-// $Id$ -*-c++-*-
-//***************************************************************************
-// File:
-// InstrSelectionSupport.h
+//===-- InstrSelectionSupport.cpp -----------------------------------------===//
+//
+// Target-independent instruction selection code. See SparcInstrSelection.cpp
+// for usage.
//
-// Purpose:
-// Target-independent instruction selection code.
-// See SparcInstrSelection.cpp for usage.
-//
-// History:
-// 10/10/01 - Vikram Adve - Created
-//**************************************************************************/
+//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/InstrSelectionSupport.h"
#include "llvm/CodeGen/InstrSelection.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineInstrAnnot.h"
#include "llvm/CodeGen/MachineCodeForInstruction.h"
-#include "llvm/CodeGen/MachineCodeForMethod.h"
+#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/InstrForest.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/MachineRegInfo.h"
+#include "llvm/Target/MachineInstrInfo.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
-#include "llvm/BasicBlock.h"
#include "llvm/Type.h"
#include "llvm/iMemory.h"
using std::vector;
//*************************** Local Functions ******************************/
+// Generate code to load the constant into a TmpInstruction (virtual reg) and
+// returns the virtual register.
+//
static TmpInstruction*
InsertCodeToLoadConstant(Function *F,
Value* opValue,
vector<MachineInstr*>& loadConstVec,
TargetMachine& target)
{
- vector<TmpInstruction*> tempVec;
-
// Create a tmp virtual register to hold the constant.
TmpInstruction* tmpReg = new TmpInstruction(opValue);
- MachineCodeForInstruction &MCFI = MachineCodeForInstruction::get(vmInstr);
- MCFI.addTemp(tmpReg);
+ MachineCodeForInstruction &mcfi = MachineCodeForInstruction::get(vmInstr);
+ mcfi.addTemp(tmpReg);
- target.getInstrInfo().CreateCodeToLoadConst(F, opValue, tmpReg,
- loadConstVec, tempVec);
-
- // Register the new tmp values created for this m/c instruction sequence
- for (unsigned i=0; i < tempVec.size(); i++)
- MCFI.addTemp(tempVec[i]);
+ target.getInstrInfo().CreateCodeToLoadConst(target, F, opValue, tmpReg,
+ loadConstVec, mcfi);
// Record the mapping from the tmp VM instruction to machine instruction.
// Do this for all machine instructions that were not mapped to any
//---------------------------------------------------------------------------
+// Function GetConstantValueAsUnsignedInt
// Function GetConstantValueAsSignedInt
//
-// Convenience function to get the value of an integer constant, for an
-// appropriate integer or non-integer type that can be held in an integer.
-// The type of the argument must be the following:
+// 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.
//---------------------------------------------------------------------------
+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)
{
- if (!isa<Constant>(V))
- {
+ 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;
- }
-
- isValidConstant = true;
-
- if (V->getType() == Type::BoolTy)
- return (int64_t) cast<ConstantBool>(V)->getValue();
-
- if (V->getType()->isIntegral())
- {
- if (V->getType()->isSigned())
- return cast<ConstantSInt>(V)->getValue();
-
- assert(V->getType()->isUnsigned());
- uint64_t Val = cast<ConstantUInt>(V)->getValue();
- if (Val < INT64_MAX) // then safe to cast to signed
- return (int64_t)Val;
- }
-
- isValidConstant = false;
+ }
return 0;
}
//
// Purpose:
// Fold a chain of GetElementPtr instructions containing only
-// structure offsets into an equivalent (Pointer, IndexVector) pair.
+// constant offsets into an equivalent (Pointer, IndexVector) pair.
// Returns the pointer Value, and stores the resulting IndexVector
-// in argument chainIdxVec.
+// in argument chainIdxVec. This is a helper function for
+// FoldConstantIndices that does the actual folding.
//---------------------------------------------------------------------------
-Value*
-FoldGetElemChain(const InstructionNode* getElemInstrNode,
- vector<Value*>& chainIdxVec)
+
+// Check for a constant 0.
+inline bool
+IsZero(Value* idx)
{
- MemAccessInst* getElemInst = (MemAccessInst*)
- getElemInstrNode->getInstruction();
-
+ return (idx == ConstantSInt::getNullValue(idx->getType()));
+}
+
+static Value*
+FoldGetElemChain(InstrTreeNode* ptrNode, vector<Value*>& chainIdxVec,
+ bool lastInstHasLeadingNonZero)
+{
+ InstructionNode* gepNode = dyn_cast<InstructionNode>(ptrNode);
+ GetElementPtrInst* gepInst =
+ dyn_cast_or_null<GetElementPtrInst>(gepNode ? gepNode->getInstruction() :0);
+
+ // ptr value is not computed in this tree or ptr value does not come from GEP
+ // instruction
+ if (gepInst == NULL)
+ return NULL;
+
// Return NULL if we don't fold any instructions in.
