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

3532 lines
121 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 "X86CallingConv.h"
#include "X86InstrBuilder.h"
#include "X86InstrInfo.h"
#include "X86MachineFunctionInfo.h"
#include "X86RegisterInfo.h"
#include "X86Subtarget.h"
#include "X86TargetMachine.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Operator.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
namespace {
class X86FastISel final : 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;
/// X86ScalarSSEf32, X86ScalarSSEf64 - Select between SSE or x87
/// floating point ops.
/// When SSE is available, use it for f32 operations.
/// When SSE2 is available, use it for f64 operations.
bool X86ScalarSSEf64;
bool X86ScalarSSEf32;
public:
explicit X86FastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo)
: FastISel(funcInfo, libInfo) {
Subtarget = &funcInfo.MF->getSubtarget<X86Subtarget>();
X86ScalarSSEf64 = Subtarget->hasSSE2();
X86ScalarSSEf32 = Subtarget->hasSSE1();
}
bool fastSelectInstruction(const Instruction *I) override;
/// \brief The specified machine instr operand is a vreg, and that
/// vreg is being provided by the specified load instruction. If possible,
/// try to fold the load as an operand to the instruction, returning true if
/// possible.
bool tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo,
const LoadInst *LI) override;
bool fastLowerArguments() override;
bool fastLowerCall(CallLoweringInfo &CLI) override;
bool fastLowerIntrinsicCall(const IntrinsicInst *II) override;
#include "X86GenFastISel.inc"
private:
bool X86FastEmitCompare(const Value *LHS, const Value *RHS, EVT VT, DebugLoc DL);
bool X86FastEmitLoad(EVT VT, const X86AddressMode &AM, MachineMemOperand *MMO,
unsigned &ResultReg, unsigned Alignment = 1);
bool X86FastEmitStore(EVT VT, const Value *Val, const X86AddressMode &AM,
MachineMemOperand *MMO = nullptr, bool Aligned = false);
bool X86FastEmitStore(EVT VT, unsigned ValReg, bool ValIsKill,
const X86AddressMode &AM,
MachineMemOperand *MMO = nullptr, bool Aligned = false);
bool X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT, unsigned Src, EVT SrcVT,
unsigned &ResultReg);
bool X86SelectAddress(const Value *V, X86AddressMode &AM);
bool X86SelectCallAddress(const Value *V, X86AddressMode &AM);
bool X86SelectLoad(const Instruction *I);
bool X86SelectStore(const Instruction *I);
bool X86SelectRet(const Instruction *I);
bool X86SelectCmp(const Instruction *I);
bool X86SelectZExt(const Instruction *I);
bool X86SelectBranch(const Instruction *I);
bool X86SelectShift(const Instruction *I);
bool X86SelectDivRem(const Instruction *I);
bool X86FastEmitCMoveSelect(MVT RetVT, const Instruction *I);
bool X86FastEmitSSESelect(MVT RetVT, const Instruction *I);
bool X86FastEmitPseudoSelect(MVT RetVT, const Instruction *I);
bool X86SelectSelect(const Instruction *I);
bool X86SelectTrunc(const Instruction *I);
bool X86SelectFPExtOrFPTrunc(const Instruction *I, unsigned Opc,
const TargetRegisterClass *RC);
bool X86SelectFPExt(const Instruction *I);
bool X86SelectFPTrunc(const Instruction *I);
bool X86SelectSIToFP(const Instruction *I);
const X86InstrInfo *getInstrInfo() const {
return Subtarget->getInstrInfo();
}
const X86TargetMachine *getTargetMachine() const {
return static_cast<const X86TargetMachine *>(&TM);
}
bool handleConstantAddresses(const Value *V, X86AddressMode &AM);
unsigned X86MaterializeInt(const ConstantInt *CI, MVT VT);
unsigned X86MaterializeFP(const ConstantFP *CFP, MVT VT);
unsigned X86MaterializeGV(const GlobalValue *GV, MVT VT);
unsigned fastMaterializeConstant(const Constant *C) override;
unsigned fastMaterializeAlloca(const AllocaInst *C) override;
unsigned fastMaterializeFloatZero(const ConstantFP *CF) override;
/// isScalarFPTypeInSSEReg - Return true if the specified scalar FP type is
/// computed in an SSE register, not on the X87 floating point stack.
bool isScalarFPTypeInSSEReg(EVT VT) const {
return (VT == MVT::f64 && X86ScalarSSEf64) || // f64 is when SSE2
(VT == MVT::f32 && X86ScalarSSEf32); // f32 is when SSE1
}
bool isTypeLegal(Type *Ty, MVT &VT, bool AllowI1 = false);
bool IsMemcpySmall(uint64_t Len);
bool TryEmitSmallMemcpy(X86AddressMode DestAM,
X86AddressMode SrcAM, uint64_t Len);
bool foldX86XALUIntrinsic(X86::CondCode &CC, const Instruction *I,
const Value *Cond);
};
} // end anonymous namespace.
static std::pair<X86::CondCode, bool>
getX86ConditionCode(CmpInst::Predicate Predicate) {
X86::CondCode CC = X86::COND_INVALID;
bool NeedSwap = false;
switch (Predicate) {
default: break;
// Floating-point Predicates
case CmpInst::FCMP_UEQ: CC = X86::COND_E; break;
case CmpInst::FCMP_OLT: NeedSwap = true; // fall-through
case CmpInst::FCMP_OGT: CC = X86::COND_A; break;
case CmpInst::FCMP_OLE: NeedSwap = true; // fall-through
case CmpInst::FCMP_OGE: CC = X86::COND_AE; break;
case CmpInst::FCMP_UGT: NeedSwap = true; // fall-through
case CmpInst::FCMP_ULT: CC = X86::COND_B; break;
case CmpInst::FCMP_UGE: NeedSwap = true; // fall-through
case CmpInst::FCMP_ULE: CC = X86::COND_BE; break;
case CmpInst::FCMP_ONE: CC = X86::COND_NE; break;
case CmpInst::FCMP_UNO: CC = X86::COND_P; break;
case CmpInst::FCMP_ORD: CC = X86::COND_NP; break;
case CmpInst::FCMP_OEQ: // fall-through
case CmpInst::FCMP_UNE: CC = X86::COND_INVALID; break;
// Integer Predicates
case CmpInst::ICMP_EQ: CC = X86::COND_E; break;
case CmpInst::ICMP_NE: CC = X86::COND_NE; break;
case CmpInst::ICMP_UGT: CC = X86::COND_A; break;
case CmpInst::ICMP_UGE: CC = X86::COND_AE; break;
case CmpInst::ICMP_ULT: CC = X86::COND_B; break;
case CmpInst::ICMP_ULE: CC = X86::COND_BE; break;
case CmpInst::ICMP_SGT: CC = X86::COND_G; break;
case CmpInst::ICMP_SGE: CC = X86::COND_GE; break;
case CmpInst::ICMP_SLT: CC = X86::COND_L; break;
case CmpInst::ICMP_SLE: CC = X86::COND_LE; break;
}
return std::make_pair(CC, NeedSwap);
}
static std::pair<unsigned, bool>
getX86SSEConditionCode(CmpInst::Predicate Predicate) {
unsigned CC;
bool NeedSwap = false;
// SSE Condition code mapping:
// 0 - EQ
// 1 - LT
// 2 - LE
// 3 - UNORD
// 4 - NEQ
// 5 - NLT
// 6 - NLE
// 7 - ORD
switch (Predicate) {
default: llvm_unreachable("Unexpected predicate");
case CmpInst::FCMP_OEQ: CC = 0; break;
case CmpInst::FCMP_OGT: NeedSwap = true; // fall-through
case CmpInst::FCMP_OLT: CC = 1; break;
case CmpInst::FCMP_OGE: NeedSwap = true; // fall-through
case CmpInst::FCMP_OLE: CC = 2; break;
case CmpInst::FCMP_UNO: CC = 3; break;
case CmpInst::FCMP_UNE: CC = 4; break;
case CmpInst::FCMP_ULE: NeedSwap = true; // fall-through
case CmpInst::FCMP_UGE: CC = 5; break;
case CmpInst::FCMP_ULT: NeedSwap = true; // fall-through
case CmpInst::FCMP_UGT: CC = 6; break;
case CmpInst::FCMP_ORD: CC = 7; break;
case CmpInst::FCMP_UEQ:
case CmpInst::FCMP_ONE: CC = 8; break;
}
return std::make_pair(CC, NeedSwap);
}
/// \brief Check if it is possible to fold the condition from the XALU intrinsic
/// into the user. The condition code will only be updated on success.
bool X86FastISel::foldX86XALUIntrinsic(X86::CondCode &CC, const Instruction *I,
const Value *Cond) {
if (!isa<ExtractValueInst>(Cond))
return false;
const auto *EV = cast<ExtractValueInst>(Cond);
if (!isa<IntrinsicInst>(EV->getAggregateOperand()))
return false;
const auto *II = cast<IntrinsicInst>(EV->getAggregateOperand());
MVT RetVT;
const Function *Callee = II->getCalledFunction();
Type *RetTy =
cast<StructType>(Callee->getReturnType())->getTypeAtIndex(0U);
if (!isTypeLegal(RetTy, RetVT))
return false;
if (RetVT != MVT::i32 && RetVT != MVT::i64)
return false;
X86::CondCode TmpCC;
switch (II->getIntrinsicID()) {
default: return false;
case Intrinsic::sadd_with_overflow:
case Intrinsic::ssub_with_overflow:
case Intrinsic::smul_with_overflow:
case Intrinsic::umul_with_overflow: TmpCC = X86::COND_O; break;
case Intrinsic::uadd_with_overflow:
case Intrinsic::usub_with_overflow: TmpCC = X86::COND_B; break;
}
// Check if both instructions are in the same basic block.
if (II->getParent() != I->getParent())
return false;
// Make sure nothing is in the way
BasicBlock::const_iterator Start = I;
BasicBlock::const_iterator End = II;
for (auto Itr = std::prev(Start); Itr != End; --Itr) {
// We only expect extractvalue instructions between the intrinsic and the
// instruction to be selected.
if (!isa<ExtractValueInst>(Itr))
return false;
// Check that the extractvalue operand comes from the intrinsic.
const auto *EVI = cast<ExtractValueInst>(Itr);
if (EVI->getAggregateOperand() != II)
return false;
}
CC = TmpCC;
return true;
}
bool X86FastISel::isTypeLegal(Type *Ty, MVT &VT, bool AllowI1) {
EVT evt = TLI.getValueType(Ty, /*HandleUnknown=*/true);
if (evt == MVT::Other || !evt.isSimple())
// Unhandled type. Halt "fast" selection and bail.
return false;
VT = evt.getSimpleVT();
// For now, require SSE/SSE2 for performing floating-point operations,
// since x87 requires additional work.
if (VT == MVT::f64 && !X86ScalarSSEf64)
return false;
if (VT == MVT::f32 && !X86ScalarSSEf32)
return false;
// Similarly, no f80 support yet.
if (VT == MVT::f80)
return false;
// We only handle legal types. For example, on x86-32 the instruction
// selector contains all of the 64-bit instructions from x86-64,
// under the assumption that i64 won't be used if the target doesn't
// support it.
return (AllowI1 && VT == MVT::i1) || TLI.isTypeLegal(VT);
}
#include "X86GenCallingConv.inc"
/// X86FastEmitLoad - Emit a machine instruction to load a value of type VT.
/// The address is either pre-computed, i.e. Ptr, or a GlobalAddress, i.e. GV.
/// Return true and the result register by reference if it is possible.
bool X86FastISel::X86FastEmitLoad(EVT VT, const X86AddressMode &AM,
MachineMemOperand *MMO, unsigned &ResultReg,
unsigned Alignment) {
// Get opcode and regclass of the output for the given load instruction.
unsigned Opc = 0;
const TargetRegisterClass *RC = nullptr;
switch (VT.getSimpleVT().SimpleTy) {
default: return false;
case MVT::i1:
case MVT::i8:
Opc = X86::MOV8rm;
RC = &X86::GR8RegClass;
break;
case MVT::i16:
Opc = X86::MOV16rm;
RC = &X86::GR16RegClass;
break;
case MVT::i32:
Opc = X86::MOV32rm;
RC = &X86::GR32RegClass;
break;
case MVT::i64:
// Must be in x86-64 mode.
Opc = X86::MOV64rm;
RC = &X86::GR64RegClass;
break;
case MVT::f32:
if (X86ScalarSSEf32) {
Opc = Subtarget->hasAVX() ? X86::VMOVSSrm : X86::MOVSSrm;
RC = &X86::FR32RegClass;
} else {
Opc = X86::LD_Fp32m;
RC = &X86::RFP32RegClass;
}
break;
case MVT::f64:
if (X86ScalarSSEf64) {
Opc = Subtarget->hasAVX() ? X86::VMOVSDrm : X86::MOVSDrm;
RC = &X86::FR64RegClass;
} else {
Opc = X86::LD_Fp64m;
RC = &X86::RFP64RegClass;
}
break;
case MVT::f80:
// No f80 support yet.
return false;
case MVT::v4f32:
if (Alignment >= 16)
Opc = Subtarget->hasAVX() ? X86::VMOVAPSrm : X86::MOVAPSrm;
else
Opc = Subtarget->hasAVX() ? X86::VMOVUPSrm : X86::MOVUPSrm;
RC = &X86::VR128RegClass;
break;
case MVT::v2f64:
if (Alignment >= 16)
Opc = Subtarget->hasAVX() ? X86::VMOVAPDrm : X86::MOVAPDrm;
else
Opc = Subtarget->hasAVX() ? X86::VMOVUPDrm : X86::MOVUPDrm;
RC = &X86::VR128RegClass;
break;
case MVT::v4i32:
case MVT::v2i64:
case MVT::v8i16:
case MVT::v16i8:
if (Alignment >= 16)
Opc = Subtarget->hasAVX() ? X86::VMOVDQArm : X86::MOVDQArm;
else
Opc = Subtarget->hasAVX() ? X86::VMOVDQUrm : X86::MOVDQUrm;
RC = &X86::VR128RegClass;
break;
}
ResultReg = createResultReg(RC);
MachineInstrBuilder MIB =
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg);
addFullAddress(MIB, AM);
if (MMO)
MIB->addMemOperand(*FuncInfo.MF, MMO);
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 ValReg, bool ValIsKill,
const X86AddressMode &AM,
MachineMemOperand *MMO, bool Aligned) {
// Get opcode and regclass of the output for the given store instruction.
unsigned Opc = 0;
switch (VT.getSimpleVT().SimpleTy) {
case MVT::f80: // No f80 support yet.
default: return false;
case MVT::i1: {
// Mask out all but lowest bit.
unsigned AndResult = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(X86::AND8ri), AndResult)
.addReg(ValReg, getKillRegState(ValIsKill)).addImm(1);
ValReg = AndResult;
}
// FALLTHROUGH, handling i1 as i8.
case MVT::i8: Opc = X86::MOV8mr; break;
case MVT::i16: Opc = X86::MOV16mr; break;
case MVT::i32: Opc = X86::MOV32mr; break;
case MVT::i64: Opc = X86::MOV64mr; break; // Must be in x86-64 mode.
case MVT::f32:
Opc = X86ScalarSSEf32 ?
