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swiftshader / SwiftShader / 729b5f6cf2dec861f70db54d02f245f4338f5e60 / . / src / IceTargetLoweringX86BaseImpl.h
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//===- subzero/src/IceTargetLoweringX86BaseImpl.h - x86 lowering -*- C++ -*-==//
//
// The Subzero Code Generator
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements the TargetLoweringX86Base class, which
/// consists almost entirely of the lowering sequence for each
/// high-level instruction.
///
//===----------------------------------------------------------------------===//
#ifndef SUBZERO_SRC_ICETARGETLOWERINGX86BASEIMPL_H
#define SUBZERO_SRC_ICETARGETLOWERINGX86BASEIMPL_H
#include "IceCfg.h"
#include "IceCfgNode.h"
#include "IceClFlags.h"
#include "IceDefs.h"
#include "IceELFObjectWriter.h"
#include "IceGlobalInits.h"
#include "IceLiveness.h"
#include "IceOperand.h"
#include "IcePhiLoweringImpl.h"
#include "IceUtils.h"
#include "llvm/Support/MathExtras.h"
#include <stack>
namespace Ice {
namespace X86Internal {
/// A helper class to ease the settings of RandomizationPoolingPause to disable
/// constant blinding or pooling for some translation phases.
class BoolFlagSaver {
BoolFlagSaver() = delete;
BoolFlagSaver(const BoolFlagSaver &) = delete;
BoolFlagSaver &operator=(const BoolFlagSaver &) = delete;
public:
BoolFlagSaver(bool &F, bool NewValue) : OldValue(F), Flag(F) { F = NewValue; }
~BoolFlagSaver() { Flag = OldValue; }
private:
const bool OldValue;
bool &Flag;
};
template <class MachineTraits> class BoolFoldingEntry {
BoolFoldingEntry(const BoolFoldingEntry &) = delete;
public:
BoolFoldingEntry() = default;
explicit BoolFoldingEntry(Inst *I);
BoolFoldingEntry &operator=(const BoolFoldingEntry &) = default;
/// Instr is the instruction producing the i1-type variable of interest.
Inst *Instr = nullptr;
/// IsComplex is the cached result of BoolFolding::hasComplexLowering(Instr).
bool IsComplex = false;
/// IsLiveOut is initialized conservatively to true, and is set to false when
/// we encounter an instruction that ends Var's live range. We disable the
/// folding optimization when Var is live beyond this basic block. Note that
/// if liveness analysis is not performed (e.g. in Om1 mode), IsLiveOut will
/// always be true and the folding optimization will never be performed.
bool IsLiveOut = true;
// NumUses counts the number of times Var is used as a source operand in the
// basic block. If IsComplex is true and there is more than one use of Var,
// then the folding optimization is disabled for Var.
uint32_t NumUses = 0;
};
template <class MachineTraits> class BoolFolding {
public:
enum BoolFoldingProducerKind {
PK_None,
PK_Icmp32,
PK_Icmp64,
PK_Fcmp,
PK_Trunc
};
/// Currently the actual enum values are not used (other than CK_None), but we
/// go ahead and produce them anyway for symmetry with the
/// BoolFoldingProducerKind.
enum BoolFoldingConsumerKind { CK_None, CK_Br, CK_Select, CK_Sext, CK_Zext };
private:
BoolFolding(const BoolFolding &) = delete;
BoolFolding &operator=(const BoolFolding &) = delete;
public:
BoolFolding() = default;
static BoolFoldingProducerKind getProducerKind(const Inst *Instr);
static BoolFoldingConsumerKind getConsumerKind(const Inst *Instr);
static bool hasComplexLowering(const Inst *Instr);
void init(CfgNode *Node);
const Inst *getProducerFor(const Operand *Opnd) const;
void dump(const Cfg *Func) const;
private:
/// Returns true if Producers contains a valid entry for the given VarNum.
bool containsValid(SizeT VarNum) const {
auto Element = Producers.find(VarNum);
return Element != Producers.end() && Element->second.Instr != nullptr;
}
void setInvalid(SizeT VarNum) { Producers[VarNum].Instr = nullptr; }
/// Producers maps Variable::Number to a BoolFoldingEntry.
std::unordered_map<SizeT, BoolFoldingEntry<MachineTraits>> Producers;
};
template <class MachineTraits>
BoolFoldingEntry<MachineTraits>::BoolFoldingEntry(Inst *I)
: Instr(I), IsComplex(BoolFolding<MachineTraits>::hasComplexLowering(I)) {}
template <class MachineTraits>
typename BoolFolding<MachineTraits>::BoolFoldingProducerKind
BoolFolding<MachineTraits>::getProducerKind(const Inst *Instr) {
if (llvm::isa<InstIcmp>(Instr)) {
if (Instr->getSrc(0)->getType() != IceType_i64)
return PK_Icmp32;
return PK_None; // TODO(stichnot): actually PK_Icmp64;
}
return PK_None; // TODO(stichnot): remove this
if (llvm::isa<InstFcmp>(Instr))
return PK_Fcmp;
if (auto *Cast = llvm::dyn_cast<InstCast>(Instr)) {
switch (Cast->getCastKind()) {
default:
return PK_None;
case InstCast::Trunc:
return PK_Trunc;
}
}
return PK_None;
}
template <class MachineTraits>
typename BoolFolding<MachineTraits>::BoolFoldingConsumerKind
BoolFolding<MachineTraits>::getConsumerKind(const Inst *Instr) {
if (llvm::isa<InstBr>(Instr))
return CK_Br;
if (llvm::isa<InstSelect>(Instr))
return CK_Select;
return CK_None; // TODO(stichnot): remove this
if (auto *Cast = llvm::dyn_cast<InstCast>(Instr)) {
switch (Cast->getCastKind()) {
default:
return CK_None;
case InstCast::Sext:
return CK_Sext;
case InstCast::Zext:
return CK_Zext;
}
}
return CK_None;
}
/// Returns true if the producing instruction has a "complex" lowering sequence.
/// This generally means that its lowering sequence requires more than one
/// conditional branch, namely 64-bit integer compares and some floating-point
/// compares. When this is true, and there is more than one consumer, we prefer
/// to disable the folding optimization because it minimizes branches.
template <class MachineTraits>
bool BoolFolding<MachineTraits>::hasComplexLowering(const Inst *Instr) {
switch (getProducerKind(Instr)) {
default:
return false;
case PK_Icmp64:
return true;
case PK_Fcmp:
return MachineTraits::TableFcmp[llvm::cast<InstFcmp>(Instr)->getCondition()]
.C2 != MachineTraits::Cond::Br_None;
}
}
template <class MachineTraits>
void BoolFolding<MachineTraits>::init(CfgNode *Node) {
Producers.clear();
for (Inst &Instr : Node->getInsts()) {
// Check whether Instr is a valid producer.
Variable *Var = Instr.getDest();
if (!Instr.isDeleted() // only consider non-deleted instructions
&& Var // only instructions with an actual dest var
&& Var->getType() == IceType_i1 // only bool-type dest vars
&& getProducerKind(&Instr) != PK_None) { // white-listed instructions
Producers[Var->getIndex()] = BoolFoldingEntry<MachineTraits>(&Instr);
}
// Check each src variable against the map.
for (SizeT I = 0; I < Instr.getSrcSize(); ++I) {
Operand *Src = Instr.getSrc(I);
SizeT NumVars = Src->getNumVars();
for (SizeT J = 0; J < NumVars; ++J) {
const Variable *Var = Src->getVar(J);
SizeT VarNum = Var->getIndex();
if (containsValid(VarNum)) {
if (I != 0 // All valid consumers use Var as the first source operand
|| getConsumerKind(&Instr) == CK_None // must be white-listed
|| (Producers[VarNum].IsComplex && // complex can't be multi-use
Producers[VarNum].NumUses > 0)) {
setInvalid(VarNum);
continue;
}
++Producers[VarNum].NumUses;
if (Instr.isLastUse(Var)) {
Producers[VarNum].IsLiveOut = false;
}
}
}
}
}
for (auto &I : Producers) {
// Ignore entries previously marked invalid.
if (I.second.Instr == nullptr)
continue;
// Disable the producer if its dest may be live beyond this block.
if (I.second.IsLiveOut) {
setInvalid(I.first);
continue;
}
// Mark as "dead" rather than outright deleting. This is so that other
// peephole style optimizations during or before lowering have access to
// this instruction in undeleted form. See for example
// tryOptimizedCmpxchgCmpBr().
I.second.Instr->setDead();
}
}
template <class MachineTraits>
const Inst *
BoolFolding<MachineTraits>::getProducerFor(const Operand *Opnd) const {
auto *Var = llvm::dyn_cast<const Variable>(Opnd);
if (Var == nullptr)
return nullptr;
SizeT VarNum = Var->getIndex();
auto Element = Producers.find(VarNum);
if (Element == Producers.end())
return nullptr;
return Element->second.Instr;
}
template <class MachineTraits>
void BoolFolding<MachineTraits>::dump(const Cfg *Func) const {
if (!BuildDefs::dump() || !Func->isVerbose(IceV_Folding))
return;
OstreamLocker L(Func->getContext());
Ostream &Str = Func->getContext()->getStrDump();
for (auto &I : Producers) {
if (I.second.Instr == nullptr)
continue;
Str << "Found foldable producer:\n ";
I.second.Instr->dump(Func);
Str << "\n";
}
}
template <class Machine>
void TargetX86Base<Machine>::initNodeForLowering(CfgNode *Node) {
FoldingInfo.init(Node);
FoldingInfo.dump(Func);
}
template <class Machine>
TargetX86Base<Machine>::TargetX86Base(Cfg *Func)
: TargetLowering(Func) {
static_assert(
(Traits::InstructionSet::End - Traits::InstructionSet::Begin) ==
(TargetInstructionSet::X86InstructionSet_End -
TargetInstructionSet::X86InstructionSet_Begin),
"Traits::InstructionSet range different from TargetInstructionSet");
if (Func->getContext()->getFlags().getTargetInstructionSet() !=
TargetInstructionSet::BaseInstructionSet) {
InstructionSet = static_cast<typename Traits::InstructionSet>(
(Func->getContext()->getFlags().getTargetInstructionSet() -
TargetInstructionSet::X86InstructionSet_Begin) +
Traits::InstructionSet::Begin);
}
// TODO: Don't initialize IntegerRegisters and friends every time. Instead,
// initialize in some sort of static initializer for the class.
llvm::SmallBitVector IntegerRegisters(Traits::RegisterSet::Reg_NUM);
llvm::SmallBitVector IntegerRegistersI8(Traits::RegisterSet::Reg_NUM);
llvm::SmallBitVector FloatRegisters(Traits::RegisterSet::Reg_NUM);
llvm::SmallBitVector VectorRegisters(Traits::RegisterSet::Reg_NUM);
llvm::SmallBitVector InvalidRegisters(Traits::RegisterSet::Reg_NUM);
ScratchRegs.resize(Traits::RegisterSet::Reg_NUM);
Traits::initRegisterSet(&IntegerRegisters, &IntegerRegistersI8,
&FloatRegisters, &VectorRegisters, &ScratchRegs);
TypeToRegisterSet[IceType_void] = InvalidRegisters;
TypeToRegisterSet[IceType_i1] = IntegerRegistersI8;
TypeToRegisterSet[IceType_i8] = IntegerRegistersI8;
TypeToRegisterSet[IceType_i16] = IntegerRegisters;
TypeToRegisterSet[IceType_i32] = IntegerRegisters;
TypeToRegisterSet[IceType_i64] = IntegerRegisters;
TypeToRegisterSet[IceType_f32] = FloatRegisters;
TypeToRegisterSet[IceType_f64] = FloatRegisters;
TypeToRegisterSet[IceType_v4i1] = VectorRegisters;
TypeToRegisterSet[IceType_v8i1] = VectorRegisters;
TypeToRegisterSet[IceType_v16i1] = VectorRegisters;
TypeToRegisterSet[IceType_v16i8] = VectorRegisters;
TypeToRegisterSet[IceType_v8i16] = VectorRegisters;
TypeToRegisterSet[IceType_v4i32] = VectorRegisters;
TypeToRegisterSet[IceType_v4f32] = VectorRegisters;
}
template <class Machine> void TargetX86Base<Machine>::translateO2() {
TimerMarker T(TimerStack::TT_O2, Func);
if (!Ctx->getFlags().getPhiEdgeSplit()) {
// Lower Phi instructions.
Func->placePhiLoads();
if (Func->hasError())
return;
Func->placePhiStores();
if (Func->hasError())
return;
Func->deletePhis();
if (Func->hasError())
return;
Func->dump("After Phi lowering");
}
// Address mode optimization.
Func->getVMetadata()->init(VMK_SingleDefs);
Func->doAddressOpt();
// Find read-modify-write opportunities. Do this after address mode
// optimization so that doAddressOpt() doesn't need to be applied to RMW
// instructions as well.
findRMW();
Func->dump("After RMW transform");
// Argument lowering
Func->doArgLowering();
// Target lowering. This requires liveness analysis for some parts of the
// lowering decisions, such as compare/branch fusing. If non-lightweight
// liveness analysis is used, the instructions need to be renumbered first
// TODO: This renumbering should only be necessary if we're actually
// calculating live intervals, which we only do for register allocation.
Func->renumberInstructions();
if (Func->hasError())
return;
// TODO: It should be sufficient to use the fastest liveness calculation, i.e.
// livenessLightweight(). However, for some reason that slows down the rest
// of the translation. Investigate.
Func->liveness(Liveness_Basic);
if (Func->hasError())
return;
Func->dump("After x86 address mode opt");
// Disable constant blinding or pooling for load optimization.
{
BoolFlagSaver B(RandomizationPoolingPaused, true);
doLoadOpt();
}
Func->genCode();
if (Func->hasError())
return;
Func->dump("After x86 codegen");
// Register allocation. This requires instruction renumbering and full
// liveness analysis.
Func->renumberInstructions();
if (Func->hasError())
return;
Func->liveness(Liveness_Intervals);
if (Func->hasError())
return;
// Validate the live range computations. The expensive validation call is
// deliberately only made when assertions are enabled.
assert(Func->validateLiveness());
// The post-codegen dump is done here, after liveness analysis and associated
// cleanup, to make the dump cleaner and more useful.
Func->dump("After initial x8632 codegen");
Func->getVMetadata()->init(VMK_All);
regAlloc(RAK_Global);
if (Func->hasError())
return;
Func->dump("After linear scan regalloc");
if (Ctx->getFlags().getPhiEdgeSplit()) {
Func->advancedPhiLowering();
Func->dump("After advanced Phi lowering");
}
// Stack frame mapping.
Func->genFrame();
if (Func->hasError())
return;
Func->dump("After stack frame mapping");
Func->contractEmptyNodes();
Func->reorderNodes();
// Shuffle basic block order if -reorder-basic-blocks is enabled.
Func->shuffleNodes();
// Branch optimization. This needs to be done just before code emission. In
// particular, no transformations that insert or reorder CfgNodes should be
// done after branch optimization. We go ahead and do it before nop insertion
// to reduce the amount of work needed for searching for opportunities.
Func->doBranchOpt();
Func->dump("After branch optimization");
// Nop insertion if -nop-insertion is enabled.
Func->doNopInsertion();
// Mark nodes that require sandbox alignment
if (Ctx->getFlags().getUseSandboxing())
Func->markNodesForSandboxing();
}
template <class Machine> void TargetX86Base<Machine>::translateOm1() {
TimerMarker T(TimerStack::TT_Om1, Func);
Func->placePhiLoads();
if (Func->hasError())
return;
Func->placePhiStores();
if (Func->hasError())
return;
Func->deletePhis();
if (Func->hasError())
return;
Func->dump("After Phi lowering");
Func->doArgLowering();
Func->genCode();
if (Func->hasError())
return;
Func->dump("After initial x8632 codegen");
regAlloc(RAK_InfOnly);
if (Func->hasError())
return;
Func->dump("After regalloc of infinite-weight variables");
Func->genFrame();
if (Func->hasError())
return;
Func->dump("After stack frame mapping");
// Shuffle basic block order if -reorder-basic-blocks is enabled.
Func->shuffleNodes();
// Nop insertion if -nop-insertion is enabled.
Func->doNopInsertion();
// Mark nodes that require sandbox alignment
if (Ctx->getFlags().getUseSandboxing())
Func->markNodesForSandboxing();
}
inline bool canRMW(const InstArithmetic *Arith) {
Type Ty = Arith->getDest()->getType();
// X86 vector instructions write to a register and have no RMW option.
if (isVectorType(Ty))
return false;
bool isI64 = Ty == IceType_i64;
switch (Arith->getOp()) {
// Not handled for lack of simple lowering:
// shift on i64
// mul, udiv, urem, sdiv, srem, frem
// Not handled for lack of RMW instructions:
// fadd, fsub, fmul, fdiv (also vector types)
default:
return false;
case InstArithmetic::Add:
case InstArithmetic::Sub:
case InstArithmetic::And:
case InstArithmetic::Or:
case InstArithmetic::Xor:
return true;
case InstArithmetic::Shl:
case InstArithmetic::Lshr:
case InstArithmetic::Ashr:
return false; // TODO(stichnot): implement
return !isI64;
}
}
template <class Machine>
bool isSameMemAddressOperand(const Operand *A, const Operand *B) {
if (A == B)
return true;
if (auto *MemA = llvm::dyn_cast<
typename TargetX86Base<Machine>::Traits::X86OperandMem>(A)) {
if (auto *MemB = llvm::dyn_cast<
typename TargetX86Base<Machine>::Traits::X86OperandMem>(B)) {
return MemA->getBase() == MemB->getBase() &&
MemA->getOffset() == MemB->getOffset() &&
MemA->getIndex() == MemB->getIndex() &&
MemA->getShift() == MemB->getShift() &&
MemA->getSegmentRegister() == MemB->getSegmentRegister();
}
}
return false;
}
template <class Machine> void TargetX86Base<Machine>::findRMW() {
Func->dump("Before RMW");
OstreamLocker L(Func->getContext());
Ostream &Str = Func->getContext()->getStrDump();
for (CfgNode *Node : Func->getNodes()) {
// Walk through the instructions, considering each sequence of 3
// instructions, and look for the particular RMW pattern. Note that this
// search can be "broken" (false negatives) if there are intervening deleted
// instructions, or intervening instructions that could be safely moved out
// of the way to reveal an RMW pattern.
auto E = Node->getInsts().end();
auto I1 = E, I2 = E, I3 = Node->getInsts().begin();
for (; I3 != E; I1 = I2, I2 = I3, ++I3) {
// Make I3 skip over deleted instructions.
while (I3 != E && I3->isDeleted())
++I3;
if (I1 == E || I2 == E || I3 == E)
continue;
assert(!I1->isDeleted());
assert(!I2->isDeleted());
assert(!I3->isDeleted());
if (auto *Load = llvm::dyn_cast<InstLoad>(I1)) {
if (auto *Arith = llvm::dyn_cast<InstArithmetic>(I2)) {
if (auto *Store = llvm::dyn_cast<InstStore>(I3)) {
// Look for:
// a = Load addr
// b = <op> a, other
// Store b, addr
// Change to:
// a = Load addr
// b = <op> a, other
// x = FakeDef
// RMW <op>, addr, other, x
// b = Store b, addr, x
// Note that inferTwoAddress() makes sure setDestNonKillable() gets
// called on the updated Store instruction, to avoid liveness
// problems later.
//
// With this transformation, the Store instruction acquires a Dest
// variable and is now subject to dead code elimination if there are
// no more uses of "b". Variable "x" is a beacon for determining
// whether the Store instruction gets dead-code eliminated. If the
// Store instruction is eliminated, then it must be the case that
// the RMW instruction ends x's live range, and therefore the RMW
// instruction will be retained and later lowered. On the other
// hand, if the RMW instruction does not end x's live range, then
// the Store instruction must still be present, and therefore the
// RMW instruction is ignored during lowering because it is
// redundant with the Store instruction.
//
// Note that if "a" has further uses, the RMW transformation may
// still trigger, resulting in two loads and one store, which is
// worse than the original one load and one store. However, this is
// probably rare, and caching probably keeps it just as fast.
if (!isSameMemAddressOperand<Machine>(Load->getSourceAddress(),
Store->getAddr()))
continue;
Operand *ArithSrcFromLoad = Arith->getSrc(0);
Operand *ArithSrcOther = Arith->getSrc(1);
if (ArithSrcFromLoad != Load->getDest()) {
if (!Arith->isCommutative() || ArithSrcOther != Load->getDest())
continue;
std::swap(ArithSrcFromLoad, ArithSrcOther);
}
if (Arith->getDest() != Store->getData())
continue;
if (!canRMW(Arith))
continue;
if (Func->isVerbose(IceV_RMW)) {
Str << "Found RMW in " << Func->getFunctionName() << ":\n ";
Load->dump(Func);
Str << "\n ";
Arith->dump(Func);
Str << "\n ";
Store->dump(Func);
Str << "\n";
}
Variable *Beacon = Func->makeVariable(IceType_i32);
Beacon->setWeight(0);
Store->setRmwBeacon(Beacon);
InstFakeDef *BeaconDef = InstFakeDef::create(Func, Beacon);
Node->getInsts().insert(I3, BeaconDef);
auto *RMW = Traits::Insts::FakeRMW::create(
Func, ArithSrcOther, Store->getAddr(), Beacon, Arith->getOp());
Node->getInsts().insert(I3, RMW);
}
}
}
}
}
}
// Converts a ConstantInteger32 operand into its constant value, or
// MemoryOrderInvalid if the operand is not a ConstantInteger32.
inline uint64_t getConstantMemoryOrder(Operand *Opnd) {
if (auto Integer = llvm::dyn_cast<ConstantInteger32>(Opnd))
return Integer->getValue();
return Intrinsics::MemoryOrderInvalid;
}
/// Determines whether the dest of a Load instruction can be folded
/// into one of the src operands of a 2-operand instruction. This is
/// true as long as the load dest matches exactly one of the binary
/// instruction's src operands. Replaces Src0 or Src1 with LoadSrc if
/// the answer is true.
inline bool canFoldLoadIntoBinaryInst(Operand *LoadSrc, Variable *LoadDest,
Operand *&Src0, Operand *&Src1) {
if (Src0 == LoadDest && Src1 != LoadDest) {
Src0 = LoadSrc;
return true;
}
if (Src0 != LoadDest && Src1 == LoadDest) {
Src1 = LoadSrc;
return true;
}
return false;
}
template <class Machine> void TargetX86Base<Machine>::doLoadOpt() {
for (CfgNode *Node : Func->getNodes()) {
Context.init(Node);
while (!Context.atEnd()) {
Variable *LoadDest = nullptr;
Operand *LoadSrc = nullptr;
Inst *CurInst = Context.getCur();
Inst *Next = Context.getNextInst();
// Determine whether the current instruction is a Load
// instruction or equivalent.
if (auto *Load = llvm::dyn_cast<InstLoad>(CurInst)) {
// An InstLoad always qualifies.
LoadDest = Load->getDest();
const bool DoLegalize = false;
LoadSrc = formMemoryOperand(Load->getSourceAddress(),
LoadDest->getType(), DoLegalize);
} else if (auto *Intrin = llvm::dyn_cast<InstIntrinsicCall>(CurInst)) {
// An AtomicLoad intrinsic qualifies as long as it has a valid
// memory ordering, and can be implemented in a single
// instruction (i.e., not i64).
