third_party/subzero/src/IceInstX8664.cpp - SwiftShader - Git at Google

 //===- subzero/src/IceInstX8664.cpp - X86-64 instruction implementation ---===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief This file defines X8664 specific data related to X8664 Instructions
 /// and Instruction traits.
 ///
 /// These are declared in the IceTargetLoweringX8664Traits.h header file.
 ///
 /// This file also defines X8664 operand specific methods (dump and emit.)
 ///
 //===----------------------------------------------------------------------===//
 #include "IceInstX8664.h"

 #include "IceAssemblerX8664.h"
 #include "IceCfg.h"
 #include "IceCfgNode.h"
 #include "IceConditionCodesX8664.h"
 #include "IceInst.h"
 #include "IceRegistersX8664.h"
 #include "IceTargetLoweringX8664.h"
 #include "IceOperand.h"

 namespace Ice {

 namespace X8664 {

 const TargetX8664Traits::InstBrAttributesType
     TargetX8664Traits::InstBrAttributes[] = {
 #define X(val, encode, opp, dump, emit)                                        \
   { X8664::Traits::Cond::opp, dump, emit }                                     \
   ,
         ICEINSTX8664BR_TABLE
 #undef X
 };

 const TargetX8664Traits::InstCmppsAttributesType
     TargetX8664Traits::InstCmppsAttributes[] = {
 #define X(val, emit)                                                           \
   { emit }                                                                     \
   ,
         ICEINSTX8664CMPPS_TABLE
 #undef X
 };

 const TargetX8664Traits::TypeAttributesType
     TargetX8664Traits::TypeAttributes[] = {
 #define X(tag, elty, cvt, sdss, pdps, spsd, int_, unpack, pack, width, fld)    \
   { cvt, sdss, pdps, spsd, int_, unpack, pack, width, fld }                    \
   ,
         ICETYPEX8664_TABLE
 #undef X
 };

 void TargetX8664Traits::X86Operand::dump(const Cfg *, Ostream &Str) const {
   if (BuildDefs::dump())
     Str << "<OperandX8664>";
 }

 TargetX8664Traits::X86OperandMem::X86OperandMem(Cfg *Func, Type Ty,
                                                 Variable *Base,
                                                 Constant *Offset,
                                                 Variable *Index, uint16_t Shift,
                                                 bool IsRebased)
     : X86Operand(kMem, Ty), Base(Base), Offset(Offset), Index(Index),
       Shift(Shift), IsRebased(IsRebased) {
   assert(Shift <= 3);
   Vars = nullptr;
   NumVars = 0;
   if (Base)
     ++NumVars;
   if (Index)
     ++NumVars;
   if (NumVars) {
     Vars = Func->allocateArrayOf<Variable *>(NumVars);
     SizeT I = 0;
     if (Base)
       Vars[I++] = Base;
     if (Index)
       Vars[I++] = Index;
     assert(I == NumVars);
   }
 }

 namespace {
 int32_t getRematerializableOffset(Variable *Var,
                                   const ::Ice::X8664::TargetX8664 *Target) {
   int32_t Disp = Var->getStackOffset();
   const auto RegNum = Var->getRegNum();
   if (RegNum == Target->getFrameReg()) {
     Disp += Target->getFrameFixedAllocaOffset();
   } else if (RegNum != Target->getStackReg()) {
     llvm::report_fatal_error("Unexpected rematerializable register type");
   }
   return Disp;
 }
 } // end of anonymous namespace