(Subtarget->hasAVX() ? X86::VMOVSSmr : X86::MOVSSmr) : X86::ST_Fp32m;
break;
case MVT::f64:
Opc = X86ScalarSSEf64 ?
(Subtarget->hasAVX() ? X86::VMOVSDmr : X86::MOVSDmr) : X86::ST_Fp64m;
break;
case MVT::v4f32:
if (Aligned)
Opc = Subtarget->hasAVX() ? X86::VMOVAPSmr : X86::MOVAPSmr;
else
Opc = Subtarget->hasAVX() ? X86::VMOVUPSmr : X86::MOVUPSmr;
break;
case MVT::v2f64:
if (Aligned)
Opc = Subtarget->hasAVX() ? X86::VMOVAPDmr : X86::MOVAPDmr;
else
Opc = Subtarget->hasAVX() ? X86::VMOVUPDmr : X86::MOVUPDmr;
break;
case MVT::v4i32:
case MVT::v2i64:
case MVT::v8i16:
case MVT::v16i8:
if (Aligned)
Opc = Subtarget->hasAVX() ? X86::VMOVDQAmr : X86::MOVDQAmr;
else
Opc = Subtarget->hasAVX() ? X86::VMOVDQUmr : X86::MOVDQUmr;
break;
}
MachineInstrBuilder MIB =
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc));
addFullAddress(MIB, AM).addReg(ValReg, getKillRegState(ValIsKill));
if (MMO)
MIB->addMemOperand(*FuncInfo.MF, MMO);
return true;
}
bool X86FastISel::X86FastEmitStore(EVT VT, const Value *Val,
const X86AddressMode &AM,
MachineMemOperand *MMO, bool Aligned) {
// Handle 'null' like i32/i64 0.
if (isa<ConstantPointerNull>(Val))
Val = Constant::getNullValue(DL.getIntPtrType(Val->getContext()));
// If this is a store of a simple constant, fold the constant into the store.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
unsigned Opc = 0;
bool Signed = true;
switch (VT.getSimpleVT().SimpleTy) {
default: break;
case MVT::i1: Signed = false; // FALLTHROUGH to handle as i8.
case MVT::i8: Opc = X86::MOV8mi; break;
case MVT::i16: Opc = X86::MOV16mi; break;
case MVT::i32: Opc = X86::MOV32mi; break;
case MVT::i64:
// Must be a 32-bit sign extended value.
if (isInt<32>(CI->getSExtValue()))
Opc = X86::MOV64mi32;
break;
}
if (Opc) {
MachineInstrBuilder MIB =
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc));
addFullAddress(MIB, AM).addImm(Signed ? (uint64_t) CI->getSExtValue()
: CI->getZExtValue());
if (MMO)
MIB->addMemOperand(*FuncInfo.MF, MMO);
return true;
}
}
unsigned ValReg = getRegForValue(Val);
if (ValReg == 0)
return false;
bool ValKill = hasTrivialKill(Val);
return X86FastEmitStore(VT, ValReg, ValKill, AM, MMO, Aligned);
}
/// X86FastEmitExtend - Emit a machine instruction to extend a value Src of
/// type SrcVT to type DstVT using the specified extension opcode Opc (e.g.
/// ISD::SIGN_EXTEND).
bool X86FastISel::X86FastEmitExtend(ISD::NodeType Opc, EVT DstVT,
unsigned Src, EVT SrcVT,
unsigned &ResultReg) {
unsigned RR = fastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Opc,
Src, /*TODO: Kill=*/false);
if (RR == 0)
return false;
ResultReg = RR;
return true;
}
bool X86FastISel::handleConstantAddresses(const Value *V, X86AddressMode &AM) {
// Handle constant address.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Can't handle alternate code models yet.
if (TM.getCodeModel() != CodeModel::Small)
return false;
// Can't handle TLS yet.
if (GV->isThreadLocal())
return false;
// RIP-relative addresses can't have additional register operands, so if
// we've already folded stuff into the addressing mode, just force the
// global value into its own register, which we can use as the basereg.
if (!Subtarget->isPICStyleRIPRel() ||
(AM.Base.Reg == 0 && AM.IndexReg == 0)) {
// Okay, we've committed to selecting this global. Set up the address.
AM.GV = GV;
// Allow the subtarget to classify the global.
unsigned char GVFlags = Subtarget->ClassifyGlobalReference(GV, TM);
// If this reference is relative to the pic base, set it now.
if (isGlobalRelativeToPICBase(GVFlags)) {
// FIXME: How do we know Base.Reg is free??
AM.Base.Reg = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
}
// Unless the ABI requires an extra load, return a direct reference to
// the global.
if (!isGlobalStubReference(GVFlags)) {
if (Subtarget->isPICStyleRIPRel()) {
// Use rip-relative addressing if we can. Above we verified that the
// base and index registers are unused.
assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
AM.Base.Reg = X86::RIP;
}
AM.GVOpFlags = GVFlags;
return true;
}
// Ok, we need to do a load from a stub. If we've already loaded from
// this stub, reuse the loaded pointer, otherwise emit the load now.
DenseMap<const Value *, unsigned>::iterator I = LocalValueMap.find(V);
unsigned LoadReg;
if (I != LocalValueMap.end() && I->second != 0) {
LoadReg = I->second;
} else {
// Issue load from stub.
unsigned Opc = 0;
const TargetRegisterClass *RC = nullptr;
X86AddressMode StubAM;
StubAM.Base.Reg = AM.Base.Reg;
StubAM.GV = GV;
StubAM.GVOpFlags = GVFlags;
// Prepare for inserting code in the local-value area.
SavePoint SaveInsertPt = enterLocalValueArea();
if (TLI.getPointerTy() == MVT::i64) {
Opc = X86::MOV64rm;
RC = &X86::GR64RegClass;
if (Subtarget->isPICStyleRIPRel())
StubAM.Base.Reg = X86::RIP;
} else {
Opc = X86::MOV32rm;
RC = &X86::GR32RegClass;
}
LoadReg = createResultReg(RC);
MachineInstrBuilder LoadMI =
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), LoadReg);
addFullAddress(LoadMI, StubAM);
// Ok, back to normal mode.
leaveLocalValueArea(SaveInsertPt);
// Prevent loading GV stub multiple times in same MBB.
LocalValueMap[V] = LoadReg;
}
// Now construct the final address. Note that the Disp, Scale,
// and Index values may already be set here.
AM.Base.Reg = LoadReg;
AM.GV = nullptr;
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;
}
/// X86SelectAddress - Attempt to fill in an address from the given value.
///
bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
SmallVector<const Value *, 32> GEPs;
redo_gep:
const User *U = nullptr;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(V)) {
// Don't walk into other basic blocks; it's possible we haven't
// visited them yet, so the instructions may not yet be assigned
// virtual registers.
if (FuncInfo.StaticAllocaMap.count(static_cast<const AllocaInst *>(V)) ||
FuncInfo.MBBMap[I->getParent()] == FuncInfo.MBB) {
Opcode = I->getOpcode();
U = I;
}
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
Opcode = C->getOpcode();
U = C;
}
if (PointerType *Ty = dyn_cast<PointerType>(V->getType()))
if (Ty->getAddressSpace() > 255)
// Fast instruction selection doesn't support the special
// address spaces.
return false;
switch (Opcode) {
default: break;
case Instruction::BitCast:
// Look past bitcasts.
return X86SelectAddress(U->getOperand(0), AM);
case Instruction::IntToPtr:
// Look past no-op inttoptrs.
if (TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
return X86SelectAddress(U->getOperand(0), AM);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints.
if (TLI.getValueType(U->getType()) == TLI.getPointerTy())
return X86SelectAddress(U->getOperand(0), AM);
break;
case Instruction::Alloca: {
// Do static allocas.
const AllocaInst *A = cast<AllocaInst>(V);
DenseMap<const AllocaInst *, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(A);
if (SI != FuncInfo.StaticAllocaMap.end()) {
AM.BaseType = X86AddressMode::FrameIndexBase;
AM.Base.FrameIndex = SI->second;
return true;
}
break;
}
case Instruction::Add: {
// Adds of constants are common and easy enough.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(U->getOperand(1))) {
uint64_t Disp = (int32_t)AM.Disp + (uint64_t)CI->getSExtValue();
// They have to fit in the 32-bit signed displacement field though.
if (isInt<32>(Disp)) {
AM.Disp = (uint32_t)Disp;
return X86SelectAddress(U->getOperand(0), AM);
}
}
break;
}
case Instruction::GetElementPtr: {
X86AddressMode SavedAM = AM;
// Pattern-match simple GEPs.
uint64_t Disp = (int32_t)AM.Disp;
unsigned IndexReg = AM.IndexReg;
unsigned Scale = AM.Scale;
gep_type_iterator GTI = gep_type_begin(U);
// Iterate through the indices, folding what we can. Constants can be
// folded, and one dynamic index can be handled, if the scale is supported.
for (User::const_op_iterator i = U->op_begin() + 1, e = U->op_end();
i != e; ++i, ++GTI) {
const Value *Op = *i;
if (StructType *STy = dyn_cast<StructType>(*GTI)) {
const StructLayout *SL = DL.getStructLayout(STy);
Disp += SL->getElementOffset(cast<ConstantInt>(Op)->getZExtValue());
continue;
}
// A array/variable index is always of the form i*S where S is the
// constant scale size. See if we can push the scale into immediates.
uint64_t S = DL.getTypeAllocSize(GTI.getIndexedType());
for (;;) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
// Constant-offset addressing.
Disp += CI->getSExtValue() * S;
break;
}
if (canFoldAddIntoGEP(U, Op)) {
// A compatible add with a constant operand. Fold the constant.
ConstantInt *CI =
cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
Disp += CI->getSExtValue() * S;
// Iterate on the other operand.
Op = cast<AddOperator>(Op)->getOperand(0);
continue;
}
if (IndexReg == 0 &&
(!AM.GV || !Subtarget->isPICStyleRIPRel()) &&
(S == 1 || S == 2 || S == 4 || S == 8)) {
// Scaled-index addressing.
Scale = S;
IndexReg = getRegForGEPIndex(Op).first;
if (IndexReg == 0)
return false;
break;
}
// Unsupported.
goto unsupported_gep;
}
}
// Check for displacement overflow.
if (!isInt<32>(Disp))
break;
AM.IndexReg = IndexReg;
AM.Scale = Scale;
AM.Disp = (uint32_t)Disp;
GEPs.push_back(V);
if (const GetElementPtrInst *GEP =
dyn_cast<GetElementPtrInst>(U->getOperand(0))) {
// Ok, the GEP indices were covered by constant-offset and scaled-index
// addressing. Update the address state and move on to examining the base.
V = GEP;
goto redo_gep;
} else if (X86SelectAddress(U->getOperand(0), AM)) {
return true;
}
// If we couldn't merge the gep value into this addr mode, revert back to
// our address and just match the value instead of completely failing.
AM = SavedAM;
for (SmallVectorImpl<const Value *>::reverse_iterator
I = GEPs.rbegin(), E = GEPs.rend(); I != E; ++I)
if (handleConstantAddresses(*I, AM))
return true;
return false;
unsupported_gep:
// Ok, the GEP indices weren't all covered.
break;
}
}
return handleConstantAddresses(V, AM);
}
/// X86SelectCallAddress - Attempt to fill in an address from the given value.
///
bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) {
const User *U = nullptr;
unsigned Opcode = Instruction::UserOp1;
const Instruction *I = dyn_cast<Instruction>(V);
// Record if the value is defined in the same basic block.
//
// This information is crucial to know whether or not folding an
// operand is valid.
// Indeed, FastISel generates or reuses a virtual register for all
// operands of all instructions it selects. Obviously, the definition and
// its uses must use the same virtual register otherwise the produced
// code is incorrect.
// Before instruction selection, FunctionLoweringInfo::set sets the virtual
// registers for values that are alive across basic blocks. This ensures
// that the values are consistently set between across basic block, even
// if different instruction selection mechanisms are used (e.g., a mix of
// SDISel and FastISel).
// For values local to a basic block, the instruction selection process
// generates these virtual registers with whatever method is appropriate
// for its needs. In particular, FastISel and SDISel do not share the way
// local virtual registers are set.
// Therefore, this is impossible (or at least unsafe) to share values
// between basic blocks unless they use the same instruction selection
// method, which is not guarantee for X86.
// Moreover, things like hasOneUse could not be used accurately, if we
// allow to reference values across basic blocks whereas they are not
// alive across basic blocks initially.
bool InMBB = true;
if (I) {
Opcode = I->getOpcode();
U = I;
InMBB = I->getParent() == FuncInfo.MBB->getBasicBlock();
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default: break;
case Instruction::BitCast:
// Look past bitcasts if its operand is in the same BB.
if (InMBB)
return X86SelectCallAddress(U->getOperand(0), AM);
break;
case Instruction::IntToPtr:
// Look past no-op inttoptrs if its operand is in the same BB.
if (InMBB &&
TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
return X86SelectCallAddress(U->getOperand(0), AM);
break;
case Instruction::PtrToInt:
// Look past no-op ptrtoints if its operand is in the same BB.
if (InMBB &&
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 DLL Import.
if (GV->hasDLLImportStorageClass())
return false;
// Can't handle TLS.
if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
if (GVar->isThreadLocal())
return false;
// Okay, we've committed to selecting this global. Set up the basic address.
AM.GV = GV;
// No ABI requires an extra load for anything other than DLLImport, which
// we rejected above. Return a direct reference to the global.
if (Subtarget->isPICStyleRIPRel()) {
// Use rip-relative addressing if we can. Above we verified that the
// base and index registers are unused.
assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
AM.Base.Reg = X86::RIP;
} else if (Subtarget->isPICStyleStubPIC()) {
AM.GVOpFlags = X86II::MO_PIC_BASE_OFFSET;
} else if (Subtarget->isPICStyleGOT()) {
AM.GVOpFlags = X86II::MO_GOTOFF;
}
return true;
}
// If all else fails, try to materialize the value in a register.
if (!AM.GV || !Subtarget->isPICStyleRIPRel()) {
if (AM.Base.Reg == 0) {
AM.Base.Reg = getRegForValue(V);
return AM.Base.Reg != 0;
}
if (AM.IndexReg == 0) {
assert(AM.Scale == 1 && "Scale with no index!");
AM.IndexReg = getRegForValue(V);
return AM.IndexReg != 0;
}
}
return false;
}
/// X86SelectStore - Select and emit code to implement store instructions.
bool X86FastISel::X86SelectStore(const Instruction *I) {
// Atomic stores need special handling.
const StoreInst *S = cast<StoreInst>(I);
if (S->isAtomic())
return false;
const Value *Val = S->getValueOperand();
const Value *Ptr = S->getPointerOperand();
MVT VT;
if (!isTypeLegal(Val->getType(), VT, /*AllowI1=*/true))
return false;
unsigned Alignment = S->getAlignment();
unsigned ABIAlignment = DL.getABITypeAlignment(Val->getType());
if (Alignment == 0) // Ensure that codegen never sees alignment 0
Alignment = ABIAlignment;
bool Aligned = Alignment >= ABIAlignment;
X86AddressMode AM;
if (!X86SelectAddress(Ptr, AM))
return false;
return X86FastEmitStore(VT, Val, AM, createMachineMemOperandFor(I), Aligned);
}
/// X86SelectRet - Select and emit code to implement ret instructions.
bool X86FastISel::X86SelectRet(const Instruction *I) {
const ReturnInst *Ret = cast<ReturnInst>(I);
const Function &F = *I->getParent()->getParent();
const X86MachineFunctionInfo *X86MFInfo =
FuncInfo.MF->getInfo<X86MachineFunctionInfo>();
if (!FuncInfo.CanLowerReturn)
return false;
CallingConv::ID CC = F.getCallingConv();
if (CC != CallingConv::C &&
CC != CallingConv::Fast &&
CC != CallingConv::X86_FastCall &&
CC != CallingConv::X86_64_SysV)
return false;
if (Subtarget->isCallingConvWin64(CC))
return false;
// Don't handle popping bytes on return for now.
if (X86MFInfo->getBytesToPopOnReturn() != 0)
return false;
// fastcc with -tailcallopt is intended to provide a guaranteed
// tail call optimization. Fastisel doesn't know how to do that.
if (CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt)
return false;
// Let SDISel handle vararg functions.
if (F.isVarArg())
return false;
// Build a list of return value registers.