Intrinsics::IntrinsicID ID = Intrin->getIntrinsicInfo().ID;
if (ID == Intrinsics::AtomicLoad &&
Intrin->getDest()->getType() != IceType_i64 &&
Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Intrin->getArg(1)))) {
LoadDest = Intrin->getDest();
const bool DoLegalize = false;
LoadSrc = formMemoryOperand(Intrin->getArg(0), LoadDest->getType(),
DoLegalize);
}
}
// A Load instruction can be folded into the following
// instruction only if the following instruction ends the Load's
// Dest variable's live range.
if (LoadDest && Next && Next->isLastUse(LoadDest)) {
assert(LoadSrc);
Inst *NewInst = nullptr;
if (auto *Arith = llvm::dyn_cast<InstArithmetic>(Next)) {
Operand *Src0 = Arith->getSrc(0);
Operand *Src1 = Arith->getSrc(1);
if (canFoldLoadIntoBinaryInst(LoadSrc, LoadDest, Src0, Src1)) {
NewInst = InstArithmetic::create(Func, Arith->getOp(),
Arith->getDest(), Src0, Src1);
}
} else if (auto *Icmp = llvm::dyn_cast<InstIcmp>(Next)) {
Operand *Src0 = Icmp->getSrc(0);
Operand *Src1 = Icmp->getSrc(1);
if (canFoldLoadIntoBinaryInst(LoadSrc, LoadDest, Src0, Src1)) {
NewInst = InstIcmp::create(Func, Icmp->getCondition(),
Icmp->getDest(), Src0, Src1);
}
} else if (auto *Fcmp = llvm::dyn_cast<InstFcmp>(Next)) {
Operand *Src0 = Fcmp->getSrc(0);
Operand *Src1 = Fcmp->getSrc(1);
if (canFoldLoadIntoBinaryInst(LoadSrc, LoadDest, Src0, Src1)) {
NewInst = InstFcmp::create(Func, Fcmp->getCondition(),
Fcmp->getDest(), Src0, Src1);
}
} else if (auto *Select = llvm::dyn_cast<InstSelect>(Next)) {
Operand *Src0 = Select->getTrueOperand();
Operand *Src1 = Select->getFalseOperand();
if (canFoldLoadIntoBinaryInst(LoadSrc, LoadDest, Src0, Src1)) {
NewInst = InstSelect::create(Func, Select->getDest(),
Select->getCondition(), Src0, Src1);
}
} else if (auto *Cast = llvm::dyn_cast<InstCast>(Next)) {
// The load dest can always be folded into a Cast
// instruction.
Variable *Src0 = llvm::dyn_cast<Variable>(Cast->getSrc(0));
if (Src0 == LoadDest) {
NewInst = InstCast::create(Func, Cast->getCastKind(),
Cast->getDest(), LoadSrc);
}
}
if (NewInst) {
CurInst->setDeleted();
Next->setDeleted();
Context.insert(NewInst);
// Update NewInst->LiveRangesEnded so that target lowering
// may benefit. Also update NewInst->HasSideEffects.
NewInst->spliceLivenessInfo(Next, CurInst);
}
}
Context.advanceCur();
Context.advanceNext();
}
}
Func->dump("After load optimization");
}
template <class Machine>
bool TargetX86Base<Machine>::doBranchOpt(Inst *I, const CfgNode *NextNode) {
if (auto *Br = llvm::dyn_cast<typename Traits::Insts::Br>(I)) {
return Br->optimizeBranch(NextNode);
}
return false;
}
template <class Machine>
Variable *TargetX86Base<Machine>::getPhysicalRegister(SizeT RegNum, Type Ty) {
if (Ty == IceType_void)
Ty = IceType_i32;
if (PhysicalRegisters[Ty].empty())
PhysicalRegisters[Ty].resize(Traits::RegisterSet::Reg_NUM);
assert(RegNum < PhysicalRegisters[Ty].size());
Variable *Reg = PhysicalRegisters[Ty][RegNum];
if (Reg == nullptr) {
Reg = Func->makeVariable(Ty);
Reg->setRegNum(RegNum);
PhysicalRegisters[Ty][RegNum] = Reg;
// Specially mark esp as an "argument" so that it is considered
// live upon function entry.
if (RegNum == Traits::RegisterSet::Reg_esp) {
Func->addImplicitArg(Reg);
Reg->setIgnoreLiveness();
}
}
return Reg;
}
template <class Machine>
IceString TargetX86Base<Machine>::getRegName(SizeT RegNum, Type Ty) const {
return Traits::getRegName(RegNum, Ty);
}
template <class Machine>
void TargetX86Base<Machine>::emitVariable(const Variable *Var) const {
if (!BuildDefs::dump())
return;
Ostream &Str = Ctx->getStrEmit();
if (Var->hasReg()) {
Str << "%" << getRegName(Var->getRegNum(), Var->getType());
return;
}
if (Var->getWeight().isInf()) {
llvm_unreachable("Infinite-weight Variable has no register assigned");
}
int32_t Offset = Var->getStackOffset();
int32_t BaseRegNum = Var->getBaseRegNum();
if (BaseRegNum == Variable::NoRegister) {
BaseRegNum = getFrameOrStackReg();
if (!hasFramePointer())
Offset += getStackAdjustment();
}
if (Offset)
Str << Offset;
const Type FrameSPTy = IceType_i32;
Str << "(%" << getRegName(BaseRegNum, FrameSPTy) << ")";
}
template <class Machine>
typename TargetX86Base<Machine>::Traits::Address
TargetX86Base<Machine>::stackVarToAsmOperand(const Variable *Var) const {
if (Var->hasReg())
llvm_unreachable("Stack Variable has a register assigned");
if (Var->getWeight().isInf()) {
llvm_unreachable("Infinite-weight Variable has no register assigned");
}
int32_t Offset = Var->getStackOffset();
int32_t BaseRegNum = Var->getBaseRegNum();
if (Var->getBaseRegNum() == Variable::NoRegister) {
BaseRegNum = getFrameOrStackReg();
if (!hasFramePointer())
Offset += getStackAdjustment();
}
return typename Traits::Address(
Traits::RegisterSet::getEncodedGPR(BaseRegNum), Offset);
}
/// Helper function for addProlog().
///
/// This assumes Arg is an argument passed on the stack. This sets the
/// frame offset for Arg and updates InArgsSizeBytes according to Arg's
/// width. For an I64 arg that has been split into Lo and Hi components,
/// it calls itself recursively on the components, taking care to handle
/// Lo first because of the little-endian architecture. Lastly, this
/// function generates an instruction to copy Arg into its assigned
/// register if applicable.
template <class Machine>
void TargetX86Base<Machine>::finishArgumentLowering(Variable *Arg,
Variable *FramePtr,
size_t BasicFrameOffset,
size_t &InArgsSizeBytes) {
Variable *Lo = Arg->getLo();
Variable *Hi = Arg->getHi();
Type Ty = Arg->getType();
if (Lo && Hi && Ty == IceType_i64) {
// TODO(jpp): This special case is not needed for x86-64.
assert(Lo->getType() != IceType_i64); // don't want infinite recursion
assert(Hi->getType() != IceType_i64); // don't want infinite recursion
finishArgumentLowering(Lo, FramePtr, BasicFrameOffset, InArgsSizeBytes);
finishArgumentLowering(Hi, FramePtr, BasicFrameOffset, InArgsSizeBytes);
return;
}
if (isVectorType(Ty)) {
InArgsSizeBytes = Traits::applyStackAlignment(InArgsSizeBytes);
}
Arg->setStackOffset(BasicFrameOffset + InArgsSizeBytes);
InArgsSizeBytes += typeWidthInBytesOnStack(Ty);
if (Arg->hasReg()) {
assert(Ty != IceType_i64);
typename Traits::X86OperandMem *Mem = Traits::X86OperandMem::create(
Func, Ty, FramePtr, Ctx->getConstantInt32(Arg->getStackOffset()));
if (isVectorType(Arg->getType())) {
_movp(Arg, Mem);
} else {
_mov(Arg, Mem);
}
// This argument-copying instruction uses an explicit Traits::X86OperandMem
// operand instead of a Variable, so its fill-from-stack operation has to be
// tracked separately for statistics.
Ctx->statsUpdateFills();
}
}
template <class Machine> Type TargetX86Base<Machine>::stackSlotType() {
// TODO(jpp): this is wrong for x86-64.
return IceType_i32;
}
template <class Machine> void TargetX86Base<Machine>::split64(Variable *Var) {
switch (Var->getType()) {
default:
return;
case IceType_i64:
// TODO: Only consider F64 if we need to push each half when
// passing as an argument to a function call. Note that each half
// is still typed as I32.
case IceType_f64:
break;
}
Variable *Lo = Var->getLo();
Variable *Hi = Var->getHi();
if (Lo) {
assert(Hi);
return;
}
assert(Hi == nullptr);
Lo = Func->makeVariable(IceType_i32);
Hi = Func->makeVariable(IceType_i32);
if (BuildDefs::dump()) {
Lo->setName(Func, Var->getName(Func) + "__lo");
Hi->setName(Func, Var->getName(Func) + "__hi");
}
Var->setLoHi(Lo, Hi);
if (Var->getIsArg()) {
Lo->setIsArg();
Hi->setIsArg();
}
}
template <class Machine>
Operand *TargetX86Base<Machine>::loOperand(Operand *Operand) {
assert(Operand->getType() == IceType_i64 ||
Operand->getType() == IceType_f64);
if (Operand->getType() != IceType_i64 && Operand->getType() != IceType_f64)
return Operand;
if (auto *Var = llvm::dyn_cast<Variable>(Operand)) {
split64(Var);
return Var->getLo();
}
if (auto *Const = llvm::dyn_cast<ConstantInteger64>(Operand)) {
auto *ConstInt = llvm::dyn_cast<ConstantInteger32>(
Ctx->getConstantInt32(static_cast<int32_t>(Const->getValue())));
// Check if we need to blind/pool the constant.
return legalize(ConstInt);
}
if (auto *Mem = llvm::dyn_cast<typename Traits::X86OperandMem>(Operand)) {
auto *MemOperand = Traits::X86OperandMem::create(
Func, IceType_i32, Mem->getBase(), Mem->getOffset(), Mem->getIndex(),
Mem->getShift(), Mem->getSegmentRegister());
// Test if we should randomize or pool the offset, if so randomize it or
// pool it then create mem operand with the blinded/pooled constant.
// Otherwise, return the mem operand as ordinary mem operand.
return legalize(MemOperand);
}
llvm_unreachable("Unsupported operand type");
return nullptr;
}
template <class Machine>
Operand *TargetX86Base<Machine>::hiOperand(Operand *Operand) {
assert(Operand->getType() == IceType_i64 ||
Operand->getType() == IceType_f64);
if (Operand->getType() != IceType_i64 && Operand->getType() != IceType_f64)
return Operand;
if (auto *Var = llvm::dyn_cast<Variable>(Operand)) {
split64(Var);
return Var->getHi();
}
if (auto *Const = llvm::dyn_cast<ConstantInteger64>(Operand)) {
auto *ConstInt = llvm::dyn_cast<ConstantInteger32>(
Ctx->getConstantInt32(static_cast<int32_t>(Const->getValue() >> 32)));
// Check if we need to blind/pool the constant.
return legalize(ConstInt);
}
if (auto *Mem = llvm::dyn_cast<typename Traits::X86OperandMem>(Operand)) {
Constant *Offset = Mem->getOffset();
if (Offset == nullptr) {
Offset = Ctx->getConstantInt32(4);
} else if (auto *IntOffset = llvm::dyn_cast<ConstantInteger32>(Offset)) {
Offset = Ctx->getConstantInt32(4 + IntOffset->getValue());
} else if (auto *SymOffset = llvm::dyn_cast<ConstantRelocatable>(Offset)) {
assert(!Utils::WouldOverflowAdd(SymOffset->getOffset(), 4));
Offset =
Ctx->getConstantSym(4 + SymOffset->getOffset(), SymOffset->getName(),
SymOffset->getSuppressMangling());
}
auto *MemOperand = Traits::X86OperandMem::create(
Func, IceType_i32, Mem->getBase(), Offset, Mem->getIndex(),
Mem->getShift(), Mem->getSegmentRegister());
// Test if the Offset is an eligible i32 constants for randomization and
// pooling. Blind/pool it if it is. Otherwise return as oridinary mem
// operand.
return legalize(MemOperand);
}
llvm_unreachable("Unsupported operand type");
return nullptr;
}
template <class Machine>
llvm::SmallBitVector
TargetX86Base<Machine>::getRegisterSet(RegSetMask Include,
RegSetMask Exclude) const {
return Traits::getRegisterSet(Include, Exclude);
}
template <class Machine>
void TargetX86Base<Machine>::lowerAlloca(const InstAlloca *Inst) {
IsEbpBasedFrame = true;
// Conservatively require the stack to be aligned. Some stack
// adjustment operations implemented below assume that the stack is
// aligned before the alloca. All the alloca code ensures that the
// stack alignment is preserved after the alloca. The stack alignment
// restriction can be relaxed in some cases.
NeedsStackAlignment = true;
// TODO(stichnot): minimize the number of adjustments of esp, etc.
Variable *esp = getPhysicalRegister(Traits::RegisterSet::Reg_esp);
Operand *TotalSize = legalize(Inst->getSizeInBytes());
Variable *Dest = Inst->getDest();
uint32_t AlignmentParam = Inst->getAlignInBytes();
// For default align=0, set it to the real value 1, to avoid any
// bit-manipulation problems below.
AlignmentParam = std::max(AlignmentParam, 1u);
// LLVM enforces power of 2 alignment.
assert(llvm::isPowerOf2_32(AlignmentParam));
assert(llvm::isPowerOf2_32(Traits::X86_STACK_ALIGNMENT_BYTES));
uint32_t Alignment =
std::max(AlignmentParam, Traits::X86_STACK_ALIGNMENT_BYTES);
if (Alignment > Traits::X86_STACK_ALIGNMENT_BYTES) {
_and(esp, Ctx->getConstantInt32(-Alignment));
}
if (const auto *ConstantTotalSize =
llvm::dyn_cast<ConstantInteger32>(TotalSize)) {
uint32_t Value = ConstantTotalSize->getValue();
Value = Utils::applyAlignment(Value, Alignment);
_sub(esp, Ctx->getConstantInt32(Value));
} else {
// Non-constant sizes need to be adjusted to the next highest
// multiple of the required alignment at runtime.
Variable *T = makeReg(IceType_i32);
_mov(T, TotalSize);
_add(T, Ctx->getConstantInt32(Alignment - 1));
_and(T, Ctx->getConstantInt32(-Alignment));
_sub(esp, T);
}
_mov(Dest, esp);
}
/// Strength-reduce scalar integer multiplication by a constant (for
/// i32 or narrower) for certain constants. The lea instruction can be
/// used to multiply by 3, 5, or 9, and the lsh instruction can be used
/// to multiply by powers of 2. These can be combined such that
/// e.g. multiplying by 100 can be done as 2 lea-based multiplies by 5,
/// combined with left-shifting by 2.
template <class Machine>
bool TargetX86Base<Machine>::optimizeScalarMul(Variable *Dest, Operand *Src0,
int32_t Src1) {
// Disable this optimization for Om1 and O0, just to keep things
// simple there.
if (Ctx->getFlags().getOptLevel() < Opt_1)
return false;
Type Ty = Dest->getType();
Variable *T = nullptr;
if (Src1 == -1) {
_mov(T, Src0);
_neg(T);
_mov(Dest, T);
return true;
}
if (Src1 == 0) {
_mov(Dest, Ctx->getConstantZero(Ty));
return true;
}
if (Src1 == 1) {
_mov(T, Src0);
_mov(Dest, T);
return true;
}
// Don't bother with the edge case where Src1 == MININT.
if (Src1 == -Src1)
return false;
const bool Src1IsNegative = Src1 < 0;
if (Src1IsNegative)
Src1 = -Src1;
uint32_t Count9 = 0;
uint32_t Count5 = 0;
uint32_t Count3 = 0;
uint32_t Count2 = 0;
uint32_t CountOps = 0;
while (Src1 > 1) {
if (Src1 % 9 == 0) {
++CountOps;
++Count9;
Src1 /= 9;
} else if (Src1 % 5 == 0) {
++CountOps;
++Count5;
Src1 /= 5;
} else if (Src1 % 3 == 0) {
++CountOps;
++Count3;
Src1 /= 3;
} else if (Src1 % 2 == 0) {
if (Count2 == 0)
++CountOps;
++Count2;
Src1 /= 2;
} else {
return false;
}
}
// Lea optimization only works for i16 and i32 types, not i8.
if (Ty != IceType_i16 && Ty != IceType_i32 && (Count3 || Count5 || Count9))
return false;
// Limit the number of lea/shl operations for a single multiply, to
// a somewhat arbitrary choice of 3.
const uint32_t MaxOpsForOptimizedMul = 3;
if (CountOps > MaxOpsForOptimizedMul)
return false;
_mov(T, Src0);
Constant *Zero = Ctx->getConstantZero(IceType_i32);
for (uint32_t i = 0; i < Count9; ++i) {
const uint16_t Shift = 3; // log2(9-1)
_lea(T,
Traits::X86OperandMem::create(Func, IceType_void, T, Zero, T, Shift));
_set_dest_nonkillable();
}
for (uint32_t i = 0; i < Count5; ++i) {
const uint16_t Shift = 2; // log2(5-1)
_lea(T,
Traits::X86OperandMem::create(Func, IceType_void, T, Zero, T, Shift));
_set_dest_nonkillable();
}
for (uint32_t i = 0; i < Count3; ++i) {
const uint16_t Shift = 1; // log2(3-1)
_lea(T,
Traits::X86OperandMem::create(Func, IceType_void, T, Zero, T, Shift));
_set_dest_nonkillable();
}
if (Count2) {
_shl(T, Ctx->getConstantInt(Ty, Count2));
}
if (Src1IsNegative)
_neg(T);
_mov(Dest, T);
return true;
}
template <class Machine>
void TargetX86Base<Machine>::lowerArithmetic(const InstArithmetic *Inst) {
Variable *Dest = Inst->getDest();
Operand *Src0 = legalize(Inst->getSrc(0));
Operand *Src1 = legalize(Inst->getSrc(1));
if (Inst->isCommutative()) {
if (!llvm::isa<Variable>(Src0) && llvm::isa<Variable>(Src1))
std::swap(Src0, Src1);
if (llvm::isa<Constant>(Src0) && !llvm::isa<Constant>(Src1))
std::swap(Src0, Src1);
}
if (Dest->getType() == IceType_i64) {
// These helper-call-involved instructions are lowered in this
// separate switch. This is because loOperand() and hiOperand()
// may insert redundant instructions for constant blinding and
// pooling. Such redundant instructions will fail liveness analysis
// under -Om1 setting. And, actually these arguments do not need
// to be processed with loOperand() and hiOperand() to be used.
switch (Inst->getOp()) {
case InstArithmetic::Udiv: {
const SizeT MaxSrcs = 2;
InstCall *Call = makeHelperCall(H_udiv_i64, Dest, MaxSrcs);
Call->addArg(Inst->getSrc(0));
Call->addArg(Inst->getSrc(1));
lowerCall(Call);
return;
}
case InstArithmetic::Sdiv: {
const SizeT MaxSrcs = 2;
InstCall *Call = makeHelperCall(H_sdiv_i64, Dest, MaxSrcs);
Call->addArg(Inst->getSrc(0));
Call->addArg(Inst->getSrc(1));
lowerCall(Call);
return;
}
case InstArithmetic::Urem: {
const SizeT MaxSrcs = 2;
InstCall *Call = makeHelperCall(H_urem_i64, Dest, MaxSrcs);
Call->addArg(Inst->getSrc(0));
Call->addArg(Inst->getSrc(1));
lowerCall(Call);
return;
}
case InstArithmetic::Srem: {
const SizeT MaxSrcs = 2;
InstCall *Call = makeHelperCall(H_srem_i64, Dest, MaxSrcs);
Call->addArg(Inst->getSrc(0));
Call->addArg(Inst->getSrc(1));
lowerCall(Call);
return;
}
default:
break;
}
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Operand *Src0Lo = loOperand(Src0);
Operand *Src0Hi = hiOperand(Src0);
Operand *Src1Lo = loOperand(Src1);
Operand *Src1Hi = hiOperand(Src1);
Variable *T_Lo = nullptr, *T_Hi = nullptr;
switch (Inst->getOp()) {
case InstArithmetic::_num:
llvm_unreachable("Unknown arithmetic operator");
break;
case InstArithmetic::Add:
_mov(T_Lo, Src0Lo);
_add(T_Lo, Src1Lo);
_mov(DestLo, T_Lo);
_mov(T_Hi, Src0Hi);
_adc(T_Hi, Src1Hi);
_mov(DestHi, T_Hi);
break;
case InstArithmetic::And:
_mov(T_Lo, Src0Lo);
_and(T_Lo, Src1Lo);
_mov(DestLo, T_Lo);
_mov(T_Hi, Src0Hi);
_and(T_Hi, Src1Hi);
_mov(DestHi, T_Hi);
break;
case InstArithmetic::Or:
_mov(T_Lo, Src0Lo);
_or(T_Lo, Src1Lo);
_mov(DestLo, T_Lo);
_mov(T_Hi, Src0Hi);
_or(T_Hi, Src1Hi);
_mov(DestHi, T_Hi);
break;
case InstArithmetic::Xor:
_mov(T_Lo, Src0Lo);
_xor(T_Lo, Src1Lo);
_mov(DestLo, T_Lo);
_mov(T_Hi, Src0Hi);
_xor(T_Hi, Src1Hi);
_mov(DestHi, T_Hi);
break;
case InstArithmetic::Sub:
_mov(T_Lo, Src0Lo);
_sub(T_Lo, Src1Lo);
_mov(DestLo, T_Lo);
_mov(T_Hi, Src0Hi);
_sbb(T_Hi, Src1Hi);
_mov(DestHi, T_Hi);
break;
case InstArithmetic::Mul: {
Variable *T_1 = nullptr, *T_2 = nullptr, *T_3 = nullptr;
Variable *T_4Lo = makeReg(IceType_i32, Traits::RegisterSet::Reg_eax);
Variable *T_4Hi = makeReg(IceType_i32, Traits::RegisterSet::Reg_edx);
// gcc does the following:
// a=b*c ==>
// t1 = b.hi; t1 *=(imul) c.lo
// t2 = c.hi; t2 *=(imul) b.lo
// t3:eax = b.lo
// t4.hi:edx,t4.lo:eax = t3:eax *(mul) c.lo
// a.lo = t4.lo
// t4.hi += t1
// t4.hi += t2
// a.hi = t4.hi
// The mul instruction cannot take an immediate operand.
Src1Lo = legalize(Src1Lo, Legal_Reg | Legal_Mem);
_mov(T_1, Src0Hi);
_imul(T_1, Src1Lo);
_mov(T_2, Src1Hi);
_imul(T_2, Src0Lo);
_mov(T_3, Src0Lo, Traits::RegisterSet::Reg_eax);
_mul(T_4Lo, T_3, Src1Lo);
// The mul instruction produces two dest variables, edx:eax. We
// create a fake definition of edx to account for this.
Context.insert(InstFakeDef::create(Func, T_4Hi, T_4Lo));
_mov(DestLo, T_4Lo);
_add(T_4Hi, T_1);
_add(T_4Hi, T_2);
_mov(DestHi, T_4Hi);
} break;
case InstArithmetic::Shl: {
// TODO: Refactor the similarities between Shl, Lshr, and Ashr.
// gcc does the following:
// a=b<<c ==>
// t1:ecx = c.lo & 0xff
// t2 = b.lo
// t3 = b.hi
// t3 = shld t3, t2, t1
// t2 = shl t2, t1
// test t1, 0x20
// je L1
// use(t3)
// t3 = t2
// t2 = 0
// L1:
// a.lo = t2
// a.hi = t3
Variable *T_1 = nullptr, *T_2 = nullptr, *T_3 = nullptr;
Constant *BitTest = Ctx->getConstantInt32(0x20);
Constant *Zero = Ctx->getConstantZero(IceType_i32);
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
_mov(T_1, Src1Lo, Traits::RegisterSet::Reg_ecx);
_mov(T_2, Src0Lo);
_mov(T_3, Src0Hi);
_shld(T_3, T_2, T_1);
_shl(T_2, T_1);
_test(T_1, BitTest);
_br(Traits::Cond::Br_e, Label);
// T_2 and T_3 are being assigned again because of the
// intra-block control flow, so we need the _mov_nonkillable
// variant to avoid liveness problems.