 void TargetX8664Traits::X86OperandMem::emit(const Cfg *Func) const {
   if (!BuildDefs::dump())
     return;
   const auto *Target =
       static_cast<const ::Ice::X8664::TargetX8664 *>(Func->getTarget());
   // If the base is rematerializable, we need to replace it with the correct
   // physical register (stack or base pointer), and update the Offset.
   const bool NeedSandboxing = Target->needSandboxing();
   int32_t Disp = 0;
   if (getBase() && getBase()->isRematerializable()) {
     Disp += getRematerializableOffset(getBase(), Target);
   }
   // The index should never be rematerializable.  But if we ever allow it, then
   // we should make sure the rematerialization offset is shifted by the Shift
   // value.
   if (getIndex())
     assert(!getIndex()->isRematerializable());
   Ostream &Str = Func->getContext()->getStrEmit();
   // Emit as Offset(Base,Index,1<<Shift). Offset is emitted without the leading
   // '$'. Omit the (Base,Index,1<<Shift) part if Base==nullptr.
   if (getOffset() == nullptr && Disp == 0) {
     // No offset, emit nothing.
   } else if (getOffset() == nullptr && Disp != 0) {
     Str << Disp;
   } else if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(Offset)) {
     if (Base == nullptr || CI->getValue() || Disp != 0)
       // Emit a non-zero offset without a leading '$'.
       Str << CI->getValue() + Disp;
   } else if (const auto *CR = llvm::dyn_cast<ConstantRelocatable>(Offset)) {
     // TODO(sehr): ConstantRelocatable still needs updating for
     // rematerializable base/index and Disp.
     assert(Disp == 0);
     const bool UseNonsfi = getFlags().getUseNonsfi();
     CR->emitWithoutPrefix(Target, UseNonsfi ? "@GOTOFF" : "");
     assert(!UseNonsfi);
     if (Base == nullptr && Index == nullptr) {
       // rip-relative addressing.
       if (NeedSandboxing) {
         Str << "(%rip)";
       } else {
         Str << "(%eip)";
       }
     }
   } else {
     llvm_unreachable("Invalid offset type for x86 mem operand");
   }

   if (Base == nullptr && Index == nullptr) {
     return;
   }

   Str << "(";
   if (Base != nullptr) {
     const Variable *B = Base;
     if (!NeedSandboxing) {
       // TODO(jpp): stop abusing the operand's type to identify LEAs.
       const Type MemType = getType();
       if (Base->getType() != IceType_i32 && MemType != IceType_void && !isVectorType(MemType)) {
         // X86-64 is ILP32, but %rsp and %rbp are accessed as 64-bit registers.
         // For filetype=asm, they need to be emitted as their 32-bit siblings.
         assert(Base->getType() == IceType_i64);
         assert(getEncodedGPR(Base->getRegNum()) == RegX8664::Encoded_Reg_rsp ||
                getEncodedGPR(Base->getRegNum()) == RegX8664::Encoded_Reg_rbp ||
                getType() == IceType_void);
         B = B->asType(Func, IceType_i32, X8664::Traits::getGprForType(
                                              IceType_i32, Base->getRegNum()));
       }
     }

     B->emit(Func);
   }

   if (Index != nullptr) {
     Variable *I = Index;
     Str << ",";
     I->emit(Func);
     if (Shift)
       Str << "," << (1u << Shift);
   }

   Str << ")";
 }

 void TargetX8664Traits::X86OperandMem::dump(const Cfg *Func,
                                             Ostream &Str) const {
   if (!BuildDefs::dump())
     return;
   bool Dumped = false;
   Str << "[";
   int32_t Disp = 0;
   const auto *Target =
       static_cast<const ::Ice::X8664::TargetX8664 *>(Func->getTarget());
   if (getBase() && getBase()->isRematerializable()) {
     Disp += getRematerializableOffset(getBase(), Target);
   }
   if (Base) {
     if (Func)
       Base->dump(Func);
     else
       Base->dump(Str);
     Dumped = true;
   }
   if (Index) {
     if (Base)
       Str << "+";
     if (Shift > 0)
       Str << (1u << Shift) << "*";
     if (Func)
       Index->dump(Func);
     else
       Index->dump(Str);
     Dumped = true;
   }
   if (Disp) {
     if (Disp > 0)
       Str << "+";
     Str << Disp;
     Dumped = true;
   }
   // Pretty-print the Offset.
   bool OffsetIsZero = false;
   bool OffsetIsNegative = false;
   if (!Offset) {
     OffsetIsZero = true;
   } else if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(Offset)) {
     OffsetIsZero = (CI->getValue() == 0);
     OffsetIsNegative = (static_cast<int32_t>(CI->getValue()) < 0);
   } else {
     assert(llvm::isa<ConstantRelocatable>(Offset));
   }
   if (Dumped) {
     if (!OffsetIsZero) {     // Suppress if Offset is known to be 0
       if (!OffsetIsNegative) // Suppress if Offset is known to be negative
         Str << "+";
       Offset->dump(Func, Str);
     }
   } else {
     // There is only the offset.
     Offset->dump(Func, Str);
   }
   Str << "]";
 }

