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llvm-6502/lib/Target/SparcV9/SparcV9InstrInfo.cpp
Vikram S. Adve d0d06ad4f3 Extensive changes to the way code generation occurs for function 
call arguments and return values:
Now all copy operations before and after a call are generated during
selection instead of during register allocation.
The values are copied to virtual registers (or to the stack), but
in the former case these operands are marked with the correct physical
registers according to the calling convention.
Although this complicates scheduling and does not work well with
live range analysis, it simplifies the machine-dependent part of
register allocation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6465 91177308-0d34-0410-b5e6-96231b3b80d8
2003-05-31 07:32:01 +00:00

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//===-- SparcInstrInfo.cpp ------------------------------------------------===//
//
//===----------------------------------------------------------------------===//
#include "SparcInternals.h"
#include "SparcInstrSelectionSupport.h"
#include "llvm/CodeGen/InstrSelection.h"
#include "llvm/CodeGen/InstrSelectionSupport.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionInfo.h"
#include "llvm/CodeGen/MachineCodeForInstruction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Function.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include <stdlib.h>
static const uint32_t MAXLO = (1 << 10) - 1; // set bits set by %lo(*)
static const uint32_t MAXSIMM = (1 << 12) - 1; // set bits in simm13 field of OR
//---------------------------------------------------------------------------
// Function GetConstantValueAsUnsignedInt
// Function GetConstantValueAsSignedInt
//
// Convenience functions to get the value of an integral constant, for an
// appropriate integer or non-integer type that can be held in a signed
// or unsigned integer respectively. The type of the argument must be
// the following:
// Signed or unsigned integer
// Boolean
// Pointer
//
// isValidConstant is set to true if a valid constant was found.
//---------------------------------------------------------------------------
static uint64_t
GetConstantValueAsUnsignedInt(const Value *V,
bool &isValidConstant)
{
isValidConstant = true;
if (isa<Constant>(V))
if (const ConstantBool *CB = dyn_cast<ConstantBool>(V))
return (int64_t)CB->getValue();
else if (const ConstantSInt *CS = dyn_cast<ConstantSInt>(V))
return (uint64_t)CS->getValue();
else if (const ConstantUInt *CU = dyn_cast<ConstantUInt>(V))
return CU->getValue();
isValidConstant = false;
return 0;
}
int64_t
GetConstantValueAsSignedInt(const Value *V, bool &isValidConstant)
{
uint64_t C = GetConstantValueAsUnsignedInt(V, isValidConstant);
if (isValidConstant) {
if (V->getType()->isSigned() || C < INT64_MAX) // safe to cast to signed
return (int64_t) C;
else
isValidConstant = false;
}
return 0;
}
//----------------------------------------------------------------------------
// Function: CreateSETUWConst
//
// Set a 32-bit unsigned constant in the register `dest', using
// SETHI, OR in the worst case. This function correctly emulates
// the SETUW pseudo-op for SPARC v9 (if argument isSigned == false).
//
// The isSigned=true case is used to implement SETSW without duplicating code.
//
// Optimize some common cases:
// (1) Small value that fits in simm13 field of OR: don't need SETHI.
// (2) isSigned = true and C is a small negative signed value, i.e.,
// high bits are 1, and the remaining bits fit in simm13(OR).
//----------------------------------------------------------------------------
static inline void
CreateSETUWConst(const TargetMachine& target, uint32_t C,
Instruction* dest, std::vector<MachineInstr*>& mvec,
bool isSigned = false)
{
MachineInstr *miSETHI = NULL, *miOR = NULL;
// In order to get efficient code, we should not generate the SETHI if
// all high bits are 1 (i.e., this is a small signed value that fits in
// the simm13 field of OR). So we check for and handle that case specially.
// NOTE: The value C = 0x80000000 is bad: sC < 0 *and* -sC < 0.