_mov_nonkillable(T_3, T_2);
_mov_nonkillable(T_2, Zero);
Context.insert(Label);
_mov(DestLo, T_2);
_mov(DestHi, T_3);
} break;
case InstArithmetic::Lshr: {
// a=b>>c (unsigned) ==>
// t1:ecx = c.lo & 0xff
// t2 = b.lo
// t3 = b.hi
// t2 = shrd t2, t3, t1
// t3 = shr t3, t1
// test t1, 0x20
// je L1
// use(t2)
// t2 = t3
// t3 = 0
// L1:
// a.lo = t2
// a.hi = t3
Variable *T_1 = nullptr, *T_2 = nullptr, *T_3 = nullptr;
Constant *BitTest = Ctx->getConstantInt32(0x20);
Constant *Zero = Ctx->getConstantZero(IceType_i32);
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
_mov(T_1, Src1Lo, Traits::RegisterSet::Reg_ecx);
_mov(T_2, Src0Lo);
_mov(T_3, Src0Hi);
_shrd(T_2, T_3, T_1);
_shr(T_3, T_1);
_test(T_1, BitTest);
_br(Traits::Cond::Br_e, Label);
// T_2 and T_3 are being assigned again because of the
// intra-block control flow, so we need the _mov_nonkillable
// variant to avoid liveness problems.
_mov_nonkillable(T_2, T_3);
_mov_nonkillable(T_3, Zero);
Context.insert(Label);
_mov(DestLo, T_2);
_mov(DestHi, T_3);
} break;
case InstArithmetic::Ashr: {
// a=b>>c (signed) ==>
// t1:ecx = c.lo & 0xff
// t2 = b.lo
// t3 = b.hi
// t2 = shrd t2, t3, t1
// t3 = sar t3, t1
// test t1, 0x20
// je L1
// use(t2)
// t2 = t3
// t3 = sar t3, 0x1f
// L1:
// a.lo = t2
// a.hi = t3
Variable *T_1 = nullptr, *T_2 = nullptr, *T_3 = nullptr;
Constant *BitTest = Ctx->getConstantInt32(0x20);
Constant *SignExtend = Ctx->getConstantInt32(0x1f);
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
_mov(T_1, Src1Lo, Traits::RegisterSet::Reg_ecx);
_mov(T_2, Src0Lo);
_mov(T_3, Src0Hi);
_shrd(T_2, T_3, T_1);
_sar(T_3, T_1);
_test(T_1, BitTest);
_br(Traits::Cond::Br_e, Label);
// T_2 and T_3 are being assigned again because of the
// intra-block control flow, so T_2 needs the _mov_nonkillable
// variant to avoid liveness problems. T_3 doesn't need special
// treatment because it is reassigned via _sar instead of _mov.
_mov_nonkillable(T_2, T_3);
_sar(T_3, SignExtend);
Context.insert(Label);
_mov(DestLo, T_2);
_mov(DestHi, T_3);
} break;
case InstArithmetic::Fadd:
case InstArithmetic::Fsub:
case InstArithmetic::Fmul:
case InstArithmetic::Fdiv:
case InstArithmetic::Frem:
llvm_unreachable("FP instruction with i64 type");
break;
case InstArithmetic::Udiv:
case InstArithmetic::Sdiv:
case InstArithmetic::Urem:
case InstArithmetic::Srem:
llvm_unreachable("Call-helper-involved instruction for i64 type \
should have already been handled before");
break;
}
return;
}
if (isVectorType(Dest->getType())) {
// TODO: Trap on integer divide and integer modulo by zero.
// See: https://code.google.com/p/nativeclient/issues/detail?id=3899
if (llvm::isa<typename Traits::X86OperandMem>(Src1))
Src1 = legalizeToReg(Src1);
switch (Inst->getOp()) {
case InstArithmetic::_num:
llvm_unreachable("Unknown arithmetic operator");
break;
case InstArithmetic::Add: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_padd(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::And: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_pand(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Or: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_por(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Xor: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_pxor(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Sub: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_psub(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Mul: {
bool TypesAreValidForPmull =
Dest->getType() == IceType_v4i32 || Dest->getType() == IceType_v8i16;
bool InstructionSetIsValidForPmull =
Dest->getType() == IceType_v8i16 || InstructionSet >= Traits::SSE4_1;
if (TypesAreValidForPmull && InstructionSetIsValidForPmull) {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_pmull(T, Src1);
_movp(Dest, T);
} else if (Dest->getType() == IceType_v4i32) {
// Lowering sequence:
// Note: The mask arguments have index 0 on the left.
//
// movups T1, Src0
// pshufd T2, Src0, {1,0,3,0}
// pshufd T3, Src1, {1,0,3,0}
// # T1 = {Src0[0] * Src1[0], Src0[2] * Src1[2]}
// pmuludq T1, Src1
// # T2 = {Src0[1] * Src1[1], Src0[3] * Src1[3]}
// pmuludq T2, T3
// # T1 = {lo(T1[0]), lo(T1[2]), lo(T2[0]), lo(T2[2])}
// shufps T1, T2, {0,2,0,2}
// pshufd T4, T1, {0,2,1,3}
// movups Dest, T4
// Mask that directs pshufd to create a vector with entries
// Src[1, 0, 3, 0]
const unsigned Constant1030 = 0x31;
Constant *Mask1030 = Ctx->getConstantInt32(Constant1030);
// Mask that directs shufps to create a vector with entries
// Dest[0, 2], Src[0, 2]
const unsigned Mask0202 = 0x88;
// Mask that directs pshufd to create a vector with entries
// Src[0, 2, 1, 3]
const unsigned Mask0213 = 0xd8;
Variable *T1 = makeReg(IceType_v4i32);
Variable *T2 = makeReg(IceType_v4i32);
Variable *T3 = makeReg(IceType_v4i32);
Variable *T4 = makeReg(IceType_v4i32);
_movp(T1, Src0);
_pshufd(T2, Src0, Mask1030);
_pshufd(T3, Src1, Mask1030);
_pmuludq(T1, Src1);
_pmuludq(T2, T3);
_shufps(T1, T2, Ctx->getConstantInt32(Mask0202));
_pshufd(T4, T1, Ctx->getConstantInt32(Mask0213));
_movp(Dest, T4);
} else {
assert(Dest->getType() == IceType_v16i8);
scalarizeArithmetic(Inst->getOp(), Dest, Src0, Src1);
}
} break;
case InstArithmetic::Shl:
case InstArithmetic::Lshr:
case InstArithmetic::Ashr:
case InstArithmetic::Udiv:
case InstArithmetic::Urem:
case InstArithmetic::Sdiv:
case InstArithmetic::Srem:
scalarizeArithmetic(Inst->getOp(), Dest, Src0, Src1);
break;
case InstArithmetic::Fadd: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_addps(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Fsub: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_subps(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Fmul: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_mulps(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Fdiv: {
Variable *T = makeReg(Dest->getType());
_movp(T, Src0);
_divps(T, Src1);
_movp(Dest, T);
} break;
case InstArithmetic::Frem:
scalarizeArithmetic(Inst->getOp(), Dest, Src0, Src1);
break;
}
return;
}
Variable *T_edx = nullptr;
Variable *T = nullptr;
switch (Inst->getOp()) {
case InstArithmetic::_num:
llvm_unreachable("Unknown arithmetic operator");
break;
case InstArithmetic::Add:
_mov(T, Src0);
_add(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::And:
_mov(T, Src0);
_and(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Or:
_mov(T, Src0);
_or(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Xor:
_mov(T, Src0);
_xor(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Sub:
_mov(T, Src0);
_sub(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Mul:
if (auto *C = llvm::dyn_cast<ConstantInteger32>(Src1)) {
if (optimizeScalarMul(Dest, Src0, C->getValue()))
return;
}
// The 8-bit version of imul only allows the form "imul r/m8"
// where T must be in eax.
if (isByteSizedArithType(Dest->getType())) {
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
Src1 = legalize(Src1, Legal_Reg | Legal_Mem);
} else {
_mov(T, Src0);
}
_imul(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Shl:
_mov(T, Src0);
if (!llvm::isa<ConstantInteger32>(Src1))
Src1 = legalizeToReg(Src1, Traits::RegisterSet::Reg_ecx);
_shl(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Lshr:
_mov(T, Src0);
if (!llvm::isa<ConstantInteger32>(Src1))
Src1 = legalizeToReg(Src1, Traits::RegisterSet::Reg_ecx);
_shr(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Ashr:
_mov(T, Src0);
if (!llvm::isa<ConstantInteger32>(Src1))
Src1 = legalizeToReg(Src1, Traits::RegisterSet::Reg_ecx);
_sar(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Udiv:
// div and idiv are the few arithmetic operators that do not allow
// immediates as the operand.
Src1 = legalize(Src1, Legal_Reg | Legal_Mem);
if (isByteSizedArithType(Dest->getType())) {
// For 8-bit unsigned division we need to zero-extend al into ah. A mov
// $0, %ah (or xor %ah, %ah) would work just fine, except that the x86-64
// assembler refuses to encode %ah (encoding %spl with a REX prefix
// instead.) Accessing %ah in 64-bit is "tricky" as you can't encode %ah
// with any other 8-bit register except for %a[lh], %b[lh], %c[lh], and
// d[%lh], which means the X86 target lowering (and the register
// allocator) would have to be aware of this restriction. For now, we
// simply zero %eax completely, and move the dividend into %al.
Variable *T_eax = makeReg(IceType_i32, Traits::RegisterSet::Reg_eax);
Context.insert(InstFakeDef::create(Func, T_eax));
_xor(T_eax, T_eax);
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
_div(T, Src1, T);
_mov(Dest, T);
Context.insert(InstFakeUse::create(Func, T_eax));
} else {
Constant *Zero = Ctx->getConstantZero(IceType_i32);
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
_mov(T_edx, Zero, Traits::RegisterSet::Reg_edx);
_div(T, Src1, T_edx);
_mov(Dest, T);
}
break;
case InstArithmetic::Sdiv:
// TODO(stichnot): Enable this after doing better performance
// and cross testing.
if (false && Ctx->getFlags().getOptLevel() >= Opt_1) {
// Optimize division by constant power of 2, but not for Om1
// or O0, just to keep things simple there.
if (auto *C = llvm::dyn_cast<ConstantInteger32>(Src1)) {
int32_t Divisor = C->getValue();
uint32_t UDivisor = static_cast<uint32_t>(Divisor);
if (Divisor > 0 && llvm::isPowerOf2_32(UDivisor)) {
uint32_t LogDiv = llvm::Log2_32(UDivisor);
Type Ty = Dest->getType();
// LLVM does the following for dest=src/(1<<log):
// t=src
// sar t,typewidth-1 // -1 if src is negative, 0 if not
// shr t,typewidth-log
// add t,src
// sar t,log
// dest=t
uint32_t TypeWidth = Traits::X86_CHAR_BIT * typeWidthInBytes(Ty);
_mov(T, Src0);
// If for some reason we are dividing by 1, just treat it
// like an assignment.
if (LogDiv > 0) {
// The initial sar is unnecessary when dividing by 2.
if (LogDiv > 1)
_sar(T, Ctx->getConstantInt(Ty, TypeWidth - 1));
_shr(T, Ctx->getConstantInt(Ty, TypeWidth - LogDiv));
_add(T, Src0);
_sar(T, Ctx->getConstantInt(Ty, LogDiv));
}
_mov(Dest, T);
return;
}
}
}
Src1 = legalize(Src1, Legal_Reg | Legal_Mem);
if (isByteSizedArithType(Dest->getType())) {
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
_cbwdq(T, T);
_idiv(T, Src1, T);
_mov(Dest, T);
} else {
T_edx = makeReg(IceType_i32, Traits::RegisterSet::Reg_edx);
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
_cbwdq(T_edx, T);
_idiv(T, Src1, T_edx);
_mov(Dest, T);
}
break;
case InstArithmetic::Urem:
Src1 = legalize(Src1, Legal_Reg | Legal_Mem);
if (isByteSizedArithType(Dest->getType())) {
Variable *T_eax = makeReg(IceType_i32, Traits::RegisterSet::Reg_eax);
Context.insert(InstFakeDef::create(Func, T_eax));
_xor(T_eax, T_eax);
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
_div(T, Src1, T);
// shr $8, %eax shifts ah (i.e., the 8 bit remainder) into al. We don't
// mov %ah, %al because it would make x86-64 codegen more complicated. If
// this ever becomes a problem we can introduce a pseudo rem instruction
// that returns the remainder in %al directly (and uses a mov for copying
// %ah to %al.)
static constexpr uint8_t AlSizeInBits = 8;
_shr(T_eax, Ctx->getConstantInt8(AlSizeInBits));
_mov(Dest, T);
Context.insert(InstFakeUse::create(Func, T_eax));
} else {
Constant *Zero = Ctx->getConstantZero(IceType_i32);
_mov(T_edx, Zero, Traits::RegisterSet::Reg_edx);
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
_div(T_edx, Src1, T);
_mov(Dest, T_edx);
}
break;
case InstArithmetic::Srem:
// TODO(stichnot): Enable this after doing better performance
// and cross testing.
if (false && Ctx->getFlags().getOptLevel() >= Opt_1) {
// Optimize mod by constant power of 2, but not for Om1 or O0,
// just to keep things simple there.
if (auto *C = llvm::dyn_cast<ConstantInteger32>(Src1)) {
int32_t Divisor = C->getValue();
uint32_t UDivisor = static_cast<uint32_t>(Divisor);
if (Divisor > 0 && llvm::isPowerOf2_32(UDivisor)) {
uint32_t LogDiv = llvm::Log2_32(UDivisor);
Type Ty = Dest->getType();
// LLVM does the following for dest=src%(1<<log):
// t=src
// sar t,typewidth-1 // -1 if src is negative, 0 if not
// shr t,typewidth-log
// add t,src
// and t, -(1<<log)
// sub t,src
// neg t
// dest=t
uint32_t TypeWidth = Traits::X86_CHAR_BIT * typeWidthInBytes(Ty);
// If for some reason we are dividing by 1, just assign 0.
if (LogDiv == 0) {
_mov(Dest, Ctx->getConstantZero(Ty));
return;
}
_mov(T, Src0);
// The initial sar is unnecessary when dividing by 2.
if (LogDiv > 1)
_sar(T, Ctx->getConstantInt(Ty, TypeWidth - 1));
_shr(T, Ctx->getConstantInt(Ty, TypeWidth - LogDiv));
_add(T, Src0);
_and(T, Ctx->getConstantInt(Ty, -(1 << LogDiv)));
_sub(T, Src0);
_neg(T);
_mov(Dest, T);
return;
}
}
}
Src1 = legalize(Src1, Legal_Reg | Legal_Mem);
if (isByteSizedArithType(Dest->getType())) {
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
// T is %al.
_cbwdq(T, T);
_idiv(T, Src1, T);
Variable *T_eax = makeReg(IceType_i32, Traits::RegisterSet::Reg_eax);
Context.insert(InstFakeDef::create(Func, T_eax));
// shr $8, %eax shifts ah (i.e., the 8 bit remainder) into al. We don't
// mov %ah, %al because it would make x86-64 codegen more complicated. If
// this ever becomes a problem we can introduce a pseudo rem instruction
// that returns the remainder in %al directly (and uses a mov for copying
// %ah to %al.)
static constexpr uint8_t AlSizeInBits = 8;
_shr(T_eax, Ctx->getConstantInt8(AlSizeInBits));
_mov(Dest, T);
Context.insert(InstFakeUse::create(Func, T_eax));
} else {
T_edx = makeReg(IceType_i32, Traits::RegisterSet::Reg_edx);
_mov(T, Src0, Traits::RegisterSet::Reg_eax);
_cbwdq(T_edx, T);
_idiv(T_edx, Src1, T);
_mov(Dest, T_edx);
}
break;
case InstArithmetic::Fadd:
_mov(T, Src0);
_addss(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Fsub:
_mov(T, Src0);
_subss(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Fmul:
_mov(T, Src0);
_mulss(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Fdiv:
_mov(T, Src0);
_divss(T, Src1);
_mov(Dest, T);
break;
case InstArithmetic::Frem: {
const SizeT MaxSrcs = 2;
Type Ty = Dest->getType();
InstCall *Call = makeHelperCall(
isFloat32Asserting32Or64(Ty) ? H_frem_f32 : H_frem_f64, Dest, MaxSrcs);
Call->addArg(Src0);
Call->addArg(Src1);
return lowerCall(Call);
}
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerAssign(const InstAssign *Inst) {
Variable *Dest = Inst->getDest();
Operand *Src0 = Inst->getSrc(0);
assert(Dest->getType() == Src0->getType());
if (Dest->getType() == IceType_i64) {
Src0 = legalize(Src0);
Operand *Src0Lo = loOperand(Src0);
Operand *Src0Hi = hiOperand(Src0);
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *T_Lo = nullptr, *T_Hi = nullptr;
_mov(T_Lo, Src0Lo);
_mov(DestLo, T_Lo);
_mov(T_Hi, Src0Hi);
_mov(DestHi, T_Hi);
} else {
Operand *Src0Legal;
if (Dest->hasReg()) {
// If Dest already has a physical register, then only basic legalization
// is needed, as the source operand can be a register, immediate, or
// memory.
Src0Legal = legalize(Src0);
} else {
// If Dest could be a stack operand, then RI must be a physical
// register or a scalar integer immediate.
Src0Legal = legalize(Src0, Legal_Reg | Legal_Imm);
}
if (isVectorType(Dest->getType()))
_movp(Dest, Src0Legal);
else
_mov(Dest, Src0Legal);
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerBr(const InstBr *Inst) {
if (Inst->isUnconditional()) {
_br(Inst->getTargetUnconditional());
return;
}
Operand *Cond = Inst->getCondition();
// Handle folding opportunities.
if (const class Inst *Producer = FoldingInfo.getProducerFor(Cond)) {
assert(Producer->isDeleted());
switch (BoolFolding::getProducerKind(Producer)) {
default:
break;
case BoolFolding::PK_Icmp32: {
// TODO(stichnot): Refactor similarities between this block and
// the corresponding code in lowerIcmp().
auto *Cmp = llvm::dyn_cast<InstIcmp>(Producer);
Operand *Src0 = Producer->getSrc(0);
Operand *Src1 = legalize(Producer->getSrc(1));
Operand *Src0RM = legalizeSrc0ForCmp(Src0, Src1);
_cmp(Src0RM, Src1);
_br(Traits::getIcmp32Mapping(Cmp->getCondition()), Inst->getTargetTrue(),
Inst->getTargetFalse());
return;
}
}
}
Operand *Src0 = legalize(Cond, Legal_Reg | Legal_Mem);
Constant *Zero = Ctx->getConstantZero(IceType_i32);
_cmp(Src0, Zero);
_br(Traits::Cond::Br_ne, Inst->getTargetTrue(), Inst->getTargetFalse());
}
template <class Machine>
void TargetX86Base<Machine>::lowerCast(const InstCast *Inst) {
// a = cast(b) ==> t=cast(b); a=t; (link t->b, link a->t, no overlap)
InstCast::OpKind CastKind = Inst->getCastKind();
Variable *Dest = Inst->getDest();
switch (CastKind) {
default:
Func->setError("Cast type not supported");
return;
case InstCast::Sext: {
// Src0RM is the source operand legalized to physical register or memory,
// but not immediate, since the relevant x86 native instructions don't
// allow an immediate operand. If the operand is an immediate, we could
// consider computing the strength-reduced result at translation time,
// but we're unlikely to see something like that in the bitcode that
// the optimizer wouldn't have already taken care of.
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
if (isVectorType(Dest->getType())) {
Type DestTy = Dest->getType();
if (DestTy == IceType_v16i8) {
// onemask = materialize(1,1,...); dst = (src & onemask) > 0
Variable *OneMask = makeVectorOfOnes(Dest->getType());
Variable *T = makeReg(DestTy);
_movp(T, Src0RM);
_pand(T, OneMask);
Variable *Zeros = makeVectorOfZeros(Dest->getType());
_pcmpgt(T, Zeros);
_movp(Dest, T);
} else {
/// width = width(elty) - 1; dest = (src << width) >> width
SizeT ShiftAmount =
Traits::X86_CHAR_BIT * typeWidthInBytes(typeElementType(DestTy)) -
1;
Constant *ShiftConstant = Ctx->getConstantInt8(ShiftAmount);
Variable *T = makeReg(DestTy);
_movp(T, Src0RM);
_psll(T, ShiftConstant);
_psra(T, ShiftConstant);
_movp(Dest, T);
}
} else if (Dest->getType() == IceType_i64) {
// t1=movsx src; t2=t1; t2=sar t2, 31; dst.lo=t1; dst.hi=t2
Constant *Shift = Ctx->getConstantInt32(31);
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *T_Lo = makeReg(DestLo->getType());
if (Src0RM->getType() == IceType_i32) {
_mov(T_Lo, Src0RM);
} else if (Src0RM->getType() == IceType_i1) {
_movzx(T_Lo, Src0RM);
_shl(T_Lo, Shift);
_sar(T_Lo, Shift);
} else {
_movsx(T_Lo, Src0RM);
}
_mov(DestLo, T_Lo);
Variable *T_Hi = nullptr;
_mov(T_Hi, T_Lo);
if (Src0RM->getType() != IceType_i1)
// For i1, the sar instruction is already done above.
_sar(T_Hi, Shift);
_mov(DestHi, T_Hi);
} else if (Src0RM->getType() == IceType_i1) {
// t1 = src
// shl t1, dst_bitwidth - 1
// sar t1, dst_bitwidth - 1
// dst = t1
size_t DestBits =
Traits::X86_CHAR_BIT * typeWidthInBytes(Dest->getType());
Constant *ShiftAmount = Ctx->getConstantInt32(DestBits - 1);
Variable *T = makeReg(Dest->getType());
if (typeWidthInBytes(Dest->getType()) <=
typeWidthInBytes(Src0RM->getType())) {
_mov(T, Src0RM);
} else {
// Widen the source using movsx or movzx. (It doesn't matter
// which one, since the following shl/sar overwrite the bits.)
_movzx(T, Src0RM);
}
_shl(T, ShiftAmount);
_sar(T, ShiftAmount);
_mov(Dest, T);
} else {
// t1 = movsx src; dst = t1
Variable *T = makeReg(Dest->getType());
_movsx(T, Src0RM);
_mov(Dest, T);
}
break;
}
case InstCast::Zext: {
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
if (isVectorType(Dest->getType())) {
// onemask = materialize(1,1,...); dest = onemask & src
Type DestTy = Dest->getType();
Variable *OneMask = makeVectorOfOnes(DestTy);
Variable *T = makeReg(DestTy);
_movp(T, Src0RM);
_pand(T, OneMask);
_movp(Dest, T);
} else if (Dest->getType() == IceType_i64) {
// t1=movzx src; dst.lo=t1; dst.hi=0
Constant *Zero = Ctx->getConstantZero(IceType_i32);
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *Tmp = makeReg(DestLo->getType());
if (Src0RM->getType() == IceType_i32) {
_mov(Tmp, Src0RM);
} else {
_movzx(Tmp, Src0RM);
}
if (Src0RM->getType() == IceType_i1) {
Constant *One = Ctx->getConstantInt32(1);
_and(Tmp, One);
}
_mov(DestLo, Tmp);
_mov(DestHi, Zero);
} else if (Src0RM->getType() == IceType_i1) {
// t = Src0RM; t &= 1; Dest = t
Constant *One = Ctx->getConstantInt32(1);
Type DestTy = Dest->getType();
Variable *T;
if (DestTy == IceType_i8) {
T = makeReg(DestTy);
_mov(T, Src0RM);
} else {
// Use 32-bit for both 16-bit and 32-bit, since 32-bit ops are shorter.