SmallVector<unsigned, 4> RetRegs;
if (Ret->getNumOperands() > 0) {
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(F.getReturnType(), F.getAttributes(), Outs, TLI);
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ValLocs;
CCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, ValLocs, I->getContext());
CCInfo.AnalyzeReturn(Outs, RetCC_X86);
const Value *RV = Ret->getOperand(0);
unsigned Reg = getRegForValue(RV);
if (Reg == 0)
return false;
// Only handle a single return value for now.
if (ValLocs.size() != 1)
return false;
CCValAssign &VA = ValLocs[0];
// Don't bother handling odd stuff for now.
if (VA.getLocInfo() != CCValAssign::Full)
return false;
// Only handle register returns for now.
if (!VA.isRegLoc())
return false;
// The calling-convention tables for x87 returns don't tell
// the whole story.
if (VA.getLocReg() == X86::FP0 || VA.getLocReg() == X86::FP1)
return false;
unsigned SrcReg = Reg + VA.getValNo();
EVT SrcVT = TLI.getValueType(RV->getType());
EVT DstVT = VA.getValVT();
// Special handling for extended integers.
if (SrcVT != DstVT) {
if (SrcVT != MVT::i1 && SrcVT != MVT::i8 && SrcVT != MVT::i16)
return false;
if (!Outs[0].Flags.isZExt() && !Outs[0].Flags.isSExt())
return false;
assert(DstVT == MVT::i32 && "X86 should always ext to i32");
if (SrcVT == MVT::i1) {
if (Outs[0].Flags.isSExt())
return false;
SrcReg = fastEmitZExtFromI1(MVT::i8, SrcReg, /*TODO: Kill=*/false);
SrcVT = MVT::i8;
}
unsigned Op = Outs[0].Flags.isZExt() ? ISD::ZERO_EXTEND :
ISD::SIGN_EXTEND;
SrcReg = fastEmit_r(SrcVT.getSimpleVT(), DstVT.getSimpleVT(), Op,
SrcReg, /*TODO: Kill=*/false);
}
// Make the copy.
unsigned DstReg = VA.getLocReg();
const TargetRegisterClass *SrcRC = MRI.getRegClass(SrcReg);
// Avoid a cross-class copy. This is very unlikely.
if (!SrcRC->contains(DstReg))
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), DstReg).addReg(SrcReg);
// Add register to return instruction.
RetRegs.push_back(VA.getLocReg());
}
// The x86-64 ABI for returning structs by value requires that we copy
// the sret argument into %rax for the return. We saved the argument into
// a virtual register in the entry block, so now we copy the value out
// and into %rax. We also do the same with %eax for Win32.
if (F.hasStructRetAttr() &&
(Subtarget->is64Bit() || Subtarget->isTargetKnownWindowsMSVC())) {
unsigned Reg = X86MFInfo->getSRetReturnReg();
assert(Reg &&
"SRetReturnReg should have been set in LowerFormalArguments()!");
unsigned RetReg = Subtarget->is64Bit() ? X86::RAX : X86::EAX;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), RetReg).addReg(Reg);
RetRegs.push_back(RetReg);
}
// Now emit the RET.
MachineInstrBuilder MIB =
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Subtarget->is64Bit() ? X86::RETQ : X86::RETL));
for (unsigned i = 0, e = RetRegs.size(); i != e; ++i)
MIB.addReg(RetRegs[i], RegState::Implicit);
return true;
}
/// X86SelectLoad - Select and emit code to implement load instructions.
///
bool X86FastISel::X86SelectLoad(const Instruction *I) {
const LoadInst *LI = cast<LoadInst>(I);
// Atomic loads need special handling.
if (LI->isAtomic())
return false;
MVT VT;
if (!isTypeLegal(LI->getType(), VT, /*AllowI1=*/true))
return false;
const Value *Ptr = LI->getPointerOperand();
X86AddressMode AM;
if (!X86SelectAddress(Ptr, AM))
return false;
unsigned Alignment = LI->getAlignment();
unsigned ABIAlignment = DL.getABITypeAlignment(LI->getType());
if (Alignment == 0) // Ensure that codegen never sees alignment 0
Alignment = ABIAlignment;
unsigned ResultReg = 0;
if (!X86FastEmitLoad(VT, AM, createMachineMemOperandFor(LI), ResultReg,
Alignment))
return false;
updateValueMap(I, ResultReg);
return true;
}
static unsigned X86ChooseCmpOpcode(EVT VT, const X86Subtarget *Subtarget) {
bool HasAVX = Subtarget->hasAVX();
bool X86ScalarSSEf32 = Subtarget->hasSSE1();
bool X86ScalarSSEf64 = Subtarget->hasSSE2();
switch (VT.getSimpleVT().SimpleTy) {
default: return 0;
case MVT::i8: return X86::CMP8rr;
case MVT::i16: return X86::CMP16rr;
case MVT::i32: return X86::CMP32rr;
case MVT::i64: return X86::CMP64rr;
case MVT::f32:
return X86ScalarSSEf32 ? (HasAVX ? X86::VUCOMISSrr : X86::UCOMISSrr) : 0;
case MVT::f64:
return X86ScalarSSEf64 ? (HasAVX ? X86::VUCOMISDrr : X86::UCOMISDrr) : 0;
}
}
/// 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) {
int64_t Val = RHSC->getSExtValue();
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:
if (isInt<8>(Val))
return X86::CMP16ri8;
return X86::CMP16ri;
case MVT::i32:
if (isInt<8>(Val))
return X86::CMP32ri8;
return X86::CMP32ri;
case MVT::i64:
if (isInt<8>(Val))
return X86::CMP64ri8;
// 64-bit comparisons are only valid if the immediate fits in a 32-bit sext
// field.
if (isInt<32>(Val))
return X86::CMP64ri32;
return 0;
}
}
bool X86FastISel::X86FastEmitCompare(const Value *Op0, const Value *Op1,
EVT VT, DebugLoc CurDbgLoc) {
unsigned Op0Reg = getRegForValue(Op0);
if (Op0Reg == 0) return false;
// Handle 'null' like i32/i64 0.
if (isa<ConstantPointerNull>(Op1))
Op1 = Constant::getNullValue(DL.getIntPtrType(Op0->getContext()));
// We have two options: compare with register or immediate. If the RHS of
// the compare is an immediate that we can fold into this compare, use
// CMPri, otherwise use CMPrr.
if (const ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
if (unsigned CompareImmOpc = X86ChooseCmpImmediateOpcode(VT, Op1C)) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, CurDbgLoc, TII.get(CompareImmOpc))
.addReg(Op0Reg)
.addImm(Op1C->getSExtValue());
return true;
}
}
unsigned CompareOpc = X86ChooseCmpOpcode(VT, Subtarget);
if (CompareOpc == 0) return false;
unsigned Op1Reg = getRegForValue(Op1);
if (Op1Reg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, CurDbgLoc, TII.get(CompareOpc))
.addReg(Op0Reg)
.addReg(Op1Reg);
return true;
}
bool X86FastISel::X86SelectCmp(const Instruction *I) {
const CmpInst *CI = cast<CmpInst>(I);
MVT VT;
if (!isTypeLegal(I->getOperand(0)->getType(), VT))
return false;
// Try to optimize or fold the cmp.
CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
unsigned ResultReg = 0;
switch (Predicate) {
default: break;
case CmpInst::FCMP_FALSE: {
ResultReg = createResultReg(&X86::GR32RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV32r0),
ResultReg);
ResultReg = fastEmitInst_extractsubreg(MVT::i8, ResultReg, /*Kill=*/true,
X86::sub_8bit);
if (!ResultReg)
return false;
break;
}
case CmpInst::FCMP_TRUE: {
ResultReg = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV8ri),
ResultReg).addImm(1);
break;
}
}
if (ResultReg) {
updateValueMap(I, ResultReg);
return true;
}
const Value *LHS = CI->getOperand(0);
const Value *RHS = CI->getOperand(1);
// The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x, 0.0.
// We don't have to materialize a zero constant for this case and can just use
// %x again on the RHS.
if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) {
const auto *RHSC = dyn_cast<ConstantFP>(RHS);
if (RHSC && RHSC->isNullValue())
RHS = LHS;
}
// FCMP_OEQ and FCMP_UNE cannot be checked with a single instruction.
static unsigned SETFOpcTable[2][3] = {
{ X86::SETEr, X86::SETNPr, X86::AND8rr },
{ X86::SETNEr, X86::SETPr, X86::OR8rr }
};
unsigned *SETFOpc = nullptr;
switch (Predicate) {
default: break;
case CmpInst::FCMP_OEQ: SETFOpc = &SETFOpcTable[0][0]; break;
case CmpInst::FCMP_UNE: SETFOpc = &SETFOpcTable[1][0]; break;
}
ResultReg = createResultReg(&X86::GR8RegClass);
if (SETFOpc) {
if (!X86FastEmitCompare(LHS, RHS, VT, I->getDebugLoc()))
return false;
unsigned FlagReg1 = createResultReg(&X86::GR8RegClass);
unsigned FlagReg2 = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[0]),
FlagReg1);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[1]),
FlagReg2);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[2]),
ResultReg).addReg(FlagReg1).addReg(FlagReg2);
updateValueMap(I, ResultReg);
return true;
}
X86::CondCode CC;
bool SwapArgs;
std::tie(CC, SwapArgs) = getX86ConditionCode(Predicate);
assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code.");
unsigned Opc = X86::getSETFromCond(CC);
if (SwapArgs)
std::swap(LHS, RHS);
// Emit a compare of LHS/RHS.
if (!X86FastEmitCompare(LHS, RHS, VT, I->getDebugLoc()))
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg);
updateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectZExt(const Instruction *I) {
EVT DstVT = TLI.getValueType(I->getType());
if (!TLI.isTypeLegal(DstVT))
return false;
unsigned ResultReg = getRegForValue(I->getOperand(0));
if (ResultReg == 0)
return false;
// Handle zero-extension from i1 to i8, which is common.
MVT SrcVT = TLI.getSimpleValueType(I->getOperand(0)->getType());
if (SrcVT.SimpleTy == MVT::i1) {
// Set the high bits to zero.
ResultReg = fastEmitZExtFromI1(MVT::i8, ResultReg, /*TODO: Kill=*/false);
SrcVT = MVT::i8;
if (ResultReg == 0)
return false;
}
if (DstVT == MVT::i64) {
// Handle extension to 64-bits via sub-register shenanigans.
unsigned MovInst;
switch (SrcVT.SimpleTy) {
case MVT::i8: MovInst = X86::MOVZX32rr8; break;
case MVT::i16: MovInst = X86::MOVZX32rr16; break;
case MVT::i32: MovInst = X86::MOV32rr; break;
default: llvm_unreachable("Unexpected zext to i64 source type");
}
unsigned Result32 = createResultReg(&X86::GR32RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(MovInst), Result32)
.addReg(ResultReg);
ResultReg = createResultReg(&X86::GR64RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::SUBREG_TO_REG),
ResultReg)
.addImm(0).addReg(Result32).addImm(X86::sub_32bit);
} else if (DstVT != MVT::i8) {
ResultReg = fastEmit_r(MVT::i8, DstVT.getSimpleVT(), ISD::ZERO_EXTEND,
ResultReg, /*Kill=*/true);
if (ResultReg == 0)
return false;
}
updateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectBranch(const Instruction *I) {
// Unconditional branches are selected by tablegen-generated code.
// Handle a conditional branch.
const BranchInst *BI = cast<BranchInst>(I);
MachineBasicBlock *TrueMBB = FuncInfo.MBBMap[BI->getSuccessor(0)];
MachineBasicBlock *FalseMBB = FuncInfo.MBBMap[BI->getSuccessor(1)];
// Fold the common case of a conditional branch with a comparison
// in the same block (values defined on other blocks may not have
// initialized registers).
X86::CondCode CC;
if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) {
if (CI->hasOneUse() && CI->getParent() == I->getParent()) {
EVT VT = TLI.getValueType(CI->getOperand(0)->getType());
// Try to optimize or fold the cmp.
CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
switch (Predicate) {
default: break;
case CmpInst::FCMP_FALSE: fastEmitBranch(FalseMBB, DbgLoc); return true;
case CmpInst::FCMP_TRUE: fastEmitBranch(TrueMBB, DbgLoc); return true;
}
const Value *CmpLHS = CI->getOperand(0);
const Value *CmpRHS = CI->getOperand(1);
// The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x,
// 0.0.
// We don't have to materialize a zero constant for this case and can just
// use %x again on the RHS.
if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) {
const auto *CmpRHSC = dyn_cast<ConstantFP>(CmpRHS);
if (CmpRHSC && CmpRHSC->isNullValue())
CmpRHS = CmpLHS;
}
// Try to take advantage of fallthrough opportunities.
if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) {
std::swap(TrueMBB, FalseMBB);
Predicate = CmpInst::getInversePredicate(Predicate);
}
// FCMP_OEQ and FCMP_UNE cannot be expressed with a single flag/condition
// code check. Instead two branch instructions are required to check all
// the flags. First we change the predicate to a supported condition code,
// which will be the first branch. Later one we will emit the second
// branch.
bool NeedExtraBranch = false;
switch (Predicate) {
default: break;
case CmpInst::FCMP_OEQ:
std::swap(TrueMBB, FalseMBB); // fall-through
case CmpInst::FCMP_UNE:
NeedExtraBranch = true;
Predicate = CmpInst::FCMP_ONE;
break;
}
bool SwapArgs;
unsigned BranchOpc;
std::tie(CC, SwapArgs) = getX86ConditionCode(Predicate);
assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code.");
BranchOpc = X86::GetCondBranchFromCond(CC);
if (SwapArgs)
std::swap(CmpLHS, CmpRHS);
// Emit a compare of the LHS and RHS, setting the flags.
if (!X86FastEmitCompare(CmpLHS, CmpRHS, VT, CI->getDebugLoc()))
return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(BranchOpc))
.addMBB(TrueMBB);
// X86 requires a second branch to handle UNE (and OEQ, which is mapped
// to UNE above).
if (NeedExtraBranch) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JP_1))
.addMBB(TrueMBB);
}
// Obtain the branch weight and add the TrueBB to the successor list.
uint32_t BranchWeight = 0;
if (FuncInfo.BPI)
BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(),
TrueMBB->getBasicBlock());
FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight);
// Emits an unconditional branch to the FalseBB, obtains the branch
// weight, and adds it to the successor list.
fastEmitBranch(FalseMBB, DbgLoc);
return true;
}
} else if (TruncInst *TI = dyn_cast<TruncInst>(BI->getCondition())) {
// Handle things like "%cond = trunc i32 %X to i1 / br i1 %cond", which
// typically happen for _Bool and C++ bools.