// In fact, sC == -sC, so we have to check for this explicitly.
int32_t sC = (int32_t) C;
bool smallNegValue =isSigned && sC < 0 && sC != -sC && -sC < (int32_t)MAXSIMM;
// Set the high 22 bits in dest if non-zero and simm13 field of OR not enough
if (!smallNegValue && (C & ~MAXLO) && C > MAXSIMM) {
miSETHI = BuildMI(V9::SETHI, 2).addZImm(C).addRegDef(dest);
miSETHI->setOperandHi32(0);
mvec.push_back(miSETHI);
}
// Set the low 10 or 12 bits in dest. This is necessary if no SETHI
// was generated, or if the low 10 bits are non-zero.
if (miSETHI==NULL || C & MAXLO) {
if (miSETHI) {
// unsigned value with high-order bits set using SETHI
miOR = BuildMI(V9::ORi,3).addReg(dest).addZImm(C).addRegDef(dest);
miOR->setOperandLo32(1);
} else {
// unsigned or small signed value that fits in simm13 field of OR
assert(smallNegValue || (C & ~MAXSIMM) == 0);
miOR = BuildMI(V9::ORi, 3).addMReg(target.getRegInfo()
.getZeroRegNum())
.addSImm(sC).addRegDef(dest);
}
mvec.push_back(miOR);
}
assert((miSETHI || miOR) && "Oops, no code was generated!");
}
//----------------------------------------------------------------------------
// Function: CreateSETSWConst
//
// Set a 32-bit signed constant in the register `dest', with sign-extension
// to 64 bits. This uses SETHI, OR, SRA in the worst case.
// This function correctly emulates the SETSW pseudo-op for SPARC v9.
//
// Optimize the same cases as SETUWConst, plus:
// (1) SRA is not needed for positive or small negative values.
//----------------------------------------------------------------------------
static inline void
CreateSETSWConst(const TargetMachine& target, int32_t C,
Instruction* dest, std::vector<MachineInstr*>& mvec)
{
// Set the low 32 bits of dest
CreateSETUWConst(target, (uint32_t) C, dest, mvec, /*isSigned*/true);
// Sign-extend to the high 32 bits if needed.
// NOTE: The value C = 0x80000000 is bad: -C == C and so -C is < MAXSIMM
if (C < 0 && (C == -C || -C > (int32_t) MAXSIMM))
mvec.push_back(BuildMI(V9::SRAi6, 3).addReg(dest).addZImm(0).addRegDef(dest));
}
//----------------------------------------------------------------------------
// Function: CreateSETXConst
//
// Set a 64-bit signed or unsigned constant in the register `dest'.
// Use SETUWConst for each 32 bit word, plus a left-shift-by-32 in between.
// This function correctly emulates the SETX pseudo-op for SPARC v9.
//
// Optimize the same cases as SETUWConst for each 32 bit word.
//----------------------------------------------------------------------------
static inline void
CreateSETXConst(const TargetMachine& target, uint64_t C,
Instruction* tmpReg, Instruction* dest,
std::vector<MachineInstr*>& mvec)
{
assert(C > (unsigned int) ~0 && "Use SETUW/SETSW for 32-bit values!");
MachineInstr* MI;
// Code to set the upper 32 bits of the value in register `tmpReg'
CreateSETUWConst(target, (C >> 32), tmpReg, mvec);
// Shift tmpReg left by 32 bits
mvec.push_back(BuildMI(V9::SLLXi6, 3).addReg(tmpReg).addZImm(32)
.addRegDef(tmpReg));
// Code to set the low 32 bits of the value in register `dest'
CreateSETUWConst(target, C, dest, mvec);
// dest = OR(tmpReg, dest)
mvec.push_back(BuildMI(V9::ORr,3).addReg(dest).addReg(tmpReg).addRegDef(dest));
}
//----------------------------------------------------------------------------
// Function: CreateSETUWLabel
//
// Set a 32-bit constant (given by a symbolic label) in the register `dest'.