T = makeReg(IceType_i32);
_movzx(T, Src0RM);
}
_and(T, One);
_mov(Dest, T);
} else {
// t1 = movzx src; dst = t1
Variable *T = makeReg(Dest->getType());
_movzx(T, Src0RM);
_mov(Dest, T);
}
break;
}
case InstCast::Trunc: {
if (isVectorType(Dest->getType())) {
// onemask = materialize(1,1,...); dst = src & onemask
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
Type Src0Ty = Src0RM->getType();
Variable *OneMask = makeVectorOfOnes(Src0Ty);
Variable *T = makeReg(Dest->getType());
_movp(T, Src0RM);
_pand(T, OneMask);
_movp(Dest, T);
} else {
Operand *Src0 = legalizeUndef(Inst->getSrc(0));
if (Src0->getType() == IceType_i64)
Src0 = loOperand(Src0);
Operand *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
// t1 = trunc Src0RM; Dest = t1
Variable *T = nullptr;
_mov(T, Src0RM);
if (Dest->getType() == IceType_i1)
_and(T, Ctx->getConstantInt1(1));
_mov(Dest, T);
}
break;
}
case InstCast::Fptrunc:
case InstCast::Fpext: {
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
// t1 = cvt Src0RM; Dest = t1
Variable *T = makeReg(Dest->getType());
_cvt(T, Src0RM, Traits::Insts::Cvt::Float2float);
_mov(Dest, T);
break;
}
case InstCast::Fptosi:
if (isVectorType(Dest->getType())) {
assert(Dest->getType() == IceType_v4i32 &&
Inst->getSrc(0)->getType() == IceType_v4f32);
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
if (llvm::isa<typename Traits::X86OperandMem>(Src0RM))
Src0RM = legalizeToReg(Src0RM);
Variable *T = makeReg(Dest->getType());
_cvt(T, Src0RM, Traits::Insts::Cvt::Tps2dq);
_movp(Dest, T);
} else if (Dest->getType() == IceType_i64) {
// Use a helper for converting floating-point values to 64-bit
// integers. SSE2 appears to have no way to convert from xmm
// registers to something like the edx:eax register pair, and
// gcc and clang both want to use x87 instructions complete with
// temporary manipulation of the status word. This helper is
// not needed for x86-64.
split64(Dest);
const SizeT MaxSrcs = 1;
Type SrcType = Inst->getSrc(0)->getType();
InstCall *Call =
makeHelperCall(isFloat32Asserting32Or64(SrcType) ? H_fptosi_f32_i64
: H_fptosi_f64_i64,
Dest, MaxSrcs);
Call->addArg(Inst->getSrc(0));
lowerCall(Call);
} else {
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
// t1.i32 = cvt Src0RM; t2.dest_type = t1; Dest = t2.dest_type
Variable *T_1 = makeReg(IceType_i32);
Variable *T_2 = makeReg(Dest->getType());
_cvt(T_1, Src0RM, Traits::Insts::Cvt::Tss2si);
_mov(T_2, T_1); // T_1 and T_2 may have different integer types
if (Dest->getType() == IceType_i1)
_and(T_2, Ctx->getConstantInt1(1));
_mov(Dest, T_2);
}
break;
case InstCast::Fptoui:
if (isVectorType(Dest->getType())) {
assert(Dest->getType() == IceType_v4i32 &&
Inst->getSrc(0)->getType() == IceType_v4f32);
const SizeT MaxSrcs = 1;
InstCall *Call = makeHelperCall(H_fptoui_4xi32_f32, Dest, MaxSrcs);
Call->addArg(Inst->getSrc(0));
lowerCall(Call);
} else if (Dest->getType() == IceType_i64 ||
Dest->getType() == IceType_i32) {
// Use a helper for both x86-32 and x86-64.
split64(Dest);
const SizeT MaxSrcs = 1;
Type DestType = Dest->getType();
Type SrcType = Inst->getSrc(0)->getType();
IceString TargetString;
if (isInt32Asserting32Or64(DestType)) {
TargetString = isFloat32Asserting32Or64(SrcType) ? H_fptoui_f32_i32
: H_fptoui_f64_i32;
} else {
TargetString = isFloat32Asserting32Or64(SrcType) ? H_fptoui_f32_i64
: H_fptoui_f64_i64;
}
InstCall *Call = makeHelperCall(TargetString, Dest, MaxSrcs);
Call->addArg(Inst->getSrc(0));
lowerCall(Call);
return;
} else {
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
// t1.i32 = cvt Src0RM; t2.dest_type = t1; Dest = t2.dest_type
Variable *T_1 = makeReg(IceType_i32);
Variable *T_2 = makeReg(Dest->getType());
_cvt(T_1, Src0RM, Traits::Insts::Cvt::Tss2si);
_mov(T_2, T_1); // T_1 and T_2 may have different integer types
if (Dest->getType() == IceType_i1)
_and(T_2, Ctx->getConstantInt1(1));
_mov(Dest, T_2);
}
break;
case InstCast::Sitofp:
if (isVectorType(Dest->getType())) {
assert(Dest->getType() == IceType_v4f32 &&
Inst->getSrc(0)->getType() == IceType_v4i32);
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
if (llvm::isa<typename Traits::X86OperandMem>(Src0RM))
Src0RM = legalizeToReg(Src0RM);
Variable *T = makeReg(Dest->getType());
_cvt(T, Src0RM, Traits::Insts::Cvt::Dq2ps);
_movp(Dest, T);
} else if (Inst->getSrc(0)->getType() == IceType_i64) {
// Use a helper for x86-32.
const SizeT MaxSrcs = 1;
Type DestType = Dest->getType();
InstCall *Call =
makeHelperCall(isFloat32Asserting32Or64(DestType) ? H_sitofp_i64_f32
: H_sitofp_i64_f64,
Dest, MaxSrcs);
// TODO: Call the correct compiler-rt helper function.
Call->addArg(Inst->getSrc(0));
lowerCall(Call);
return;
} else {
Operand *Src0RM = legalize(Inst->getSrc(0), Legal_Reg | Legal_Mem);
// Sign-extend the operand.
// t1.i32 = movsx Src0RM; t2 = Cvt t1.i32; Dest = t2
Variable *T_1 = makeReg(IceType_i32);
Variable *T_2 = makeReg(Dest->getType());
if (Src0RM->getType() == IceType_i32)
_mov(T_1, Src0RM);
else
_movsx(T_1, Src0RM);
_cvt(T_2, T_1, Traits::Insts::Cvt::Si2ss);
_mov(Dest, T_2);
}
break;
case InstCast::Uitofp: {
Operand *Src0 = Inst->getSrc(0);
if (isVectorType(Src0->getType())) {
assert(Dest->getType() == IceType_v4f32 &&
Src0->getType() == IceType_v4i32);
const SizeT MaxSrcs = 1;
InstCall *Call = makeHelperCall(H_uitofp_4xi32_4xf32, Dest, MaxSrcs);
Call->addArg(Src0);
lowerCall(Call);
} else if (Src0->getType() == IceType_i64 ||
Src0->getType() == IceType_i32) {
// Use a helper for x86-32 and x86-64. Also use a helper for
// i32 on x86-32.
const SizeT MaxSrcs = 1;
Type DestType = Dest->getType();
IceString TargetString;
if (isInt32Asserting32Or64(Src0->getType())) {
TargetString = isFloat32Asserting32Or64(DestType) ? H_uitofp_i32_f32
: H_uitofp_i32_f64;
} else {
TargetString = isFloat32Asserting32Or64(DestType) ? H_uitofp_i64_f32
: H_uitofp_i64_f64;
}
InstCall *Call = makeHelperCall(TargetString, Dest, MaxSrcs);
Call->addArg(Src0);
lowerCall(Call);
return;
} else {
Operand *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
// Zero-extend the operand.
// t1.i32 = movzx Src0RM; t2 = Cvt t1.i32; Dest = t2
Variable *T_1 = makeReg(IceType_i32);
Variable *T_2 = makeReg(Dest->getType());
if (Src0RM->getType() == IceType_i32)
_mov(T_1, Src0RM);
else
_movzx(T_1, Src0RM);
_cvt(T_2, T_1, Traits::Insts::Cvt::Si2ss);
_mov(Dest, T_2);
}
break;
}
case InstCast::Bitcast: {
Operand *Src0 = Inst->getSrc(0);
if (Dest->getType() == Src0->getType()) {
InstAssign *Assign = InstAssign::create(Func, Dest, Src0);
lowerAssign(Assign);
return;
}
switch (Dest->getType()) {
default:
llvm_unreachable("Unexpected Bitcast dest type");
case IceType_i8: {
assert(Src0->getType() == IceType_v8i1);
InstCall *Call = makeHelperCall(H_bitcast_8xi1_i8, Dest, 1);
Call->addArg(Src0);
lowerCall(Call);
} break;
case IceType_i16: {
assert(Src0->getType() == IceType_v16i1);
InstCall *Call = makeHelperCall(H_bitcast_16xi1_i16, Dest, 1);
Call->addArg(Src0);
lowerCall(Call);
} break;
case IceType_i32:
case IceType_f32: {
Operand *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
Type DestType = Dest->getType();
Type SrcType = Src0RM->getType();
(void)DestType;
assert((DestType == IceType_i32 && SrcType == IceType_f32) ||
(DestType == IceType_f32 && SrcType == IceType_i32));
// a.i32 = bitcast b.f32 ==>
// t.f32 = b.f32
// s.f32 = spill t.f32
// a.i32 = s.f32
Variable *T = nullptr;
// TODO: Should be able to force a spill setup by calling legalize() with
// Legal_Mem and not Legal_Reg or Legal_Imm.
typename Traits::SpillVariable *SpillVar =
Func->makeVariable<typename Traits::SpillVariable>(SrcType);
SpillVar->setLinkedTo(Dest);
Variable *Spill = SpillVar;
Spill->setWeight(RegWeight::Zero);
_mov(T, Src0RM);
_mov(Spill, T);
_mov(Dest, Spill);
} break;
case IceType_i64: {
Operand *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
assert(Src0RM->getType() == IceType_f64);
// a.i64 = bitcast b.f64 ==>
// s.f64 = spill b.f64
// t_lo.i32 = lo(s.f64)
// a_lo.i32 = t_lo.i32
// t_hi.i32 = hi(s.f64)
// a_hi.i32 = t_hi.i32
Operand *SpillLo, *SpillHi;
if (auto *Src0Var = llvm::dyn_cast<Variable>(Src0RM)) {
typename Traits::SpillVariable *SpillVar =
Func->makeVariable<typename Traits::SpillVariable>(IceType_f64);
SpillVar->setLinkedTo(Src0Var);
Variable *Spill = SpillVar;
Spill->setWeight(RegWeight::Zero);
_movq(Spill, Src0RM);
SpillLo = Traits::VariableSplit::create(Func, Spill,
Traits::VariableSplit::Low);
SpillHi = Traits::VariableSplit::create(Func, Spill,
Traits::VariableSplit::High);
} else {
SpillLo = loOperand(Src0RM);
SpillHi = hiOperand(Src0RM);
}
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *T_Lo = makeReg(IceType_i32);
Variable *T_Hi = makeReg(IceType_i32);
_mov(T_Lo, SpillLo);
_mov(DestLo, T_Lo);
_mov(T_Hi, SpillHi);
_mov(DestHi, T_Hi);
} break;
case IceType_f64: {
Src0 = legalize(Src0);
assert(Src0->getType() == IceType_i64);
if (llvm::isa<typename Traits::X86OperandMem>(Src0)) {
Variable *T = Func->makeVariable(Dest->getType());
_movq(T, Src0);
_movq(Dest, T);
break;
}
// a.f64 = bitcast b.i64 ==>
// t_lo.i32 = b_lo.i32
// FakeDef(s.f64)
// lo(s.f64) = t_lo.i32
// t_hi.i32 = b_hi.i32
// hi(s.f64) = t_hi.i32
// a.f64 = s.f64
typename Traits::SpillVariable *SpillVar =
Func->makeVariable<typename Traits::SpillVariable>(IceType_f64);
SpillVar->setLinkedTo(Dest);
Variable *Spill = SpillVar;
Spill->setWeight(RegWeight::Zero);
Variable *T_Lo = nullptr, *T_Hi = nullptr;
typename Traits::VariableSplit *SpillLo = Traits::VariableSplit::create(
Func, Spill, Traits::VariableSplit::Low);
typename Traits::VariableSplit *SpillHi = Traits::VariableSplit::create(
Func, Spill, Traits::VariableSplit::High);
_mov(T_Lo, loOperand(Src0));
// Technically, the Spill is defined after the _store happens, but
// SpillLo is considered a "use" of Spill so define Spill before it
// is used.
Context.insert(InstFakeDef::create(Func, Spill));
_store(T_Lo, SpillLo);
_mov(T_Hi, hiOperand(Src0));
_store(T_Hi, SpillHi);
_movq(Dest, Spill);
} break;
case IceType_v8i1: {
assert(Src0->getType() == IceType_i8);
InstCall *Call = makeHelperCall(H_bitcast_i8_8xi1, Dest, 1);
Variable *Src0AsI32 = Func->makeVariable(stackSlotType());
// Arguments to functions are required to be at least 32 bits wide.
lowerCast(InstCast::create(Func, InstCast::Zext, Src0AsI32, Src0));
Call->addArg(Src0AsI32);
lowerCall(Call);
} break;
case IceType_v16i1: {
assert(Src0->getType() == IceType_i16);
InstCall *Call = makeHelperCall(H_bitcast_i16_16xi1, Dest, 1);
Variable *Src0AsI32 = Func->makeVariable(stackSlotType());
// Arguments to functions are required to be at least 32 bits wide.
lowerCast(InstCast::create(Func, InstCast::Zext, Src0AsI32, Src0));
Call->addArg(Src0AsI32);
lowerCall(Call);
} break;
case IceType_v8i16:
case IceType_v16i8:
case IceType_v4i32:
case IceType_v4f32: {
_movp(Dest, legalizeToReg(Src0));
} break;
}
break;
}
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerExtractElement(
const InstExtractElement *Inst) {
Operand *SourceVectNotLegalized = Inst->getSrc(0);
ConstantInteger32 *ElementIndex =
llvm::dyn_cast<ConstantInteger32>(Inst->getSrc(1));
// Only constant indices are allowed in PNaCl IR.
assert(ElementIndex);
unsigned Index = ElementIndex->getValue();
Type Ty = SourceVectNotLegalized->getType();
Type ElementTy = typeElementType(Ty);
Type InVectorElementTy = Traits::getInVectorElementType(Ty);
Variable *ExtractedElementR = makeReg(InVectorElementTy);
// TODO(wala): Determine the best lowering sequences for each type.
bool CanUsePextr = Ty == IceType_v8i16 || Ty == IceType_v8i1 ||
InstructionSet >= Traits::SSE4_1;
if (CanUsePextr && Ty != IceType_v4f32) {
// Use pextrb, pextrw, or pextrd.
Constant *Mask = Ctx->getConstantInt32(Index);
Variable *SourceVectR = legalizeToReg(SourceVectNotLegalized);
_pextr(ExtractedElementR, SourceVectR, Mask);
} else if (Ty == IceType_v4i32 || Ty == IceType_v4f32 || Ty == IceType_v4i1) {
// Use pshufd and movd/movss.
Variable *T = nullptr;
if (Index) {
// The shuffle only needs to occur if the element to be extracted
// is not at the lowest index.
Constant *Mask = Ctx->getConstantInt32(Index);
T = makeReg(Ty);
_pshufd(T, legalize(SourceVectNotLegalized, Legal_Reg | Legal_Mem), Mask);
} else {
T = legalizeToReg(SourceVectNotLegalized);
}
if (InVectorElementTy == IceType_i32) {
_movd(ExtractedElementR, T);
} else { // Ty == IceType_f32
// TODO(wala): _movss is only used here because _mov does not
// allow a vector source and a scalar destination. _mov should be
// able to be used here.
// _movss is a binary instruction, so the FakeDef is needed to
// keep the live range analysis consistent.
Context.insert(InstFakeDef::create(Func, ExtractedElementR));
_movss(ExtractedElementR, T);
}
} else {
assert(Ty == IceType_v16i8 || Ty == IceType_v16i1);
// Spill the value to a stack slot and do the extraction in memory.
//
// TODO(wala): use legalize(SourceVectNotLegalized, Legal_Mem) when
// support for legalizing to mem is implemented.
Variable *Slot = Func->makeVariable(Ty);
Slot->setWeight(RegWeight::Zero);
_movp(Slot, legalizeToReg(SourceVectNotLegalized));
// Compute the location of the element in memory.
unsigned Offset = Index * typeWidthInBytes(InVectorElementTy);
typename Traits::X86OperandMem *Loc =
getMemoryOperandForStackSlot(InVectorElementTy, Slot, Offset);
_mov(ExtractedElementR, Loc);
}
if (ElementTy == IceType_i1) {
// Truncate extracted integers to i1s if necessary.
Variable *T = makeReg(IceType_i1);
InstCast *Cast =
InstCast::create(Func, InstCast::Trunc, T, ExtractedElementR);
lowerCast(Cast);
ExtractedElementR = T;
}
// Copy the element to the destination.
Variable *Dest = Inst->getDest();
_mov(Dest, ExtractedElementR);
}
template <class Machine>
void TargetX86Base<Machine>::lowerFcmp(const InstFcmp *Inst) {
Operand *Src0 = Inst->getSrc(0);
Operand *Src1 = Inst->getSrc(1);
Variable *Dest = Inst->getDest();
if (isVectorType(Dest->getType())) {
InstFcmp::FCond Condition = Inst->getCondition();
size_t Index = static_cast<size_t>(Condition);
assert(Index < Traits::TableFcmpSize);
if (Traits::TableFcmp[Index].SwapVectorOperands) {
Operand *T = Src0;
Src0 = Src1;
Src1 = T;
}
Variable *T = nullptr;
if (Condition == InstFcmp::True) {
// makeVectorOfOnes() requires an integer vector type.
T = makeVectorOfMinusOnes(IceType_v4i32);
} else if (Condition == InstFcmp::False) {
T = makeVectorOfZeros(Dest->getType());
} else {
Operand *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
Operand *Src1RM = legalize(Src1, Legal_Reg | Legal_Mem);
if (llvm::isa<typename Traits::X86OperandMem>(Src1RM))
Src1RM = legalizeToReg(Src1RM);
switch (Condition) {
default: {
typename Traits::Cond::CmppsCond Predicate =
Traits::TableFcmp[Index].Predicate;
assert(Predicate != Traits::Cond::Cmpps_Invalid);
T = makeReg(Src0RM->getType());
_movp(T, Src0RM);
_cmpps(T, Src1RM, Predicate);
} break;
case InstFcmp::One: {
// Check both unequal and ordered.
T = makeReg(Src0RM->getType());
Variable *T2 = makeReg(Src0RM->getType());
_movp(T, Src0RM);
_cmpps(T, Src1RM, Traits::Cond::Cmpps_neq);
_movp(T2, Src0RM);
_cmpps(T2, Src1RM, Traits::Cond::Cmpps_ord);
_pand(T, T2);
} break;
case InstFcmp::Ueq: {
// Check both equal or unordered.
T = makeReg(Src0RM->getType());
Variable *T2 = makeReg(Src0RM->getType());
_movp(T, Src0RM);
_cmpps(T, Src1RM, Traits::Cond::Cmpps_eq);
_movp(T2, Src0RM);
_cmpps(T2, Src1RM, Traits::Cond::Cmpps_unord);
_por(T, T2);
} break;
}
}
_movp(Dest, T);
eliminateNextVectorSextInstruction(Dest);
return;
}
// Lowering a = fcmp cond, b, c
// ucomiss b, c /* only if C1 != Br_None */
// /* but swap b,c order if SwapOperands==true */
// mov a, <default>
// j<C1> label /* only if C1 != Br_None */
// j<C2> label /* only if C2 != Br_None */
// FakeUse(a) /* only if C1 != Br_None */
// mov a, !<default> /* only if C1 != Br_None */
// label: /* only if C1 != Br_None */
//
// setcc lowering when C1 != Br_None && C2 == Br_None:
// ucomiss b, c /* but swap b,c order if SwapOperands==true */
// setcc a, C1
InstFcmp::FCond Condition = Inst->getCondition();
size_t Index = static_cast<size_t>(Condition);
assert(Index < Traits::TableFcmpSize);
if (Traits::TableFcmp[Index].SwapScalarOperands)
std::swap(Src0, Src1);
bool HasC1 = (Traits::TableFcmp[Index].C1 != Traits::Cond::Br_None);
bool HasC2 = (Traits::TableFcmp[Index].C2 != Traits::Cond::Br_None);
if (HasC1) {
Src0 = legalize(Src0);
Operand *Src1RM = legalize(Src1, Legal_Reg | Legal_Mem);
Variable *T = nullptr;
_mov(T, Src0);
_ucomiss(T, Src1RM);
if (!HasC2) {
assert(Traits::TableFcmp[Index].Default);
_setcc(Dest, Traits::TableFcmp[Index].C1);
return;
}
}
Constant *Default = Ctx->getConstantInt32(Traits::TableFcmp[Index].Default);
_mov(Dest, Default);
if (HasC1) {
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
_br(Traits::TableFcmp[Index].C1, Label);
if (HasC2) {
_br(Traits::TableFcmp[Index].C2, Label);
}
Constant *NonDefault =
Ctx->getConstantInt32(!Traits::TableFcmp[Index].Default);
_mov_nonkillable(Dest, NonDefault);
Context.insert(Label);
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerIcmp(const InstIcmp *Inst) {
Operand *Src0 = legalize(Inst->getSrc(0));
Operand *Src1 = legalize(Inst->getSrc(1));
Variable *Dest = Inst->getDest();
if (isVectorType(Dest->getType())) {
Type Ty = Src0->getType();
// Promote i1 vectors to 128 bit integer vector types.
if (typeElementType(Ty) == IceType_i1) {
Type NewTy = IceType_NUM;
switch (Ty) {
default:
llvm_unreachable("unexpected type");
break;
case IceType_v4i1:
NewTy = IceType_v4i32;
break;
case IceType_v8i1:
NewTy = IceType_v8i16;
break;
case IceType_v16i1:
NewTy = IceType_v16i8;
break;
}
Variable *NewSrc0 = Func->makeVariable(NewTy);
Variable *NewSrc1 = Func->makeVariable(NewTy);
lowerCast(InstCast::create(Func, InstCast::Sext, NewSrc0, Src0));
lowerCast(InstCast::create(Func, InstCast::Sext, NewSrc1, Src1));
Src0 = NewSrc0;
Src1 = NewSrc1;
Ty = NewTy;
}
InstIcmp::ICond Condition = Inst->getCondition();
Operand *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
Operand *Src1RM = legalize(Src1, Legal_Reg | Legal_Mem);
// SSE2 only has signed comparison operations. Transform unsigned
// inputs in a manner that allows for the use of signed comparison
// operations by flipping the high order bits.
if (Condition == InstIcmp::Ugt || Condition == InstIcmp::Uge ||
Condition == InstIcmp::Ult || Condition == InstIcmp::Ule) {
Variable *T0 = makeReg(Ty);
Variable *T1 = makeReg(Ty);
Variable *HighOrderBits = makeVectorOfHighOrderBits(Ty);
_movp(T0, Src0RM);
_pxor(T0, HighOrderBits);
_movp(T1, Src1RM);
_pxor(T1, HighOrderBits);
Src0RM = T0;
Src1RM = T1;
}
Variable *T = makeReg(Ty);
switch (Condition) {
default:
llvm_unreachable("unexpected condition");
break;
case InstIcmp::Eq: {
if (llvm::isa<typename Traits::X86OperandMem>(Src1RM))
Src1RM = legalizeToReg(Src1RM);
_movp(T, Src0RM);
_pcmpeq(T, Src1RM);
} break;
case InstIcmp::Ne: {
if (llvm::isa<typename Traits::X86OperandMem>(Src1RM))
Src1RM = legalizeToReg(Src1RM);
_movp(T, Src0RM);
_pcmpeq(T, Src1RM);
Variable *MinusOne = makeVectorOfMinusOnes(Ty);
_pxor(T, MinusOne);
} break;
case InstIcmp::Ugt:
case InstIcmp::Sgt: {
if (llvm::isa<typename Traits::X86OperandMem>(Src1RM))
Src1RM = legalizeToReg(Src1RM);
_movp(T, Src0RM);
_pcmpgt(T, Src1RM);
} break;
case InstIcmp::Uge:
case InstIcmp::Sge: {
// !(Src1RM > Src0RM)
if (llvm::isa<typename Traits::X86OperandMem>(Src0RM))
Src0RM = legalizeToReg(Src0RM);
_movp(T, Src1RM);
_pcmpgt(T, Src0RM);
Variable *MinusOne = makeVectorOfMinusOnes(Ty);
_pxor(T, MinusOne);
} break;
case InstIcmp::Ult:
case InstIcmp::Slt: {
if (llvm::isa<typename Traits::X86OperandMem>(Src0RM))
Src0RM = legalizeToReg(Src0RM);
_movp(T, Src1RM);
_pcmpgt(T, Src0RM);
} break;
case InstIcmp::Ule:
case InstIcmp::Sle: {
// !(Src0RM > Src1RM)
if (llvm::isa<typename Traits::X86OperandMem>(Src1RM))
Src1RM = legalizeToReg(Src1RM);
_movp(T, Src0RM);
_pcmpgt(T, Src1RM);
Variable *MinusOne = makeVectorOfMinusOnes(Ty);
_pxor(T, MinusOne);
} break;
}
_movp(Dest, T);
eliminateNextVectorSextInstruction(Dest);
return;
}
// a=icmp cond, b, c ==> cmp b,c; a=1; br cond,L1; FakeUse(a); a=0; L1:
if (Src0->getType() == IceType_i64) {
InstIcmp::ICond Condition = Inst->getCondition();
size_t Index = static_cast<size_t>(Condition);
assert(Index < Traits::TableIcmp64Size);
Operand *Src0LoRM = legalize(loOperand(Src0), Legal_Reg | Legal_Mem);
Operand *Src0HiRM = legalize(hiOperand(Src0), Legal_Reg | Legal_Mem);
Operand *Src1LoRI = legalize(loOperand(Src1), Legal_Reg | Legal_Imm);
Operand *Src1HiRI = legalize(hiOperand(Src1), Legal_Reg | Legal_Imm);
Constant *Zero = Ctx->getConstantZero(IceType_i32);
Constant *One = Ctx->getConstantInt32(1);
typename Traits::Insts::Label *LabelFalse =
Traits::Insts::Label::create(Func, this);
typename Traits::Insts::Label *LabelTrue =
Traits::Insts::Label::create(Func, this);
_mov(Dest, One);
_cmp(Src0HiRM, Src1HiRI);
if (Traits::TableIcmp64[Index].C1 != Traits::Cond::Br_None)
_br(Traits::TableIcmp64[Index].C1, LabelTrue);
if (Traits::TableIcmp64[Index].C2 != Traits::Cond::Br_None)
_br(Traits::TableIcmp64[Index].C2, LabelFalse);
_cmp(Src0LoRM, Src1LoRI);
_br(Traits::TableIcmp64[Index].C3, LabelTrue);
Context.insert(LabelFalse);
_mov_nonkillable(Dest, Zero);
Context.insert(LabelTrue);
return;
}
// cmp b, c
Operand *Src0RM = legalizeSrc0ForCmp(Src0, Src1);
_cmp(Src0RM, Src1);
_setcc(Dest, Traits::getIcmp32Mapping(Inst->getCondition()));
}
template <class Machine>
void TargetX86Base<Machine>::lowerInsertElement(const InstInsertElement *Inst) {
Operand *SourceVectNotLegalized = Inst->getSrc(0);
Operand *ElementToInsertNotLegalized = Inst->getSrc(1);
ConstantInteger32 *ElementIndex =
llvm::dyn_cast<ConstantInteger32>(Inst->getSrc(2));
// Only constant indices are allowed in PNaCl IR.
assert(ElementIndex);
unsigned Index = ElementIndex->getValue();
assert(Index < typeNumElements(SourceVectNotLegalized->getType()));
Type Ty = SourceVectNotLegalized->getType();
Type ElementTy = typeElementType(Ty);
Type InVectorElementTy = Traits::getInVectorElementType(Ty);
if (ElementTy == IceType_i1) {
// Expand the element to the appropriate size for it to be inserted
// in the vector.
