub.
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
X86AddressMode StubAM;
StubAM.Base.Reg = AM.Base.Reg;
StubAM.GV = GV;
StubAM.GVOpFlags = GVFlags;
if (TLI.getPointerTy() == MVT::i64) {
Opc = X86::MOV64rm;
RC = X86::GR64RegisterClass;
if (Subtarget->isPICStyleRIPRel())
StubAM.Base.Reg = X86::RIP;
} else {
Opc = X86::MOV32rm;
RC = X86::GR32RegisterClass;
}
LoadReg = createResultReg(RC);
addFullAddress(BuildMI(MBB, DL, TII.get(Opc), LoadReg), StubAM);
// Prevent loading GV stub multiple times in same MBB.
LocalValueMap[V] = LoadReg;
}
// Now construct the final address. Note that the Disp, Scale,
// and Index values may already be set here.
AM.Base.Reg = LoadReg;
AM.GV = 0;
return true;
}
// If all else fails, try to materialize the value in a register.
if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
if (AM.Base.Reg == 0) {
AM.Base.Reg = getRegForValue(V);
return AM.Base.Reg != 0;
}
if (AM.IndexReg == 0) {
assert(AM.Scale == 1 && "Scale with no index!");
AM.IndexReg = getRegForValue(V);
return AM.IndexReg != 0;
}
}
return false;
}
/// X86SelectCallAddress - Attempt to fill in an address from the given value.
///
bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) {
const User *U = NULL;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(V)) {
Opcode = I->getOpcode();
U = I;
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default: break;
case Instruction::BitCast:
// Look past bitcasts.
return X86SelectCallAddress(U->getOperand(0), AM);
case Instruction::IntToPtr:
// Look past no-op inttoptrs.
if (TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
return X86SelectCallAddress(U->getOperand(0), AM);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints.
if (TLI.getValueType(U->getType()) == TLI.getPointerTy())
return X86SelectCallAddress(U->getOperand(0), AM);
break;
}
// Handle constant address.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Can't handle alternate code models yet.
if (TM.getCodeModel() != CodeModel::Small)
return false;
// RIP-relative addresses can't have additional register operands.
if (Subtarget->isPICStyleRIPRel() &&
(AM.Base.Reg != 0 || AM.IndexReg != 0))
return false;
// Can't handle TLS or DLLImport.
if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
if (GVar->isThreadLocal() || GVar->hasDLLImportLinkage())
return false;
// Okay, we've committed to selecting this global. Set up the basic address.
AM.GV = GV;
// No ABI requires an extra load for anything other than DLLImport, which
// we rejected above. Return a direct reference to the global.
if (Subtarget->isPICStyleRIPRel()) {
// Use rip-relative addressing if we can. Above we verified that the
// base and index registers are unused.
assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
AM.Base.Reg = X86::RIP;
} else if (Subtarget->isPICStyleStubPIC()) {
AM.GVOpFlags = X86II::MO_PIC_BASE_OFFSET;
} else if (Subtarget->isPICStyleGOT()) {
AM.GVOpFlags = X86II::MO_GOTOFF;
}
return true;
}
// If all else fails, try to materialize the value in a register.
if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
if (AM.Base.Reg == 0) {
AM.Base.Reg = getRegForValue(V);
return AM.Base.Reg != 0;
}
if (AM.IndexReg == 0) {
assert(AM.Scale == 1 && "Scale with no index!");
AM.IndexReg = getRegForValue(V);
return AM.IndexReg != 0;
}
}
return false;
}
/// X86SelectStore - Select and emit code to implement store instructions.
bool X86FastISel::X86SelectStore(const Instruction *I) {
EVT VT;
if (!isTypeLegal(I->getOperand(0)->getType(), VT, /*AllowI1=*/true))
return false;
X86AddressMode AM;
if (!X86SelectAddress(I->getOperand(1), AM))
return false;
return X86FastEmitStore(VT, I->getOperand(0), AM);
}
/// X86SelectLoad - Select and emit code to implement load instructions.
///
bool X86FastISel::X86SelectLoad(const Instruction *I) {
EVT VT;
if (!isTypeLegal(I->getType(), VT, /*AllowI1=*/true))
return false;
X86AddressMode AM;
if (!X86SelectAddress(I->getOperand(0), AM))
return false;
unsigned ResultReg = 0;
if (X86FastEmitLoad(VT, AM, ResultReg)) {
UpdateValueMap(I, ResultReg);
return true;
}
return false;
}
static unsigned X86ChooseCmpOpcode(EVT VT) {
switch (VT.getSimpleVT().SimpleTy) {
default: return 0;
case MVT::i8: return X86::CMP8rr;
case MVT::i16: return X86::CMP16rr;
case MVT::i32: return X86::CMP32rr;
case MVT::i64: return X86::CMP64rr;
case MVT::f32: return X86::UCOMISSrr;
case MVT::f64: return X86::UCOMISDrr;
}
}
/// X86ChooseCmpImmediateOpcode - If we have a comparison with RHS as the RHS
/// of the comparison, return an opcode that works for the compare (e.g.
/// CMP32ri) otherwise return 0.
static unsigned X86ChooseCmpImmediateOpcode(EVT VT, const ConstantInt *RHSC) {
switch (VT.getSimpleVT().SimpleTy) {
// Otherwise, we can't fold the immediate into this comparison.
default: return 0;
case MVT::i8: return X86::CMP8ri;
case MVT::i16: return X86::CMP16ri;
case MVT::i32: return X86::CMP32ri;
case MVT::i64:
// 64-bit comparisons are only valid if the immediate fits in a 32-bit sext
// field.
if ((int)RHSC->getSExtValue() == RHSC->getSExtValue())
return X86::CMP64ri32;
return 0;
}
}
bool X86FastISel::X86FastEmitCompare(const Value *Op0, const Value *Op1,
EVT VT) {
unsigned Op0Reg = getRegForValue(Op0);
if (Op0Reg == 0) return false;
// Handle 'null' like i32/i64 0.
if (isa<ConstantPointerNull>(Op1))
Op1 = Constant::getNullValue(TD.getIntPtrType(Op0->getContext()));
// We have two options: compare with register or immediate. If the RHS of
// the compare is an immediate that we can fold into this compare, use
// CMPri, otherwise use CMPrr.