//----------------------------------------------------------------------------
static inline void
CreateSETUWLabel(const TargetMachine& target, Value* val,
Instruction* dest, std::vector<MachineInstr*>& mvec)
{
MachineInstr* MI;
// Set the high 22 bits in dest
MI = BuildMI(V9::SETHI, 2).addReg(val).addRegDef(dest);
MI->setOperandHi32(0);
mvec.push_back(MI);
// Set the low 10 bits in dest
MI = BuildMI(V9::ORr, 3).addReg(dest).addReg(val).addRegDef(dest);
MI->setOperandLo32(1);
mvec.push_back(MI);
}
//----------------------------------------------------------------------------
// Function: CreateSETXLabel
//
// Set a 64-bit constant (given by a symbolic label) in the register `dest'.
//----------------------------------------------------------------------------
static inline void
CreateSETXLabel(const TargetMachine& target,
Value* val, Instruction* tmpReg, Instruction* dest,
std::vector<MachineInstr*>& mvec)
{
assert(isa<Constant>(val) || isa<GlobalValue>(val) &&
"I only know about constant values and global addresses");
MachineInstr* MI;
MI = BuildMI(V9::SETHI, 2).addPCDisp(val).addRegDef(tmpReg);
MI->setOperandHi64(0);
mvec.push_back(MI);
MI = BuildMI(V9::ORi, 3).addReg(tmpReg).addPCDisp(val).addRegDef(tmpReg);
MI->setOperandLo64(1);
mvec.push_back(MI);
mvec.push_back(BuildMI(V9::SLLXi6, 3).addReg(tmpReg).addZImm(32)
.addRegDef(tmpReg));
MI = BuildMI(V9::SETHI, 2).addPCDisp(val).addRegDef(dest);
MI->setOperandHi32(0);
mvec.push_back(MI);
MI = BuildMI(V9::ORr, 3).addReg(dest).addReg(tmpReg).addRegDef(dest);
mvec.push_back(MI);
MI = BuildMI(V9::ORi, 3).addReg(dest).addPCDisp(val).addRegDef(dest);
MI->setOperandLo32(1);
mvec.push_back(MI);
}
//----------------------------------------------------------------------------
// Function: CreateUIntSetInstruction
//
// Create code to Set an unsigned constant in the register `dest'.
// Uses CreateSETUWConst, CreateSETSWConst or CreateSETXConst as needed.
// CreateSETSWConst is an optimization for the case that the unsigned value
// has all ones in the 33 high bits (so that sign-extension sets them all).
//----------------------------------------------------------------------------
static inline void
CreateUIntSetInstruction(const TargetMachine& target,
uint64_t C, Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi)
{
static const uint64_t lo32 = (uint32_t) ~0;
if (C <= lo32) // High 32 bits are 0. Set low 32 bits.
CreateSETUWConst(target, (uint32_t) C, dest, mvec);
else if ((C & ~lo32) == ~lo32 && (C & (1 << 31))) {
// All high 33 (not 32) bits are 1s: sign-extension will take care
// of high 32 bits, so use the sequence for signed int
CreateSETSWConst(target, (int32_t) C, dest, mvec);
} else if (C > lo32) {
// C does not fit in 32 bits
TmpInstruction* tmpReg = new TmpInstruction(mcfi, Type::IntTy);
CreateSETXConst(target, C, tmpReg, dest, mvec);
}
}
//----------------------------------------------------------------------------
// Function: CreateIntSetInstruction
//
// Create code to Set a signed constant in the register `dest'.
// Really the same as CreateUIntSetInstruction.
//----------------------------------------------------------------------------
static inline void
CreateIntSetInstruction(const TargetMachine& target,
int64_t C, Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi)
{
CreateUIntSetInstruction(target, (uint64_t) C, dest, mvec, mcfi);
}
//---------------------------------------------------------------------------
// Create a table of LLVM opcode -> max. immediate constant likely to
// be usable for that operation.