Variable *Expanded = Func->makeVariable(InVectorElementTy);
InstCast *Cast = InstCast::create(Func, InstCast::Zext, Expanded,
ElementToInsertNotLegalized);
lowerCast(Cast);
ElementToInsertNotLegalized = Expanded;
}
if (Ty == IceType_v8i16 || Ty == IceType_v8i1 ||
InstructionSet >= Traits::SSE4_1) {
// Use insertps, pinsrb, pinsrw, or pinsrd.
Operand *ElementRM =
legalize(ElementToInsertNotLegalized, Legal_Reg | Legal_Mem);
Operand *SourceVectRM =
legalize(SourceVectNotLegalized, Legal_Reg | Legal_Mem);
Variable *T = makeReg(Ty);
_movp(T, SourceVectRM);
if (Ty == IceType_v4f32)
_insertps(T, ElementRM, Ctx->getConstantInt32(Index << 4));
else
_pinsr(T, ElementRM, Ctx->getConstantInt32(Index));
_movp(Inst->getDest(), T);
} else if (Ty == IceType_v4i32 || Ty == IceType_v4f32 || Ty == IceType_v4i1) {
// Use shufps or movss.
Variable *ElementR = nullptr;
Operand *SourceVectRM =
legalize(SourceVectNotLegalized, Legal_Reg | Legal_Mem);
if (InVectorElementTy == IceType_f32) {
// ElementR will be in an XMM register since it is floating point.
ElementR = legalizeToReg(ElementToInsertNotLegalized);
} else {
// Copy an integer to an XMM register.
Operand *T = legalize(ElementToInsertNotLegalized, Legal_Reg | Legal_Mem);
ElementR = makeReg(Ty);
_movd(ElementR, T);
}
if (Index == 0) {
Variable *T = makeReg(Ty);
_movp(T, SourceVectRM);
_movss(T, ElementR);
_movp(Inst->getDest(), T);
return;
}
// shufps treats the source and desination operands as vectors of
// four doublewords. The destination's two high doublewords are
// selected from the source operand and the two low doublewords are
// selected from the (original value of) the destination operand.
// An insertelement operation can be effected with a sequence of two
// shufps operations with appropriate masks. In all cases below,
// Element[0] is being inserted into SourceVectOperand. Indices are
// ordered from left to right.
//
// insertelement into index 1 (result is stored in ElementR):
// ElementR := ElementR[0, 0] SourceVectRM[0, 0]
// ElementR := ElementR[3, 0] SourceVectRM[2, 3]
//
// insertelement into index 2 (result is stored in T):
// T := SourceVectRM
// ElementR := ElementR[0, 0] T[0, 3]
// T := T[0, 1] ElementR[0, 3]
//
// insertelement into index 3 (result is stored in T):
// T := SourceVectRM
// ElementR := ElementR[0, 0] T[0, 2]
// T := T[0, 1] ElementR[3, 0]
const unsigned char Mask1[3] = {0, 192, 128};
const unsigned char Mask2[3] = {227, 196, 52};
Constant *Mask1Constant = Ctx->getConstantInt32(Mask1[Index - 1]);
Constant *Mask2Constant = Ctx->getConstantInt32(Mask2[Index - 1]);
if (Index == 1) {
_shufps(ElementR, SourceVectRM, Mask1Constant);
_shufps(ElementR, SourceVectRM, Mask2Constant);
_movp(Inst->getDest(), ElementR);
} else {
Variable *T = makeReg(Ty);
_movp(T, SourceVectRM);
_shufps(ElementR, T, Mask1Constant);
_shufps(T, ElementR, Mask2Constant);
_movp(Inst->getDest(), T);
}
} else {
assert(Ty == IceType_v16i8 || Ty == IceType_v16i1);
// Spill the value to a stack slot and perform the insertion in
// memory.
//
// TODO(wala): use legalize(SourceVectNotLegalized, Legal_Mem) when
// support for legalizing to mem is implemented.
Variable *Slot = Func->makeVariable(Ty);
Slot->setWeight(RegWeight::Zero);
_movp(Slot, legalizeToReg(SourceVectNotLegalized));
// Compute the location of the position to insert in memory.
unsigned Offset = Index * typeWidthInBytes(InVectorElementTy);
typename Traits::X86OperandMem *Loc =
getMemoryOperandForStackSlot(InVectorElementTy, Slot, Offset);
_store(legalizeToReg(ElementToInsertNotLegalized), Loc);
Variable *T = makeReg(Ty);
_movp(T, Slot);
_movp(Inst->getDest(), T);
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerIntrinsicCall(
const InstIntrinsicCall *Instr) {
switch (Intrinsics::IntrinsicID ID = Instr->getIntrinsicInfo().ID) {
case Intrinsics::AtomicCmpxchg: {
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(3)),
getConstantMemoryOrder(Instr->getArg(4)))) {
Func->setError("Unexpected memory ordering for AtomicCmpxchg");
return;
}
Variable *DestPrev = Instr->getDest();
Operand *PtrToMem = legalize(Instr->getArg(0));
Operand *Expected = legalize(Instr->getArg(1));
Operand *Desired = legalize(Instr->getArg(2));
if (tryOptimizedCmpxchgCmpBr(DestPrev, PtrToMem, Expected, Desired))
return;
lowerAtomicCmpxchg(DestPrev, PtrToMem, Expected, Desired);
return;
}
case Intrinsics::AtomicFence:
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(0)))) {
Func->setError("Unexpected memory ordering for AtomicFence");
return;
}
_mfence();
return;
case Intrinsics::AtomicFenceAll:
// NOTE: FenceAll should prevent and load/store from being moved
// across the fence (both atomic and non-atomic). The InstX8632Mfence
// instruction is currently marked coarsely as "HasSideEffects".
_mfence();
return;
case Intrinsics::AtomicIsLockFree: {
// X86 is always lock free for 8/16/32/64 bit accesses.
// TODO(jvoung): Since the result is constant when given a constant
// byte size, this opens up DCE opportunities.
Operand *ByteSize = Instr->getArg(0);
Variable *Dest = Instr->getDest();
if (ConstantInteger32 *CI = llvm::dyn_cast<ConstantInteger32>(ByteSize)) {
Constant *Result;
switch (CI->getValue()) {
default:
// Some x86-64 processors support the cmpxchg16b intruction, which
// can make 16-byte operations lock free (when used with the LOCK
// prefix). However, that's not supported in 32-bit mode, so just
// return 0 even for large sizes.
Result = Ctx->getConstantZero(IceType_i32);
break;
case 1:
case 2:
case 4:
case 8:
Result = Ctx->getConstantInt32(1);
break;
}
_mov(Dest, Result);
return;
}
// The PNaCl ABI requires the byte size to be a compile-time constant.
Func->setError("AtomicIsLockFree byte size should be compile-time const");
return;
}
case Intrinsics::AtomicLoad: {
// We require the memory address to be naturally aligned.
// Given that is the case, then normal loads are atomic.
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(1)))) {
Func->setError("Unexpected memory ordering for AtomicLoad");
return;
}
Variable *Dest = Instr->getDest();
if (Dest->getType() == IceType_i64) {
// Follow what GCC does and use a movq instead of what lowerLoad()
// normally does (split the load into two).
// Thus, this skips load/arithmetic op folding. Load/arithmetic folding
// can't happen anyway, since this is x86-32 and integer arithmetic only
// happens on 32-bit quantities.
Variable *T = makeReg(IceType_f64);
typename Traits::X86OperandMem *Addr =
formMemoryOperand(Instr->getArg(0), IceType_f64);
_movq(T, Addr);
// Then cast the bits back out of the XMM register to the i64 Dest.
InstCast *Cast = InstCast::create(Func, InstCast::Bitcast, Dest, T);
lowerCast(Cast);
// Make sure that the atomic load isn't elided when unused.
Context.insert(InstFakeUse::create(Func, Dest->getLo()));
Context.insert(InstFakeUse::create(Func, Dest->getHi()));
return;
}
InstLoad *Load = InstLoad::create(Func, Dest, Instr->getArg(0));
lowerLoad(Load);
// Make sure the atomic load isn't elided when unused, by adding a FakeUse.
// Since lowerLoad may fuse the load w/ an arithmetic instruction,
// insert the FakeUse on the last-inserted instruction's dest.
Context.insert(
InstFakeUse::create(Func, Context.getLastInserted()->getDest()));
return;
}
case Intrinsics::AtomicRMW:
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(3)))) {
Func->setError("Unexpected memory ordering for AtomicRMW");
return;
}
lowerAtomicRMW(
Instr->getDest(),
static_cast<uint32_t>(
llvm::cast<ConstantInteger32>(Instr->getArg(0))->getValue()),
Instr->getArg(1), Instr->getArg(2));
return;
case Intrinsics::AtomicStore: {
if (!Intrinsics::isMemoryOrderValid(
ID, getConstantMemoryOrder(Instr->getArg(2)))) {
Func->setError("Unexpected memory ordering for AtomicStore");
return;
}
// We require the memory address to be naturally aligned.
// Given that is the case, then normal stores are atomic.
// Add a fence after the store to make it visible.
Operand *Value = Instr->getArg(0);
Operand *Ptr = Instr->getArg(1);
if (Value->getType() == IceType_i64) {
// Use a movq instead of what lowerStore() normally does
// (split the store into two), following what GCC does.
// Cast the bits from int -> to an xmm register first.
Variable *T = makeReg(IceType_f64);
InstCast *Cast = InstCast::create(Func, InstCast::Bitcast, T, Value);
lowerCast(Cast);
// Then store XMM w/ a movq.
typename Traits::X86OperandMem *Addr =
formMemoryOperand(Ptr, IceType_f64);
_storeq(T, Addr);
_mfence();
return;
}
InstStore *Store = InstStore::create(Func, Value, Ptr);
lowerStore(Store);
_mfence();
return;
}
case Intrinsics::Bswap: {
Variable *Dest = Instr->getDest();
Operand *Val = Instr->getArg(0);
// In 32-bit mode, bswap only works on 32-bit arguments, and the
// argument must be a register. Use rotate left for 16-bit bswap.
if (Val->getType() == IceType_i64) {
Val = legalizeUndef(Val);
Variable *T_Lo = legalizeToReg(loOperand(Val));
Variable *T_Hi = legalizeToReg(hiOperand(Val));
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
_bswap(T_Lo);
_bswap(T_Hi);
_mov(DestLo, T_Hi);
_mov(DestHi, T_Lo);
} else if (Val->getType() == IceType_i32) {
Variable *T = legalizeToReg(Val);
_bswap(T);
_mov(Dest, T);
} else {
assert(Val->getType() == IceType_i16);
Constant *Eight = Ctx->getConstantInt16(8);
Variable *T = nullptr;
Val = legalize(Val);
_mov(T, Val);
_rol(T, Eight);
_mov(Dest, T);
}
return;
}
case Intrinsics::Ctpop: {
Variable *Dest = Instr->getDest();
Operand *Val = Instr->getArg(0);
InstCall *Call = makeHelperCall(isInt32Asserting32Or64(Val->getType())
? H_call_ctpop_i32
: H_call_ctpop_i64,
Dest, 1);
Call->addArg(Val);
lowerCall(Call);
// The popcount helpers always return 32-bit values, while the intrinsic's
// signature matches the native POPCNT instruction and fills a 64-bit reg
// (in 64-bit mode). Thus, clear the upper bits of the dest just in case
// the user doesn't do that in the IR. If the user does that in the IR,
// then this zero'ing instruction is dead and gets optimized out.
if (Val->getType() == IceType_i64) {
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Constant *Zero = Ctx->getConstantZero(IceType_i32);
_mov(DestHi, Zero);
}
return;
}
case Intrinsics::Ctlz: {
// The "is zero undef" parameter is ignored and we always return
// a well-defined value.
Operand *Val = legalize(Instr->getArg(0));
Operand *FirstVal;
Operand *SecondVal = nullptr;
if (Val->getType() == IceType_i64) {
FirstVal = loOperand(Val);
SecondVal = hiOperand(Val);
} else {
FirstVal = Val;
}
const bool IsCttz = false;
lowerCountZeros(IsCttz, Val->getType(), Instr->getDest(), FirstVal,
SecondVal);
return;
}
case Intrinsics::Cttz: {
// The "is zero undef" parameter is ignored and we always return
// a well-defined value.
Operand *Val = legalize(Instr->getArg(0));
Operand *FirstVal;
Operand *SecondVal = nullptr;
if (Val->getType() == IceType_i64) {
FirstVal = hiOperand(Val);
SecondVal = loOperand(Val);
} else {
FirstVal = Val;
}
const bool IsCttz = true;
lowerCountZeros(IsCttz, Val->getType(), Instr->getDest(), FirstVal,
SecondVal);
return;
}
case Intrinsics::Fabs: {
Operand *Src = legalize(Instr->getArg(0));
Type Ty = Src->getType();
Variable *Dest = Instr->getDest();
Variable *T = makeVectorOfFabsMask(Ty);
// The pand instruction operates on an m128 memory operand, so if
// Src is an f32 or f64, we need to make sure it's in a register.
if (isVectorType(Ty)) {
if (llvm::isa<typename Traits::X86OperandMem>(Src))
Src = legalizeToReg(Src);
} else {
Src = legalizeToReg(Src);
}
_pand(T, Src);
if (isVectorType(Ty))
_movp(Dest, T);
else
_mov(Dest, T);
return;
}
case Intrinsics::Longjmp: {
InstCall *Call = makeHelperCall(H_call_longjmp, nullptr, 2);
Call->addArg(Instr->getArg(0));
Call->addArg(Instr->getArg(1));
lowerCall(Call);
return;
}
case Intrinsics::Memcpy: {
// In the future, we could potentially emit an inline memcpy/memset, etc.
// for intrinsic calls w/ a known length.
InstCall *Call = makeHelperCall(H_call_memcpy, nullptr, 3);
Call->addArg(Instr->getArg(0));
Call->addArg(Instr->getArg(1));
Call->addArg(Instr->getArg(2));
lowerCall(Call);
return;
}
case Intrinsics::Memmove: {
InstCall *Call = makeHelperCall(H_call_memmove, nullptr, 3);
Call->addArg(Instr->getArg(0));
Call->addArg(Instr->getArg(1));
Call->addArg(Instr->getArg(2));
lowerCall(Call);
return;
}
case Intrinsics::Memset: {
lowerMemset(Instr->getArg(0), Instr->getArg(1), Instr->getArg(2));
return;
}
case Intrinsics::NaClReadTP: {
if (Ctx->getFlags().getUseSandboxing()) {
Operand *Src = dispatchToConcrete(&Machine::createNaClReadTPSrcOperand);
Variable *Dest = Instr->getDest();
Variable *T = nullptr;
_mov(T, Src);
_mov(Dest, T);
} else {
InstCall *Call = makeHelperCall(H_call_read_tp, Instr->getDest(), 0);
lowerCall(Call);
}
return;
}
case Intrinsics::Setjmp: {
InstCall *Call = makeHelperCall(H_call_setjmp, Instr->getDest(), 1);
Call->addArg(Instr->getArg(0));
lowerCall(Call);
return;
}
case Intrinsics::Sqrt: {
Operand *Src = legalize(Instr->getArg(0));
Variable *Dest = Instr->getDest();
Variable *T = makeReg(Dest->getType());
_sqrtss(T, Src);
_mov(Dest, T);
return;
}
case Intrinsics::Stacksave: {
Variable *esp =
Func->getTarget()->getPhysicalRegister(Traits::RegisterSet::Reg_esp);
Variable *Dest = Instr->getDest();
_mov(Dest, esp);
return;
}
case Intrinsics::Stackrestore: {
Variable *esp =
Func->getTarget()->getPhysicalRegister(Traits::RegisterSet::Reg_esp);
_mov_nonkillable(esp, Instr->getArg(0));
return;
}
case Intrinsics::Trap:
_ud2();
return;
case Intrinsics::UnknownIntrinsic:
Func->setError("Should not be lowering UnknownIntrinsic");
return;
}
return;
}
template <class Machine>
void TargetX86Base<Machine>::lowerAtomicCmpxchg(Variable *DestPrev,
Operand *Ptr, Operand *Expected,
Operand *Desired) {
if (Expected->getType() == IceType_i64) {
// Reserve the pre-colored registers first, before adding any more
// infinite-weight variables from formMemoryOperand's legalization.
Variable *T_edx = makeReg(IceType_i32, Traits::RegisterSet::Reg_edx);
Variable *T_eax = makeReg(IceType_i32, Traits::RegisterSet::Reg_eax);
Variable *T_ecx = makeReg(IceType_i32, Traits::RegisterSet::Reg_ecx);
Variable *T_ebx = makeReg(IceType_i32, Traits::RegisterSet::Reg_ebx);
_mov(T_eax, loOperand(Expected));
_mov(T_edx, hiOperand(Expected));
_mov(T_ebx, loOperand(Desired));
_mov(T_ecx, hiOperand(Desired));
typename Traits::X86OperandMem *Addr =
formMemoryOperand(Ptr, Expected->getType());
const bool Locked = true;
_cmpxchg8b(Addr, T_edx, T_eax, T_ecx, T_ebx, Locked);
Variable *DestLo = llvm::cast<Variable>(loOperand(DestPrev));
Variable *DestHi = llvm::cast<Variable>(hiOperand(DestPrev));
_mov(DestLo, T_eax);
_mov(DestHi, T_edx);
return;
}
Variable *T_eax = makeReg(Expected->getType(), Traits::RegisterSet::Reg_eax);
_mov(T_eax, Expected);
typename Traits::X86OperandMem *Addr =
formMemoryOperand(Ptr, Expected->getType());
Variable *DesiredReg = legalizeToReg(Desired);
const bool Locked = true;
_cmpxchg(Addr, T_eax, DesiredReg, Locked);
_mov(DestPrev, T_eax);
}
template <class Machine>
bool TargetX86Base<Machine>::tryOptimizedCmpxchgCmpBr(Variable *Dest,
Operand *PtrToMem,
Operand *Expected,
Operand *Desired) {
if (Ctx->getFlags().getOptLevel() == Opt_m1)
return false;
// Peek ahead a few instructions and see how Dest is used.
// It's very common to have:
//
// %x = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* ptr, i32 %expected, ...)
// [%y_phi = ...] // list of phi stores
// %p = icmp eq i32 %x, %expected
// br i1 %p, label %l1, label %l2
//
// which we can optimize into:
//
// %x = <cmpxchg code>
// [%y_phi = ...] // list of phi stores
// br eq, %l1, %l2
InstList::iterator I = Context.getCur();
// I is currently the InstIntrinsicCall. Peek past that.
// This assumes that the atomic cmpxchg has not been lowered yet,
// so that the instructions seen in the scan from "Cur" is simple.
assert(llvm::isa<InstIntrinsicCall>(*I));
Inst *NextInst = Context.getNextInst(I);
if (!NextInst)
return false;
// There might be phi assignments right before the compare+branch, since this
// could be a backward branch for a loop. This placement of assignments is
// determined by placePhiStores().
std::vector<InstAssign *> PhiAssigns;
while (InstAssign *PhiAssign = llvm::dyn_cast<InstAssign>(NextInst)) {
if (PhiAssign->getDest() == Dest)
return false;
PhiAssigns.push_back(PhiAssign);
NextInst = Context.getNextInst(I);
if (!NextInst)
return false;
}
if (InstIcmp *NextCmp = llvm::dyn_cast<InstIcmp>(NextInst)) {
if (!(NextCmp->getCondition() == InstIcmp::Eq &&
((NextCmp->getSrc(0) == Dest && NextCmp->getSrc(1) == Expected) ||
(NextCmp->getSrc(1) == Dest && NextCmp->getSrc(0) == Expected)))) {
return false;
}
NextInst = Context.getNextInst(I);
if (!NextInst)
return false;
if (InstBr *NextBr = llvm::dyn_cast<InstBr>(NextInst)) {
if (!NextBr->isUnconditional() &&
NextCmp->getDest() == NextBr->getCondition() &&
NextBr->isLastUse(NextCmp->getDest())) {
lowerAtomicCmpxchg(Dest, PtrToMem, Expected, Desired);
for (size_t i = 0; i < PhiAssigns.size(); ++i) {
// Lower the phi assignments now, before the branch (same placement
// as before).
InstAssign *PhiAssign = PhiAssigns[i];
PhiAssign->setDeleted();
lowerAssign(PhiAssign);
Context.advanceNext();
}
_br(Traits::Cond::Br_e, NextBr->getTargetTrue(),
NextBr->getTargetFalse());
// Skip over the old compare and branch, by deleting them.
NextCmp->setDeleted();
NextBr->setDeleted();
Context.advanceNext();
Context.advanceNext();
return true;
}
}
}
return false;
}
template <class Machine>
void TargetX86Base<Machine>::lowerAtomicRMW(Variable *Dest, uint32_t Operation,
Operand *Ptr, Operand *Val) {
bool NeedsCmpxchg = false;
LowerBinOp Op_Lo = nullptr;
LowerBinOp Op_Hi = nullptr;
switch (Operation) {
default:
Func->setError("Unknown AtomicRMW operation");
return;
case Intrinsics::AtomicAdd: {
if (Dest->getType() == IceType_i64) {
// All the fall-through paths must set this to true, but use this
// for asserting.