MVT SourceVT;
if (TI->hasOneUse() && TI->getParent() == I->getParent() &&
isTypeLegal(TI->getOperand(0)->getType(), SourceVT)) {
unsigned TestOpc = 0;
switch (SourceVT.SimpleTy) {
default: break;
case MVT::i8: TestOpc = X86::TEST8ri; break;
case MVT::i16: TestOpc = X86::TEST16ri; break;
case MVT::i32: TestOpc = X86::TEST32ri; break;
case MVT::i64: TestOpc = X86::TEST64ri32; break;
}
if (TestOpc) {
unsigned OpReg = getRegForValue(TI->getOperand(0));
if (OpReg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TestOpc))
.addReg(OpReg).addImm(1);
unsigned JmpOpc = X86::JNE_1;
if (FuncInfo.MBB->isLayoutSuccessor(TrueMBB)) {
std::swap(TrueMBB, FalseMBB);
JmpOpc = X86::JE_1;
}
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(JmpOpc))
.addMBB(TrueMBB);
fastEmitBranch(FalseMBB, DbgLoc);
uint32_t BranchWeight = 0;
if (FuncInfo.BPI)
BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(),
TrueMBB->getBasicBlock());
FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight);
return true;
}
}
} else if (foldX86XALUIntrinsic(CC, BI, BI->getCondition())) {
// Fake request the condition, otherwise the intrinsic might be completely
// optimized away.
unsigned TmpReg = getRegForValue(BI->getCondition());
if (TmpReg == 0)
return false;
unsigned BranchOpc = X86::GetCondBranchFromCond(CC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(BranchOpc))
.addMBB(TrueMBB);
fastEmitBranch(FalseMBB, DbgLoc);
uint32_t BranchWeight = 0;
if (FuncInfo.BPI)
BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(),
TrueMBB->getBasicBlock());
FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight);
return true;
}
// Otherwise do a clumsy setcc and re-test it.
// Note that i1 essentially gets ANY_EXTEND'ed to i8 where it isn't used
// in an explicit cast, so make sure to handle that correctly.
unsigned OpReg = getRegForValue(BI->getCondition());
if (OpReg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri))
.addReg(OpReg).addImm(1);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::JNE_1))
.addMBB(TrueMBB);
fastEmitBranch(FalseMBB, DbgLoc);
uint32_t BranchWeight = 0;
if (FuncInfo.BPI)
BranchWeight = FuncInfo.BPI->getEdgeWeight(BI->getParent(),
TrueMBB->getBasicBlock());
FuncInfo.MBB->addSuccessor(TrueMBB, BranchWeight);
return true;
}
bool X86FastISel::X86SelectShift(const Instruction *I) {
unsigned CReg = 0, OpReg = 0;
const TargetRegisterClass *RC = nullptr;
if (I->getType()->isIntegerTy(8)) {
CReg = X86::CL;
RC = &X86::GR8RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR8rCL; break;
case Instruction::AShr: OpReg = X86::SAR8rCL; break;
case Instruction::Shl: OpReg = X86::SHL8rCL; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(16)) {
CReg = X86::CX;
RC = &X86::GR16RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR16rCL; break;
case Instruction::AShr: OpReg = X86::SAR16rCL; break;
case Instruction::Shl: OpReg = X86::SHL16rCL; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(32)) {
CReg = X86::ECX;
RC = &X86::GR32RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR32rCL; break;
case Instruction::AShr: OpReg = X86::SAR32rCL; break;
case Instruction::Shl: OpReg = X86::SHL32rCL; break;
default: return false;
}
} else if (I->getType()->isIntegerTy(64)) {
CReg = X86::RCX;
RC = &X86::GR64RegClass;
switch (I->getOpcode()) {
case Instruction::LShr: OpReg = X86::SHR64rCL; break;
case Instruction::AShr: OpReg = X86::SAR64rCL; break;
case Instruction::Shl: OpReg = X86::SHL64rCL; break;
default: return false;
}
} else {
return false;
}
MVT VT;
if (!isTypeLegal(I->getType(), VT))
return false;
unsigned Op0Reg = getRegForValue(I->getOperand(0));
if (Op0Reg == 0) return false;
unsigned Op1Reg = getRegForValue(I->getOperand(1));
if (Op1Reg == 0) return false;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpcode::COPY),
CReg).addReg(Op1Reg);
// The shift instruction uses X86::CL. If we defined a super-register
// of X86::CL, emit a subreg KILL to precisely describe what we're doing here.
if (CReg != X86::CL)
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::KILL), X86::CL)
.addReg(CReg, RegState::Kill);
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(OpReg), ResultReg)
.addReg(Op0Reg);
updateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectDivRem(const Instruction *I) {
const static unsigned NumTypes = 4; // i8, i16, i32, i64
const static unsigned NumOps = 4; // SDiv, SRem, UDiv, URem
const static bool S = true; // IsSigned
const static bool U = false; // !IsSigned
const static unsigned Copy = TargetOpcode::COPY;
// For the X86 DIV/IDIV instruction, in most cases the dividend
// (numerator) must be in a specific register pair highreg:lowreg,
// producing the quotient in lowreg and the remainder in highreg.
// For most data types, to set up the instruction, the dividend is
// copied into lowreg, and lowreg is sign-extended or zero-extended
// into highreg. The exception is i8, where the dividend is defined
// as a single register rather than a register pair, and we
// therefore directly sign-extend or zero-extend the dividend into
// lowreg, instead of copying, and ignore the highreg.
const static struct DivRemEntry {
// The following portion depends only on the data type.
const TargetRegisterClass *RC;
unsigned LowInReg; // low part of the register pair
unsigned HighInReg; // high part of the register pair
// The following portion depends on both the data type and the operation.
struct DivRemResult {
unsigned OpDivRem; // The specific DIV/IDIV opcode to use.
unsigned OpSignExtend; // Opcode for sign-extending lowreg into
// highreg, or copying a zero into highreg.
unsigned OpCopy; // Opcode for copying dividend into lowreg, or
// zero/sign-extending into lowreg for i8.
unsigned DivRemResultReg; // Register containing the desired result.
bool IsOpSigned; // Whether to use signed or unsigned form.
} ResultTable[NumOps];
} OpTable[NumTypes] = {
{ &X86::GR8RegClass, X86::AX, 0, {
{ X86::IDIV8r, 0, X86::MOVSX16rr8, X86::AL, S }, // SDiv
{ X86::IDIV8r, 0, X86::MOVSX16rr8, X86::AH, S }, // SRem
{ X86::DIV8r, 0, X86::MOVZX16rr8, X86::AL, U }, // UDiv
{ X86::DIV8r, 0, X86::MOVZX16rr8, X86::AH, U }, // URem
}
}, // i8
{ &X86::GR16RegClass, X86::AX, X86::DX, {
{ X86::IDIV16r, X86::CWD, Copy, X86::AX, S }, // SDiv
{ X86::IDIV16r, X86::CWD, Copy, X86::DX, S }, // SRem
{ X86::DIV16r, X86::MOV32r0, Copy, X86::AX, U }, // UDiv
{ X86::DIV16r, X86::MOV32r0, Copy, X86::DX, U }, // URem
}
}, // i16
{ &X86::GR32RegClass, X86::EAX, X86::EDX, {
{ X86::IDIV32r, X86::CDQ, Copy, X86::EAX, S }, // SDiv
{ X86::IDIV32r, X86::CDQ, Copy, X86::EDX, S }, // SRem
{ X86::DIV32r, X86::MOV32r0, Copy, X86::EAX, U }, // UDiv
{ X86::DIV32r, X86::MOV32r0, Copy, X86::EDX, U }, // URem
}
}, // i32
{ &X86::GR64RegClass, X86::RAX, X86::RDX, {
{ X86::IDIV64r, X86::CQO, Copy, X86::RAX, S }, // SDiv
{ X86::IDIV64r, X86::CQO, Copy, X86::RDX, S }, // SRem
{ X86::DIV64r, X86::MOV32r0, Copy, X86::RAX, U }, // UDiv
{ X86::DIV64r, X86::MOV32r0, Copy, X86::RDX, U }, // URem
}
}, // i64
};
MVT VT;
if (!isTypeLegal(I->getType(), VT))
return false;
unsigned TypeIndex, OpIndex;
switch (VT.SimpleTy) {
default: return false;
case MVT::i8: TypeIndex = 0; break;
case MVT::i16: TypeIndex = 1; break;
case MVT::i32: TypeIndex = 2; break;
case MVT::i64: TypeIndex = 3;
if (!Subtarget->is64Bit())
return false;
break;
}
switch (I->getOpcode()) {
default: llvm_unreachable("Unexpected div/rem opcode");
case Instruction::SDiv: OpIndex = 0; break;
case Instruction::SRem: OpIndex = 1; break;
case Instruction::UDiv: OpIndex = 2; break;
case Instruction::URem: OpIndex = 3; break;
}
const DivRemEntry &TypeEntry = OpTable[TypeIndex];
const DivRemEntry::DivRemResult &OpEntry = TypeEntry.ResultTable[OpIndex];
unsigned Op0Reg = getRegForValue(I->getOperand(0));
if (Op0Reg == 0)
return false;
unsigned Op1Reg = getRegForValue(I->getOperand(1));
if (Op1Reg == 0)
return false;
// Move op0 into low-order input register.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(OpEntry.OpCopy), TypeEntry.LowInReg).addReg(Op0Reg);
// Zero-extend or sign-extend into high-order input register.
if (OpEntry.OpSignExtend) {
if (OpEntry.IsOpSigned)
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(OpEntry.OpSignExtend));
else {
unsigned Zero32 = createResultReg(&X86::GR32RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(X86::MOV32r0), Zero32);
// Copy the zero into the appropriate sub/super/identical physical
// register. Unfortunately the operations needed are not uniform enough
// to fit neatly into the table above.
if (VT.SimpleTy == MVT::i16) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Copy), TypeEntry.HighInReg)
.addReg(Zero32, 0, X86::sub_16bit);
} else if (VT.SimpleTy == MVT::i32) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Copy), TypeEntry.HighInReg)
.addReg(Zero32);
} else if (VT.SimpleTy == MVT::i64) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::SUBREG_TO_REG), TypeEntry.HighInReg)
.addImm(0).addReg(Zero32).addImm(X86::sub_32bit);
}
}
}
// Generate the DIV/IDIV instruction.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(OpEntry.OpDivRem)).addReg(Op1Reg);
// For i8 remainder, we can't reference AH directly, as we'll end
// up with bogus copies like %R9B = COPY %AH. Reference AX
// instead to prevent AH references in a REX instruction.
//
// The current assumption of the fast register allocator is that isel
// won't generate explicit references to the GPR8_NOREX registers. If
// the allocator and/or the backend get enhanced to be more robust in
// that regard, this can be, and should be, removed.
unsigned ResultReg = 0;
if ((I->getOpcode() == Instruction::SRem ||
I->getOpcode() == Instruction::URem) &&
OpEntry.DivRemResultReg == X86::AH && Subtarget->is64Bit()) {
unsigned SourceSuperReg = createResultReg(&X86::GR16RegClass);
unsigned ResultSuperReg = createResultReg(&X86::GR16RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Copy), SourceSuperReg).addReg(X86::AX);
// Shift AX right by 8 bits instead of using AH.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::SHR16ri),
ResultSuperReg).addReg(SourceSuperReg).addImm(8);
// Now reference the 8-bit subreg of the result.
ResultReg = fastEmitInst_extractsubreg(MVT::i8, ResultSuperReg,
/*Kill=*/true, X86::sub_8bit);
}
// Copy the result out of the physreg if we haven't already.
if (!ResultReg) {
ResultReg = createResultReg(TypeEntry.RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Copy), ResultReg)
.addReg(OpEntry.DivRemResultReg);
}
updateValueMap(I, ResultReg);
return true;
}
/// \brief Emit a conditional move instruction (if the are supported) to lower
/// the select.
bool X86FastISel::X86FastEmitCMoveSelect(MVT RetVT, const Instruction *I) {
// Check if the subtarget supports these instructions.
if (!Subtarget->hasCMov())
return false;
// FIXME: Add support for i8.
if (RetVT < MVT::i16 || RetVT > MVT::i64)
return false;
const Value *Cond = I->getOperand(0);
const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
bool NeedTest = true;
X86::CondCode CC = X86::COND_NE;
// Optimize conditions coming from a compare if both instructions are in the
// same basic block (values defined in other basic blocks may not have
// initialized registers).
const auto *CI = dyn_cast<CmpInst>(Cond);
if (CI && (CI->getParent() == I->getParent())) {
CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
// FCMP_OEQ and FCMP_UNE cannot be checked with a single instruction.
static unsigned SETFOpcTable[2][3] = {
{ X86::SETNPr, X86::SETEr , X86::TEST8rr },
{ X86::SETPr, X86::SETNEr, X86::OR8rr }
};
unsigned *SETFOpc = nullptr;
switch (Predicate) {
default: break;
case CmpInst::FCMP_OEQ:
SETFOpc = &SETFOpcTable[0][0];
Predicate = CmpInst::ICMP_NE;
break;
case CmpInst::FCMP_UNE:
SETFOpc = &SETFOpcTable[1][0];
Predicate = CmpInst::ICMP_NE;
break;
}
bool NeedSwap;
std::tie(CC, NeedSwap) = getX86ConditionCode(Predicate);
assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code.");
const Value *CmpLHS = CI->getOperand(0);
const Value *CmpRHS = CI->getOperand(1);
if (NeedSwap)
std::swap(CmpLHS, CmpRHS);
EVT CmpVT = TLI.getValueType(CmpLHS->getType());
// Emit a compare of the LHS and RHS, setting the flags.
if (!X86FastEmitCompare(CmpLHS, CmpRHS, CmpVT, CI->getDebugLoc()))
return false;
if (SETFOpc) {
unsigned FlagReg1 = createResultReg(&X86::GR8RegClass);
unsigned FlagReg2 = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[0]),
FlagReg1);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(SETFOpc[1]),
FlagReg2);
auto const &II = TII.get(SETFOpc[2]);
if (II.getNumDefs()) {
unsigned TmpReg = createResultReg(&X86::GR8RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II, TmpReg)
.addReg(FlagReg2).addReg(FlagReg1);
} else {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II)
.addReg(FlagReg2).addReg(FlagReg1);
}
}
NeedTest = false;
} else if (foldX86XALUIntrinsic(CC, I, Cond)) {
// Fake request the condition, otherwise the intrinsic might be completely
// optimized away.
unsigned TmpReg = getRegForValue(Cond);
if (TmpReg == 0)
return false;
NeedTest = false;
}
if (NeedTest) {
// Selects operate on i1, however, CondReg is 8 bits width and may contain
// garbage. Indeed, only the less significant bit is supposed to be
// accurate. If we read more than the lsb, we may see non-zero values
// whereas lsb is zero. Therefore, we have to truncate Op0Reg to i1 for
// the select. This is achieved by performing TEST against 1.
unsigned CondReg = getRegForValue(Cond);
if (CondReg == 0)
return false;
bool CondIsKill = hasTrivialKill(Cond);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri))
.addReg(CondReg, getKillRegState(CondIsKill)).addImm(1);
}
const Value *LHS = I->getOperand(1);
const Value *RHS = I->getOperand(2);
unsigned RHSReg = getRegForValue(RHS);
bool RHSIsKill = hasTrivialKill(RHS);
unsigned LHSReg = getRegForValue(LHS);
bool LHSIsKill = hasTrivialKill(LHS);
if (!LHSReg || !RHSReg)
return false;
unsigned Opc = X86::getCMovFromCond(CC, RC->getSize());
unsigned ResultReg = fastEmitInst_rr(Opc, RC, RHSReg, RHSIsKill,
LHSReg, LHSIsKill);
updateValueMap(I, ResultReg);
return true;
}
/// \brief Emit SSE or AVX instructions to lower the select.