//---------------------------------------------------------------------------
// Entry == 0 ==> no immediate constant field exists at all.
// Entry > 0 ==> abs(immediate constant) <= Entry
//
std::vector<int> MaxConstantsTable(Instruction::OtherOpsEnd);
static int
MaxConstantForInstr(unsigned llvmOpCode)
{
int modelOpCode = -1;
if (llvmOpCode >= Instruction::BinaryOpsBegin &&
llvmOpCode < Instruction::BinaryOpsEnd)
modelOpCode = V9::ADDi;
else
switch(llvmOpCode) {
case Instruction::Ret: modelOpCode = V9::JMPLCALLi; break;
case Instruction::Malloc:
case Instruction::Alloca:
case Instruction::GetElementPtr:
case Instruction::PHINode:
case Instruction::Cast:
case Instruction::Call: modelOpCode = V9::ADDi; break;
case Instruction::Shl:
case Instruction::Shr: modelOpCode = V9::SLLXi6; break;
default: break;
};
return (modelOpCode < 0)? 0: SparcMachineInstrDesc[modelOpCode].maxImmedConst;
}
static void
InitializeMaxConstantsTable()
{
unsigned op;
assert(MaxConstantsTable.size() == Instruction::OtherOpsEnd &&
"assignments below will be illegal!");
for (op = Instruction::TermOpsBegin; op < Instruction::TermOpsEnd; ++op)
MaxConstantsTable[op] = MaxConstantForInstr(op);
for (op = Instruction::BinaryOpsBegin; op < Instruction::BinaryOpsEnd; ++op)
MaxConstantsTable[op] = MaxConstantForInstr(op);
for (op = Instruction::MemoryOpsBegin; op < Instruction::MemoryOpsEnd; ++op)
MaxConstantsTable[op] = MaxConstantForInstr(op);
for (op = Instruction::OtherOpsBegin; op < Instruction::OtherOpsEnd; ++op)
MaxConstantsTable[op] = MaxConstantForInstr(op);
}
//---------------------------------------------------------------------------
// class UltraSparcInstrInfo
//
// Purpose:
// Information about individual instructions.
// Most information is stored in the SparcMachineInstrDesc array above.
// Other information is computed on demand, and most such functions
// default to member functions in base class TargetInstrInfo.
//---------------------------------------------------------------------------
/*ctor*/
UltraSparcInstrInfo::UltraSparcInstrInfo()
: TargetInstrInfo(SparcMachineInstrDesc,
/*descSize = */ V9::NUM_TOTAL_OPCODES,
/*numRealOpCodes = */ V9::NUM_REAL_OPCODES)
{
InitializeMaxConstantsTable();
}
bool
UltraSparcInstrInfo::ConstantMayNotFitInImmedField(const Constant* CV,
const Instruction* I) const
{
if (I->getOpcode() >= MaxConstantsTable.size()) // user-defined op (or bug!)
return true;
if (isa<ConstantPointerNull>(CV)) // can always use %g0
return false;
if (const ConstantUInt* U = dyn_cast<ConstantUInt>(CV))
/* Large unsigned longs may really just be small negative signed longs */
return (labs((int64_t) U->getValue()) > MaxConstantsTable[I->getOpcode()]);
if (const ConstantSInt* S = dyn_cast<ConstantSInt>(CV))
return (labs(S->getValue()) > MaxConstantsTable[I->getOpcode()]);
if (isa<ConstantBool>(CV))
return (1 > MaxConstantsTable[I->getOpcode()]);
return true;
}
//
// Create an instruction sequence to put the constant `val' into
// the virtual register `dest'. `val' may be a Constant or a
// GlobalValue, viz., the constant address of a global variable or function.
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via MachineFunction.