 TargetX8664Traits::Address TargetX8664Traits::X86OperandMem::toAsmAddress(
     TargetX8664Traits::Assembler *Asm,
     const Ice::TargetLowering *TargetLowering, bool IsLeaAddr) const {
   (void)IsLeaAddr;
   const auto *Target =
       static_cast<const ::Ice::X8664::TargetX8664 *>(TargetLowering);
   int32_t Disp = 0;
   if (getBase() && getBase()->isRematerializable()) {
     Disp += getRematerializableOffset(getBase(), Target);
   }
   if (getIndex() != nullptr) {
     assert(!getIndex()->isRematerializable());
   }

   AssemblerFixup *Fixup = nullptr;
   // Determine the offset (is it relocatable?)
   if (getOffset() != nullptr) {
     if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(getOffset())) {
       Disp += static_cast<int32_t>(CI->getValue());
     } else if (const auto *CR =
                    llvm::dyn_cast<ConstantRelocatable>(getOffset())) {
       const auto FixupKind =
           (getBase() != nullptr || getIndex() != nullptr) ? FK_Abs : FK_PcRel;
       const RelocOffsetT DispAdjustment = FixupKind == FK_PcRel ? 4 : 0;
       Fixup = Asm->createFixup(FixupKind, CR);
       Fixup->set_addend(-DispAdjustment);
       Disp = CR->getOffset();
     } else {
       llvm_unreachable("Unexpected offset type");
     }
   }

   // Now convert to the various possible forms.
   if (getBase() && getIndex()) {
     const bool NeedSandboxing = Target->needSandboxing();
     (void)NeedSandboxing;
     assert(!NeedSandboxing || IsLeaAddr ||
            (getBase()->getRegNum() == Traits::RegisterSet::Reg_r15) ||
            (getBase()->getRegNum() == Traits::RegisterSet::Reg_rsp) ||
            (getBase()->getRegNum() == Traits::RegisterSet::Reg_rbp));
     return X8664::Traits::Address(getEncodedGPR(getBase()->getRegNum()),
                                   getEncodedGPR(getIndex()->getRegNum()),
                                   X8664::Traits::ScaleFactor(getShift()), Disp,
                                   Fixup);
   }

   if (getBase()) {
     return X8664::Traits::Address(getEncodedGPR(getBase()->getRegNum()), Disp,
                                   Fixup);
   }

   if (getIndex()) {
     return X8664::Traits::Address(getEncodedGPR(getIndex()->getRegNum()),
                                   X8664::Traits::ScaleFactor(getShift()), Disp,
                                   Fixup);
   }

   if (Fixup == nullptr) {
     // Absolute addresses are not allowed in Nexes -- they must be rebased
     // w.r.t. %r15.
     // Exception: LEAs are fine because they do not touch memory.
     assert(!Target->needSandboxing() || IsLeaAddr);
     return X8664::Traits::Address::Absolute(Disp);
   }

   return X8664::Traits::Address::RipRelative(Disp, Fixup);
 }

 TargetX8664Traits::Address
 TargetX8664Traits::VariableSplit::toAsmAddress(const Cfg *Func) const {
   assert(!Var->hasReg());
   const ::Ice::TargetLowering *Target = Func->getTarget();
   int32_t Offset = Var->getStackOffset() + getOffset();
   return X8664::Traits::Address(getEncodedGPR(Target->getFrameOrStackReg()),
                                 Offset, AssemblerFixup::NoFixup);
 }

 void TargetX8664Traits::VariableSplit::emit(const Cfg *Func) const {
   if (!BuildDefs::dump())
     return;
   Ostream &Str = Func->getContext()->getStrEmit();
   assert(!Var->hasReg());
   // The following is copied/adapted from TargetX8664::emitVariable().
   const ::Ice::TargetLowering *Target = Func->getTarget();
   constexpr Type Ty = IceType_i32;
   int32_t Offset = Var->getStackOffset() + getOffset();
   if (Offset)
     Str << Offset;
   Str << "(%" << Target->getRegName(Target->getFrameOrStackReg(), Ty) << ")";
 }

 void TargetX8664Traits::VariableSplit::dump(const Cfg *Func,
                                             Ostream &Str) const {
   if (!BuildDefs::dump())
     return;
   switch (Part) {
   case Low:
     Str << "low";
     break;
   case High:
     Str << "high";
     break;
   }
   Str << "(";
   if (Func)
     Var->dump(Func);
   else
     Var->dump(Str);
   Str << ")";
 }