Value* ptrVal = NULL;
- // The incoming index vector must be for the user of the chain.
- // Its leading index must be [0] and we insert indices after that.
- assert(chainIdxVec.size() > 0 &&
- isa<ConstantUInt>(chainIdxVec.front()) &&
- cast<ConstantUInt>(chainIdxVec.front())->getValue() == 0);
-
// Now chase the chain of getElementInstr instructions, if any.
- // Check for any array indices and stop there.
+ // Check for any non-constant indices and stop there.
+ // Also, stop if the first index of child is a non-zero array index
+ // and the last index of the current node is a non-array index:
+ // in that case, a non-array declared type is being accessed as an array
+ // which is not type-safe, but could be legal.
//
- const InstrTreeNode* ptrChild = getElemInstrNode;
- while (ptrChild->getOpLabel() == Instruction::GetElementPtr ||
- ptrChild->getOpLabel() == GetElemPtrIdx)
+ InstructionNode* ptrChild = gepNode;
+ while (ptrChild && (ptrChild->getOpLabel() == Instruction::GetElementPtr ||
+ ptrChild->getOpLabel() == GetElemPtrIdx))
{
// Child is a GetElemPtr instruction
- getElemInst = (MemAccessInst*)
- ((InstructionNode*) ptrChild)->getInstruction();
- const vector<Value*>& idxVec = getElemInst->copyIndices();
- bool allStructureOffsets = true;
-
- // If it is a struct* access, the first offset must be array index [0],
- // and all other offsets must be structure (not array) offsets
- if (!isa<ConstantUInt>(idxVec.front()) ||
- cast<ConstantUInt>(idxVec.front())->getValue() != 0)
- allStructureOffsets = false;
-
- if (allStructureOffsets)
- for (unsigned int i=1; i < idxVec.size(); i++)
- if (idxVec[i]->getType() == Type::UIntTy)
- {
- allStructureOffsets = false;
- break;
- }
-
- if (allStructureOffsets)
+ gepInst = cast<GetElementPtrInst>(ptrChild->getValue());
+ User::op_iterator OI, firstIdx = gepInst->idx_begin();
+ User::op_iterator lastIdx = gepInst->idx_end();
+ bool allConstantOffsets = true;
+
+ // The first index of every GEP must be an array index.
+ assert((*firstIdx)->getType() == Type::LongTy &&
+ "INTERNAL ERROR: Structure index for a pointer type!");
+
+ // If the last instruction had a leading non-zero index, check if the
+ // current one references a sequential (i.e., indexable) type.
+ // If not, the code is not type-safe and we would create an illegal GEP
+ // by folding them, so don't fold any more instructions.
+ //
+ if (lastInstHasLeadingNonZero)
+ if (! isa<SequentialType>(gepInst->getType()->getElementType()))
+ break; // cannot fold in any preceding getElementPtr instrs.
+
+ // Check that all offsets are constant for this instruction
+ for (OI = firstIdx; allConstantOffsets && OI != lastIdx; ++OI)
+ allConstantOffsets = isa<ConstantInt>(*OI);
+
+ if (allConstantOffsets)
{ // Get pointer value out of ptrChild.
- ptrVal = getElemInst->getPointerOperand();
+ ptrVal = gepInst->getPointerOperand();
+
+ // Remember if it has leading zero index: it will be discarded later.
+ lastInstHasLeadingNonZero = ! IsZero(*firstIdx);
+
+ // Insert its index vector at the start, skipping any leading [0]
+ chainIdxVec.insert(chainIdxVec.begin(),
+ firstIdx + !lastInstHasLeadingNonZero, lastIdx);
- // Insert its index vector at the start, but after the leading [0]
- chainIdxVec.insert(chainIdxVec.begin()+1,
- idxVec.begin()+1, idxVec.end());
-
// Mark the folded node so no code is generated for it.
((InstructionNode*) ptrChild)->markFoldedIntoParent();
+
+ // Get the previous GEP instruction and continue trying to fold
+ ptrChild = dyn_cast<InstructionNode>(ptrChild->leftChild());
}
- else // cannot fold this getElementPtr instr. or any further ones
+ else // cannot fold this getElementPtr instr. or any preceding ones
break;
-
- ptrChild = ptrChild->leftChild();
}
-
+
+ // If the first getElementPtr instruction had a leading [0], add it back.