///
/// Try to use SSE1/SSE2 instructions to simulate a select without branches.
/// This lowers fp selects into a CMP/AND/ANDN/OR sequence when the necessary
/// SSE instructions are available. If AVX is available, try to use a VBLENDV.
bool X86FastISel::X86FastEmitSSESelect(MVT RetVT, const Instruction *I) {
// Optimize conditions coming from a compare if both instructions are in the
// same basic block (values defined in other basic blocks may not have
// initialized registers).
const auto *CI = dyn_cast<FCmpInst>(I->getOperand(0));
if (!CI || (CI->getParent() != I->getParent()))
return false;
if (I->getType() != CI->getOperand(0)->getType() ||
!((Subtarget->hasSSE1() && RetVT == MVT::f32) ||
(Subtarget->hasSSE2() && RetVT == MVT::f64)))
return false;
const Value *CmpLHS = CI->getOperand(0);
const Value *CmpRHS = CI->getOperand(1);
CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
// The optimizer might have replaced fcmp oeq %x, %x with fcmp ord %x, 0.0.
// We don't have to materialize a zero constant for this case and can just use
// %x again on the RHS.
if (Predicate == CmpInst::FCMP_ORD || Predicate == CmpInst::FCMP_UNO) {
const auto *CmpRHSC = dyn_cast<ConstantFP>(CmpRHS);
if (CmpRHSC && CmpRHSC->isNullValue())
CmpRHS = CmpLHS;
}
unsigned CC;
bool NeedSwap;
std::tie(CC, NeedSwap) = getX86SSEConditionCode(Predicate);
if (CC > 7)
return false;
if (NeedSwap)
std::swap(CmpLHS, CmpRHS);
// Choose the SSE instruction sequence based on data type (float or double).
static unsigned OpcTable[2][4] = {
{ X86::CMPSSrr, X86::FsANDPSrr, X86::FsANDNPSrr, X86::FsORPSrr },
{ X86::CMPSDrr, X86::FsANDPDrr, X86::FsANDNPDrr, X86::FsORPDrr }
};
unsigned *Opc = nullptr;
switch (RetVT.SimpleTy) {
default: return false;
case MVT::f32: Opc = &OpcTable[0][0]; break;
case MVT::f64: Opc = &OpcTable[1][0]; break;
}
const Value *LHS = I->getOperand(1);
const Value *RHS = I->getOperand(2);
unsigned LHSReg = getRegForValue(LHS);
bool LHSIsKill = hasTrivialKill(LHS);
unsigned RHSReg = getRegForValue(RHS);
bool RHSIsKill = hasTrivialKill(RHS);
unsigned CmpLHSReg = getRegForValue(CmpLHS);
bool CmpLHSIsKill = hasTrivialKill(CmpLHS);
unsigned CmpRHSReg = getRegForValue(CmpRHS);
bool CmpRHSIsKill = hasTrivialKill(CmpRHS);
if (!LHSReg || !RHSReg || !CmpLHS || !CmpRHS)
return false;
const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
unsigned ResultReg;
if (Subtarget->hasAVX()) {
// If we have AVX, create 1 blendv instead of 3 logic instructions.
// Blendv was introduced with SSE 4.1, but the 2 register form implicitly
// uses XMM0 as the selection register. That may need just as many
// instructions as the AND/ANDN/OR sequence due to register moves, so
// don't bother.
unsigned CmpOpcode =
(RetVT.SimpleTy == MVT::f32) ? X86::VCMPSSrr : X86::VCMPSDrr;
unsigned BlendOpcode =
(RetVT.SimpleTy == MVT::f32) ? X86::VBLENDVPSrr : X86::VBLENDVPDrr;
unsigned CmpReg = fastEmitInst_rri(CmpOpcode, RC, CmpLHSReg, CmpLHSIsKill,
CmpRHSReg, CmpRHSIsKill, CC);
ResultReg = fastEmitInst_rrr(BlendOpcode, RC, RHSReg, RHSIsKill,
LHSReg, LHSIsKill, CmpReg, true);
} else {
unsigned CmpReg = fastEmitInst_rri(Opc[0], RC, CmpLHSReg, CmpLHSIsKill,
CmpRHSReg, CmpRHSIsKill, CC);
unsigned AndReg = fastEmitInst_rr(Opc[1], RC, CmpReg, /*IsKill=*/false,
LHSReg, LHSIsKill);
unsigned AndNReg = fastEmitInst_rr(Opc[2], RC, CmpReg, /*IsKill=*/true,
RHSReg, RHSIsKill);
ResultReg = fastEmitInst_rr(Opc[3], RC, AndNReg, /*IsKill=*/true,
AndReg, /*IsKill=*/true);
}
updateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86FastEmitPseudoSelect(MVT RetVT, const Instruction *I) {
// These are pseudo CMOV instructions and will be later expanded into control-
// flow.
unsigned Opc;
switch (RetVT.SimpleTy) {
default: return false;
case MVT::i8: Opc = X86::CMOV_GR8; break;
case MVT::i16: Opc = X86::CMOV_GR16; break;
case MVT::i32: Opc = X86::CMOV_GR32; break;
case MVT::f32: Opc = X86::CMOV_FR32; break;
case MVT::f64: Opc = X86::CMOV_FR64; break;
}
const Value *Cond = I->getOperand(0);
X86::CondCode CC = X86::COND_NE;
// Optimize conditions coming from a compare if both instructions are in the
// same basic block (values defined in other basic blocks may not have
// initialized registers).
const auto *CI = dyn_cast<CmpInst>(Cond);
if (CI && (CI->getParent() == I->getParent())) {
bool NeedSwap;
std::tie(CC, NeedSwap) = getX86ConditionCode(CI->getPredicate());
if (CC > X86::LAST_VALID_COND)
return false;
const Value *CmpLHS = CI->getOperand(0);
const Value *CmpRHS = CI->getOperand(1);
if (NeedSwap)
std::swap(CmpLHS, CmpRHS);
EVT CmpVT = TLI.getValueType(CmpLHS->getType());
if (!X86FastEmitCompare(CmpLHS, CmpRHS, CmpVT, CI->getDebugLoc()))
return false;
} else {
unsigned CondReg = getRegForValue(Cond);
if (CondReg == 0)
return false;
bool CondIsKill = hasTrivialKill(Cond);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TEST8ri))
.addReg(CondReg, getKillRegState(CondIsKill)).addImm(1);
}
const Value *LHS = I->getOperand(1);
const Value *RHS = I->getOperand(2);
unsigned LHSReg = getRegForValue(LHS);
bool LHSIsKill = hasTrivialKill(LHS);
unsigned RHSReg = getRegForValue(RHS);
bool RHSIsKill = hasTrivialKill(RHS);
if (!LHSReg || !RHSReg)
return false;
const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
unsigned ResultReg =
fastEmitInst_rri(Opc, RC, RHSReg, RHSIsKill, LHSReg, LHSIsKill, CC);
updateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectSelect(const Instruction *I) {
MVT RetVT;
if (!isTypeLegal(I->getType(), RetVT))
return false;
// Check if we can fold the select.
if (const auto *CI = dyn_cast<CmpInst>(I->getOperand(0))) {
CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
const Value *Opnd = nullptr;
switch (Predicate) {
default: break;
case CmpInst::FCMP_FALSE: Opnd = I->getOperand(2); break;
case CmpInst::FCMP_TRUE: Opnd = I->getOperand(1); break;
}
// No need for a select anymore - this is an unconditional move.
if (Opnd) {
unsigned OpReg = getRegForValue(Opnd);
if (OpReg == 0)
return false;
bool OpIsKill = hasTrivialKill(Opnd);
const TargetRegisterClass *RC = TLI.getRegClassFor(RetVT);
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(OpReg, getKillRegState(OpIsKill));
updateValueMap(I, ResultReg);
return true;
}
}
// First try to use real conditional move instructions.
if (X86FastEmitCMoveSelect(RetVT, I))
return true;
// Try to use a sequence of SSE instructions to simulate a conditional move.
if (X86FastEmitSSESelect(RetVT, I))
return true;
// Fall-back to pseudo conditional move instructions, which will be later
// converted to control-flow.
if (X86FastEmitPseudoSelect(RetVT, I))
return true;
return false;
}
bool X86FastISel::X86SelectSIToFP(const Instruction *I) {
if (!I->getOperand(0)->getType()->isIntegerTy(32))
return false;
// Select integer to float/double conversion.
unsigned OpReg = getRegForValue(I->getOperand(0));
if (OpReg == 0)
return false;
const TargetRegisterClass *RC = nullptr;
unsigned Opcode;
if (I->getType()->isDoubleTy()) {
// sitofp int -> double
Opcode = X86::VCVTSI2SDrr;
RC = &X86::FR64RegClass;
} else if (I->getType()->isFloatTy()) {
// sitofp int -> float
Opcode = X86::VCVTSI2SSrr;
RC = &X86::FR32RegClass;
} else
return false;
// The target-independent selection algorithm in FastISel already knows how
// to select a SINT_TO_FP if the target is SSE but not AVX. This code is only
// reachable if the subtarget has AVX.
assert(Subtarget->hasAVX() && "Expected a subtarget with AVX!");
unsigned ImplicitDefReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg);
unsigned ResultReg =
fastEmitInst_rr(Opcode, RC, ImplicitDefReg, true, OpReg, false);
updateValueMap(I, ResultReg);
return true;
}
// Helper method used by X86SelectFPExt and X86SelectFPTrunc.
bool X86FastISel::X86SelectFPExtOrFPTrunc(const Instruction *I,
unsigned TargetOpc,
const TargetRegisterClass *RC) {
assert((I->getOpcode() == Instruction::FPExt ||
I->getOpcode() == Instruction::FPTrunc) &&
"Instruction must be an FPExt or FPTrunc!");
unsigned OpReg = getRegForValue(I->getOperand(0));
if (OpReg == 0)
return false;
unsigned ResultReg = createResultReg(RC);
MachineInstrBuilder MIB;
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(TargetOpc),
ResultReg);
if (Subtarget->hasAVX())
MIB.addReg(OpReg);
MIB.addReg(OpReg);
updateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::X86SelectFPExt(const Instruction *I) {
if (X86ScalarSSEf64 && I->getType()->isDoubleTy() &&
I->getOperand(0)->getType()->isFloatTy()) {
// fpext from float to double.
unsigned Opc = Subtarget->hasAVX() ? X86::VCVTSS2SDrr : X86::CVTSS2SDrr;
return X86SelectFPExtOrFPTrunc(I, Opc, &X86::FR64RegClass);
}
return false;
}
bool X86FastISel::X86SelectFPTrunc(const Instruction *I) {
if (X86ScalarSSEf64 && I->getType()->isFloatTy() &&
I->getOperand(0)->getType()->isDoubleTy()) {
// fptrunc from double to float.
unsigned Opc = Subtarget->hasAVX() ? X86::VCVTSD2SSrr : X86::CVTSD2SSrr;
return X86SelectFPExtOrFPTrunc(I, Opc, &X86::FR32RegClass);
}
return false;
}
bool X86FastISel::X86SelectTrunc(const Instruction *I) {
EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType());
EVT DstVT = TLI.getValueType(I->getType());
// This code only handles truncation to byte.
if (DstVT != MVT::i8 && DstVT != MVT::i1)
return false;
if (!TLI.isTypeLegal(SrcVT))
return false;
unsigned InputReg = getRegForValue(I->getOperand(0));
if (!InputReg)
// Unhandled operand. Halt "fast" selection and bail.
return false;
if (SrcVT == MVT::i8) {
// Truncate from i8 to i1; no code needed.
updateValueMap(I, InputReg);
return true;
}
if (!Subtarget->is64Bit()) {
// If we're on x86-32; we can't extract an i8 from a general register.