 } // namespace X8664
 } // end of namespace Ice

 X86INSTS_DEFINE_STATIC_DATA(X8664, X8664::Traits)
	//===- subzero/src/IceInstX8664.cpp - X86-64 instruction implementation ---===//
	//
	// The Subzero Code Generator
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	///
	/// \file
	/// \brief This file defines X8664 specific data related to X8664 Instructions
	/// and Instruction traits.
	///
	/// These are declared in the IceTargetLoweringX8664Traits.h header file.
	///
	/// This file also defines X8664 operand specific methods (dump and emit.)
	///
	//===----------------------------------------------------------------------===//
	#include "IceInstX8664.h"

	#include "IceAssemblerX8664.h"
	#include "IceCfg.h"
	#include "IceCfgNode.h"
	#include "IceConditionCodesX8664.h"
	#include "IceInst.h"
	#include "IceRegistersX8664.h"
	#include "IceTargetLoweringX8664.h"
	#include "IceOperand.h"

	namespace Ice {

	namespace X8664 {

	const TargetX8664Traits::InstBrAttributesType
	TargetX8664Traits::InstBrAttributes[] = {
	#define X(val, encode, opp, dump, emit) \
	{ X8664::Traits::Cond::opp, dump, emit } \
	,
	ICEINSTX8664BR_TABLE
	#undef X
	};

	const TargetX8664Traits::InstCmppsAttributesType
	TargetX8664Traits::InstCmppsAttributes[] = {
	#define X(val, emit) \
	{ emit } \
	,
	ICEINSTX8664CMPPS_TABLE
	#undef X
	};

	const TargetX8664Traits::TypeAttributesType
	TargetX8664Traits::TypeAttributes[] = {
	#define X(tag, elty, cvt, sdss, pdps, spsd, int_, unpack, pack, width, fld) \
	{ cvt, sdss, pdps, spsd, int_, unpack, pack, width, fld } \
	,
	ICETYPEX8664_TABLE
	#undef X
	};

	void TargetX8664Traits::X86Operand::dump(const Cfg *, Ostream &Str) const {
	if (BuildDefs::dump())
	Str << "<OperandX8664>";
	}

	TargetX8664Traits::X86OperandMem::X86OperandMem(Cfg *Func, Type Ty,
	Variable *Base,
	Constant *Offset,
	Variable *Index, uint16_t Shift,
	bool IsRebased)
	: X86Operand(kMem, Ty), Base(Base), Offset(Offset), Index(Index),
	Shift(Shift), IsRebased(IsRebased) {
	assert(Shift <= 3);
	Vars = nullptr;
	NumVars = 0;
	if (Base)
	++NumVars;
	if (Index)
	++NumVars;
	if (NumVars) {
	Vars = Func->allocateArrayOf<Variable *>(NumVars);
	SizeT I = 0;
	if (Base)
	Vars[I++] = Base;
	if (Index)
	Vars[I++] = Index;
	assert(I == NumVars);
	}
	}

	namespace {
	int32_t getRematerializableOffset(Variable *Var,
	const ::Ice::X8664::TargetX8664 *Target) {
	int32_t Disp = Var->getStackOffset();
	const auto RegNum = Var->getRegNum();
	if (RegNum == Target->getFrameReg()) {
	Disp += Target->getFrameFixedAllocaOffset();
	} else if (RegNum != Target->getStackReg()) {
	llvm::report_fatal_error("Unexpected rematerializable register type");
	}
	return Disp;
	}
	} // end of anonymous namespace