if (const ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
if (unsigned CompareImmOpc = X86ChooseCmpImmediateOpcode(VT, Op1C)) {
BuildMI(MBB, DL, TII.get(CompareImmOpc)).addReg(Op0Reg)
.addImm(Op1C->getSExtValue());
return true;
}
}
unsigned CompareOpc = X86ChooseCmpOpcode(VT);
if (CompareOpc == 0) return false;
unsigned Op1Reg = getRegForValue(Op1);
if (Op1Reg == 0) return false;
BuildMI(MBB, DL, TII.get(CompareOpc)).addReg(Op0Reg).addReg(Op1Reg);
return true;
}
bool X86FastISel::X86SelectCmp(const Instruction *I) {
const CmpInst *CI = cast<CmpInst>(I);
EVT VT;
if (!isTypeLegal(I->getOperand(0)->getType(), VT))
return false;
unsigned ResultReg = createResultReg(&X86::GR8RegClass);
unsigned SetCCOpc;
bool SwapArgs; // false -> compare Op0, Op1. true -> compare Op1, Op0.
switch (CI->getPredicate()) {
case CmpInst::FCMP_OEQ: {
if (!X86FastEmitCompare(CI->getOperand(0), CI->getOperand(1), VT))
return false;
unsigned EReg = createResultReg(&X86::GR8RegClass);
unsigned NPReg = createResultReg(&X86::GR8RegClass);
BuildMI(MBB, DL, TII.get(X86::SETEr), EReg);
BuildMI(MBB, DL, TII.get(X86::SETNPr), NPReg);
BuildMI(MBB, DL,
TII.get(X86::AND8rr), ResultReg).addReg(NPReg).addReg(EReg);
UpdateValueMap(I, ResultReg);
return true;
}
case CmpInst::FCMP_UNE: {
if (!X86FastEmitCompare(CI->getOperand(0), CI->getOperand(1), VT))
return false;
unsigned NEReg = createResultReg(&X86::GR8RegClass);
unsigned PReg = createResultReg(&X86::GR8RegClass);
BuildMI(MBB, DL, TII.get(X86::SETNEr), NEReg);
BuildMI(MBB, DL, TII.get(X86::SETPr), PReg);
BuildMI(MBB, DL, TII.get(X86::OR8rr), ResultReg).addReg(PReg).addReg(NEReg);
UpdateValueMap(I, ResultReg);
return true;
}
case CmpInst::FCMP_OGT: SwapArgs = false; SetCCOpc = X86::SETAr; break;
case CmpInst::FCMP_OGE: SwapArgs = false; SetCCOpc = X86::SETAEr; break;
case CmpInst::FCMP_OLT: SwapArgs = true; SetCCOpc = X86::SETAr; break;
case CmpInst::FCMP_OLE: SwapArgs = true; SetCCOpc = X86::SETAEr; break;
case CmpInst::FCMP_ONE: SwapArgs = false; SetCCOpc = X86::SETNEr; break;
case CmpInst::FCMP_ORD: SwapArgs = false; SetCCOpc = X86::SETNPr; break;
case CmpInst::FCMP_UNO: SwapArgs = false; SetCCOpc = X86::SETPr; break;
case CmpInst::FCMP_UEQ: SwapArgs = false; SetCCOpc = X86::SETEr; break;
case CmpInst::FCMP_UGT: SwapArgs = true; SetCCOpc = X86::SETBr; break;
case CmpInst::FCMP_UGE: SwapArgs = true; SetCCOpc = X86::SETBEr; break;
case CmpInst::FCMP_ULT: SwapArgs = false; SetCCOpc = X86::SETBr; break;
case CmpInst::FCMP_ULE: SwapArgs = false; SetCCOpc = X86::SETBEr; break;
case CmpInst::ICMP_EQ: SwapArgs = false; SetCCOpc = X86::SETEr; break;
case CmpInst::ICMP_NE: SwapArgs = false; SetCCOpc = X86::SETNEr; break;
case CmpInst::ICMP_UGT: SwapArgs = false; SetCCOpc = X86::SETAr; break;
case CmpInst::ICMP_UGE: SwapArgs = false; SetCCOpc = X86::SETAEr; break;
case CmpInst::ICMP_ULT: SwapArgs = false; SetCCOpc = X86::SETBr; break;
case CmpInst::ICMP_ULE: SwapArgs = false; SetCCOpc = X86::SETBEr; break;
case CmpInst::ICMP_SGT: SwapArgs = false; SetCCOpc = X86::SETGr; break;
case CmpInst::ICMP_SGE: SwapArgs = false; SetCCOpc = X86::SETGEr; break;
case CmpInst::ICMP_SLT: SwapArgs = false; SetCCOpc = X86::SETLr; break;
case CmpInst::ICMP_SLE: SwapArgs = false; SetCCOpc = X86::SETLEr; break;
default:
return false;
}
const Value *Op0 = CI->getOperand(0), *Op1 = CI->getOperand(1);
if (SwapArgs)
std::swap(Op0, Op1);
// Emit a compare of Op0/Op1.
if (!X86FastEmitCompare(Op0, Op1, VT))
return false;
BuildMI(MBB, DL, TII.get(SetCCOpc), ResultReg);
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectZExt(const Instruction *I) {
// Handle zero-extension from i1 to i8, which is common.
if (I->getType()->isIntegerTy(8) &&
I->getOperand(0)->getType()->isIntegerTy(1)) {
unsigned ResultReg = getRegForValue(I->getOperand(0));
if (ResultReg == 0) return false;
// Set the high bits to zero.
ResultReg = FastEmitZExtFromI1(MVT::i8, ResultReg);
if (ResultReg == 0) return false;
UpdateValueMap(I, ResultReg);
return true;
}
return false;
}
bool X86FastISel::X86SelectBranch(const Instruction *I) {
// Unconditional branches are selected by tablegen-generated code.