NeedsCmpxchg = true;
Op_Lo = &TargetX86Base<Machine>::_add;
Op_Hi = &TargetX86Base<Machine>::_adc;
break;
}
typename Traits::X86OperandMem *Addr =
formMemoryOperand(Ptr, Dest->getType());
const bool Locked = true;
Variable *T = nullptr;
_mov(T, Val);
_xadd(Addr, T, Locked);
_mov(Dest, T);
return;
}
case Intrinsics::AtomicSub: {
if (Dest->getType() == IceType_i64) {
NeedsCmpxchg = true;
Op_Lo = &TargetX86Base<Machine>::_sub;
Op_Hi = &TargetX86Base<Machine>::_sbb;
break;
}
typename Traits::X86OperandMem *Addr =
formMemoryOperand(Ptr, Dest->getType());
const bool Locked = true;
Variable *T = nullptr;
_mov(T, Val);
_neg(T);
_xadd(Addr, T, Locked);
_mov(Dest, T);
return;
}
case Intrinsics::AtomicOr:
// TODO(jvoung): If Dest is null or dead, then some of these
// operations do not need an "exchange", but just a locked op.
// That appears to be "worth" it for sub, or, and, and xor.
// xadd is probably fine vs lock add for add, and xchg is fine
// vs an atomic store.
NeedsCmpxchg = true;
Op_Lo = &TargetX86Base<Machine>::_or;
Op_Hi = &TargetX86Base<Machine>::_or;
break;
case Intrinsics::AtomicAnd:
NeedsCmpxchg = true;
Op_Lo = &TargetX86Base<Machine>::_and;
Op_Hi = &TargetX86Base<Machine>::_and;
break;
case Intrinsics::AtomicXor:
NeedsCmpxchg = true;
Op_Lo = &TargetX86Base<Machine>::_xor;
Op_Hi = &TargetX86Base<Machine>::_xor;
break;
case Intrinsics::AtomicExchange:
if (Dest->getType() == IceType_i64) {
NeedsCmpxchg = true;
// NeedsCmpxchg, but no real Op_Lo/Op_Hi need to be done. The values
// just need to be moved to the ecx and ebx registers.
Op_Lo = nullptr;
Op_Hi = nullptr;
break;
}
typename Traits::X86OperandMem *Addr =
formMemoryOperand(Ptr, Dest->getType());
Variable *T = nullptr;
_mov(T, Val);
_xchg(Addr, T);
_mov(Dest, T);
return;
}
// Otherwise, we need a cmpxchg loop.
(void)NeedsCmpxchg;
assert(NeedsCmpxchg);
expandAtomicRMWAsCmpxchg(Op_Lo, Op_Hi, Dest, Ptr, Val);
}
template <class Machine>
void TargetX86Base<Machine>::expandAtomicRMWAsCmpxchg(LowerBinOp Op_Lo,
LowerBinOp Op_Hi,
Variable *Dest,
Operand *Ptr,
Operand *Val) {
// Expand a more complex RMW operation as a cmpxchg loop:
// For 64-bit:
// mov eax, [ptr]
// mov edx, [ptr + 4]
// .LABEL:
// mov ebx, eax
// <Op_Lo> ebx, <desired_adj_lo>
// mov ecx, edx
// <Op_Hi> ecx, <desired_adj_hi>
// lock cmpxchg8b [ptr]
// jne .LABEL
// mov <dest_lo>, eax
// mov <dest_lo>, edx
//
// For 32-bit:
// mov eax, [ptr]
// .LABEL:
// mov <reg>, eax
// op <reg>, [desired_adj]
// lock cmpxchg [ptr], <reg>
// jne .LABEL
// mov <dest>, eax
//
// If Op_{Lo,Hi} are nullptr, then just copy the value.
Val = legalize(Val);
Type Ty = Val->getType();
if (Ty == IceType_i64) {
Variable *T_edx = makeReg(IceType_i32, Traits::RegisterSet::Reg_edx);
Variable *T_eax = makeReg(IceType_i32, Traits::RegisterSet::Reg_eax);
typename Traits::X86OperandMem *Addr = formMemoryOperand(Ptr, Ty);
_mov(T_eax, loOperand(Addr));
_mov(T_edx, hiOperand(Addr));
Variable *T_ecx = makeReg(IceType_i32, Traits::RegisterSet::Reg_ecx);
Variable *T_ebx = makeReg(IceType_i32, Traits::RegisterSet::Reg_ebx);
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
const bool IsXchg8b = Op_Lo == nullptr && Op_Hi == nullptr;
if (!IsXchg8b) {
Context.insert(Label);
_mov(T_ebx, T_eax);
(this->*Op_Lo)(T_ebx, loOperand(Val));
_mov(T_ecx, T_edx);
(this->*Op_Hi)(T_ecx, hiOperand(Val));
} else {
// This is for xchg, which doesn't need an actual Op_Lo/Op_Hi.
// It just needs the Val loaded into ebx and ecx.
// That can also be done before the loop.
_mov(T_ebx, loOperand(Val));
_mov(T_ecx, hiOperand(Val));
Context.insert(Label);
}
const bool Locked = true;
_cmpxchg8b(Addr, T_edx, T_eax, T_ecx, T_ebx, Locked);
_br(Traits::Cond::Br_ne, Label);
if (!IsXchg8b) {
// If Val is a variable, model the extended live range of Val through
// the end of the loop, since it will be re-used by the loop.
if (Variable *ValVar = llvm::dyn_cast<Variable>(Val)) {
Variable *ValLo = llvm::cast<Variable>(loOperand(ValVar));
Variable *ValHi = llvm::cast<Variable>(hiOperand(ValVar));
Context.insert(InstFakeUse::create(Func, ValLo));
Context.insert(InstFakeUse::create(Func, ValHi));
}
} else {
// For xchg, the loop is slightly smaller and ebx/ecx are used.
Context.insert(InstFakeUse::create(Func, T_ebx));
Context.insert(InstFakeUse::create(Func, T_ecx));
}
// The address base (if any) is also reused in the loop.
if (Variable *Base = Addr->getBase())
Context.insert(InstFakeUse::create(Func, Base));
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
_mov(DestLo, T_eax);
_mov(DestHi, T_edx);
return;
}
typename Traits::X86OperandMem *Addr = formMemoryOperand(Ptr, Ty);
Variable *T_eax = makeReg(Ty, Traits::RegisterSet::Reg_eax);
_mov(T_eax, Addr);
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
Context.insert(Label);
// We want to pick a different register for T than Eax, so don't use
// _mov(T == nullptr, T_eax).
Variable *T = makeReg(Ty);
_mov(T, T_eax);
(this->*Op_Lo)(T, Val);
const bool Locked = true;
_cmpxchg(Addr, T_eax, T, Locked);
_br(Traits::Cond::Br_ne, Label);
// If Val is a variable, model the extended live range of Val through
// the end of the loop, since it will be re-used by the loop.
if (Variable *ValVar = llvm::dyn_cast<Variable>(Val)) {
Context.insert(InstFakeUse::create(Func, ValVar));
}
// The address base (if any) is also reused in the loop.
if (Variable *Base = Addr->getBase())
Context.insert(InstFakeUse::create(Func, Base));
_mov(Dest, T_eax);
}
/// Lowers count {trailing, leading} zeros intrinsic.
///
/// We could do constant folding here, but that should have
/// been done by the front-end/middle-end optimizations.
template <class Machine>
void TargetX86Base<Machine>::lowerCountZeros(bool Cttz, Type Ty, Variable *Dest,
Operand *FirstVal,
Operand *SecondVal) {
// TODO(jvoung): Determine if the user CPU supports LZCNT (BMI).
// Then the instructions will handle the Val == 0 case much more simply
// and won't require conversion from bit position to number of zeros.
//
// Otherwise:
// bsr IF_NOT_ZERO, Val
// mov T_DEST, 63
// cmovne T_DEST, IF_NOT_ZERO
// xor T_DEST, 31
// mov DEST, T_DEST
//
// NOTE: T_DEST must be a register because cmov requires its dest to be a
// register. Also, bsf and bsr require their dest to be a register.
//
// The xor DEST, 31 converts a bit position to # of leading zeroes.
// E.g., for 000... 00001100, bsr will say that the most significant bit
// set is at position 3, while the number of leading zeros is 28. Xor is
// like (31 - N) for N <= 31, and converts 63 to 32 (for the all-zeros case).
//
// Similar for 64-bit, but start w/ speculating that the upper 32 bits
// are all zero, and compute the result for that case (checking the lower
// 32 bits). Then actually compute the result for the upper bits and
// cmov in the result from the lower computation if the earlier speculation
// was correct.
//
// Cttz, is similar, but uses bsf instead, and doesn't require the xor
// bit position conversion, and the speculation is reversed.
assert(Ty == IceType_i32 || Ty == IceType_i64);
Variable *T = makeReg(IceType_i32);
Operand *FirstValRM = legalize(FirstVal, Legal_Mem | Legal_Reg);
if (Cttz) {
_bsf(T, FirstValRM);
} else {
_bsr(T, FirstValRM);
}
Variable *T_Dest = makeReg(IceType_i32);
Constant *ThirtyTwo = Ctx->getConstantInt32(32);
Constant *ThirtyOne = Ctx->getConstantInt32(31);
if (Cttz) {
_mov(T_Dest, ThirtyTwo);
} else {
Constant *SixtyThree = Ctx->getConstantInt32(63);
_mov(T_Dest, SixtyThree);
}
_cmov(T_Dest, T, Traits::Cond::Br_ne);
if (!Cttz) {
_xor(T_Dest, ThirtyOne);
}
if (Ty == IceType_i32) {
_mov(Dest, T_Dest);
return;
}
_add(T_Dest, ThirtyTwo);
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
// Will be using "test" on this, so we need a registerized variable.
Variable *SecondVar = legalizeToReg(SecondVal);
Variable *T_Dest2 = makeReg(IceType_i32);
if (Cttz) {
_bsf(T_Dest2, SecondVar);
} else {
_bsr(T_Dest2, SecondVar);
_xor(T_Dest2, ThirtyOne);
}
_test(SecondVar, SecondVar);
_cmov(T_Dest2, T_Dest, Traits::Cond::Br_e);
_mov(DestLo, T_Dest2);
_mov(DestHi, Ctx->getConstantZero(IceType_i32));
}
template <class Machine>
void TargetX86Base<Machine>::lowerMemset(Operand *Dest, Operand *Val,
Operand *Count) {
constexpr uint32_t UNROLL_LIMIT = 16;
assert(Val->getType() == IceType_i8);
// Check if the operands are constants
const auto *CountConst = llvm::dyn_cast<const ConstantInteger32>(Count);
const auto *ValConst = llvm::dyn_cast<const ConstantInteger32>(Val);
const bool IsCountConst = CountConst != nullptr;
const bool IsValConst = ValConst != nullptr;
const uint32_t CountValue = IsCountConst ? CountConst->getValue() : 0;
const uint32_t ValValue = IsValConst ? ValConst->getValue() : 0;
// Unlikely, but nothing to do if it does happen
if (IsCountConst && CountValue == 0)
return;
// TODO(ascull): if the count is constant but val is not it would be possible
// to inline by spreading the value across 4 bytes and accessing subregs e.g.
// eax, ax and al.
if (IsCountConst && IsValConst) {
Variable *Base = legalizeToReg(Dest);
// Add a FakeUse in case Base is ultimately not used, e.g. it falls back to
// calling memset(). Otherwise Om1 register allocation fails because this
// infinite-weight variable has a definition but no uses.
Context.insert(InstFakeUse::create(Func, Base));
// 3 is the awkward size as it is too small for the vector or 32-bit
// operations and will not work with lowerLeftOvers as there is no valid
// overlap.
if (CountValue == 3) {
Constant *Offset = nullptr;
auto *Mem =
Traits::X86OperandMem::create(Func, IceType_i16, Base, Offset);
_store(Ctx->getConstantInt16((ValValue << 8) | ValValue), Mem);
Offset = Ctx->getConstantInt8(2);
Mem = Traits::X86OperandMem::create(Func, IceType_i8, Base, Offset);
_store(Ctx->getConstantInt8(ValValue), Mem);
return;
}
// Lowers the assignment to the remaining bytes. Assumes the original size
// was large enough to allow for overlaps.
auto lowerLeftOvers = [this, Base, CountValue](
uint32_t SpreadValue, uint32_t Size, Variable *VecReg) {
auto lowerStoreSpreadValue =
[this, Base, CountValue, SpreadValue](Type Ty) {
Constant *Offset =
Ctx->getConstantInt32(CountValue - typeWidthInBytes(Ty));
auto *Mem = Traits::X86OperandMem::create(Func, Ty, Base, Offset);
_store(Ctx->getConstantInt(Ty, SpreadValue), Mem);
};
if (Size > 8) {
assert(VecReg != nullptr);
Constant *Offset = Ctx->getConstantInt32(CountValue - 16);
auto *Mem = Traits::X86OperandMem::create(Func, VecReg->getType(), Base,
Offset);
_storep(VecReg, Mem);
} else if (Size > 4) {
assert(VecReg != nullptr);
Constant *Offset = Ctx->getConstantInt32(CountValue - 8);
auto *Mem =
Traits::X86OperandMem::create(Func, IceType_i64, Base, Offset);
_storeq(VecReg, Mem);
} else if (Size > 2) {
lowerStoreSpreadValue(IceType_i32);
} else if (Size > 1) {
lowerStoreSpreadValue(IceType_i16);
} else if (Size == 1) {
lowerStoreSpreadValue(IceType_i8);
}
};
// When the value is zero it can be loaded into a register cheaply using
// the xor trick.
constexpr uint32_t BytesPerStorep = 16;
if (ValValue == 0 && CountValue >= 8 &&
CountValue <= BytesPerStorep * UNROLL_LIMIT) {
Variable *Zero = makeVectorOfZeros(IceType_v16i8);
// Too small to use large vector operations so use small ones instead
if (CountValue < 16) {
Constant *Offset = nullptr;
auto *Mem =
Traits::X86OperandMem::create(Func, IceType_i64, Base, Offset);
_storeq(Zero, Mem);
lowerLeftOvers(0, CountValue - 8, Zero);
return;
}
assert(CountValue >= 16);
// Use large vector operations
for (uint32_t N = CountValue & 0xFFFFFFF0; N != 0;) {
N -= 16;
Constant *Offset = Ctx->getConstantInt32(N);
auto *Mem =
Traits::X86OperandMem::create(Func, Zero->getType(), Base, Offset);
_storep(Zero, Mem);
}
uint32_t LeftOver = CountValue & 0xF;
lowerLeftOvers(0, LeftOver, Zero);
return;
}
// TODO(ascull): load val into reg and select subregs e.g. eax, ax, al?
constexpr uint32_t BytesPerStore = 4;
if (CountValue <= BytesPerStore * UNROLL_LIMIT) {
// TODO(ascull); 64-bit can do better with 64-bit mov
uint32_t SpreadValue =
(ValValue << 24) | (ValValue << 16) | (ValValue << 8) | ValValue;
if (CountValue >= 4) {
Constant *ValueConst = Ctx->getConstantInt32(SpreadValue);
for (uint32_t N = CountValue & 0xFFFFFFFC; N != 0;) {
N -= 4;
Constant *Offset = Ctx->getConstantInt32(N);
auto *Mem =
Traits::X86OperandMem::create(Func, IceType_i32, Base, Offset);
_store(ValueConst, Mem);
}
}
uint32_t LeftOver = CountValue & 0x3;
lowerLeftOvers(SpreadValue, LeftOver, nullptr);
return;
}
}
// Fall back on calling the memset function. The value operand needs to be
// extended to a stack slot size because the PNaCl ABI requires arguments to
// be at least 32 bits wide.
Operand *ValExt;
if (IsValConst) {
ValExt = Ctx->getConstantInt(stackSlotType(), ValValue);
} else {
Variable *ValExtVar = Func->makeVariable(stackSlotType());
lowerCast(InstCast::create(Func, InstCast::Zext, ValExtVar, Val));
ValExt = ValExtVar;
}
InstCall *Call = makeHelperCall(H_call_memset, nullptr, 3);
Call->addArg(Dest);
Call->addArg(ValExt);
Call->addArg(Count);
lowerCall(Call);
}
template <class Machine>
void TargetX86Base<Machine>::lowerIndirectJump(Variable *Target) {
const bool NeedSandboxing = Ctx->getFlags().getUseSandboxing();
if (NeedSandboxing) {
_bundle_lock();
const SizeT BundleSize =
1 << Func->getAssembler<>()->getBundleAlignLog2Bytes();
_and(Target, Ctx->getConstantInt32(~(BundleSize - 1)));
}
_jmp(Target);
if (NeedSandboxing)
_bundle_unlock();
}
inline bool isAdd(const Inst *Inst) {
if (const InstArithmetic *Arith =
llvm::dyn_cast_or_null<const InstArithmetic>(Inst)) {
return (Arith->getOp() == InstArithmetic::Add);
}
return false;
}
inline void dumpAddressOpt(const Cfg *Func, const Variable *Base,
const Variable *Index, uint16_t Shift,
int32_t Offset, const Inst *Reason) {
if (!BuildDefs::dump())
return;
if (!Func->isVerbose(IceV_AddrOpt))
return;
OstreamLocker L(Func->getContext());
Ostream &Str = Func->getContext()->getStrDump();
Str << "Instruction: ";
Reason->dumpDecorated(Func);
Str << " results in Base=";
if (Base)
Base->dump(Func);
else
Str << "<null>";
Str << ", Index=";
if (Index)
Index->dump(Func);
else
Str << "<null>";
Str << ", Shift=" << Shift << ", Offset=" << Offset << "\n";
}
inline bool matchTransitiveAssign(const VariablesMetadata *VMetadata,
Variable *&Var, const Inst *&Reason) {
// Var originates from Var=SrcVar ==>
// set Var:=SrcVar
if (Var == nullptr)
return false;
if (const Inst *VarAssign = VMetadata->getSingleDefinition(Var)) {
assert(!VMetadata->isMultiDef(Var));
if (llvm::isa<InstAssign>(VarAssign)) {
Operand *SrcOp = VarAssign->getSrc(0);
assert(SrcOp);
if (Variable *SrcVar = llvm::dyn_cast<Variable>(SrcOp)) {
if (!VMetadata->isMultiDef(SrcVar) &&
// TODO: ensure SrcVar stays single-BB
true) {
Var = SrcVar;
Reason = VarAssign;
return true;
}
}
}
}
return false;
}
inline bool matchCombinedBaseIndex(const VariablesMetadata *VMetadata,
Variable *&Base, Variable *&Index,
uint16_t &Shift, const Inst *&Reason) {
// Index==nullptr && Base is Base=Var1+Var2 ==>
// set Base=Var1, Index=Var2, Shift=0
if (Base == nullptr)
return false;
if (Index != nullptr)
return false;
const Inst *BaseInst = VMetadata->getSingleDefinition(Base);
if (BaseInst == nullptr)
return false;
assert(!VMetadata->isMultiDef(Base));
if (BaseInst->getSrcSize() < 2)
return false;
if (Variable *Var1 = llvm::dyn_cast<Variable>(BaseInst->getSrc(0))) {
if (VMetadata->isMultiDef(Var1))
return false;
if (Variable *Var2 = llvm::dyn_cast<Variable>(BaseInst->getSrc(1))) {
if (VMetadata->isMultiDef(Var2))
return false;
if (isAdd(BaseInst) &&
// TODO: ensure Var1 and Var2 stay single-BB
true) {
Base = Var1;
Index = Var2;
Shift = 0; // should already have been 0
Reason = BaseInst;
return true;
}
}
}
return false;
}
inline bool matchShiftedIndex(const VariablesMetadata *VMetadata,
Variable *&Index, uint16_t &Shift,
const Inst *&Reason) {
// Index is Index=Var*Const && log2(Const)+Shift<=3 ==>
// Index=Var, Shift+=log2(Const)
if (Index == nullptr)
return false;
const Inst *IndexInst = VMetadata->getSingleDefinition(Index);
if (IndexInst == nullptr)
return false;
assert(!VMetadata->isMultiDef(Index));
if (IndexInst->getSrcSize() < 2)
return false;
if (const InstArithmetic *ArithInst =
llvm::dyn_cast<InstArithmetic>(IndexInst)) {
if (Variable *Var = llvm::dyn_cast<Variable>(ArithInst->getSrc(0))) {
if (ConstantInteger32 *Const =
llvm::dyn_cast<ConstantInteger32>(ArithInst->getSrc(1))) {
if (ArithInst->getOp() == InstArithmetic::Mul &&
!VMetadata->isMultiDef(Var) && Const->getType() == IceType_i32) {
uint64_t Mult = Const->getValue();
uint32_t LogMult;
switch (Mult) {
case 1:
LogMult = 0;
break;
case 2:
LogMult = 1;
break;
case 4:
LogMult = 2;
break;
case 8:
LogMult = 3;
break;
default:
return false;
}
if (Shift + LogMult <= 3) {
Index = Var;
Shift += LogMult;
Reason = IndexInst;
return true;
}
}
}
}
}
return false;
}
inline bool matchOffsetBase(const VariablesMetadata *VMetadata, Variable *&Base,
int32_t &Offset, const Inst *&Reason) {
// Base is Base=Var+Const || Base is Base=Const+Var ==>
// set Base=Var, Offset+=Const
// Base is Base=Var-Const ==>
// set Base=Var, Offset-=Const
if (Base == nullptr)
return false;
const Inst *BaseInst = VMetadata->getSingleDefinition(Base);
if (BaseInst == nullptr)
return false;
assert(!VMetadata->isMultiDef(Base));
if (const InstArithmetic *ArithInst =
llvm::dyn_cast<const InstArithmetic>(BaseInst)) {
if (ArithInst->getOp() != InstArithmetic::Add &&
ArithInst->getOp() != InstArithmetic::Sub)
return false;
bool IsAdd = ArithInst->getOp() == InstArithmetic::Add;
Variable *Var = nullptr;
ConstantInteger32 *Const = nullptr;
if (Variable *VariableOperand =
llvm::dyn_cast<Variable>(ArithInst->getSrc(0))) {
Var = VariableOperand;
Const = llvm::dyn_cast<ConstantInteger32>(ArithInst->getSrc(1));
} else if (IsAdd) {
Const = llvm::dyn_cast<ConstantInteger32>(ArithInst->getSrc(0));
Var = llvm::dyn_cast<Variable>(ArithInst->getSrc(1));
}
if (Var == nullptr || Const == nullptr || VMetadata->isMultiDef(Var))
return false;
int32_t MoreOffset = IsAdd ? Const->getValue() : -Const->getValue();
if (Utils::WouldOverflowAdd(Offset, MoreOffset))
return false;
Base = Var;
Offset += MoreOffset;
Reason = BaseInst;
return true;
}
return false;
}
inline void computeAddressOpt(Cfg *Func, const Inst *Instr, Variable *&Base,
Variable *&Index, uint16_t &Shift,
int32_t &Offset) {
Func->resetCurrentNode();
if (Func->isVerbose(IceV_AddrOpt)) {
OstreamLocker L(Func->getContext());
Ostream &Str = Func->getContext()->getStrDump();
Str << "\nStarting computeAddressOpt for instruction:\n ";
Instr->dumpDecorated(Func);
}
(void)Offset; // TODO: pattern-match for non-zero offsets.
if (Base == nullptr)
return;
// If the Base has more than one use or is live across multiple
// blocks, then don't go further. Alternatively (?), never consider
// a transformation that would change a variable that is currently
// *not* live across basic block boundaries into one that *is*.
if (Func->getVMetadata()->isMultiBlock(Base) /* || Base->getUseCount() > 1*/)
return;
const VariablesMetadata *VMetadata = Func->getVMetadata();
bool Continue = true;
while (Continue) {
const Inst *Reason = nullptr;
if (matchTransitiveAssign(VMetadata, Base, Reason) ||
matchTransitiveAssign(VMetadata, Index, Reason) ||
matchCombinedBaseIndex(VMetadata, Base, Index, Shift, Reason) ||
matchShiftedIndex(VMetadata, Index, Shift, Reason) ||
matchOffsetBase(VMetadata, Base, Offset, Reason)) {
dumpAddressOpt(Func, Base, Index, Shift, Offset, Reason);
} else {
Continue = false;
}
// Index is Index=Var<<Const && Const+Shift<=3 ==>
// Index=Var, Shift+=Const
// Index is Index=Const*Var && log2(Const)+Shift<=3 ==>
// Index=Var, Shift+=log2(Const)
// Index && Shift==0 && Base is Base=Var*Const && log2(Const)+Shift<=3 ==>
// swap(Index,Base)
// Similar for Base=Const*Var and Base=Var<<Const
// Index is Index=Var+Const ==>
// set Index=Var, Offset+=(Const<<Shift)
// Index is Index=Const+Var ==>
// set Index=Var, Offset+=(Const<<Shift)
// Index is Index=Var-Const ==>
// set Index=Var, Offset-=(Const<<Shift)
// TODO: consider overflow issues with respect to Offset.