// First issue a copy to GR16_ABCD or GR32_ABCD.
const TargetRegisterClass *CopyRC =
(SrcVT == MVT::i16) ? &X86::GR16_ABCDRegClass : &X86::GR32_ABCDRegClass;
unsigned CopyReg = createResultReg(CopyRC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), CopyReg).addReg(InputReg);
InputReg = CopyReg;
}
// Issue an extract_subreg.
unsigned ResultReg = fastEmitInst_extractsubreg(MVT::i8,
InputReg, /*Kill=*/true,
X86::sub_8bit);
if (!ResultReg)
return false;
updateValueMap(I, ResultReg);
return true;
}
bool X86FastISel::IsMemcpySmall(uint64_t Len) {
return Len <= (Subtarget->is64Bit() ? 32 : 16);
}
bool X86FastISel::TryEmitSmallMemcpy(X86AddressMode DestAM,
X86AddressMode SrcAM, uint64_t Len) {
// Make sure we don't bloat code by inlining very large memcpy's.
if (!IsMemcpySmall(Len))
return false;
bool i64Legal = Subtarget->is64Bit();
// We don't care about alignment here since we just emit integer accesses.
while (Len) {
MVT VT;
if (Len >= 8 && i64Legal)
VT = MVT::i64;
else if (Len >= 4)
VT = MVT::i32;
else if (Len >= 2)
VT = MVT::i16;
else
VT = MVT::i8;
unsigned Reg;
bool RV = X86FastEmitLoad(VT, SrcAM, nullptr, Reg);
RV &= X86FastEmitStore(VT, Reg, /*Kill=*/true, DestAM);
assert(RV && "Failed to emit load or store??");
unsigned Size = VT.getSizeInBits()/8;
Len -= Size;
DestAM.Disp += Size;
SrcAM.Disp += Size;
}
return true;
}
bool X86FastISel::fastLowerIntrinsicCall(const IntrinsicInst *II) {
// FIXME: Handle more intrinsics.
switch (II->getIntrinsicID()) {
default: return false;
case Intrinsic::convert_from_fp16:
case Intrinsic::convert_to_fp16: {
if (TM.Options.UseSoftFloat || !Subtarget->hasF16C())
return false;
const Value *Op = II->getArgOperand(0);
unsigned InputReg = getRegForValue(Op);
if (InputReg == 0)
return false;
// F16C only allows converting from float to half and from half to float.
bool IsFloatToHalf = II->getIntrinsicID() == Intrinsic::convert_to_fp16;
if (IsFloatToHalf) {
if (!Op->getType()->isFloatTy())
return false;
} else {
if (!II->getType()->isFloatTy())
return false;
}
unsigned ResultReg = 0;
const TargetRegisterClass *RC = TLI.getRegClassFor(MVT::v8i16);
if (IsFloatToHalf) {
// 'InputReg' is implicitly promoted from register class FR32 to
// register class VR128 by method 'constrainOperandRegClass' which is
// directly called by 'fastEmitInst_ri'.
// Instruction VCVTPS2PHrr takes an extra immediate operand which is
// used to provide rounding control.
InputReg = fastEmitInst_ri(X86::VCVTPS2PHrr, RC, InputReg, false, 0);
// Move the lower 32-bits of ResultReg to another register of class GR32.
ResultReg = createResultReg(&X86::GR32RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(X86::VMOVPDI2DIrr), ResultReg)
.addReg(InputReg, RegState::Kill);
// The result value is in the lower 16-bits of ResultReg.
unsigned RegIdx = X86::sub_16bit;
ResultReg = fastEmitInst_extractsubreg(MVT::i16, ResultReg, true, RegIdx);
} else {
assert(Op->getType()->isIntegerTy(16) && "Expected a 16-bit integer!");
// Explicitly sign-extend the input to 32-bit.
InputReg = fastEmit_r(MVT::i16, MVT::i32, ISD::SIGN_EXTEND, InputReg,
/*Kill=*/false);
// The following SCALAR_TO_VECTOR will be expanded into a VMOVDI2PDIrr.
InputReg = fastEmit_r(MVT::i32, MVT::v4i32, ISD::SCALAR_TO_VECTOR,
InputReg, /*Kill=*/true);
InputReg = fastEmitInst_r(X86::VCVTPH2PSrr, RC, InputReg, /*Kill=*/true);
// The result value is in the lower 32-bits of ResultReg.
// Emit an explicit copy from register class VR128 to register class FR32.
ResultReg = createResultReg(&X86::FR32RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(InputReg, RegState::Kill);
}
updateValueMap(II, ResultReg);
return true;
}
case Intrinsic::frameaddress: {
MachineFunction *MF = FuncInfo.MF;
if (MF->getTarget().getMCAsmInfo()->usesWindowsCFI())
return false;
Type *RetTy = II->getCalledFunction()->getReturnType();
MVT VT;
if (!isTypeLegal(RetTy, VT))
return false;
unsigned Opc;
const TargetRegisterClass *RC = nullptr;
switch (VT.SimpleTy) {
default: llvm_unreachable("Invalid result type for frameaddress.");
case MVT::i32: Opc = X86::MOV32rm; RC = &X86::GR32RegClass; break;
case MVT::i64: Opc = X86::MOV64rm; RC = &X86::GR64RegClass; break;
}
// This needs to be set before we call getPtrSizedFrameRegister, otherwise
// we get the wrong frame register.
MachineFrameInfo *MFI = MF->getFrameInfo();
MFI->setFrameAddressIsTaken(true);
const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
unsigned FrameReg = RegInfo->getPtrSizedFrameRegister(*MF);
assert(((FrameReg == X86::RBP && VT == MVT::i64) ||
(FrameReg == X86::EBP && VT == MVT::i32)) &&
"Invalid Frame Register!");
// Always make a copy of the frame register to to a vreg first, so that we
// never directly reference the frame register (the TwoAddressInstruction-
// Pass doesn't like that).
unsigned SrcReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), SrcReg).addReg(FrameReg);
// Now recursively load from the frame address.
// movq (%rbp), %rax
// movq (%rax), %rax
// movq (%rax), %rax
// ...
unsigned DestReg;
unsigned Depth = cast<ConstantInt>(II->getOperand(0))->getZExtValue();
while (Depth--) {
DestReg = createResultReg(RC);
addDirectMem(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc), DestReg), SrcReg);
SrcReg = DestReg;
}
updateValueMap(II, SrcReg);
return true;
}
case Intrinsic::memcpy: {
const MemCpyInst *MCI = cast<MemCpyInst>(II);
// Don't handle volatile or variable length memcpys.
if (MCI->isVolatile())
return false;
if (isa<ConstantInt>(MCI->getLength())) {
// Small memcpy's are common enough that we want to do them
// without a call if possible.
uint64_t Len = cast<ConstantInt>(MCI->getLength())->getZExtValue();
if (IsMemcpySmall(Len)) {
X86AddressMode DestAM, SrcAM;
if (!X86SelectAddress(MCI->getRawDest(), DestAM) ||
!X86SelectAddress(MCI->getRawSource(), SrcAM))
return false;
TryEmitSmallMemcpy(DestAM, SrcAM, Len);
return true;
}
}
unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
if (!MCI->getLength()->getType()->isIntegerTy(SizeWidth))
return false;
if (MCI->getSourceAddressSpace() > 255 || MCI->getDestAddressSpace() > 255)
return false;
return lowerCallTo(II, "memcpy", II->getNumArgOperands() - 2);
}
case Intrinsic::memset: {
const MemSetInst *MSI = cast<MemSetInst>(II);
if (MSI->isVolatile())
return false;
unsigned SizeWidth = Subtarget->is64Bit() ? 64 : 32;
if (!MSI->getLength()->getType()->isIntegerTy(SizeWidth))
return false;
if (MSI->getDestAddressSpace() > 255)
return false;
return lowerCallTo(II, "memset", II->getNumArgOperands() - 2);
}
case Intrinsic::stackprotector: {
// Emit code to store the stack guard onto the stack.
EVT PtrTy = TLI.getPointerTy();
const Value *Op1 = II->getArgOperand(0); // The guard's value.
const AllocaInst *Slot = cast<AllocaInst>(II->getArgOperand(1));
MFI.setStackProtectorIndex(FuncInfo.StaticAllocaMap[Slot]);
// Grab the frame index.
X86AddressMode AM;
if (!X86SelectAddress(Slot, AM)) return false;
if (!X86FastEmitStore(PtrTy, Op1, AM)) return false;
return true;
}
case Intrinsic::dbg_declare: {
const DbgDeclareInst *DI = cast<DbgDeclareInst>(II);
X86AddressMode AM;
assert(DI->getAddress() && "Null address should be checked earlier!");
if (!X86SelectAddress(DI->getAddress(), AM))
return false;
const MCInstrDesc &II = TII.get(TargetOpcode::DBG_VALUE);
// FIXME may need to add RegState::Debug to any registers produced,
// although ESP/EBP should be the only ones at the moment.
assert(DI->getVariable()->isValidLocationForIntrinsic(DbgLoc) &&
"Expected inlined-at fields to agree");
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II), AM)
.addImm(0)
.addMetadata(DI->getVariable())
.addMetadata(DI->getExpression());
return true;
}
case Intrinsic::trap: {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::TRAP));
return true;
}
case Intrinsic::sqrt: {
if (!Subtarget->hasSSE1())
return false;
Type *RetTy = II->getCalledFunction()->getReturnType();
MVT VT;
if (!isTypeLegal(RetTy, VT))
return false;
// Unfortunately we can't use fastEmit_r, because the AVX version of FSQRT
// is not generated by FastISel yet.
// FIXME: Update this code once tablegen can handle it.
static const unsigned SqrtOpc[2][2] = {
{X86::SQRTSSr, X86::VSQRTSSr},
{X86::SQRTSDr, X86::VSQRTSDr}
};
bool HasAVX = Subtarget->hasAVX();
unsigned Opc;
const TargetRegisterClass *RC;
switch (VT.SimpleTy) {
default: return false;
case MVT::f32: Opc = SqrtOpc[0][HasAVX]; RC = &X86::FR32RegClass; break;
case MVT::f64: Opc = SqrtOpc[1][HasAVX]; RC = &X86::FR64RegClass; break;
}
const Value *SrcVal = II->getArgOperand(0);
unsigned SrcReg = getRegForValue(SrcVal);
if (SrcReg == 0)
return false;
unsigned ImplicitDefReg = 0;
if (HasAVX) {
ImplicitDefReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::IMPLICIT_DEF), ImplicitDefReg);
}
unsigned ResultReg = createResultReg(RC);
MachineInstrBuilder MIB;
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc),
ResultReg);
if (ImplicitDefReg)
MIB.addReg(ImplicitDefReg);
MIB.addReg(SrcReg);
updateValueMap(II, ResultReg);
return true;
}
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::ssub_with_overflow:
case Intrinsic::usub_with_overflow:
case Intrinsic::smul_with_overflow:
case Intrinsic::umul_with_overflow: {
// This implements the basic lowering of the xalu with overflow intrinsics
// into add/sub/mul followed by either seto or setb.
const Function *Callee = II->getCalledFunction();
auto *Ty = cast<StructType>(Callee->getReturnType());
Type *RetTy = Ty->getTypeAtIndex(0U);
Type *CondTy = Ty->getTypeAtIndex(1);
MVT VT;
if (!isTypeLegal(RetTy, VT))
return false;
if (VT < MVT::i8 || VT > MVT::i64)
return false;
const Value *LHS = II->getArgOperand(0);
const Value *RHS = II->getArgOperand(1);
// Canonicalize immediate to the RHS.
if (isa<ConstantInt>(LHS) && !isa<ConstantInt>(RHS) &&
isCommutativeIntrinsic(II))
std::swap(LHS, RHS);
bool UseIncDec = false;
if (isa<ConstantInt>(RHS) && cast<ConstantInt>(RHS)->isOne())
UseIncDec = true;
unsigned BaseOpc, CondOpc;
switch (II->getIntrinsicID()) {
default: llvm_unreachable("Unexpected intrinsic!");
case Intrinsic::sadd_with_overflow:
BaseOpc = UseIncDec ? unsigned(X86ISD::INC) : unsigned(ISD::ADD);
CondOpc = X86::SETOr;
break;
case Intrinsic::uadd_with_overflow:
BaseOpc = ISD::ADD; CondOpc = X86::SETBr; break;
case Intrinsic::ssub_with_overflow:
BaseOpc = UseIncDec ? unsigned(X86ISD::DEC) : unsigned(ISD::SUB);
CondOpc = X86::SETOr;
break;
case Intrinsic::usub_with_overflow:
BaseOpc = ISD::SUB; CondOpc = X86::SETBr; break;
case Intrinsic::smul_with_overflow:
BaseOpc = X86ISD::SMUL; CondOpc = X86::SETOr; break;
case Intrinsic::umul_with_overflow:
BaseOpc = X86ISD::UMUL; CondOpc = X86::SETOr; break;
}
unsigned LHSReg = getRegForValue(LHS);
if (LHSReg == 0)
return false;
bool LHSIsKill = hasTrivialKill(LHS);
unsigned ResultReg = 0;
// Check if we have an immediate version.
if (const auto *CI = dyn_cast<ConstantInt>(RHS)) {
static const unsigned Opc[2][4] = {
{ X86::INC8r, X86::INC16r, X86::INC32r, X86::INC64r },
{ X86::DEC8r, X86::DEC16r, X86::DEC32r, X86::DEC64r }
};
if (BaseOpc == X86ISD::INC || BaseOpc == X86ISD::DEC) {
ResultReg = createResultReg(TLI.getRegClassFor(VT));
bool IsDec = BaseOpc == X86ISD::DEC;
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc[IsDec][VT.SimpleTy-MVT::i8]), ResultReg)
.addReg(LHSReg, getKillRegState(LHSIsKill));
} else
ResultReg = fastEmit_ri(VT, VT, BaseOpc, LHSReg, LHSIsKill,
CI->getZExtValue());
}
unsigned RHSReg;
bool RHSIsKill;
if (!ResultReg) {
RHSReg = getRegForValue(RHS);
if (RHSReg == 0)
return false;
RHSIsKill = hasTrivialKill(RHS);
ResultReg = fastEmit_rr(VT, VT, BaseOpc, LHSReg, LHSIsKill, RHSReg,
RHSIsKill);
}
// FastISel doesn't have a pattern for all X86::MUL*r and X86::IMUL*r. Emit
// it manually.
if (BaseOpc == X86ISD::UMUL && !ResultReg) {
static const unsigned MULOpc[] =
{ X86::MUL8r, X86::MUL16r, X86::MUL32r, X86::MUL64r };
static const unsigned Reg[] = { X86::AL, X86::AX, X86::EAX, X86::RAX };
// First copy the first operand into RAX, which is an implicit input to
// the X86::MUL*r instruction.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), Reg[VT.SimpleTy-MVT::i8])
.addReg(LHSReg, getKillRegState(LHSIsKill));
ResultReg = fastEmitInst_r(MULOpc[VT.SimpleTy-MVT::i8],
TLI.getRegClassFor(VT), RHSReg, RHSIsKill);
} else if (BaseOpc == X86ISD::SMUL && !ResultReg) {
static const unsigned MULOpc[] =
{ X86::IMUL8r, X86::IMUL16rr, X86::IMUL32rr, X86::IMUL64rr };
if (VT == MVT::i8) {
// Copy the first operand into AL, which is an implicit input to the
// X86::IMUL8r instruction.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), X86::AL)
.addReg(LHSReg, getKillRegState(LHSIsKill));
ResultReg = fastEmitInst_r(MULOpc[0], TLI.getRegClassFor(VT), RHSReg,
RHSIsKill);
} else
ResultReg = fastEmitInst_rr(MULOpc[VT.SimpleTy-MVT::i8],
TLI.getRegClassFor(VT), LHSReg, LHSIsKill,
RHSReg, RHSIsKill);
}
if (!ResultReg)
return false;
unsigned ResultReg2 = FuncInfo.CreateRegs(CondTy);
assert((ResultReg+1) == ResultReg2 && "Nonconsecutive result registers.");
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CondOpc),
ResultReg2);
updateValueMap(II, ResultReg, 2);
return true;
}
case Intrinsic::x86_sse_cvttss2si:
case Intrinsic::x86_sse_cvttss2si64:
case Intrinsic::x86_sse2_cvttsd2si:
case Intrinsic::x86_sse2_cvttsd2si64: {
bool IsInputDouble;
switch (II->getIntrinsicID()) {
default: llvm_unreachable("Unexpected intrinsic.");
case Intrinsic::x86_sse_cvttss2si:
case Intrinsic::x86_sse_cvttss2si64:
if (!Subtarget->hasSSE1())
return false;
IsInputDouble = false;
break;
case Intrinsic::x86_sse2_cvttsd2si:
case Intrinsic::x86_sse2_cvttsd2si64:
if (!Subtarget->hasSSE2())
return false;
IsInputDouble = true;
break;
}
Type *RetTy = II->getCalledFunction()->getReturnType();
MVT VT;
if (!isTypeLegal(RetTy, VT))
return false;
static const unsigned CvtOpc[2][2][2] = {
{ { X86::CVTTSS2SIrr, X86::VCVTTSS2SIrr },
{ X86::CVTTSS2SI64rr, X86::VCVTTSS2SI64rr } },
{ { X86::CVTTSD2SIrr, X86::VCVTTSD2SIrr },
{ X86::CVTTSD2SI64rr, X86::VCVTTSD2SI64rr } }
};
bool HasAVX = Subtarget->hasAVX();
unsigned Opc;
switch (VT.SimpleTy) {
default: llvm_unreachable("Unexpected result type.");
case MVT::i32: Opc = CvtOpc[IsInputDouble][0][HasAVX]; break;
case MVT::i64: Opc = CvtOpc[IsInputDouble][1][HasAVX]; break;
}
// Check if we can fold insertelement instructions into the convert.