// Handle a conditional branch.
const BranchInst *BI = cast<BranchInst>(I);
MachineBasicBlock *TrueMBB = MBBMap[BI->getSuccessor(0)];
MachineBasicBlock *FalseMBB = MBBMap[BI->getSuccessor(1)];
// Fold the common case of a conditional branch with a comparison.
if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) {
if (CI->hasOneUse()) {
EVT VT = TLI.getValueType(CI->getOperand(0)->getType());
// Try to take advantage of fallthrough opportunities.
CmpInst::Predicate Predicate = CI->getPredicate();
if (MBB->isLayoutSuccessor(TrueMBB)) {
std::swap(TrueMBB, FalseMBB);
Predicate = CmpInst::getInversePredicate(Predicate);
}
bool SwapArgs; // false -> compare Op0, Op1. true -> compare Op1, Op0.
unsigned BranchOpc; // Opcode to jump on, e.g. "X86::JA"
switch (Predicate) {
case CmpInst::FCMP_OEQ:
std::swap(TrueMBB, FalseMBB);
Predicate = CmpInst::FCMP_UNE;
// FALL THROUGH
case CmpInst::FCMP_UNE: SwapArgs = false; BranchOpc = X86::JNE_4; break;
case CmpInst::FCMP_OGT: SwapArgs = false; BranchOpc = X86::JA_4; break;
case CmpInst::FCMP_OGE: SwapArgs = false; BranchOpc = X86::JAE_4; break;
case CmpInst::FCMP_OLT: SwapArgs = true; BranchOpc = X86::JA_4; break;
case CmpInst::FCMP_OLE: SwapArgs = true; BranchOpc = X86::JAE_4; break;
case CmpInst::FCMP_ONE: SwapArgs = false; BranchOpc = X86::JNE_4; break;
case CmpInst::FCMP_ORD: SwapArgs = false; BranchOpc = X86::JNP_4; break;
case CmpInst::FCMP_UNO: SwapArgs = false; BranchOpc = X86::JP_4; break;
case CmpInst::FCMP_UEQ: SwapArgs = false; BranchOpc = X86::JE_4; break;
case CmpInst::FCMP_UGT: SwapArgs = true; BranchOpc = X86::JB_4; break;
case CmpInst::FCMP_UGE: SwapArgs = true; BranchOpc = X86::JBE_4; break;
case CmpInst::FCMP_ULT: SwapArgs = false; BranchOpc = X86::JB_4; break;
case CmpInst::FCMP_ULE: SwapArgs = false; BranchOpc = X86::JBE_4; break;
case CmpInst::ICMP_EQ: SwapArgs = false; BranchOpc = X86::JE_4; break;
case CmpInst::ICMP_NE: SwapArgs = false; BranchOpc = X86::JNE_4; break;
case CmpInst::ICMP_UGT: SwapArgs = false; BranchOpc = X86::JA_4; break;
case CmpInst::ICMP_UGE: SwapArgs = false; BranchOpc = X86::JAE_4; break;
case CmpInst::ICMP_ULT: SwapArgs = false; BranchOpc = X86::JB_4; break;
case CmpInst::ICMP_ULE: SwapArgs = false; BranchOpc = X86::JBE_4; break;
case CmpInst::ICMP_SGT: SwapArgs = false; BranchOpc = X86::JG_4; break;
case CmpInst::ICMP_SGE: SwapArgs = false; BranchOpc = X86::JGE_4; break;
case CmpInst::ICMP_SLT: SwapArgs = false; BranchOpc = X86::JL_4; break;
case CmpInst::ICMP_SLE: SwapArgs = false; BranchOpc = X86::JLE_4; break;
default:
return false;
}
const Value *Op0 = CI->getOperand(0), *Op1 = CI->getOperand(1);
if (SwapArgs)
std::swap(Op0, Op1);
// Emit a compare of the LHS and RHS, setting the flags.
if (!X86FastEmitCompare(Op0, Op1, VT))
return false;
BuildMI(MBB, DL, TII.get(BranchOpc)).addMBB(TrueMBB);
if (Predicate == CmpInst::FCMP_UNE) {
// X86 requires a second branch to handle UNE (and OEQ,
// which is mapped to UNE above).
BuildMI(MBB, DL, TII.get(X86::JP_4)).addMBB(TrueMBB);
}
FastEmitBranch(FalseMBB);
MBB->addSuccessor(TrueMBB);
return true;
}
} else if (ExtractValueInst *EI =
dyn_cast<ExtractValueInst>(BI->getCondition())) {
// Check to see if the branch instruction is from an "arithmetic with
// overflow" intrinsic. The main way these intrinsics are used is:
//
// %t = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %v1, i32 %v2)
// %sum = extractvalue { i32, i1 } %t, 0
// %obit = extractvalue { i32, i1 } %t, 1
// br i1 %obit, label %overflow, label %normal
//
// The %sum and %obit are converted in an ADD and a SETO/SETB before
// reaching the branch. Therefore, we search backwards through the MBB
// looking for the SETO/SETB instruction. If an instruction modifies the
// EFLAGS register before we reach the SETO/SETB instruction, then we can't
// convert the branch into a JO/JB instruction.
if (const IntrinsicInst *CI =
dyn_cast<IntrinsicInst>(EI->getAggregateOperand())){
if (CI->getIntrinsicID() == Intrinsic::sadd_with_overflow ||
CI->getIntrinsicID() == Intrinsic::uadd_with_overflow) {
const MachineInstr *SetMI = 0;
unsigned Reg = lookUpRegForValue(EI);
for (MachineBasicBlock::const_reverse_iterator
RI = MBB->rbegin(), RE = MBB->rend(); RI != RE; ++RI) {
const MachineInstr &MI = *RI;
if (MI.modifiesRegister(Reg)) {
unsigned Src, Dst, SrcSR, DstSR;
if (getInstrInfo()->isMoveInstr(MI, Src, Dst, SrcSR, DstSR)) {
Reg = Src;
continue;
}
SetMI = &MI;
break;
}
const TargetInstrDesc &TID = MI.getDesc();
if (TID.hasUnmodeledSideEffects() ||
TID.hasImplicitDefOfPhysReg(X86::EFLAGS))
break;
}
if (SetMI) {
unsigned OpCode = SetMI->getOpcode();
if (OpCode == X86::SETOr || OpCode == X86::SETBr) {
BuildMI(MBB, DL, TII.get(OpCode == X86::SETOr ?