//
void
UltraSparcInstrInfo::CreateCodeToLoadConst(const TargetMachine& target,
Function* F,
Value* val,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const
{
assert(isa<Constant>(val) || isa<GlobalValue>(val) &&
"I only know about constant values and global addresses");
// Use a "set" instruction for known constants or symbolic constants (labels)
// that can go in an integer reg.
// We have to use a "load" instruction for all other constants,
// in particular, floating point constants.
//
const Type* valType = val->getType();
// Unfortunate special case: a ConstantPointerRef is just a
// reference to GlobalValue.
if (isa<ConstantPointerRef>(val))
val = cast<ConstantPointerRef>(val)->getValue();
if (isa<GlobalValue>(val)) {
TmpInstruction* tmpReg =
new TmpInstruction(mcfi, PointerType::get(val->getType()), val);
CreateSETXLabel(target, val, tmpReg, dest, mvec);
} else if (valType->isIntegral()) {
bool isValidConstant;
unsigned opSize = target.getTargetData().getTypeSize(val->getType());
unsigned destSize = target.getTargetData().getTypeSize(dest->getType());
if (! dest->getType()->isSigned()) {
uint64_t C = GetConstantValueAsUnsignedInt(val, isValidConstant);
assert(isValidConstant && "Unrecognized constant");
if (opSize > destSize || (val->getType()->isSigned() && destSize < 8)) {
// operand is larger than dest,
// OR both are equal but smaller than the full register size
// AND operand is signed, so it may have extra sign bits:
// mask high bits
C = C & ((1U << 8*destSize) - 1);
}
CreateUIntSetInstruction(target, C, dest, mvec, mcfi);
} else {
int64_t C = GetConstantValueAsSignedInt(val, isValidConstant);
assert(isValidConstant && "Unrecognized constant");
if (opSize > destSize)
// operand is larger than dest: mask high bits
C = C & ((1U << 8*destSize) - 1);
if (opSize > destSize ||
(opSize == destSize && !val->getType()->isSigned()))
// sign-extend from destSize to 64 bits
C = ((C & (1U << (8*destSize - 1)))
? C | ~((1U << 8*destSize) - 1)
: C);
CreateIntSetInstruction(target, C, dest, mvec, mcfi);
}
} else {
// Make an instruction sequence to load the constant, viz:
// SETX <addr-of-constant>, tmpReg, addrReg
// LOAD /*addr*/ addrReg, /*offset*/ 0, dest
// First, create a tmp register to be used by the SETX sequence.
TmpInstruction* tmpReg =
new TmpInstruction(mcfi, PointerType::get(val->getType()), val);
// Create another TmpInstruction for the address register
TmpInstruction* addrReg =
new TmpInstruction(mcfi, PointerType::get(val->getType()), val);
// Put the address (a symbolic name) into a register
CreateSETXLabel(target, val, tmpReg, addrReg, mvec);
// Generate the load instruction
int64_t zeroOffset = 0; // to avoid ambiguity with (Value*) 0
unsigned Opcode = ChooseLoadInstruction(val->getType());
mvec.push_back(BuildMI(Opcode, 3).addReg(addrReg).
addSImm(zeroOffset).addRegDef(dest));
// Make sure constant is emitted to constant pool in assembly code.
MachineFunction::get(F).getInfo()->addToConstantPool(cast<Constant>(val));
}
}
// Create an instruction sequence to copy an integer register `val'
// to a floating point register `dest' by copying to memory and back.
// val must be an integral type. dest must be a Float or Double.
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via MachineFunction.
//
void
UltraSparcInstrInfo::CreateCodeToCopyIntToFloat(const TargetMachine& target,
Function* F,
Value* val,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const
{
assert((val->getType()->isIntegral() || isa<PointerType>(val->getType()))
&& "Source type must be integral (integer or bool) or pointer");
assert(dest->getType()->isFloatingPoint()
&& "Dest type must be float/double");
// Get a stack slot to use for the copy
int offset = MachineFunction::get(F).getInfo()->allocateLocalVar(val);
// Get the size of the source value being copied.
size_t srcSize = target.getTargetData().getTypeSize(val->getType());
// Store instruction stores `val' to [%fp+offset].