const Value *Op = II->getArgOperand(0);
while (auto *IE = dyn_cast<InsertElementInst>(Op)) {
const Value *Index = IE->getOperand(2);
if (!isa<ConstantInt>(Index))
break;
unsigned Idx = cast<ConstantInt>(Index)->getZExtValue();
if (Idx == 0) {
Op = IE->getOperand(1);
break;
}
Op = IE->getOperand(0);
}
unsigned Reg = getRegForValue(Op);
if (Reg == 0)
return false;
unsigned ResultReg = createResultReg(TLI.getRegClassFor(VT));
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
.addReg(Reg);
updateValueMap(II, ResultReg);
return true;
}
}
}
bool X86FastISel::fastLowerArguments() {
if (!FuncInfo.CanLowerReturn)
return false;
const Function *F = FuncInfo.Fn;
if (F->isVarArg())
return false;
CallingConv::ID CC = F->getCallingConv();
if (CC != CallingConv::C)
return false;
if (Subtarget->isCallingConvWin64(CC))
return false;
if (!Subtarget->is64Bit())
return false;
// Only handle simple cases. i.e. Up to 6 i32/i64 scalar arguments.
unsigned GPRCnt = 0;
unsigned FPRCnt = 0;
unsigned Idx = 0;
for (auto const &Arg : F->args()) {
// The first argument is at index 1.
++Idx;
if (F->getAttributes().hasAttribute(Idx, Attribute::ByVal) ||
F->getAttributes().hasAttribute(Idx, Attribute::InReg) ||
F->getAttributes().hasAttribute(Idx, Attribute::StructRet) ||
F->getAttributes().hasAttribute(Idx, Attribute::Nest))
return false;
Type *ArgTy = Arg.getType();
if (ArgTy->isStructTy() || ArgTy->isArrayTy() || ArgTy->isVectorTy())
return false;
EVT ArgVT = TLI.getValueType(ArgTy);
if (!ArgVT.isSimple()) return false;
switch (ArgVT.getSimpleVT().SimpleTy) {
default: return false;
case MVT::i32:
case MVT::i64:
++GPRCnt;
break;
case MVT::f32:
case MVT::f64:
if (!Subtarget->hasSSE1())
return false;
++FPRCnt;
break;
}
if (GPRCnt > 6)
return false;
if (FPRCnt > 8)
return false;
}
static const MCPhysReg GPR32ArgRegs[] = {
X86::EDI, X86::ESI, X86::EDX, X86::ECX, X86::R8D, X86::R9D
};
static const MCPhysReg GPR64ArgRegs[] = {
X86::RDI, X86::RSI, X86::RDX, X86::RCX, X86::R8 , X86::R9
};
static const MCPhysReg XMMArgRegs[] = {
X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3,
X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7
};
unsigned GPRIdx = 0;
unsigned FPRIdx = 0;
for (auto const &Arg : F->args()) {
MVT VT = TLI.getSimpleValueType(Arg.getType());
const TargetRegisterClass *RC = TLI.getRegClassFor(VT);
unsigned SrcReg;
switch (VT.SimpleTy) {
default: llvm_unreachable("Unexpected value type.");
case MVT::i32: SrcReg = GPR32ArgRegs[GPRIdx++]; break;
case MVT::i64: SrcReg = GPR64ArgRegs[GPRIdx++]; break;
case MVT::f32: // fall-through
case MVT::f64: SrcReg = XMMArgRegs[FPRIdx++]; break;
}
unsigned DstReg = FuncInfo.MF->addLiveIn(SrcReg, RC);
// FIXME: Unfortunately it's necessary to emit a copy from the livein copy.
// Without this, EmitLiveInCopies may eliminate the livein if its only
// use is a bitcast (which isn't turned into an instruction).
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(DstReg, getKillRegState(true));
updateValueMap(&Arg, ResultReg);
}
return true;
}
static unsigned computeBytesPoppedByCallee(const X86Subtarget *Subtarget,
CallingConv::ID CC,
ImmutableCallSite *CS) {
if (Subtarget->is64Bit())
return 0;
if (Subtarget->getTargetTriple().isOSMSVCRT())
return 0;
if (CC == CallingConv::Fast || CC == CallingConv::GHC ||
CC == CallingConv::HiPE)
return 0;
if (CS && !CS->paramHasAttr(1, Attribute::StructRet))
return 0;
if (CS && CS->paramHasAttr(1, Attribute::InReg))
return 0;
return 4;
}
bool X86FastISel::fastLowerCall(CallLoweringInfo &CLI) {
auto &OutVals = CLI.OutVals;
auto &OutFlags = CLI.OutFlags;
auto &OutRegs = CLI.OutRegs;
auto &Ins = CLI.Ins;
auto &InRegs = CLI.InRegs;
CallingConv::ID CC = CLI.CallConv;
bool &IsTailCall = CLI.IsTailCall;
bool IsVarArg = CLI.IsVarArg;
const Value *Callee = CLI.Callee;
const char *SymName = CLI.SymName;
bool Is64Bit = Subtarget->is64Bit();
bool IsWin64 = Subtarget->isCallingConvWin64(CC);
// Handle only C, fastcc, and webkit_js calling conventions for now.
switch (CC) {
default: return false;
case CallingConv::C:
case CallingConv::Fast:
case CallingConv::WebKit_JS:
case CallingConv::X86_FastCall:
case CallingConv::X86_64_Win64:
case CallingConv::X86_64_SysV:
break;
}
// Allow SelectionDAG isel to handle tail calls.
if (IsTailCall)
return false;
// fastcc with -tailcallopt is intended to provide a guaranteed
// tail call optimization. Fastisel doesn't know how to do that.
if (CC == CallingConv::Fast && TM.Options.GuaranteedTailCallOpt)
return false;
// Don't know how to handle Win64 varargs yet. Nothing special needed for
// x86-32. Special handling for x86-64 is implemented.
if (IsVarArg && IsWin64)
return false;
// Don't know about inalloca yet.
if (CLI.CS && CLI.CS->hasInAllocaArgument())
return false;
// Fast-isel doesn't know about callee-pop yet.
if (X86::isCalleePop(CC, Subtarget->is64Bit(), IsVarArg,
TM.Options.GuaranteedTailCallOpt))
return false;
SmallVector<MVT, 16> OutVTs;
SmallVector<unsigned, 16> ArgRegs;
// If this is a constant i1/i8/i16 argument, promote to i32 to avoid an extra
// instruction. This is safe because it is common to all FastISel supported
// calling conventions on x86.
for (int i = 0, e = OutVals.size(); i != e; ++i) {
Value *&Val = OutVals[i];
ISD::ArgFlagsTy Flags = OutFlags[i];
if (auto *CI = dyn_cast<ConstantInt>(Val)) {
if (CI->getBitWidth() < 32) {
if (Flags.isSExt())
Val = ConstantExpr::getSExt(CI, Type::getInt32Ty(CI->getContext()));
else
Val = ConstantExpr::getZExt(CI, Type::getInt32Ty(CI->getContext()));
}
}
// Passing bools around ends up doing a trunc to i1 and passing it.
// Codegen this as an argument + "and 1".
MVT VT;
auto *TI = dyn_cast<TruncInst>(Val);
unsigned ResultReg;
if (TI && TI->getType()->isIntegerTy(1) && CLI.CS &&
(TI->getParent() == CLI.CS->getInstruction()->getParent()) &&
TI->hasOneUse()) {
Value *PrevVal = TI->getOperand(0);
ResultReg = getRegForValue(PrevVal);
if (!ResultReg)
return false;
if (!isTypeLegal(PrevVal->getType(), VT))
return false;
ResultReg =
fastEmit_ri(VT, VT, ISD::AND, ResultReg, hasTrivialKill(PrevVal), 1);
} else {
if (!isTypeLegal(Val->getType(), VT))
return false;
ResultReg = getRegForValue(Val);
}
if (!ResultReg)
return false;
ArgRegs.push_back(ResultReg);
OutVTs.push_back(VT);
}
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, IsVarArg, *FuncInfo.MF, ArgLocs, CLI.RetTy->getContext());
// Allocate shadow area for Win64
if (IsWin64)
CCInfo.AllocateStack(32, 8);
CCInfo.AnalyzeCallOperands(OutVTs, OutFlags, CC_X86);
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = CCInfo.getNextStackOffset();
// Issue CALLSEQ_START
unsigned AdjStackDown = TII.getCallFrameSetupOpcode();
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackDown))
.addImm(NumBytes).addImm(0);
// Walk the register/memloc assignments, inserting copies/loads.
const X86RegisterInfo *RegInfo = Subtarget->getRegisterInfo();
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign const &VA = ArgLocs[i];
const Value *ArgVal = OutVals[VA.getValNo()];
MVT ArgVT = OutVTs[VA.getValNo()];
if (ArgVT == MVT::x86mmx)
return false;
unsigned ArgReg = ArgRegs[VA.getValNo()];
// Promote the value if needed.
switch (VA.getLocInfo()) {
case CCValAssign::Full: break;
case CCValAssign::SExt: {
assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
"Unexpected extend");
bool Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(), ArgReg,
ArgVT, ArgReg);
assert(Emitted && "Failed to emit a sext!"); (void)Emitted;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::ZExt: {
assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
"Unexpected extend");
bool Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(), ArgReg,
ArgVT, ArgReg);
assert(Emitted && "Failed to emit a zext!"); (void)Emitted;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::AExt: {
assert(VA.getLocVT().isInteger() && !VA.getLocVT().isVector() &&
"Unexpected extend");
bool Emitted = X86FastEmitExtend(ISD::ANY_EXTEND, VA.getLocVT(), ArgReg,
ArgVT, ArgReg);
if (!Emitted)
Emitted = X86FastEmitExtend(ISD::ZERO_EXTEND, VA.getLocVT(), ArgReg,
ArgVT, ArgReg);
if (!Emitted)
Emitted = X86FastEmitExtend(ISD::SIGN_EXTEND, VA.getLocVT(), ArgReg,
ArgVT, ArgReg);
assert(Emitted && "Failed to emit a aext!"); (void)Emitted;
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::BCvt: {
ArgReg = fastEmit_r(ArgVT, VA.getLocVT(), ISD::BITCAST, ArgReg,
/*TODO: Kill=*/false);
assert(ArgReg && "Failed to emit a bitcast!");
ArgVT = VA.getLocVT();
break;
}
case CCValAssign::VExt:
// VExt has not been implemented, so this should be impossible to reach
// for now. However, fallback to Selection DAG isel once implemented.
return false;
case CCValAssign::AExtUpper:
case CCValAssign::SExtUpper:
case CCValAssign::ZExtUpper:
case CCValAssign::FPExt:
llvm_unreachable("Unexpected loc info!");
case CCValAssign::Indirect:
// FIXME: Indirect doesn't need extending, but fast-isel doesn't fully
// support this.
return false;
}
if (VA.isRegLoc()) {
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), VA.getLocReg()).addReg(ArgReg);
OutRegs.push_back(VA.getLocReg());
} else {
assert(VA.isMemLoc());
// Don't emit stores for undef values.
if (isa<UndefValue>(ArgVal))
continue;
unsigned LocMemOffset = VA.getLocMemOffset();
X86AddressMode AM;
AM.Base.Reg = RegInfo->getStackRegister();
AM.Disp = LocMemOffset;
ISD::ArgFlagsTy Flags = OutFlags[VA.getValNo()];
unsigned Alignment = DL.getABITypeAlignment(ArgVal->getType());
MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
MachinePointerInfo::getStack(LocMemOffset), MachineMemOperand::MOStore,
ArgVT.getStoreSize(), Alignment);
if (Flags.isByVal()) {
X86AddressMode SrcAM;
SrcAM.Base.Reg = ArgReg;
if (!TryEmitSmallMemcpy(AM, SrcAM, Flags.getByValSize()))
return false;
} else if (isa<ConstantInt>(ArgVal) || isa<ConstantPointerNull>(ArgVal)) {
// If this is a really simple value, emit this with the Value* version
// of X86FastEmitStore. If it isn't simple, we don't want to do this,
// as it can cause us to reevaluate the argument.
if (!X86FastEmitStore(ArgVT, ArgVal, AM, MMO))
return false;
} else {
bool ValIsKill = hasTrivialKill(ArgVal);
if (!X86FastEmitStore(ArgVT, ArgReg, ValIsKill, AM, MMO))
return false;
}
}
}
// ELF / PIC requires GOT in the EBX register before function calls via PLT
// GOT pointer.
if (Subtarget->isPICStyleGOT()) {
unsigned Base = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), X86::EBX).addReg(Base);
}
if (Is64Bit && IsVarArg && !IsWin64) {
// From AMD64 ABI document:
// For calls that may call functions that use varargs or stdargs
// (prototype-less calls or calls to functions containing ellipsis (...) in
// the declaration) %al is used as hidden argument to specify the number
// of SSE registers used. The contents of %al do not need to match exactly
// the number of registers, but must be an ubound on the number of SSE
// registers used and is in the range 0 - 8 inclusive.
// Count the number of XMM registers allocated.
static const MCPhysReg XMMArgRegs[] = {
X86::XMM0, X86::XMM1, X86::XMM2, X86::XMM3,
X86::XMM4, X86::XMM5, X86::XMM6, X86::XMM7
};
unsigned NumXMMRegs = CCInfo.getFirstUnallocated(XMMArgRegs);
assert((Subtarget->hasSSE1() || !NumXMMRegs)
&& "SSE registers cannot be used when SSE is disabled");
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV8ri),
X86::AL).addImm(NumXMMRegs);
}
// 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 = nullptr;
if (CalleeAM.GV != nullptr) {
GV = CalleeAM.GV;
} else if (CalleeAM.Base.Reg != 0) {
CalleeOp = CalleeAM.Base.Reg;
} else
return false;
// Issue the call.