X86::JO_4 : X86::JB_4))
.addMBB(TrueMBB);
FastEmitBranch(FalseMBB);
MBB->addSuccessor(TrueMBB);
return true;
}
}
}
}
}
// Otherwise do a clumsy setcc and re-test it.
unsigned OpReg = getRegForValue(BI->getCondition());
if (OpReg == 0) return false;
BuildMI(MBB, DL, TII.get(X86::TEST8rr)).addReg(OpReg).addReg(OpReg);
BuildMI(MBB, DL, TII.get(X86::JNE_4)).addMBB(TrueMBB);
FastEmitBranch(FalseMBB);
MBB->addSuccessor(TrueMBB);
return true;
}
bool X86FastISel::X86SelectShift(const Instruction *I) {
unsigned CReg = 0, OpReg = 0, OpImm = 0;
const TargetRegisterClass *RC = NULL;
if (I->getType()->isIntegerTy(8)) {
CReg = X86::CL;
RC = &X86::GR8RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR8rCL; OpImm = X86::SHR8ri; break;
case Instruction::AShr: OpReg = X86::SAR8rCL; OpImm = X86::SAR8ri; break;
case Instruction::Shl: OpReg = X86::SHL8rCL; OpImm = X86::SHL8ri; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(16)) {
CReg = X86::CX;
RC = &X86::GR16RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR16rCL; OpImm = X86::SHR16ri; break;
case Instruction::AShr: OpReg = X86::SAR16rCL; OpImm = X86::SAR16ri; break;
case Instruction::Shl: OpReg = X86::SHL16rCL; OpImm = X86::SHL16ri; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(32)) {
CReg = X86::ECX;
RC = &X86::GR32RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR32rCL; OpImm = X86::SHR32ri; break;
case Instruction::AShr: OpReg = X86::SAR32rCL; OpImm = X86::SAR32ri; break;
case Instruction::Shl: OpReg = X86::SHL32rCL; OpImm = X86::SHL32ri; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(64)) {
CReg = X86::RCX;
RC = &X86::GR64RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR64rCL; OpImm = X86::SHR64ri; break;
case Instruction::AShr: OpReg = X86::SAR64rCL; OpImm = X86::SAR64ri; break;
case Instruction::Shl: OpReg = X86::SHL64rCL; OpImm = X86::SHL64ri; break;
default: return false;
}
} else {
return false;
}
EVT VT = TLI.getValueType(I->getType(), /*HandleUnknown=*/true);
if (VT == MVT::Other || !isTypeLegal(I->getType(), VT))
return false;
unsigned Op0Reg = getRegForValue(I->getOperand(0));
if (Op0Reg == 0) return false;
// Fold immediate in shl(x,3).
if (const ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
unsigned ResultReg = createResultReg(RC);
BuildMI(MBB, DL, TII.get(OpImm),
ResultReg).addReg(Op0Reg).addImm(CI->getZExtValue() & 0xff);
UpdateValueMap(I, ResultReg);
return true;
}
unsigned Op1Reg = getRegForValue(I->getOperand(1));
if (Op1Reg == 0) return false;
TII.copyRegToReg(*MBB, MBB->end(), CReg, Op1Reg, RC, RC);
// The shift instruction uses X86::CL. If we defined a super-register
// of X86::CL, emit an EXTRACT_SUBREG to precisely describe what
// we're doing here.
if (CReg != X86::CL)
BuildMI(MBB, DL, TII.get(TargetOpcode::EXTRACT_SUBREG), X86::CL)
.addReg(CReg).addImm(X86::SUBREG_8BIT);
unsigned ResultReg = createResultReg(RC);
BuildMI(MBB, DL, TII.get(OpReg), ResultReg).addReg(Op0Reg);
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectSelect(const Instruction *I) {
EVT VT = TLI.getValueType(I->getType(), /*HandleUnknown=*/true);
if (VT == MVT::Other || !isTypeLegal(I->getType(), VT))
return false;
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
if (VT.getSimpleVT() == MVT::i16) {
Opc = X86::CMOVE16rr;
RC = &X86::GR16RegClass;
} else if (VT.getSimpleVT() == MVT::i32) {
Opc = X86::CMOVE32rr;
RC = &X86::GR32RegClass;
} else if (VT.getSimpleVT() == MVT::i64) {
Opc = X86::CMOVE64rr;
RC = &X86::GR64RegClass;
} else {
return false;
}
unsigned Op0Reg = getRegForValue(I->getOperand(0));
if (Op0Reg == 0) return false;
unsigned Op1Reg = getRegForValue(I->getOperand(1));
if (Op1Reg == 0) return false;
unsigned Op2Reg = getRegForValue(I->getOperand(2));
if (Op2Reg == 0) return false;
BuildMI(MBB, DL, TII.get(X86::TEST8rr)).addReg(Op0Reg).addReg(Op0Reg);
unsigned ResultReg = createResultReg(RC);
BuildMI(MBB, DL, TII.get(Opc), ResultReg).addReg(Op1Reg).addReg(Op2Reg);
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectFPExt(const Instruction *I) {
// fpext from float to double.
if (Subtarget->hasSSE2() &&
I->getType()->isDoubleTy()) {
const Value *V = I->getOperand(0);
if (V->getType()->isFloatTy()) {
unsigned OpReg = getRegForValue(V);
if (OpReg == 0) return false;
unsigned ResultReg = createResultReg(X86::FR64RegisterClass);
BuildMI(MBB, DL, TII.get(X86::CVTSS2SDrr), ResultReg).addReg(OpReg);
UpdateValueMap(I, ResultReg);
return true;
}
}
return false;
}
bool X86FastISel::X86SelectFPTrunc(const Instruction *I) {
if (Subtarget->hasSSE2()) {
if (I->getType()->isFloatTy()) {
const Value *V = I->getOperand(0);
if (V->getType()->isDoubleTy()) {
unsigned OpReg = getRegForValue(V);
if (OpReg == 0) return false;
unsigned ResultReg = createResultReg(X86::FR32RegisterClass);
BuildMI(MBB, DL, TII.get(X86::CVTSD2SSrr), ResultReg).addReg(OpReg);
UpdateValueMap(I, ResultReg);
return true;
}
}
}
return false;
}
bool X86FastISel::X86SelectTrunc(const Instruction *I) {
if (Subtarget->is64Bit())
// All other cases should be handled by the tblgen generated code.