// TODO: handle symbolic constants.
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerLoad(const InstLoad *Load) {
// A Load instruction can be treated the same as an Assign instruction, after
// the source operand is transformed into an Traits::X86OperandMem operand.
// Note that the address mode optimization already creates an
// Traits::X86OperandMem operand, so it doesn't need another level of
// transformation.
Variable *DestLoad = Load->getDest();
Type Ty = DestLoad->getType();
Operand *Src0 = formMemoryOperand(Load->getSourceAddress(), Ty);
InstAssign *Assign = InstAssign::create(Func, DestLoad, Src0);
lowerAssign(Assign);
}
template <class Machine> void TargetX86Base<Machine>::doAddressOptLoad() {
Inst *Inst = Context.getCur();
Variable *Dest = Inst->getDest();
Operand *Addr = Inst->getSrc(0);
Variable *Index = nullptr;
uint16_t Shift = 0;
int32_t Offset = 0; // TODO: make Constant
// Vanilla ICE load instructions should not use the segment registers, and
// computeAddressOpt only works at the level of Variables and Constants, not
// other Traits::X86OperandMem, so there should be no mention of segment
// registers there either.
const typename Traits::X86OperandMem::SegmentRegisters SegmentReg =
Traits::X86OperandMem::DefaultSegment;
Variable *Base = llvm::dyn_cast<Variable>(Addr);
computeAddressOpt(Func, Inst, Base, Index, Shift, Offset);
if (Base && Addr != Base) {
Inst->setDeleted();
Constant *OffsetOp = Ctx->getConstantInt32(Offset);
Addr = Traits::X86OperandMem::create(Func, Dest->getType(), Base, OffsetOp,
Index, Shift, SegmentReg);
Context.insert(InstLoad::create(Func, Dest, Addr));
}
}
template <class Machine>
void TargetX86Base<Machine>::randomlyInsertNop(float Probability) {
RandomNumberGeneratorWrapper RNG(Ctx->getRNG());
if (RNG.getTrueWithProbability(Probability)) {
_nop(RNG(Traits::X86_NUM_NOP_VARIANTS));
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerPhi(const InstPhi * /*Inst*/) {
Func->setError("Phi found in regular instruction list");
}
template <class Machine>
void TargetX86Base<Machine>::lowerSelect(const InstSelect *Inst) {
Variable *Dest = Inst->getDest();
Type DestTy = Dest->getType();
Operand *SrcT = Inst->getTrueOperand();
Operand *SrcF = Inst->getFalseOperand();
Operand *Condition = Inst->getCondition();
if (isVectorType(DestTy)) {
Type SrcTy = SrcT->getType();
Variable *T = makeReg(SrcTy);
Operand *SrcTRM = legalize(SrcT, Legal_Reg | Legal_Mem);
Operand *SrcFRM = legalize(SrcF, Legal_Reg | Legal_Mem);
if (InstructionSet >= Traits::SSE4_1) {
// TODO(wala): If the condition operand is a constant, use blendps
// or pblendw.
//
// Use blendvps or pblendvb to implement select.
if (SrcTy == IceType_v4i1 || SrcTy == IceType_v4i32 ||
SrcTy == IceType_v4f32) {
Operand *ConditionRM = legalize(Condition, Legal_Reg | Legal_Mem);
Variable *xmm0 = makeReg(IceType_v4i32, Traits::RegisterSet::Reg_xmm0);
_movp(xmm0, ConditionRM);
_psll(xmm0, Ctx->getConstantInt8(31));
_movp(T, SrcFRM);
_blendvps(T, SrcTRM, xmm0);
_movp(Dest, T);
} else {
assert(typeNumElements(SrcTy) == 8 || typeNumElements(SrcTy) == 16);
Type SignExtTy = Condition->getType() == IceType_v8i1 ? IceType_v8i16
: IceType_v16i8;
Variable *xmm0 = makeReg(SignExtTy, Traits::RegisterSet::Reg_xmm0);
lowerCast(InstCast::create(Func, InstCast::Sext, xmm0, Condition));
_movp(T, SrcFRM);
_pblendvb(T, SrcTRM, xmm0);
_movp(Dest, T);
}
return;
}
// Lower select without Traits::SSE4.1:
// a=d?b:c ==>
// if elementtype(d) != i1:
// d=sext(d);
// a=(b&d)|(c&~d);
Variable *T2 = makeReg(SrcTy);
// Sign extend the condition operand if applicable.
if (SrcTy == IceType_v4f32) {
// The sext operation takes only integer arguments.
Variable *T3 = Func->makeVariable(IceType_v4i32);
lowerCast(InstCast::create(Func, InstCast::Sext, T3, Condition));
_movp(T, T3);
} else if (typeElementType(SrcTy) != IceType_i1) {
lowerCast(InstCast::create(Func, InstCast::Sext, T, Condition));
} else {
Operand *ConditionRM = legalize(Condition, Legal_Reg | Legal_Mem);
_movp(T, ConditionRM);
}
_movp(T2, T);
_pand(T, SrcTRM);
_pandn(T2, SrcFRM);
_por(T, T2);
_movp(Dest, T);
return;
}
typename Traits::Cond::BrCond Cond = Traits::Cond::Br_ne;
Operand *CmpOpnd0 = nullptr;
Operand *CmpOpnd1 = nullptr;
// Handle folding opportunities.
if (const class Inst *Producer = FoldingInfo.getProducerFor(Condition)) {
assert(Producer->isDeleted());
switch (BoolFolding::getProducerKind(Producer)) {
default:
break;
case BoolFolding::PK_Icmp32: {
auto *Cmp = llvm::dyn_cast<InstIcmp>(Producer);
Cond = Traits::getIcmp32Mapping(Cmp->getCondition());
CmpOpnd1 = legalize(Producer->getSrc(1));
CmpOpnd0 = legalizeSrc0ForCmp(Producer->getSrc(0), CmpOpnd1);
} break;
}
}
if (CmpOpnd0 == nullptr) {
CmpOpnd0 = legalize(Condition, Legal_Reg | Legal_Mem);
CmpOpnd1 = Ctx->getConstantZero(IceType_i32);
}
assert(CmpOpnd0);
assert(CmpOpnd1);
_cmp(CmpOpnd0, CmpOpnd1);
if (typeWidthInBytes(DestTy) == 1 || isFloatingType(DestTy)) {
// The cmov instruction doesn't allow 8-bit or FP operands, so
// we need explicit control flow.
// d=cmp e,f; a=d?b:c ==> cmp e,f; a=b; jne L1; a=c; L1:
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
SrcT = legalize(SrcT, Legal_Reg | Legal_Imm);
_mov(Dest, SrcT);
_br(Cond, Label);
SrcF = legalize(SrcF, Legal_Reg | Legal_Imm);
_mov_nonkillable(Dest, SrcF);
Context.insert(Label);
return;
}
// mov t, SrcF; cmov_cond t, SrcT; mov dest, t
// But if SrcT is immediate, we might be able to do better, as
// the cmov instruction doesn't allow an immediate operand:
// mov t, SrcT; cmov_!cond t, SrcF; mov dest, t
if (llvm::isa<Constant>(SrcT) && !llvm::isa<Constant>(SrcF)) {
std::swap(SrcT, SrcF);
Cond = InstX86Base<Machine>::getOppositeCondition(Cond);
}
if (DestTy == IceType_i64) {
SrcT = legalizeUndef(SrcT);
SrcF = legalizeUndef(SrcF);
// Set the low portion.
Variable *DestLo = llvm::cast<Variable>(loOperand(Dest));
Variable *TLo = nullptr;
Operand *SrcFLo = legalize(loOperand(SrcF));
_mov(TLo, SrcFLo);
Operand *SrcTLo = legalize(loOperand(SrcT), Legal_Reg | Legal_Mem);
_cmov(TLo, SrcTLo, Cond);
_mov(DestLo, TLo);
// Set the high portion.
Variable *DestHi = llvm::cast<Variable>(hiOperand(Dest));
Variable *THi = nullptr;
Operand *SrcFHi = legalize(hiOperand(SrcF));
_mov(THi, SrcFHi);
Operand *SrcTHi = legalize(hiOperand(SrcT), Legal_Reg | Legal_Mem);
_cmov(THi, SrcTHi, Cond);
_mov(DestHi, THi);
return;
}
assert(DestTy == IceType_i16 || DestTy == IceType_i32);
Variable *T = nullptr;
SrcF = legalize(SrcF);
_mov(T, SrcF);
SrcT = legalize(SrcT, Legal_Reg | Legal_Mem);
_cmov(T, SrcT, Cond);
_mov(Dest, T);
}
template <class Machine>
void TargetX86Base<Machine>::lowerStore(const InstStore *Inst) {
Operand *Value = Inst->getData();
Operand *Addr = Inst->getAddr();
typename Traits::X86OperandMem *NewAddr =
formMemoryOperand(Addr, Value->getType());
Type Ty = NewAddr->getType();
if (Ty == IceType_i64) {
Value = legalizeUndef(Value);
Operand *ValueHi = legalize(hiOperand(Value), Legal_Reg | Legal_Imm);
Operand *ValueLo = legalize(loOperand(Value), Legal_Reg | Legal_Imm);
_store(ValueHi,
llvm::cast<typename Traits::X86OperandMem>(hiOperand(NewAddr)));
_store(ValueLo,
llvm::cast<typename Traits::X86OperandMem>(loOperand(NewAddr)));
} else if (isVectorType(Ty)) {
_storep(legalizeToReg(Value), NewAddr);
} else {
Value = legalize(Value, Legal_Reg | Legal_Imm);
_store(Value, NewAddr);
}
}
template <class Machine> void TargetX86Base<Machine>::doAddressOptStore() {
InstStore *Inst = llvm::cast<InstStore>(Context.getCur());
Operand *Data = Inst->getData();
Operand *Addr = Inst->getAddr();
Variable *Index = nullptr;
uint16_t Shift = 0;
int32_t Offset = 0; // TODO: make Constant
Variable *Base = llvm::dyn_cast<Variable>(Addr);
// Vanilla ICE store instructions should not use the segment registers, and
// computeAddressOpt only works at the level of Variables and Constants, not
// other Traits::X86OperandMem, so there should be no mention of segment
// registers there either.
const typename Traits::X86OperandMem::SegmentRegisters SegmentReg =
Traits::X86OperandMem::DefaultSegment;
computeAddressOpt(Func, Inst, Base, Index, Shift, Offset);
if (Base && Addr != Base) {
Inst->setDeleted();
Constant *OffsetOp = Ctx->getConstantInt32(Offset);
Addr = Traits::X86OperandMem::create(Func, Data->getType(), Base, OffsetOp,
Index, Shift, SegmentReg);
InstStore *NewStore = InstStore::create(Func, Data, Addr);
if (Inst->getDest())
NewStore->setRmwBeacon(Inst->getRmwBeacon());
Context.insert(NewStore);
}
}
template <class Machine>
Operand *TargetX86Base<Machine>::lowerCmpRange(Operand *Comparison,
uint64_t Min, uint64_t Max) {
// TODO(ascull): 64-bit should not reach here but only because it is not
// implemented yet. This should be able to handle the 64-bit case.
assert(Comparison->getType() != IceType_i64);
// Subtracting 0 is a nop so don't do it
if (Min != 0) {
// Avoid clobbering the comparison by copying it
Variable *T = nullptr;
_mov(T, Comparison);
_sub(T, Ctx->getConstantInt32(Min));
Comparison = T;
}
_cmp(Comparison, Ctx->getConstantInt32(Max - Min));
return Comparison;
}
template <class Machine>
void TargetX86Base<Machine>::lowerCaseCluster(const CaseCluster &Case,
Operand *Comparison, bool DoneCmp,
CfgNode *DefaultTarget) {
switch (Case.getKind()) {
case CaseCluster::JumpTable: {
typename Traits::Insts::Label *SkipJumpTable;
Operand *RangeIndex =
lowerCmpRange(Comparison, Case.getLow(), Case.getHigh());
if (DefaultTarget == nullptr) {
// Skip over jump table logic if comparison not in range and no default
SkipJumpTable = Traits::Insts::Label::create(Func, this);
_br(Traits::Cond::Br_a, SkipJumpTable);
} else {
_br(Traits::Cond::Br_a, DefaultTarget);
}
InstJumpTable *JumpTable = Case.getJumpTable();
Context.insert(JumpTable);
// Make sure the index is a register of the same width as the base
Variable *Index;
if (RangeIndex->getType() != getPointerType()) {
Index = makeReg(getPointerType());
_movzx(Index, RangeIndex);
} else {
Index = legalizeToReg(RangeIndex);
}
constexpr RelocOffsetT RelocOffset = 0;
constexpr bool SuppressMangling = true;
IceString MangledName = Ctx->mangleName(Func->getFunctionName());
Constant *Base = Ctx->getConstantSym(
RelocOffset, InstJumpTable::makeName(MangledName, JumpTable->getId()),
SuppressMangling);
Constant *Offset = nullptr;
uint16_t Shift = typeWidthInBytesLog2(getPointerType());
// TODO(ascull): remove need for legalize by allowing null base in memop
auto *TargetInMemory = Traits::X86OperandMem::create(
Func, getPointerType(), legalizeToReg(Base), Offset, Index, Shift);
Variable *Target = nullptr;
_mov(Target, TargetInMemory);
lowerIndirectJump(Target);
if (DefaultTarget == nullptr)
Context.insert(SkipJumpTable);
return;
}
case CaseCluster::Range: {
if (Case.isUnitRange()) {
// Single item
if (!DoneCmp) {
Constant *Value = Ctx->getConstantInt32(Case.getLow());
_cmp(Comparison, Value);
}
_br(Traits::Cond::Br_e, Case.getTarget());
} else if (DoneCmp && Case.isPairRange()) {
// Range of two items with first item aleady compared against
_br(Traits::Cond::Br_e, Case.getTarget());
Constant *Value = Ctx->getConstantInt32(Case.getHigh());
_cmp(Comparison, Value);
_br(Traits::Cond::Br_e, Case.getTarget());
} else {
// Range
lowerCmpRange(Comparison, Case.getLow(), Case.getHigh());
_br(Traits::Cond::Br_be, Case.getTarget());
}
if (DefaultTarget != nullptr)
_br(DefaultTarget);
return;
}
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerSwitch(const InstSwitch *Inst) {
// Group cases together and navigate through them with a binary search
CaseClusterArray CaseClusters = CaseCluster::clusterizeSwitch(Func, Inst);
Operand *Src0 = Inst->getComparison();
CfgNode *DefaultTarget = Inst->getLabelDefault();
assert(CaseClusters.size() != 0); // Should always be at least one
if (Src0->getType() == IceType_i64) {
Src0 = legalize(Src0); // get Base/Index into physical registers
Operand *Src0Lo = loOperand(Src0);
Operand *Src0Hi = hiOperand(Src0);
if (CaseClusters.back().getHigh() > UINT32_MAX) {
// TODO(ascull): handle 64-bit case properly (currently naive version)
// This might be handled by a higher level lowering of switches.
SizeT NumCases = Inst->getNumCases();
if (NumCases >= 2) {
Src0Lo = legalizeToReg(Src0Lo);
Src0Hi = legalizeToReg(Src0Hi);
} else {
Src0Lo = legalize(Src0Lo, Legal_Reg | Legal_Mem);
Src0Hi = legalize(Src0Hi, Legal_Reg | Legal_Mem);
}
for (SizeT I = 0; I < NumCases; ++I) {
Constant *ValueLo = Ctx->getConstantInt32(Inst->getValue(I));
Constant *ValueHi = Ctx->getConstantInt32(Inst->getValue(I) >> 32);
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
_cmp(Src0Lo, ValueLo);
_br(Traits::Cond::Br_ne, Label);
_cmp(Src0Hi, ValueHi);
_br(Traits::Cond::Br_e, Inst->getLabel(I));
Context.insert(Label);
}
_br(Inst->getLabelDefault());
return;
} else {
// All the values are 32-bit so just check the operand is too and then
// fall through to the 32-bit implementation. This is a common case.
Src0Hi = legalize(Src0Hi, Legal_Reg | Legal_Mem);
Constant *Zero = Ctx->getConstantInt32(0);
_cmp(Src0Hi, Zero);
_br(Traits::Cond::Br_ne, DefaultTarget);
Src0 = Src0Lo;
}
}
// 32-bit lowering
if (CaseClusters.size() == 1) {
// Jump straight to default if needed. Currently a common case as jump
// tables occur on their own.
constexpr bool DoneCmp = false;
lowerCaseCluster(CaseClusters.front(), Src0, DoneCmp, DefaultTarget);
return;
}
// Going to be using multiple times so get it in a register early
Variable *Comparison = legalizeToReg(Src0);
// A span is over the clusters
struct SearchSpan {
SearchSpan(SizeT Begin, SizeT Size, typename Traits::Insts::Label *Label)
: Begin(Begin), Size(Size), Label(Label) {}
SizeT Begin;
SizeT Size;
typename Traits::Insts::Label *Label;
};
// The stack will only grow to the height of the tree so 12 should be plenty
std::stack<SearchSpan, llvm::SmallVector<SearchSpan, 12>> SearchSpanStack;
SearchSpanStack.emplace(0, CaseClusters.size(), nullptr);
bool DoneCmp = false;
while (!SearchSpanStack.empty()) {
SearchSpan Span = SearchSpanStack.top();
SearchSpanStack.pop();
if (Span.Label != nullptr)
Context.insert(Span.Label);
switch (Span.Size) {
case 0:
llvm::report_fatal_error("Invalid SearchSpan size");
break;
case 1:
lowerCaseCluster(CaseClusters[Span.Begin], Comparison, DoneCmp,
SearchSpanStack.empty() ? nullptr : DefaultTarget);
DoneCmp = false;
break;
case 2: {
const CaseCluster *CaseA = &CaseClusters[Span.Begin];
const CaseCluster *CaseB = &CaseClusters[Span.Begin + 1];
// Placing a range last may allow register clobbering during the range
// test. That means there is no need to clone the register. If it is a
// unit range the comparison may have already been done in the binary
// search (DoneCmp) and so it should be placed first. If this is a range
// of two items and the comparison with the low value has already been
// done, comparing with the other element is cheaper than a range test.
// If the low end of the range is zero then there is no subtraction and
// nothing to be gained.
if (!CaseA->isUnitRange() &&
!(CaseA->getLow() == 0 || (DoneCmp && CaseA->isPairRange()))) {
std::swap(CaseA, CaseB);
DoneCmp = false;
}
lowerCaseCluster(*CaseA, Comparison, DoneCmp);
DoneCmp = false;
lowerCaseCluster(*CaseB, Comparison, DoneCmp,
SearchSpanStack.empty() ? nullptr : DefaultTarget);
} break;
default:
// Pick the middle item and branch b or ae
SizeT PivotIndex = Span.Begin + (Span.Size / 2);
const CaseCluster &Pivot = CaseClusters[PivotIndex];
Constant *Value = Ctx->getConstantInt32(Pivot.getLow());
typename Traits::Insts::Label *Label =
Traits::Insts::Label::create(Func, this);
_cmp(Comparison, Value);
// TODO(ascull): does it alway have to be far?
_br(Traits::Cond::Br_b, Label, Traits::Insts::Br::Far);
// Lower the left and (pivot+right) sides, falling through to the right
SearchSpanStack.emplace(Span.Begin, Span.Size / 2, Label);
SearchSpanStack.emplace(PivotIndex, Span.Size - (Span.Size / 2), nullptr);
DoneCmp = true;
break;
}
}
_br(DefaultTarget);
}
template <class Machine>
void TargetX86Base<Machine>::scalarizeArithmetic(InstArithmetic::OpKind Kind,
Variable *Dest, Operand *Src0,
Operand *Src1) {
assert(isVectorType(Dest->getType()));
Type Ty = Dest->getType();
Type ElementTy = typeElementType(Ty);
SizeT NumElements = typeNumElements(Ty);
Operand *T = Ctx->getConstantUndef(Ty);
for (SizeT I = 0; I < NumElements; ++I) {
Constant *Index = Ctx->getConstantInt32(I);
// Extract the next two inputs.
Variable *Op0 = Func->makeVariable(ElementTy);
lowerExtractElement(InstExtractElement::create(Func, Op0, Src0, Index));
Variable *Op1 = Func->makeVariable(ElementTy);
lowerExtractElement(InstExtractElement::create(Func, Op1, Src1, Index));
// Perform the arithmetic as a scalar operation.
Variable *Res = Func->makeVariable(ElementTy);
lowerArithmetic(InstArithmetic::create(Func, Kind, Res, Op0, Op1));
// Insert the result into position.
Variable *DestT = Func->makeVariable(Ty);
lowerInsertElement(InstInsertElement::create(Func, DestT, T, Res, Index));
T = DestT;
}
lowerAssign(InstAssign::create(Func, Dest, T));
}
/// The following pattern occurs often in lowered C and C++ code:
///
/// %cmp = fcmp/icmp pred <n x ty> %src0, %src1
/// %cmp.ext = sext <n x i1> %cmp to <n x ty>
///
/// We can eliminate the sext operation by copying the result of pcmpeqd,
/// pcmpgtd, or cmpps (which produce sign extended results) to the result
/// of the sext operation.
template <class Machine>
void TargetX86Base<Machine>::eliminateNextVectorSextInstruction(
Variable *SignExtendedResult) {
if (InstCast *NextCast =
llvm::dyn_cast_or_null<InstCast>(Context.getNextInst())) {
if (NextCast->getCastKind() == InstCast::Sext &&
NextCast->getSrc(0) == SignExtendedResult) {
NextCast->setDeleted();
_movp(NextCast->getDest(), legalizeToReg(SignExtendedResult));
// Skip over the instruction.