// The store and load opCodes are based on the size of the source value.
// If the value is smaller than 32 bits, we must sign- or zero-extend it
// to 32 bits since the load-float will load 32 bits.
// Note that the store instruction is the same for signed and unsigned ints.
const Type* storeType = (srcSize <= 4)? Type::IntTy : Type::LongTy;
Value* storeVal = val;
if (srcSize < target.getTargetData().getTypeSize(Type::FloatTy)) {
// sign- or zero-extend respectively
storeVal = new TmpInstruction(mcfi, storeType, val);
if (val->getType()->isSigned())
CreateSignExtensionInstructions(target, F, val, storeVal, 8*srcSize,
mvec, mcfi);
else
CreateZeroExtensionInstructions(target, F, val, storeVal, 8*srcSize,
mvec, mcfi);
}
unsigned FPReg = target.getRegInfo().getFramePointer();
mvec.push_back(BuildMI(ChooseStoreInstruction(storeType), 3)
.addReg(storeVal).addMReg(FPReg).addSImm(offset));
// Load instruction loads [%fp+offset] to `dest'.
// The type of the load opCode is the floating point type that matches the
// stored type in size:
// On SparcV9: float for int or smaller, double for long.
//
const Type* loadType = (srcSize <= 4)? Type::FloatTy : Type::DoubleTy;
mvec.push_back(BuildMI(ChooseLoadInstruction(loadType), 3)
.addMReg(FPReg).addSImm(offset).addRegDef(dest));
}
// Similarly, create an instruction sequence to copy an FP register
// `val' to an integer register `dest' by copying to memory and back.
// The generated instructions are returned in `mvec'.
// Any temp. virtual registers (TmpInstruction) created are recorded in mcfi.
// Temporary stack space required is allocated via MachineFunction.
//
void
UltraSparcInstrInfo::CreateCodeToCopyFloatToInt(const TargetMachine& target,
Function* F,
Value* val,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const
{
const Type* opTy = val->getType();
const Type* destTy = dest->getType();
assert(opTy->isFloatingPoint() && "Source type must be float/double");
assert((destTy->isIntegral() || isa<PointerType>(destTy))
&& "Dest type must be integer, bool or pointer");
// FIXME: For now, we allocate permanent space because the stack frame
// manager does not allow locals to be allocated (e.g., for alloca) after
// a temp is allocated!
//
int offset = MachineFunction::get(F).getInfo()->allocateLocalVar(val);
unsigned FPReg = target.getRegInfo().getFramePointer();
// Store instruction stores `val' to [%fp+offset].
// The store opCode is based only the source value being copied.
//
mvec.push_back(BuildMI(ChooseStoreInstruction(opTy), 3)
.addReg(val).addMReg(FPReg).addSImm(offset));
// Load instruction loads [%fp+offset] to `dest'.
// The type of the load opCode is the integer type that matches the
// source type in size:
// On SparcV9: int for float, long for double.
// Note that we *must* use signed loads even for unsigned dest types, to
// ensure correct sign-extension for UByte, UShort or UInt:
//
const Type* loadTy = (opTy == Type::FloatTy)? Type::IntTy : Type::LongTy;
mvec.push_back(BuildMI(ChooseLoadInstruction(loadTy), 3).addMReg(FPReg)
.addSImm(offset).addRegDef(dest));
}
// Create instruction(s) to copy src to dest, for arbitrary types
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via MachineFunction.