	void TargetX8664Traits::X86OperandMem::emit(const Cfg *Func) const {
	if (!BuildDefs::dump())
	return;
	const auto *Target =
	static_cast<const ::Ice::X8664::TargetX8664 *>(Func->getTarget());
	// If the base is rematerializable, we need to replace it with the correct
	// physical register (stack or base pointer), and update the Offset.
	const bool NeedSandboxing = Target->needSandboxing();
	int32_t Disp = 0;
	if (getBase() && getBase()->isRematerializable()) {
	Disp += getRematerializableOffset(getBase(), Target);
	}
	// The index should never be rematerializable. But if we ever allow it, then
	// we should make sure the rematerialization offset is shifted by the Shift
	// value.
	if (getIndex())
	assert(!getIndex()->isRematerializable());
	Ostream &Str = Func->getContext()->getStrEmit();
	// Emit as Offset(Base,Index,1<<Shift). Offset is emitted without the leading
	// '$'. Omit the (Base,Index,1<<Shift) part if Base==nullptr.
	if (getOffset() == nullptr && Disp == 0) {
	// No offset, emit nothing.
	} else if (getOffset() == nullptr && Disp != 0) {
	Str << Disp;
	} else if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(Offset)) {
	if (Base == nullptr \|\| CI->getValue() \|\| Disp != 0)
	// Emit a non-zero offset without a leading '$'.
	Str << CI->getValue() + Disp;
	} else if (const auto *CR = llvm::dyn_cast<ConstantRelocatable>(Offset)) {
	// TODO(sehr): ConstantRelocatable still needs updating for
	// rematerializable base/index and Disp.
	assert(Disp == 0);
	const bool UseNonsfi = getFlags().getUseNonsfi();
	CR->emitWithoutPrefix(Target, UseNonsfi ? "@GOTOFF" : "");
	assert(!UseNonsfi);
	if (Base == nullptr && Index == nullptr) {
	// rip-relative addressing.
	if (NeedSandboxing) {
	Str << "(%rip)";
	} else {
	Str << "(%eip)";
	}
	}
	} else {
	llvm_unreachable("Invalid offset type for x86 mem operand");
	}

	if (Base == nullptr && Index == nullptr) {
	return;
	}

	Str << "(";
	if (Base != nullptr) {
	const Variable *B = Base;
	if (!NeedSandboxing) {
	// TODO(jpp): stop abusing the operand's type to identify LEAs.
	const Type MemType = getType();
	if (Base->getType() != IceType_i32 && MemType != IceType_void && !isVectorType(MemType)) {
	// X86-64 is ILP32, but %rsp and %rbp are accessed as 64-bit registers.
	// For filetype=asm, they need to be emitted as their 32-bit siblings.
	assert(Base->getType() == IceType_i64);
	assert(getEncodedGPR(Base->getRegNum()) == RegX8664::Encoded_Reg_rsp \|\|
	getEncodedGPR(Base->getRegNum()) == RegX8664::Encoded_Reg_rbp \|\|
	getType() == IceType_void);
	B = B->asType(Func, IceType_i32, X8664::Traits::getGprForType(
	IceType_i32, Base->getRegNum()));
	}
	}

	B->emit(Func);
	}

	if (Index != nullptr) {
	Variable *I = Index;
	Str << ",";
	I->emit(Func);
	if (Shift)
	Str << "," << (1u << Shift);
	}

	Str << ")";
	}

	void TargetX8664Traits::X86OperandMem::dump(const Cfg *Func,
	Ostream &Str) const {
	if (!BuildDefs::dump())
	return;
	bool Dumped = false;
	Str << "[";
	int32_t Disp = 0;
	const auto *Target =
	static_cast<const ::Ice::X8664::TargetX8664 *>(Func->getTarget());
	if (getBase() && getBase()->isRematerializable()) {
	Disp += getRematerializableOffset(getBase(), Target);
	}
	if (Base) {
	if (Func)
	Base->dump(Func);
	else
	Base->dump(Str);
	Dumped = true;
	}
	if (Index) {
	if (Base)
	Str << "+";
	if (Shift > 0)
	Str << (1u << Shift) << "*";
	if (Func)
	Index->dump(Func);
	else
	Index->dump(Str);
	Dumped = true;
	}
	if (Disp) {
	if (Disp > 0)
	Str << "+";
	Str << Disp;
	Dumped = true;
	}
	// Pretty-print the Offset.
	bool OffsetIsZero = false;
	bool OffsetIsNegative = false;
	if (!Offset) {
	OffsetIsZero = true;
	} else if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(Offset)) {
	OffsetIsZero = (CI->getValue() == 0);
	OffsetIsNegative = (static_cast<int32_t>(CI->getValue()) < 0);
	} else {
	assert(llvm::isa<ConstantRelocatable>(Offset));
	}
	if (Dumped) {
	if (!OffsetIsZero) { // Suppress if Offset is known to be 0
	if (!OffsetIsNegative) // Suppress if Offset is known to be negative
	Str << "+";
	Offset->dump(Func, Str);
	}
	} else {
	// There is only the offset.
	Offset->dump(Func, Str);
	}
	Str << "]";
	}