return false;
EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
EVT DstVT = TLI.getValueType(I->getType());
// This code only handles truncation to byte right now.
if (DstVT != MVT::i8 && DstVT != MVT::i1)
// All other cases should be handled by the tblgen generated code.
return false;
if (SrcVT != MVT::i16 && SrcVT != MVT::i32)
// All other cases should be handled by the tblgen generated code.
return false;
unsigned InputReg = getRegForValue(I->getOperand(0));
if (!InputReg)
// Unhandled operand. Halt "fast" selection and bail.
return false;
// First issue a copy to GR16_ABCD or GR32_ABCD.
unsigned CopyOpc = (SrcVT == MVT::i16) ? X86::MOV16rr : X86::MOV32rr;
const TargetRegisterClass *CopyRC = (SrcVT == MVT::i16)
? X86::GR16_ABCDRegisterClass : X86::GR32_ABCDRegisterClass;
unsigned CopyReg = createResultReg(CopyRC);
BuildMI(MBB, DL, TII.get(CopyOpc), CopyReg).addReg(InputReg);
// Then issue an extract_subreg.
unsigned ResultReg = FastEmitInst_extractsubreg(MVT::i8,
CopyReg, X86::SUBREG_8BIT);
if (!ResultReg)
return false;
UpdateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectExtractValue(const Instruction *I) {
const ExtractValueInst *EI = cast<ExtractValueInst>(I);
const Value *Agg = EI->getAggregateOperand();
if (const IntrinsicInst *CI = dyn_cast<IntrinsicInst>(Agg)) {
switch (CI->getIntrinsicID()) {
default: break;
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
// Cheat a little. We know that the registers for "add" and "seto" are
// allocated sequentially. However, we only keep track of the register
// for "add" in the value map. Use extractvalue's index to get the
// correct register for "seto".
UpdateValueMap(I, lookUpRegForValue(Agg) + *EI->idx_begin());
return true;
}
}
return false;
}
bool X86FastISel::X86VisitIntrinsicCall(const IntrinsicInst &I) {
// FIXME: Handle more intrinsics.
switch (I.getIntrinsicID()) {
default: return false;
case Intrinsic::stackprotector: {
// Emit code inline code to store the stack guard onto the stack.
EVT PtrTy = TLI.getPointerTy();
const Value *Op1 = I.getOperand(1); // The guard's value.
const AllocaInst *Slot = cast<AllocaInst>(I.getOperand(2));
// Grab the frame index.
X86AddressMode AM;
if (!X86SelectAddress(Slot, AM)) return false;
if (!X86FastEmitStore(PtrTy, Op1, AM)) return false;
return true;
}
case Intrinsic::objectsize: {
ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(2));
const Type *Ty = I.getCalledFunction()->getReturnType();
assert(CI && "Non-constant type in Intrinsic::objectsize?");
EVT VT;
if (!isTypeLegal(Ty, VT))
return false;
unsigned OpC = 0;
if (VT == MVT::i32)
OpC = X86::MOV32ri;
else if (VT == MVT::i64)
OpC = X86::MOV64ri;
else
return false;
unsigned ResultReg = createResultReg(TLI.getRegClassFor(VT));
BuildMI(MBB, DL, TII.get(OpC), ResultReg).
addImm(CI->getZExtValue() == 0 ? -1ULL : 0);
UpdateValueMap(&I, ResultReg);
return true;
}
case Intrinsic::dbg_declare: {
const DbgDeclareInst *DI = cast<DbgDeclareInst>(&I);
X86AddressMode AM;
assert(DI->getAddress() && "Null address should be checked earlier!");
if (!X86SelectAddress(DI->getAddress(), AM))
return false;
const TargetInstrDesc &II = TII.get(TargetOpcode::DBG_VALUE);
// FIXME may need to add RegState::Debug to any registers produced,
// although ESP/EBP should be the only ones at the moment.
addFullAddress(BuildMI(MBB, DL, II), AM).addImm(0).
addMetadata(DI->getVariable());
return true;
}
case Intrinsic::trap: {
BuildMI(MBB, DL, TII.get(X86::TRAP));
return true;
}
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow: {
// Replace "add with overflow" intrinsics with an "add" instruction followed
// by a seto/setc instruction. Later on, when the "extractvalue"
// instructions are encountered, we use the fact that two registers were
// created sequentially to get the correct registers for the "sum" and the
// "overflow bit".
const Function *Callee = I.getCalledFunction();
const Type *RetTy =
cast<StructType>(Callee->getReturnType())->getTypeAtIndex(unsigned(0));
EVT VT;
if (!isTypeLegal(RetTy, VT))
return false;
const Value *Op1 = I.getOperand(1);
const Value *Op2 = I.getOperand(2);
unsigned Reg1 = getRegForValue(Op1);
unsigned Reg2 = getRegForValue(Op2);
if (Reg1 == 0 || Reg2 == 0)
// FIXME: Handle values *not* in registers.
return false;
unsigned OpC = 0;
if (VT == MVT::i32)
OpC = X86::ADD32rr;
else if (VT == MVT::i64)
OpC = X86::ADD64rr;
else
return false;
unsigned ResultReg = createResultReg(TLI.getRegClassFor(VT));
BuildMI(MBB, DL, TII.get(OpC), ResultReg).addReg(Reg1).addReg(Reg2);
unsigned DestReg1 = UpdateValueMap(&I, ResultReg);
// If the add with overflow is an intra-block value then we just want to
// create temporaries for it like normal. If it is a cross-block value then
// UpdateValueMap will return the cross-block register used. Since we
// *really* want the value to be live in the register pair known by
// UpdateValueMap, we have to use DestReg1+1 as the destination register in
// the cross block case. In the non-cross-block case, we should just make
// another register for the value.
if (DestReg1 != ResultReg)
ResultReg = DestReg1+1;
else
ResultReg = createResultReg(TLI.getRegClassFor(MVT::i8));
unsigned Opc = X86::SETBr;
if (I.getIntrinsicID() == Intrinsic::sadd_with_overflow)
Opc = X86::SETOr;
BuildMI(MBB, DL, TII.get(Opc), ResultReg);
return true;
}
}
}
bool X86FastISel::X86SelectCall(const Instruction *I) {
const CallInst *CI = cast<CallInst>(I);
const Value *Callee = I->getOperand(0);
// Can't handle inline asm yet.
if (isa<InlineAsm>(Callee))
return false;
// Handle intrinsic calls.
if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI))
return X86VisitIntrinsicCall(*II);
// Handle only C and fastcc calling conventions for now.