//
void
UltraSparcInstrInfo::CreateCopyInstructionsByType(const TargetMachine& target,
Function *F,
Value* src,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const
{
bool loadConstantToReg = false;
const Type* resultType = dest->getType();
MachineOpCode opCode = ChooseAddInstructionByType(resultType);
if (opCode == V9::INVALID_OPCODE) {
assert(0 && "Unsupported result type in CreateCopyInstructionsByType()");
return;
}
// if `src' is a constant that doesn't fit in the immed field or if it is
// a global variable (i.e., a constant address), generate a load
// instruction instead of an add
//
if (isa<Constant>(src)) {
unsigned int machineRegNum;
int64_t immedValue;
MachineOperand::MachineOperandType opType =
ChooseRegOrImmed(src, opCode, target, /*canUseImmed*/ true,
machineRegNum, immedValue);
if (opType == MachineOperand::MO_VirtualRegister)
loadConstantToReg = true;
}
else if (isa<GlobalValue>(src))
loadConstantToReg = true;
if (loadConstantToReg) {
// `src' is constant and cannot fit in immed field for the ADD
// Insert instructions to "load" the constant into a register
target.getInstrInfo().CreateCodeToLoadConst(target, F, src, dest,
mvec, mcfi);
} else {
// Create a reg-to-reg copy instruction for the given type:
// -- For FP values, create a FMOVS or FMOVD instruction
// -- For non-FP values, create an add-with-0 instruction (opCode as above)
// Make `src' the second operand, in case it is a small constant!
//
MachineInstr* MI;
if (resultType->isFloatingPoint())
MI = (BuildMI(resultType == Type::FloatTy? V9::FMOVS : V9::FMOVD, 2)
.addReg(src).addRegDef(dest));
else {
const Type* Ty =isa<PointerType>(resultType)? Type::ULongTy :resultType;
MI = (BuildMI(opCode, 3)
.addSImm((int64_t) 0).addReg(src).addRegDef(dest));
}
mvec.push_back(MI);
}
}
// Helper function for sign-extension and zero-extension.
// For SPARC v9, we sign-extend the given operand using SLL; SRA/SRL.
inline void
CreateBitExtensionInstructions(bool signExtend,
const TargetMachine& target,
Function* F,
Value* srcVal,
Value* destVal,
unsigned int numLowBits,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi)
{
MachineInstr* M;
assert(numLowBits <= 32 && "Otherwise, nothing should be done here!");
if (numLowBits < 32) {
// SLL is needed since operand size is < 32 bits.
TmpInstruction *tmpI = new TmpInstruction(mcfi, destVal->getType(),
srcVal, destVal, "make32");
mvec.push_back(BuildMI(V9::SLLXi6, 3).addReg(srcVal)
.addZImm(32-numLowBits).addRegDef(tmpI));
srcVal = tmpI;
}
mvec.push_back(BuildMI(signExtend? V9::SRAi6 : V9::SRLi6, 3)
.addReg(srcVal).addZImm(32-numLowBits).addRegDef(destVal));
}
// Create instruction sequence to produce a sign-extended register value
// from an arbitrary-sized integer value (sized in bits, not bytes).
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via MachineFunction.
//
void
UltraSparcInstrInfo::CreateSignExtensionInstructions(
const TargetMachine& target,
Function* F,
Value* srcVal,
Value* destVal,
unsigned int numLowBits,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const
{
CreateBitExtensionInstructions(/*signExtend*/ true, target, F, srcVal,
destVal, numLowBits, mvec, mcfi);
}
// Create instruction sequence to produce a zero-extended register value
// from an arbitrary-sized integer value (sized in bits, not bytes).
// For SPARC v9, we sign-extend the given operand using SLL; SRL.
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via MachineFunction.
//
void
UltraSparcInstrInfo::CreateZeroExtensionInstructions(
const TargetMachine& target,
Function* F,
Value* srcVal,
Value* destVal,
unsigned int numLowBits,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const
{
CreateBitExtensionInstructions(/*signExtend*/ false, target, F, srcVal,
destVal, numLowBits, mvec, mcfi);
}
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