Context.advanceNext();
}
}
}
template <class Machine>
void TargetX86Base<Machine>::lowerUnreachable(
const InstUnreachable * /*Inst*/) {
_ud2();
}
template <class Machine>
void TargetX86Base<Machine>::lowerRMW(
const typename Traits::Insts::FakeRMW *RMW) {
// If the beacon variable's live range does not end in this
// instruction, then it must end in the modified Store instruction
// that follows. This means that the original Store instruction is
// still there, either because the value being stored is used beyond
// the Store instruction, or because dead code elimination did not
// happen. In either case, we cancel RMW lowering (and the caller
// deletes the RMW instruction).
if (!RMW->isLastUse(RMW->getBeacon()))
return;
Operand *Src = RMW->getData();
Type Ty = Src->getType();
typename Traits::X86OperandMem *Addr = formMemoryOperand(RMW->getAddr(), Ty);
if (Ty == IceType_i64) {
Src = legalizeUndef(Src);
Operand *SrcLo = legalize(loOperand(Src), Legal_Reg | Legal_Imm);
Operand *SrcHi = legalize(hiOperand(Src), Legal_Reg | Legal_Imm);
typename Traits::X86OperandMem *AddrLo =
llvm::cast<typename Traits::X86OperandMem>(loOperand(Addr));
typename Traits::X86OperandMem *AddrHi =
llvm::cast<typename Traits::X86OperandMem>(hiOperand(Addr));
switch (RMW->getOp()) {
default:
// TODO(stichnot): Implement other arithmetic operators.
break;
case InstArithmetic::Add:
_add_rmw(AddrLo, SrcLo);
_adc_rmw(AddrHi, SrcHi);
return;
case InstArithmetic::Sub:
_sub_rmw(AddrLo, SrcLo);
_sbb_rmw(AddrHi, SrcHi);
return;
case InstArithmetic::And:
_and_rmw(AddrLo, SrcLo);
_and_rmw(AddrHi, SrcHi);
return;
case InstArithmetic::Or:
_or_rmw(AddrLo, SrcLo);
_or_rmw(AddrHi, SrcHi);
return;
case InstArithmetic::Xor:
_xor_rmw(AddrLo, SrcLo);
_xor_rmw(AddrHi, SrcHi);
return;
}
} else {
// i8, i16, i32
switch (RMW->getOp()) {
default:
// TODO(stichnot): Implement other arithmetic operators.
break;
case InstArithmetic::Add:
Src = legalize(Src, Legal_Reg | Legal_Imm);
_add_rmw(Addr, Src);
return;
case InstArithmetic::Sub:
Src = legalize(Src, Legal_Reg | Legal_Imm);
_sub_rmw(Addr, Src);
return;
case InstArithmetic::And:
Src = legalize(Src, Legal_Reg | Legal_Imm);
_and_rmw(Addr, Src);
return;
case InstArithmetic::Or:
Src = legalize(Src, Legal_Reg | Legal_Imm);
_or_rmw(Addr, Src);
return;
case InstArithmetic::Xor:
Src = legalize(Src, Legal_Reg | Legal_Imm);
_xor_rmw(Addr, Src);
return;
}
}
llvm::report_fatal_error("Couldn't lower RMW instruction");
}
template <class Machine>
void TargetX86Base<Machine>::lowerOther(const Inst *Instr) {
if (const auto *RMW =
llvm::dyn_cast<typename Traits::Insts::FakeRMW>(Instr)) {
lowerRMW(RMW);
} else {
TargetLowering::lowerOther(Instr);
}
}
/// Turn an i64 Phi instruction into a pair of i32 Phi instructions, to
/// preserve integrity of liveness analysis. Undef values are also
/// turned into zeroes, since loOperand() and hiOperand() don't expect
/// Undef input.
template <class Machine> void TargetX86Base<Machine>::prelowerPhis() {
// Pause constant blinding or pooling, blinding or pooling will be done later
// during phi lowering assignments
BoolFlagSaver B(RandomizationPoolingPaused, true);
PhiLowering::prelowerPhis32Bit<TargetX86Base<Machine>>(
this, Context.getNode(), Func);
}
// There is no support for loading or emitting vector constants, so the
// vector values returned from makeVectorOfZeros, makeVectorOfOnes,
// etc. are initialized with register operations.
//
// TODO(wala): Add limited support for vector constants so that
// complex initialization in registers is unnecessary.
template <class Machine>
Variable *TargetX86Base<Machine>::makeVectorOfZeros(Type Ty, int32_t RegNum) {
Variable *Reg = makeReg(Ty, RegNum);
// Insert a FakeDef, since otherwise the live range of Reg might
// be overestimated.
Context.insert(InstFakeDef::create(Func, Reg));
_pxor(Reg, Reg);
return Reg;
}
template <class Machine>
Variable *TargetX86Base<Machine>::makeVectorOfMinusOnes(Type Ty,
int32_t RegNum) {
Variable *MinusOnes = makeReg(Ty, RegNum);
// Insert a FakeDef so the live range of MinusOnes is not overestimated.
Context.insert(InstFakeDef::create(Func, MinusOnes));
_pcmpeq(MinusOnes, MinusOnes);
return MinusOnes;
}
template <class Machine>
Variable *TargetX86Base<Machine>::makeVectorOfOnes(Type Ty, int32_t RegNum) {
Variable *Dest = makeVectorOfZeros(Ty, RegNum);
Variable *MinusOne = makeVectorOfMinusOnes(Ty);
_psub(Dest, MinusOne);
return Dest;
}
template <class Machine>
Variable *TargetX86Base<Machine>::makeVectorOfHighOrderBits(Type Ty,
int32_t RegNum) {
assert(Ty == IceType_v4i32 || Ty == IceType_v4f32 || Ty == IceType_v8i16 ||
Ty == IceType_v16i8);
if (Ty == IceType_v4f32 || Ty == IceType_v4i32 || Ty == IceType_v8i16) {
Variable *Reg = makeVectorOfOnes(Ty, RegNum);
SizeT Shift =
typeWidthInBytes(typeElementType(Ty)) * Traits::X86_CHAR_BIT - 1;
_psll(Reg, Ctx->getConstantInt8(Shift));
return Reg;
} else {
// SSE has no left shift operation for vectors of 8 bit integers.
const uint32_t HIGH_ORDER_BITS_MASK = 0x80808080;
Constant *ConstantMask = Ctx->getConstantInt32(HIGH_ORDER_BITS_MASK);
Variable *Reg = makeReg(Ty, RegNum);
_movd(Reg, legalize(ConstantMask, Legal_Reg | Legal_Mem));
_pshufd(Reg, Reg, Ctx->getConstantZero(IceType_i8));
return Reg;
}
}
/// Construct a mask in a register that can be and'ed with a
/// floating-point value to mask off its sign bit. The value will be
/// <4 x 0x7fffffff> for f32 and v4f32, and <2 x 0x7fffffffffffffff>
/// for f64. Construct it as vector of ones logically right shifted
/// one bit. TODO(stichnot): Fix the wala TODO above, to represent
/// vector constants in memory.
template <class Machine>
Variable *TargetX86Base<Machine>::makeVectorOfFabsMask(Type Ty,
int32_t RegNum) {
Variable *Reg = makeVectorOfMinusOnes(Ty, RegNum);
_psrl(Reg, Ctx->getConstantInt8(1));
return Reg;
}
template <class Machine>
typename TargetX86Base<Machine>::Traits::X86OperandMem *
TargetX86Base<Machine>::getMemoryOperandForStackSlot(Type Ty, Variable *Slot,
uint32_t Offset) {
// Ensure that Loc is a stack slot.
assert(Slot->getWeight().isZero());
assert(Slot->getRegNum() == Variable::NoRegister);
// Compute the location of Loc in memory.
// TODO(wala,stichnot): lea should not be required. The address of
// the stack slot is known at compile time (although not until after
// addProlog()).
const Type PointerType = IceType_i32;
Variable *Loc = makeReg(PointerType);
_lea(Loc, Slot);
Constant *ConstantOffset = Ctx->getConstantInt32(Offset);
return Traits::X86OperandMem::create(Func, Ty, Loc, ConstantOffset);
}
/// Helper for legalize() to emit the right code to lower an operand to a
/// register of the appropriate type.
template <class Machine>
Variable *TargetX86Base<Machine>::copyToReg(Operand *Src, int32_t RegNum) {
Type Ty = Src->getType();
Variable *Reg = makeReg(Ty, RegNum);
if (isVectorType(Ty)) {
_movp(Reg, Src);
} else {
_mov(Reg, Src);
}
return Reg;
}
template <class Machine>
Operand *TargetX86Base<Machine>::legalize(Operand *From, LegalMask Allowed,
int32_t RegNum) {
Type Ty = From->getType();
// Assert that a physical register is allowed. To date, all calls
// to legalize() allow a physical register. If a physical register
// needs to be explicitly disallowed, then new code will need to be
// written to force a spill.
assert(Allowed & Legal_Reg);
// If we're asking for a specific physical register, make sure we're
// not allowing any other operand kinds. (This could be future
// work, e.g. allow the shl shift amount to be either an immediate
// or in ecx.)
assert(RegNum == Variable::NoRegister || Allowed == Legal_Reg);
if (auto Mem = llvm::dyn_cast<typename Traits::X86OperandMem>(From)) {
// Before doing anything with a Mem operand, we need to ensure
// that the Base and Index components are in physical registers.
Variable *Base = Mem->getBase();
Variable *Index = Mem->getIndex();
Variable *RegBase = nullptr;
Variable *RegIndex = nullptr;
if (Base) {
RegBase = legalizeToReg(Base);
}
if (Index) {
RegIndex = legalizeToReg(Index);
}
if (Base != RegBase || Index != RegIndex) {
Mem = Traits::X86OperandMem::create(Func, Ty, RegBase, Mem->getOffset(),
RegIndex, Mem->getShift(),
Mem->getSegmentRegister());
}
// For all Memory Operands, we do randomization/pooling here
From = randomizeOrPoolImmediate(Mem);
if (!(Allowed & Legal_Mem)) {
From = copyToReg(From, RegNum);
}
return From;
}
if (auto *Const = llvm::dyn_cast<Constant>(From)) {
if (llvm::isa<ConstantUndef>(Const)) {
From = legalizeUndef(Const, RegNum);
if (isVectorType(Ty))
return From;
Const = llvm::cast<Constant>(From);
}
// There should be no constants of vector type (other than undef).
assert(!isVectorType(Ty));
// If the operand is an 32 bit constant integer, we should check
// whether we need to randomize it or pool it.
if (ConstantInteger32 *C = llvm::dyn_cast<ConstantInteger32>(Const)) {
Operand *NewConst = randomizeOrPoolImmediate(C, RegNum);
if (NewConst != Const) {
return NewConst;
}
}
// Convert a scalar floating point constant into an explicit
// memory operand.
if (isScalarFloatingType(Ty)) {
Variable *Base = nullptr;
std::string Buffer;
llvm::raw_string_ostream StrBuf(Buffer);
llvm::cast<Constant>(From)->emitPoolLabel(StrBuf);
llvm::cast<Constant>(From)->setShouldBePooled(true);
Constant *Offset = Ctx->getConstantSym(0, StrBuf.str(), true);
From = Traits::X86OperandMem::create(Func, Ty, Base, Offset);
}
bool NeedsReg = false;
if (!(Allowed & Legal_Imm) && !isScalarFloatingType(Ty))
// Immediate specifically not allowed
NeedsReg = true;
if (!(Allowed & Legal_Mem) && isScalarFloatingType(Ty))
// On x86, FP constants are lowered to mem operands.
NeedsReg = true;
if (NeedsReg) {
From = copyToReg(From, RegNum);
}
return From;
}
if (auto Var = llvm::dyn_cast<Variable>(From)) {
// Check if the variable is guaranteed a physical register. This
// can happen either when the variable is pre-colored or when it is
// assigned infinite weight.
bool MustHaveRegister = (Var->hasReg() || Var->getWeight().isInf());
// We need a new physical register for the operand if:
// Mem is not allowed and Var isn't guaranteed a physical
// register, or
// RegNum is required and Var->getRegNum() doesn't match.
if ((!(Allowed & Legal_Mem) && !MustHaveRegister) ||
(RegNum != Variable::NoRegister && RegNum != Var->getRegNum())) {
From = copyToReg(From, RegNum);
}
return From;
}
llvm_unreachable("Unhandled operand kind in legalize()");
return From;
}
/// Provide a trivial wrapper to legalize() for this common usage.
template <class Machine>
Variable *TargetX86Base<Machine>::legalizeToReg(Operand *From, int32_t RegNum) {
return llvm::cast<Variable>(legalize(From, Legal_Reg, RegNum));
}
/// Legalize undef values to concrete values.
template <class Machine>
Operand *TargetX86Base<Machine>::legalizeUndef(Operand *From, int32_t RegNum) {
Type Ty = From->getType();
if (llvm::isa<ConstantUndef>(From)) {
// Lower undefs to zero. Another option is to lower undefs to an
// uninitialized register; however, using an uninitialized register
// results in less predictable code.
//
// If in the future the implementation is changed to lower undef
// values to uninitialized registers, a FakeDef will be needed:
// Context.insert(InstFakeDef::create(Func, Reg));
// This is in order to ensure that the live range of Reg is not
// overestimated. If the constant being lowered is a 64 bit value,
// then the result should be split and the lo and hi components will
// need to go in uninitialized registers.
if (isVectorType(Ty))
return makeVectorOfZeros(Ty, RegNum);
return Ctx->getConstantZero(Ty);
}
return From;
}
/// For the cmp instruction, if Src1 is an immediate, or known to be a
/// physical register, we can allow Src0 to be a memory operand.
/// Otherwise, Src0 must be copied into a physical register.
/// (Actually, either Src0 or Src1 can be chosen for the physical
/// register, but unfortunately we have to commit to one or the other
/// before register allocation.)
template <class Machine>
Operand *TargetX86Base<Machine>::legalizeSrc0ForCmp(Operand *Src0,
Operand *Src1) {
bool IsSrc1ImmOrReg = false;
if (llvm::isa<Constant>(Src1)) {
IsSrc1ImmOrReg = true;
} else if (auto *Var = llvm::dyn_cast<Variable>(Src1)) {
if (Var->hasReg())
IsSrc1ImmOrReg = true;
}
return legalize(Src0, IsSrc1ImmOrReg ? (Legal_Reg | Legal_Mem) : Legal_Reg);
}
template <class Machine>
typename TargetX86Base<Machine>::Traits::X86OperandMem *
TargetX86Base<Machine>::formMemoryOperand(Operand *Opnd, Type Ty,
bool DoLegalize) {
auto *Mem = llvm::dyn_cast<typename Traits::X86OperandMem>(Opnd);
// It may be the case that address mode optimization already creates an
// Traits::X86OperandMem, so in that case it wouldn't need another level of
// transformation.
if (!Mem) {
Variable *Base = llvm::dyn_cast<Variable>(Opnd);
Constant *Offset = llvm::dyn_cast<Constant>(Opnd);
assert(Base || Offset);
if (Offset) {
// During memory operand building, we do not blind or pool
// the constant offset, we will work on the whole memory
// operand later as one entity later, this save one instruction.
// By turning blinding and pooling off, we guarantee
// legalize(Offset) will return a Constant*.
{
BoolFlagSaver B(RandomizationPoolingPaused, true);
Offset = llvm::cast<Constant>(legalize(Offset));
}
assert(llvm::isa<ConstantInteger32>(Offset) ||
llvm::isa<ConstantRelocatable>(Offset));
}
Mem = Traits::X86OperandMem::create(Func, Ty, Base, Offset);
}
// Do legalization, which contains randomization/pooling
// or do randomization/pooling.
return llvm::cast<typename Traits::X86OperandMem>(
DoLegalize ? legalize(Mem) : randomizeOrPoolImmediate(Mem));
}
template <class Machine>
Variable *TargetX86Base<Machine>::makeReg(Type Type, int32_t RegNum) {
// There aren't any 64-bit integer registers for x86-32.
assert(Type != IceType_i64);
Variable *Reg = Func->makeVariable(Type);
if (RegNum == Variable::NoRegister)
Reg->setWeightInfinite();
else
Reg->setRegNum(RegNum);
return Reg;
}
template <class Machine> void TargetX86Base<Machine>::postLower() {
if (Ctx->getFlags().getOptLevel() == Opt_m1)
return;
inferTwoAddress();
}
template <class Machine>
void TargetX86Base<Machine>::makeRandomRegisterPermutation(
llvm::SmallVectorImpl<int32_t> &Permutation,
const llvm::SmallBitVector &ExcludeRegisters) const {
Traits::makeRandomRegisterPermutation(Ctx, Func, Permutation,
ExcludeRegisters);
}
template <class Machine>
void TargetX86Base<Machine>::emit(const ConstantInteger32 *C) const {
if (!BuildDefs::dump())
return;
Ostream &Str = Ctx->getStrEmit();
Str << getConstantPrefix() << C->getValue();
}
template <class Machine>
void TargetX86Base<Machine>::emit(const ConstantInteger64 *) const {
llvm::report_fatal_error("Not expecting to emit 64-bit integers");
}
template <class Machine>
void TargetX86Base<Machine>::emit(const ConstantFloat *C) const {
if (!BuildDefs::dump())
return;
Ostream &Str = Ctx->getStrEmit();
C->emitPoolLabel(Str);
}
template <class Machine>
void TargetX86Base<Machine>::emit(const ConstantDouble *C) const {
if (!BuildDefs::dump())
return;
Ostream &Str = Ctx->getStrEmit();
C->emitPoolLabel(Str);
}
template <class Machine>
void TargetX86Base<Machine>::emit(const ConstantUndef *) const {
llvm::report_fatal_error("undef value encountered by emitter.");
}
/// Randomize or pool an Immediate.
template <class Machine>
Operand *TargetX86Base<Machine>::randomizeOrPoolImmediate(Constant *Immediate,
int32_t RegNum) {
assert(llvm::isa<ConstantInteger32>(Immediate) ||
llvm::isa<ConstantRelocatable>(Immediate));
if (Ctx->getFlags().getRandomizeAndPoolImmediatesOption() == RPI_None ||
RandomizationPoolingPaused == true) {
// Immediates randomization/pooling off or paused
return Immediate;
}
if (Immediate->shouldBeRandomizedOrPooled(Ctx)) {
Ctx->statsUpdateRPImms();
if (Ctx->getFlags().getRandomizeAndPoolImmediatesOption() ==
RPI_Randomize) {
// blind the constant
// FROM:
// imm
// TO:
// insert: mov imm+cookie, Reg
// insert: lea -cookie[Reg], Reg
// => Reg
// If we have already assigned a phy register, we must come from
// andvancedPhiLowering()=>lowerAssign(). In this case we should reuse
// the assigned register as this assignment is that start of its use-def
// chain. So we add RegNum argument here.
// Note we use 'lea' instruction instead of 'xor' to avoid affecting
// the flags.
Variable *Reg = makeReg(IceType_i32, RegNum);
ConstantInteger32 *Integer = llvm::cast<ConstantInteger32>(Immediate);
uint32_t Value = Integer->getValue();
uint32_t Cookie = Ctx->getRandomizationCookie();
_mov(Reg, Ctx->getConstantInt(IceType_i32, Cookie + Value));
Constant *Offset = Ctx->getConstantInt(IceType_i32, 0 - Cookie);
_lea(Reg, Traits::X86OperandMem::create(Func, IceType_i32, Reg, Offset,
nullptr, 0));
// make sure liveness analysis won't kill this variable, otherwise a
// liveness assertion will be triggered.
_set_dest_nonkillable();
if (Immediate->getType() != IceType_i32) {
Variable *TruncReg = makeReg(Immediate->getType(), RegNum);
_mov(TruncReg, Reg);
return TruncReg;
}
return Reg;
}
if (Ctx->getFlags().getRandomizeAndPoolImmediatesOption() == RPI_Pool) {
// pool the constant
// FROM:
// imm
// TO:
// insert: mov $label, Reg
// => Reg
assert(Ctx->getFlags().getRandomizeAndPoolImmediatesOption() == RPI_Pool);
Immediate->setShouldBePooled(true);
// if we have already assigned a phy register, we must come from
// andvancedPhiLowering()=>lowerAssign(). In this case we should reuse
// the assigned register as this assignment is that start of its use-def
// chain. So we add RegNum argument here.
Variable *Reg = makeReg(Immediate->getType(), RegNum);
IceString Label;
llvm::raw_string_ostream Label_stream(Label);
Immediate->emitPoolLabel(Label_stream);
const RelocOffsetT Offset = 0;
const bool SuppressMangling = true;
Constant *Symbol =
Ctx->getConstantSym(Offset, Label_stream.str(), SuppressMangling);
typename Traits::X86OperandMem *MemOperand =
Traits::X86OperandMem::create(Func, Immediate->getType(), nullptr,
Symbol);
_mov(Reg, MemOperand);
return Reg;
}
assert("Unsupported -randomize-pool-immediates option" && false);
}
// the constant Immediate is not eligible for blinding/pooling
return Immediate;
}
template <class Machine>
typename TargetX86Base<Machine>::Traits::X86OperandMem *
TargetX86Base<Machine>::randomizeOrPoolImmediate(
typename Traits::X86OperandMem *MemOperand, int32_t RegNum) {
assert(MemOperand);
if (Ctx->getFlags().getRandomizeAndPoolImmediatesOption() == RPI_None ||
RandomizationPoolingPaused == true) {
// immediates randomization/pooling is turned off
return MemOperand;
}
// If this memory operand is already a randommized one, we do
// not randomize it again.
if (MemOperand->getRandomized())
return MemOperand;
if (Constant *C = llvm::dyn_cast_or_null<Constant>(MemOperand->getOffset())) {
if (C->shouldBeRandomizedOrPooled(Ctx)) {
// The offset of this mem operand should be blinded or pooled
Ctx->statsUpdateRPImms();
if (Ctx->getFlags().getRandomizeAndPoolImmediatesOption() ==
RPI_Randomize) {
// blind the constant offset
// FROM:
// offset[base, index, shift]
// TO:
// insert: lea offset+cookie[base], RegTemp
// => -cookie[RegTemp, index, shift]
uint32_t Value =
llvm::dyn_cast<ConstantInteger32>(MemOperand->getOffset())
->getValue();
uint32_t Cookie = Ctx->getRandomizationCookie();
Constant *Mask1 = Ctx->getConstantInt(
MemOperand->getOffset()->getType(), Cookie + Value);
Constant *Mask2 =
Ctx->getConstantInt(MemOperand->getOffset()->getType(), 0 - Cookie);
typename Traits::X86OperandMem *TempMemOperand =
Traits::X86OperandMem::create(Func, MemOperand->getType(),
MemOperand->getBase(), Mask1);
// If we have already assigned a physical register, we must come from
// advancedPhiLowering()=>lowerAssign(). In this case we should reuse
// the assigned register as this assignment is that start of its use-def
// chain. So we add RegNum argument here.
Variable *RegTemp = makeReg(MemOperand->getOffset()->getType(), RegNum);
_lea(RegTemp, TempMemOperand);
// As source operand doesn't use the dstreg, we don't need to add
// _set_dest_nonkillable().
// But if we use the same Dest Reg, that is, with RegNum
// assigned, we should add this _set_dest_nonkillable()
if (RegNum != Variable::NoRegister)
_set_dest_nonkillable();
typename Traits::X86OperandMem *NewMemOperand =
Traits::X86OperandMem::create(Func, MemOperand->getType(), RegTemp,
Mask2, MemOperand->getIndex(),
MemOperand->getShift(),
MemOperand->getSegmentRegister());
// Label this memory operand as randomized, so we won't randomize it
// again in case we call legalize() multiple times on this memory
// operand.
NewMemOperand->setRandomized(true);
return NewMemOperand;
}
if (Ctx->getFlags().getRandomizeAndPoolImmediatesOption() == RPI_Pool) {
// pool the constant offset
// FROM:
// offset[base, index, shift]
// TO:
// insert: mov $label, RegTemp
// insert: lea [base, RegTemp], RegTemp
// =>[RegTemp, index, shift]
assert(Ctx->getFlags().getRandomizeAndPoolImmediatesOption() ==
RPI_Pool);
// Memory operand should never exist as source operands in phi
// lowering assignments, so there is no need to reuse any registers
// here. For phi lowering, we should not ask for new physical
// registers in general.
// However, if we do meet Memory Operand during phi lowering, we
// should not blind or pool the immediates for now.
if (RegNum != Variable::NoRegister)
return MemOperand;
Variable *RegTemp = makeReg(IceType_i32);
IceString Label;
llvm::raw_string_ostream Label_stream(Label);
MemOperand->getOffset()->emitPoolLabel(Label_stream);
MemOperand->getOffset()->setShouldBePooled(true);
const RelocOffsetT SymOffset = 0;
bool SuppressMangling = true;
Constant *Symbol = Ctx->getConstantSym(SymOffset, Label_stream.str(),
SuppressMangling);
typename Traits::X86OperandMem *SymbolOperand =
Traits::X86OperandMem::create(
Func, MemOperand->getOffset()->getType(), nullptr, Symbol);
_mov(RegTemp, SymbolOperand);
// If we have a base variable here, we should add the lea instruction
// to add the value of the base variable to RegTemp. If there is no
// base variable, we won't need this lea instruction.
if (MemOperand->getBase()) {
typename Traits::X86OperandMem *CalculateOperand =
Traits::X86OperandMem::create(
Func, MemOperand->getType(), MemOperand->getBase(), nullptr,
RegTemp, 0, MemOperand->getSegmentRegister());
_lea(RegTemp, CalculateOperand);
_set_dest_nonkillable();
}
typename Traits::X86OperandMem *NewMemOperand =
Traits::X86OperandMem::create(Func, MemOperand->getType(), RegTemp,
nullptr, MemOperand->getIndex(),
MemOperand->getShift(),
MemOperand->getSegmentRegister());
return NewMemOperand;
}
assert("Unsupported -randomize-pool-immediates option" && false);
}
}
// the offset is not eligible for blinding or pooling, return the original
// mem operand
return MemOperand;
}
} // end of namespace X86Internal
} // end of namespace Ice
#endif // SUBZERO_SRC_ICETARGETLOWERINGX86BASEIMPL_H