ImmutableCallSite CS(CI);
CallingConv::ID CC = CS.getCallingConv();
if (CC != CallingConv::C &&
CC != CallingConv::Fast &&
CC != CallingConv::X86_FastCall)
return false;
// fastcc with -tailcallopt is intended to provide a guaranteed
// tail call optimization. Fastisel doesn't know how to do that.
if (CC == CallingConv::Fast && GuaranteedTailCallOpt)
return false;
// Let SDISel handle vararg functions.
const PointerType *PT = cast<PointerType>(CS.getCalledValue()->getType());
const FunctionType *FTy = cast<FunctionType>(PT->getElementType());
if (FTy->isVarArg())
return false;
// Handle *simple* calls for now.
const Type *RetTy = CS.getType();
EVT RetVT;
if (RetTy->isVoidTy())
RetVT = MVT::isVoid;
else if (!isTypeLegal(RetTy, RetVT, true))
return false;
// Materialize callee address in a register. FIXME: GV address can be
// handled with a CALLpcrel32 instead.
X86AddressMode CalleeAM;
if (!X86SelectCallAddress(Callee, CalleeAM))
return false;
unsigned CalleeOp = 0;
const GlobalValue *GV = 0;
if (CalleeAM.GV != 0) {
GV = CalleeAM.GV;
} else if (CalleeAM.Base.Reg != 0) {
CalleeOp = CalleeAM.Base.Reg;
} else
return false;
// Allow calls which produce i1 results.
bool AndToI1 = false;
if (RetVT == MVT::i1) {
RetVT = MVT::i8;
AndToI1 = true;
}
// Deal with call operands first.
SmallVector<const Value *, 8> ArgVals;
SmallVector<unsigned, 8> Args;
SmallVector<EVT, 8> ArgVTs;
SmallVector<ISD::ArgFlagsTy, 8> ArgFlags;
Args.reserve(CS.arg_size());
ArgVals.reserve(CS.arg_size());
ArgVTs.reserve(CS.arg_size());
ArgFlags.reserve(CS.arg_size());
for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
i != e; ++i) {
unsigned Arg = getRegForValue(*i);
if (Arg == 0)
return false;
ISD::ArgFlagsTy Flags;
unsigned AttrInd = i - CS.arg_begin() + 1;
if (CS.paramHasAttr(AttrInd, Attribute::SExt))
Flags.setSExt();
if (CS.paramHasAttr(AttrInd, Attribute::ZExt))
Flags.setZExt();
// FIXME: Only handle *easy* calls for now.
if (CS.paramHasAttr(AttrInd, Attribute::InReg) ||
CS.paramHasAttr(AttrInd, Attribute::StructRet) ||
CS.paramHasAttr(AttrInd, Attribute::Nest) ||
CS.paramHasAttr(AttrInd, Attribute::ByVal))
return false;
const Type *ArgTy = (*i)->getType();
EVT ArgVT;
if (!isTypeLegal(ArgTy, ArgVT))
return false;
unsigned OriginalAlignment = TD.getABITypeAlignment(ArgTy);
Flags.setOrigAlign(OriginalAlignment);
Args.push_back(Arg);
ArgVals.push_back(*i);
ArgVTs.push_back(ArgVT);
ArgFlags.push_back(Flags);
}
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, false, TM, ArgLocs, I->getParent()->getContext());
CCInfo.AnalyzeCallOperands(ArgVTs, ArgFlags, CCAssignFnForCall(CC));
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = CCInfo.getNextStackOffset();
// Issue CALLSEQ_START
unsigned AdjStackDown = TM.getRegisterInfo()->getCallFrameSetupOpcode();
BuildMI(MBB, DL, TII.get(AdjStackDown)).addImm(NumBytes);
// Process argument: walk the register/memloc assignments, inserting
// copies / loads.
SmallVector<unsigned, 4> RegArgs;
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
unsigned Arg = Args[VA.getValNo()];
EVT ArgVT = ArgVTs[VA.getValNo()];
// Promote the value if needed.
switch (VA.getLocInfo()) {
default: llvm_unreachable("Unknown loc info!");
case CCValAssign::Full: break;
case CCValAssign::SExt: {
bool Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
assert(Emitted && "Failed to emit a sext!"); Emitted=Emitted;
Emitted = true;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::ZExt: {
bool Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
assert(Emitted && "Failed to emit a zext!"); Emitted=Emitted;
Emitted = true;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::AExt: {
bool Emitted = X86FastEmitExtend(ISD::ANY_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
if (!Emitted)
Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
if (!Emitted)
Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(),
Arg, ArgVT, Arg);
assert(Emitted && "Failed to emit a aext!"); Emitted=Emitted;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::BCvt: {
unsigned BC = FastEmit_r(ArgVT.getSimpleVT(), VA.getLocVT().getSimpleVT(),
ISD::BIT_CONVERT, Arg);
assert(BC != 0 && "Failed to emit a bitcast!");
Arg = BC;
ArgVT = VA.getLocVT();
break;
}
}
if (VA.isRegLoc()) {
TargetRegisterClass* RC = TLI.getRegClassFor(ArgVT);
bool Emitted = TII.copyRegToReg(*MBB, MBB->end(), VA.getLocReg(),
Arg, RC, RC);
assert(Emitted && "Failed to emit a copy instruction!"); Emitted=Emitted;
Emitted = true;
RegArgs.push_back(VA.getLocReg());
} else {
unsigned LocMemOffset = VA.getLocMemOffset();
X86AddressMode AM;
AM.Base.Reg = StackPtr;
AM.Disp = LocMemOffset;
const Value *ArgVal = ArgVals[VA.getValNo()];
// If this is a really simple value, emit this with the Value* version of
// X86FastEmitStore. If it isn't simple, we don't want to do this, as it
// can cause us to reevaluate the argument.