MachineInstrBuilder MIB;
if (CalleeOp) {
// Register-indirect call.
unsigned CallOpc = Is64Bit ? X86::CALL64r : X86::CALL32r;
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CallOpc))
.addReg(CalleeOp);
} else {
// Direct call.
assert(GV && "Not a direct call");
unsigned CallOpc = 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->getTargetTriple().isMacOSX() ||
Subtarget->getTargetTriple().isMacOSXVersionLT(10, 5))) {
// PC-relative references to external symbols should go through $stub,
// unless we're building with the leopard linker or later, which
// automatically synthesizes these stubs.
OpFlags = X86II::MO_DARWIN_STUB;
}
MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(CallOpc));
if (SymName)
MIB.addExternalSymbol(SymName, OpFlags);
else
MIB.addGlobalAddress(GV, 0, OpFlags);
}
// Add a register mask operand representing the call-preserved registers.
// Proper defs for return values will be added by setPhysRegsDeadExcept().
MIB.addRegMask(TRI.getCallPreservedMask(*FuncInfo.MF, CC));
// Add an implicit use GOT pointer in EBX.
if (Subtarget->isPICStyleGOT())
MIB.addReg(X86::EBX, RegState::Implicit);
if (Is64Bit && IsVarArg && !IsWin64)
MIB.addReg(X86::AL, RegState::Implicit);
// Add implicit physical register uses to the call.
for (auto Reg : OutRegs)
MIB.addReg(Reg, RegState::Implicit);
// Issue CALLSEQ_END
unsigned NumBytesForCalleeToPop =
computeBytesPoppedByCallee(Subtarget, CC, CLI.CS);
unsigned AdjStackUp = TII.getCallFrameDestroyOpcode();
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackUp))
.addImm(NumBytes).addImm(NumBytesForCalleeToPop);
// Now handle call return values.
SmallVector<CCValAssign, 16> RVLocs;
CCState CCRetInfo(CC, IsVarArg, *FuncInfo.MF, RVLocs,
CLI.RetTy->getContext());
CCRetInfo.AnalyzeCallResult(Ins, RetCC_X86);
// Copy all of the result registers out of their specified physreg.
unsigned ResultReg = FuncInfo.CreateRegs(CLI.RetTy);
for (unsigned i = 0; i != RVLocs.size(); ++i) {
CCValAssign &VA = RVLocs[i];
EVT CopyVT = VA.getValVT();
unsigned CopyReg = ResultReg + i;
// If this is x86-64, and we disabled SSE, we can't return FP values
if ((CopyVT == MVT::f32 || CopyVT == MVT::f64) &&
((Is64Bit || Ins[i].Flags.isInReg()) && !Subtarget->hasSSE1())) {
report_fatal_error("SSE register return with SSE disabled");
}
// If 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 ((VA.getLocReg() == X86::FP0 || VA.getLocReg() == X86::FP1) &&
isScalarFPTypeInSSEReg(VA.getValVT())) {
CopyVT = MVT::f80;
CopyReg = createResultReg(&X86::RFP80RegClass);
}
// Copy out the result.
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::COPY), CopyReg).addReg(VA.getLocReg());
InRegs.push_back(VA.getLocReg());
// Round the f80 to the right size, which also moves it to the appropriate
// xmm register. This is accomplished by storing the f80 value in memory
// and then loading it back.
if (CopyVT != VA.getValVT()) {
EVT ResVT = VA.getValVT();
unsigned Opc = ResVT == MVT::f32 ? X86::ST_Fp80m32 : X86::ST_Fp80m64;
unsigned MemSize = ResVT.getSizeInBits()/8;
int FI = MFI.CreateStackObject(MemSize, MemSize, false);
addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc)), FI)
.addReg(CopyReg);
Opc = ResVT == MVT::f32 ? X86::MOVSSrm : X86::MOVSDrm;
addFrameReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc), ResultReg + i), FI);
}
}
CLI.ResultReg = ResultReg;
CLI.NumResultRegs = RVLocs.size();
CLI.Call = MIB;
return true;
}
bool
X86FastISel::fastSelectInstruction(const Instruction *I) {
switch (I->getOpcode()) {
default: break;
case Instruction::Load:
return X86SelectLoad(I);
case Instruction::Store:
return X86SelectStore(I);
case Instruction::Ret:
return X86SelectRet(I);
case Instruction::ICmp:
case Instruction::FCmp:
return X86SelectCmp(I);
case Instruction::ZExt:
return X86SelectZExt(I);
case Instruction::Br:
return X86SelectBranch(I);
case Instruction::LShr:
case Instruction::AShr:
case Instruction::Shl:
return X86SelectShift(I);
case Instruction::SDiv:
case Instruction::UDiv:
case Instruction::SRem:
case Instruction::URem:
return X86SelectDivRem(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::SIToFP:
return X86SelectSIToFP(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::X86MaterializeInt(const ConstantInt *CI, MVT VT) {
if (VT > MVT::i64)
return 0;
uint64_t Imm = CI->getZExtValue();
if (Imm == 0) {
unsigned SrcReg = fastEmitInst_(X86::MOV32r0, &X86::GR32RegClass);
switch (VT.SimpleTy) {
default: llvm_unreachable("Unexpected value type");
case MVT::i1:
case MVT::i8:
return fastEmitInst_extractsubreg(MVT::i8, SrcReg, /*Kill=*/true,
X86::sub_8bit);
case MVT::i16:
return fastEmitInst_extractsubreg(MVT::i16, SrcReg, /*Kill=*/true,
X86::sub_16bit);
case MVT::i32:
return SrcReg;
case MVT::i64: {
unsigned ResultReg = createResultReg(&X86::GR64RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::SUBREG_TO_REG), ResultReg)
.addImm(0).addReg(SrcReg).addImm(X86::sub_32bit);
return ResultReg;
}
}
}
unsigned Opc = 0;
switch (VT.SimpleTy) {
default: llvm_unreachable("Unexpected value type");
case MVT::i1: VT = MVT::i8; // fall-through
case MVT::i8: Opc = X86::MOV8ri; break;
case MVT::i16: Opc = X86::MOV16ri; break;
case MVT::i32: Opc = X86::MOV32ri; break;
case MVT::i64: {
if (isUInt<32>(Imm))
Opc = X86::MOV32ri;
else if (isInt<32>(Imm))
Opc = X86::MOV64ri32;
else
Opc = X86::MOV64ri;
break;
}
}
if (VT == MVT::i64 && Opc == X86::MOV32ri) {
unsigned SrcReg = fastEmitInst_i(Opc, &X86::GR32RegClass, Imm);
unsigned ResultReg = createResultReg(&X86::GR64RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(TargetOpcode::SUBREG_TO_REG), ResultReg)
.addImm(0).addReg(SrcReg).addImm(X86::sub_32bit);
return ResultReg;
}
return fastEmitInst_i(Opc, TLI.getRegClassFor(VT), Imm);
}
unsigned X86FastISel::X86MaterializeFP(const ConstantFP *CFP, MVT VT) {
if (CFP->isNullValue())
return fastMaterializeFloatZero(CFP);
// Can't handle alternate code models yet.
CodeModel::Model CM = TM.getCodeModel();
if (CM != CodeModel::Small && CM != CodeModel::Large)
return 0;
// Get opcode and regclass of the output for the given load instruction.
unsigned Opc = 0;
const TargetRegisterClass *RC = nullptr;
switch (VT.SimpleTy) {
default: return 0;
case MVT::f32:
if (X86ScalarSSEf32) {
Opc = Subtarget->hasAVX() ? X86::VMOVSSrm : X86::MOVSSrm;
RC = &X86::FR32RegClass;
} else {
Opc = X86::LD_Fp32m;
RC = &X86::RFP32RegClass;
}
break;
case MVT::f64:
if (X86ScalarSSEf64) {
Opc = Subtarget->hasAVX() ? X86::VMOVSDrm : X86::MOVSDrm;
RC = &X86::FR64RegClass;
} else {
Opc = X86::LD_Fp64m;
RC = &X86::RFP64RegClass;
}
break;
case MVT::f80:
// No f80 support yet.
return 0;
}
// MachineConstantPool wants an explicit alignment.
unsigned Align = DL.getPrefTypeAlignment(CFP->getType());
if (Align == 0) {
// Alignment of vector types. FIXME!
Align = DL.getTypeAllocSize(CFP->getType());
}
// x86-32 PIC requires a PIC base register for constant pools.
unsigned PICBase = 0;
unsigned char OpFlag = 0;
if (Subtarget->isPICStyleStubPIC()) { // Not dynamic-no-pic
OpFlag = X86II::MO_PIC_BASE_OFFSET;
PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
} else if (Subtarget->isPICStyleGOT()) {
OpFlag = X86II::MO_GOTOFF;
PICBase = getInstrInfo()->getGlobalBaseReg(FuncInfo.MF);
} else if (Subtarget->isPICStyleRIPRel() &&
TM.getCodeModel() == CodeModel::Small) {
PICBase = X86::RIP;
}
// Create the load from the constant pool.
unsigned CPI = MCP.getConstantPoolIndex(CFP, Align);
unsigned ResultReg = createResultReg(RC);
if (CM == CodeModel::Large) {
unsigned AddrReg = createResultReg(&X86::GR64RegClass);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV64ri),
AddrReg)
.addConstantPoolIndex(CPI, 0, OpFlag);
MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc), ResultReg);
addDirectMem(MIB, AddrReg);
MachineMemOperand *MMO = FuncInfo.MF->getMachineMemOperand(
MachinePointerInfo::getConstantPool(), MachineMemOperand::MOLoad,
TM.getDataLayout()->getPointerSize(), Align);
MIB->addMemOperand(*FuncInfo.MF, MMO);
return ResultReg;
}
addConstantPoolReference(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc), ResultReg),
CPI, PICBase, OpFlag);
return ResultReg;
}
unsigned X86FastISel::X86MaterializeGV(const GlobalValue *GV, MVT VT) {
// Can't handle alternate code models yet.
if (TM.getCodeModel() != CodeModel::Small)
return 0;
// Materialize addresses with LEA/MOV instructions.
X86AddressMode AM;
if (X86SelectAddress(GV, AM)) {
// If the expression is just a basereg, then we're done, otherwise we need
// to emit an LEA.
if (AM.BaseType == X86AddressMode::RegBase &&
AM.IndexReg == 0 && AM.Disp == 0 && AM.GV == nullptr)
return AM.Base.Reg;
unsigned ResultReg = createResultReg(TLI.getRegClassFor(VT));
if (TM.getRelocationModel() == Reloc::Static &&
TLI.getPointerTy() == MVT::i64) {
// The displacement code could be more than 32 bits away so we need to use
// an instruction with a 64 bit immediate
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(X86::MOV64ri),
ResultReg)
.addGlobalAddress(GV);
} else {
unsigned Opc = TLI.getPointerTy() == MVT::i32
? (Subtarget->isTarget64BitILP32()
? X86::LEA64_32r : X86::LEA32r)
: X86::LEA64r;
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc), ResultReg), AM);
}
return ResultReg;
}
return 0;
}
unsigned X86FastISel::fastMaterializeConstant(const Constant *C) {
EVT CEVT = TLI.getValueType(C->getType(), true);
// Only handle simple types.
if (!CEVT.isSimple())
return 0;
MVT VT = CEVT.getSimpleVT();
if (const auto *CI = dyn_cast<ConstantInt>(C))
return X86MaterializeInt(CI, VT);
else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
return X86MaterializeFP(CFP, VT);
else if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
return X86MaterializeGV(GV, VT);
return 0;
}
unsigned X86FastISel::fastMaterializeAlloca(const AllocaInst *C) {
// Fail on dynamic allocas. At this point, getRegForValue has already
// checked its CSE maps, so if we're here trying to handle a dynamic
// alloca, we're not going to succeed. X86SelectAddress has a
// check for dynamic allocas, because it's called directly from
// various places, but targetMaterializeAlloca also needs a check
// in order to avoid recursion between getRegForValue,
// X86SelectAddrss, and targetMaterializeAlloca.
if (!FuncInfo.StaticAllocaMap.count(C))
return 0;
assert(C->isStaticAlloca() && "dynamic alloca in the static alloca map?");
X86AddressMode AM;
if (!X86SelectAddress(C, AM))
return 0;
unsigned Opc = TLI.getPointerTy() == MVT::i32
? (Subtarget->isTarget64BitILP32()
? X86::LEA64_32r : X86::LEA32r)
: X86::LEA64r;
const TargetRegisterClass* RC = TLI.getRegClassFor(TLI.getPointerTy());
unsigned ResultReg = createResultReg(RC);
addFullAddress(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
TII.get(Opc), ResultReg), AM);
return ResultReg;
}
unsigned X86FastISel::fastMaterializeFloatZero(const ConstantFP *CF) {
MVT VT;
if (!isTypeLegal(CF->getType(), VT))
return 0;
// Get opcode and regclass for the given zero.
unsigned Opc = 0;
const TargetRegisterClass *RC = nullptr;
switch (VT.SimpleTy) {
default: return 0;
case MVT::f32:
if (X86ScalarSSEf32) {
Opc = X86::FsFLD0SS;
RC = &X86::FR32RegClass;
} else {
Opc = X86::LD_Fp032;
RC = &X86::RFP32RegClass;
}
break;
case MVT::f64:
if (X86ScalarSSEf64) {
Opc = X86::FsFLD0SD;
RC = &X86::FR64RegClass;
} else {
Opc = X86::LD_Fp064;
RC = &X86::RFP64RegClass;
}
break;
case MVT::f80:
// No f80 support yet.
return 0;
}
unsigned ResultReg = createResultReg(RC);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg);
return ResultReg;
}
bool X86FastISel::tryToFoldLoadIntoMI(MachineInstr *MI, unsigned OpNo,
const LoadInst *LI) {
const Value *Ptr = LI->getPointerOperand();
X86AddressMode AM;
if (!X86SelectAddress(Ptr, AM))
return false;
const X86InstrInfo &XII = (const X86InstrInfo &)TII;
unsigned Size = DL.getTypeAllocSize(LI->getType());
unsigned Alignment = LI->getAlignment();
if (Alignment == 0) // Ensure that codegen never sees alignment 0
Alignment = DL.getABITypeAlignment(LI->getType());
SmallVector<MachineOperand, 8> AddrOps;
AM.getFullAddress(AddrOps);
MachineInstr *Result =
XII.foldMemoryOperandImpl(*FuncInfo.MF, MI, OpNo, AddrOps,
Size, Alignment, /*AllowCommute=*/true);
if (!Result)
return false;
Result->addMemOperand(*FuncInfo.MF, createMachineMemOperandFor(LI));
FuncInfo.MBB->insert(FuncInfo.InsertPt, Result);
MI->eraseFromParent();
return true;
}
namespace llvm {
FastISel *X86::createFastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo) {
return new X86FastISel(funcInfo, libInfo);
}
}
Reference in New Issue View Git Blame Copy Permalink