	TargetX8664Traits::Address TargetX8664Traits::X86OperandMem::toAsmAddress(
	TargetX8664Traits::Assembler *Asm,
	const Ice::TargetLowering *TargetLowering, bool IsLeaAddr) const {
	(void)IsLeaAddr;
	const auto *Target =
	static_cast<const ::Ice::X8664::TargetX8664 *>(TargetLowering);
	int32_t Disp = 0;
	if (getBase() && getBase()->isRematerializable()) {
	Disp += getRematerializableOffset(getBase(), Target);
	}
	if (getIndex() != nullptr) {
	assert(!getIndex()->isRematerializable());
	}

	AssemblerFixup *Fixup = nullptr;
	// Determine the offset (is it relocatable?)
	if (getOffset() != nullptr) {
	if (const auto *CI = llvm::dyn_cast<ConstantInteger32>(getOffset())) {
	Disp += static_cast<int32_t>(CI->getValue());
	} else if (const auto *CR =
	llvm::dyn_cast<ConstantRelocatable>(getOffset())) {
	const auto FixupKind =
	(getBase() != nullptr \|\| getIndex() != nullptr) ? FK_Abs : FK_PcRel;
	const RelocOffsetT DispAdjustment = FixupKind == FK_PcRel ? 4 : 0;
	Fixup = Asm->createFixup(FixupKind, CR);
	Fixup->set_addend(-DispAdjustment);
	Disp = CR->getOffset();
	} else {
	llvm_unreachable("Unexpected offset type");
	}
	}

	// Now convert to the various possible forms.
	if (getBase() && getIndex()) {
	const bool NeedSandboxing = Target->needSandboxing();
	(void)NeedSandboxing;
	assert(!NeedSandboxing \|\| IsLeaAddr \|\|
	(getBase()->getRegNum() == Traits::RegisterSet::Reg_r15) \|\|
	(getBase()->getRegNum() == Traits::RegisterSet::Reg_rsp) \|\|
	(getBase()->getRegNum() == Traits::RegisterSet::Reg_rbp));
	return X8664::Traits::Address(getEncodedGPR(getBase()->getRegNum()),
	getEncodedGPR(getIndex()->getRegNum()),
	X8664::Traits::ScaleFactor(getShift()), Disp,
	Fixup);
	}

	if (getBase()) {
	return X8664::Traits::Address(getEncodedGPR(getBase()->getRegNum()), Disp,
	Fixup);
	}

	if (getIndex()) {
	return X8664::Traits::Address(getEncodedGPR(getIndex()->getRegNum()),
	X8664::Traits::ScaleFactor(getShift()), Disp,
	Fixup);
	}

	if (Fixup == nullptr) {
	// Absolute addresses are not allowed in Nexes -- they must be rebased
	// w.r.t. %r15.
	// Exception: LEAs are fine because they do not touch memory.
	assert(!Target->needSandboxing() \|\| IsLeaAddr);
	return X8664::Traits::Address::Absolute(Disp);
	}

	return X8664::Traits::Address::RipRelative(Disp, Fixup);
	}

	TargetX8664Traits::Address
	TargetX8664Traits::VariableSplit::toAsmAddress(const Cfg *Func) const {
	assert(!Var->hasReg());
	const ::Ice::TargetLowering *Target = Func->getTarget();
	int32_t Offset = Var->getStackOffset() + getOffset();
	return X8664::Traits::Address(getEncodedGPR(Target->getFrameOrStackReg()),
	Offset, AssemblerFixup::NoFixup);
	}

	void TargetX8664Traits::VariableSplit::emit(const Cfg *Func) const {
	if (!BuildDefs::dump())
	return;
	Ostream &Str = Func->getContext()->getStrEmit();
	assert(!Var->hasReg());
	// The following is copied/adapted from TargetX8664::emitVariable().
	const ::Ice::TargetLowering *Target = Func->getTarget();
	constexpr Type Ty = IceType_i32;
	int32_t Offset = Var->getStackOffset() + getOffset();
	if (Offset)
	Str << Offset;
	Str << "(%" << Target->getRegName(Target->getFrameOrStackReg(), Ty) << ")";
	}

	void TargetX8664Traits::VariableSplit::dump(const Cfg *Func,
	Ostream &Str) const {
	if (!BuildDefs::dump())
	return;
	switch (Part) {
	case Low:
	Str << "low";
	break;
	case High:
	Str << "high";
	break;
	}
	Str << "(";
	if (Func)
	Var->dump(Func);
	else
	Var->dump(Str);
	Str << ")";
	}

	} // namespace X8664
	} // end of namespace Ice

	X86INSTS_DEFINE_STATIC_DATA(X8664, X8664::Traits)