if (isa<ConstantInt>(ArgVal) || isa<ConstantPointerNull>(ArgVal))
X86FastEmitStore(ArgVT, ArgVal, AM);
else
X86FastEmitStore(ArgVT, Arg, AM);
}
}
// ELF / PIC requires GOT in the EBX register before function calls via PLT
// GOT pointer.
if (Subtarget->isPICStyleGOT()) {
TargetRegisterClass *RC = X86::GR32RegisterClass;
unsigned Base = getInstrInfo()->getGlobalBaseReg(&MF);
bool Emitted = TII.copyRegToReg(*MBB, MBB->end(), X86::EBX, Base, RC, RC);
assert(Emitted && "Failed to emit a copy instruction!"); Emitted=Emitted;
Emitted = true;
}
// Issue the call.
MachineInstrBuilder MIB;
if (CalleeOp) {
// Register-indirect call.
unsigned CallOpc = Subtarget->is64Bit() ? X86::CALL64r : X86::CALL32r;
MIB = BuildMI(MBB, DL, TII.get(CallOpc)).addReg(CalleeOp);
} else {
// Direct call.
assert(GV && "Not a direct call");
unsigned CallOpc =
Subtarget->is64Bit() ? X86::CALL64pcrel32 : X86::CALLpcrel32;
// See if we need any target-specific flags on the GV operand.
unsigned char OpFlags = 0;
// On ELF targets, in both X86-64 and X86-32 mode, direct calls to
// external symbols most go through the PLT in PIC mode. If the symbol
// has hidden or protected visibility, or if it is static or local, then
// we don't need to use the PLT - we can directly call it.
if (Subtarget->isTargetELF() &&
TM.getRelocationModel() == Reloc::PIC_ &&
GV->hasDefaultVisibility() && !GV->hasLocalLinkage()) {
OpFlags = X86II::MO_PLT;
} else if (Subtarget->isPICStyleStubAny() &&
(GV->isDeclaration() || GV->isWeakForLinker()) &&
Subtarget->getDarwinVers() < 9) {
// PC-relative references to external symbols should go through $stub,
// unless we're building with the leopard linker or later, which
// automatically synthesizes these stubs.
OpFlags = X86II::MO_DARWIN_STUB;
}
MIB = BuildMI(MBB, DL, TII.get(CallOpc)).addGlobalAddress(GV, 0, OpFlags);
}
// Add an implicit use GOT pointer in EBX.
if (Subtarget->isPICStyleGOT())
MIB.addReg(X86::EBX);
// Add implicit physical register uses to the call.
for (unsigned i = 0, e = RegArgs.size(); i != e; ++i)
MIB.addReg(RegArgs[i]);
// Issue CALLSEQ_END
unsigned AdjStackUp = TM.getRegisterInfo()->getCallFrameDestroyOpcode();
BuildMI(MBB, DL, TII.get(AdjStackUp)).addImm(NumBytes).addImm(0);
// Now handle call return value (if any).
if (RetVT.getSimpleVT().SimpleTy != MVT::isVoid) {
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CC, false, TM, RVLocs, I->getParent()->getContext());
CCInfo.AnalyzeCallResult(RetVT, RetCC_X86);
// Copy all of the result registers out of their specified physreg.
assert(RVLocs.size() == 1 && "Can't handle multi-value calls!");
EVT CopyVT = RVLocs[0].getValVT();
TargetRegisterClass* DstRC = TLI.getRegClassFor(CopyVT);
TargetRegisterClass *SrcRC = DstRC;
// If this is a call to a function that returns an fp value on the x87 fp
// stack, but where we prefer to use the value in xmm registers, copy it
// out as F80 and use a truncate to move it from fp stack reg to xmm reg.
if ((RVLocs[0].getLocReg() == X86::ST0 ||
RVLocs[0].getLocReg() == X86::ST1) &&
isScalarFPTypeInSSEReg(RVLocs[0].getValVT())) {
CopyVT = MVT::f80;
SrcRC = X86::RSTRegisterClass;
DstRC = X86::RFP80RegisterClass;
}
unsigned ResultReg = createResultReg(DstRC);
bool Emitted = TII.copyRegToReg(*MBB, MBB->end(), ResultReg,
RVLocs[0].getLocReg(), DstRC, SrcRC);
assert(Emitted && "Failed to emit a copy instruction!"); Emitted=Emitted;
Emitted = true;
if (CopyVT != RVLocs[0].getValVT()) {
// Round the F80 the right size, which also moves to the appropriate xmm
// register. This is accomplished by storing the F80 value in memory and
// then loading it back. Ewww...
EVT ResVT = RVLocs[0].getValVT();
unsigned Opc = ResVT == MVT::f32 ? X86::ST_Fp80m32 : X86::ST_Fp80m64;
unsigned MemSize = ResVT.getSizeInBits()/8;
int FI = MFI.CreateStackObject(MemSize, MemSize, false);
addFrameReference(BuildMI(MBB, DL, TII.get(Opc)), FI).addReg(ResultReg);
DstRC = ResVT == MVT::f32
? X86::FR32RegisterClass : X86::FR64RegisterClass;
Opc = ResVT == MVT::f32 ? X86::MOVSSrm : X86::MOVSDrm;
ResultReg = createResultReg(DstRC);
addFrameReference(BuildMI(MBB, DL, TII.get(Opc), ResultReg), FI);
}
if (AndToI1) {
// Mask out all but lowest bit for some call which produces an i1.
unsigned AndResult = createResultReg(X86::GR8RegisterClass);
BuildMI(MBB, DL,
TII.get(X86::AND8ri), AndResult).addReg(ResultReg).addImm(1);
ResultReg = AndResult;
}
UpdateValueMap(I, ResultReg);
}
return true;
}
bool
X86FastISel::TargetSelectInstruction(const Instruction *I) {
switch (I->getOpcode()) {
default: break;
case Instruction::Load:
return X86SelectLoad(I);
case Instruction::Store:
return X86SelectStore(I);
case Instruction::ICmp:
case Instruction::FCmp:
return X86SelectCmp(I);
case Instruction::ZExt:
return X86SelectZExt(I);
case Instruction::Br:
return X86SelectBranch(I);
case Instruction::Call:
return X86SelectCall(I);
case Instruction::LShr:
case Instruction::AShr:
case Instruction::Shl:
return X86SelectShift(I);
case Instruction::Select:
return X86SelectSelect(I);
case Instruction::Trunc:
return X86SelectTrunc(I);
case Instruction::FPExt:
return X86SelectFPExt(I);
case Instruction::FPTrunc:
return X86SelectFPTrunc(I);
case Instruction::ExtractValue:
return X86SelectExtractValue(I);
case Instruction::IntToPtr: // Deliberate fall-through.
case Instruction::PtrToInt: {
EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
EVT DstVT = TLI.getValueType(I->getType());
if (DstVT.bitsGT(SrcVT))
return X86SelectZExt(I);
if (DstVT.bitsLT(SrcVT))
return X86SelectTrunc(I);
unsigned Reg = getRegForValue(I->getOperand(0));
if (Reg == 0) return false;
UpdateValueMap(I, Reg);
return true;
}
}
return false;
}
unsigned X86FastISel::TargetMaterializeConstant(const Constant *C) {
EVT VT;
if (!isTypeLegal(C->getType(), VT))
return false;
// Get opcode and regclass of the output for the given load instruction.
unsigned Opc = 0;
const TargetRegisterClass *RC = NULL;
switch (VT.getSimpleVT().SimpleTy) {
default: return false;
case MVT::i8:
Opc = X86::MOV8rm;
RC = X86::GR8RegisterClass;
break;
case MVT::i16:
Opc = X86::MOV16rm;
RC = X86::GR16RegisterClass;
break;
case MVT::i32:
Opc = X86::MOV32rm;
RC = X86::GR32RegisterClass;
break;
case MVT::i64:
// Must be in x86-64 mode.
Opc = X86::MOV64rm;
RC = X86::GR64RegisterClass;
break;
case MVT::f32:
if (Subtarget->hasSSE1()) {
Opc = X86::MOVSSrm;
RC = X86::FR32RegisterClass;
} else {
Opc = X86::LD_Fp32m;
RC = X86::RFP32RegisterClass;
}
break;
case MVT::f64:
if (Subtarget->hasSSE2()) {
Opc = X86::MOVSDrm;
RC = X86::FR64RegisterClass;
} else {
Opc = X86::LD_Fp64m;
RC = X86::RFP64RegisterClass;
}
break;
case MVT::f80:
// No f80 support yet.
return false;
}
// Materialize addresses with LEA instructions.
if (isa<GlobalValue>(C)) {
X86AddressMode AM;
if (X86SelectAddress(C, AM)) {
if (TLI.getPointerTy() == MVT::i32)
Opc = X86::LEA32r;
else
Opc = X86::LEA64r;
unsigned ResultReg = createResultReg(RC);
addLeaAddress(BuildMI(MBB, DL, TII.get(Opc), ResultReg), AM);
return ResultReg;
}
return 0;
}
// MachineConstantPool wants an explicit alignment.
unsigned Align = TD.getPrefTypeAlignment(C->getType());
if (Align == 0) {
// Alignment of vector types. FIXME!
Align = TD.getTypeAllocSize(C->getType());
}
// x86-32 PIC requires a PIC base register for constant pools.
unsigned PICBase = 0;
unsigned char OpFlag = 0;
if (Subtarget->isPICStyleStubPIC()) { // Not dynamic-no-pic
OpFlag = X86II::MO_PIC_BASE_OFFSET;
PICBase = getInstrInfo()->getGlobalBaseReg(&MF);
} else if (Subtarget->isPICStyleGOT()) {
OpFlag = X86II::MO_GOTOFF;
PICBase = getInstrInfo()->getGlobalBaseReg(&MF);
} else if (Subtarget->isPICStyleRIPRel() &&
TM.getCodeModel() == CodeModel::Small) {
PICBase = X86::RIP;
}
// Create the load from the constant pool.
unsigned MCPOffset = MCP.getConstantPoolIndex(C, Align);
unsigned ResultReg = createResultReg(RC);
addConstantPoolReference(BuildMI(MBB, DL, TII.get(Opc), ResultReg),
MCPOffset, PICBase, OpFlag);
return ResultReg;
}
unsigned X86FastISel::TargetMaterializeAlloca(const AllocaInst *C) {
// Fail on dynamic allocas. At this point, getRegForValue has already
// checked its CSE maps, so if we're here trying to handle a dynamic
// alloca, we're not going to succeed. X86SelectAddress has a
// check for dynamic allocas, because it's called directly from
// various places, but TargetMaterializeAlloca also needs a check
// in order to avoid recursion between getRegForValue,
// X86SelectAddrss, and TargetMaterializeAlloca.
if (!StaticAllocaMap.count(C))
return 0;
X86AddressMode AM;
if (!X86SelectAddress(C, AM))
return 0;
unsigned Opc = Subtarget->is64Bit() ? X86::LEA64r : X86::LEA32r;
TargetRegisterClass* RC = TLI.getRegClassFor(TLI.getPointerTy());
unsigned ResultReg = createResultReg(RC);
addLeaAddress(BuildMI(MBB, DL, TII.get(Opc), ResultReg), AM);
return ResultReg;
}
namespace llvm {
llvm::FastISel *X86::createFastISel(MachineFunction &mf,
DenseMap<const Value *, unsigned> &vm,
DenseMap<const BasicBlock *, MachineBasicBlock *> &bm,
DenseMap<const AllocaInst *, int> &am,
std::vector<std::pair<MachineInstr*, unsigned> > &pn
#ifndef NDEBUG
, SmallSet<const Instruction *, 8> &cil
#endif
) {
return new X86FastISel(mf, vm, bm, am, pn
#ifndef NDEBUG
, cil
#endif
);
}
}
Reference in New Issue View Git Blame Copy Permalink