+ // Note that this instruction is the *last* one successfully folded above.
+ if (ptrVal && ! lastInstHasLeadingNonZero)
+ chainIdxVec.insert(chainIdxVec.begin(), ConstantSInt::get(Type::LongTy,0));
+
+ return ptrVal;
+}
+
+
+//---------------------------------------------------------------------------
+// Function: GetGEPInstArgs
+//
+// Purpose:
+// Helper function for GetMemInstArgs that handles the final getElementPtr
+// instruction used by (or same as) the memory operation.
+// Extracts the indices of the current instruction and tries to fold in
+// preceding ones if all indices of the current one are constant.
+//---------------------------------------------------------------------------
+
+Value*
+GetGEPInstArgs(InstructionNode* gepNode,
+ vector<Value*>& idxVec,
+ bool& allConstantIndices)
+{
+ allConstantIndices = true;
+ GetElementPtrInst* gepI = cast<GetElementPtrInst>(gepNode->getInstruction());
+
+ // Default pointer is the one from the current instruction.
+ Value* ptrVal = gepI->getPointerOperand();
+ InstrTreeNode* ptrChild = gepNode->leftChild();
+
+ // Extract the index vector of the GEP instructin.
+ // If all indices are constant and first index is zero, try to fold
+ // in preceding GEPs with all constant indices.
+ for (User::op_iterator OI=gepI->idx_begin(), OE=gepI->idx_end();
+ allConstantIndices && OI != OE; ++OI)
+ if (! isa<Constant>(*OI))
+ allConstantIndices = false; // note: this also terminates loop!
+
+ // If we have only constant indices, fold chains of constant indices
+ // in this and any preceding GetElemPtr instructions.
+ bool foldedGEPs = false;
+ bool leadingNonZeroIdx = gepI && ! IsZero(*gepI->idx_begin());
+ if (allConstantIndices)
+ if (Value* newPtr = FoldGetElemChain(ptrChild, idxVec, leadingNonZeroIdx))
+ {
+ ptrVal = newPtr;
+ foldedGEPs = true;
+ }
+
+ // Append the index vector of the current instruction.
+ // Skip the leading [0] index if preceding GEPs were folded into this.
+ idxVec.insert(idxVec.end(),
+ gepI->idx_begin() + (foldedGEPs && !leadingNonZeroIdx),
+ gepI->idx_end());
+
return ptrVal;
}
+//---------------------------------------------------------------------------
+// Function: GetMemInstArgs
+//
+// Purpose:
+// Get the pointer value and the index vector for a memory operation
+// (GetElementPtr, Load, or Store). If all indices of the given memory
+// operation are constant, fold in constant indices in a chain of
+// preceding GetElementPtr instructions (if any), and return the
+// pointer value of the first instruction in the chain.
+// All folded instructions are marked so no code is generated for them.
+//
+// Return values:
+// Returns the pointer Value to use.
+// Returns the resulting IndexVector in idxVec.
+// Returns true/false in allConstantIndices if all indices are/aren't const.
+//---------------------------------------------------------------------------
+
+Value*
+GetMemInstArgs(InstructionNode* memInstrNode,
+ vector<Value*>& idxVec,
+ bool& allConstantIndices)
+{
+ allConstantIndices = false;
+ Instruction* memInst = memInstrNode->getInstruction();
+ assert(idxVec.size() == 0 && "Need empty vector to return indices");
+
+ // If there is a GetElemPtr instruction to fold in to this instr,
+ // it must be in the left child for Load and GetElemPtr, and in the
+ // right child for Store instructions.
+ InstrTreeNode* ptrChild = (memInst->getOpcode() == Instruction::Store
+ ? memInstrNode->rightChild()
+ : memInstrNode->leftChild());
+
+ // Default pointer is the one from the current instruction.
+ Value* ptrVal = ptrChild->getValue();
+
+ // Find the "last" GetElemPtr instruction: this one or the immediate child.
+ // There will be none if this is a load or a store from a scalar pointer.
+ InstructionNode* gepNode = NULL;
+ if (isa<GetElementPtrInst>(memInst))
+ gepNode = memInstrNode;
+ else if (isa<InstructionNode>(ptrChild) && isa<GetElementPtrInst>(ptrVal))
+ { // Child of load/store is a GEP and memInst is its only use.
+ // Use its indices and mark it as folded.
+ gepNode = cast<InstructionNode>(ptrChild);
+ gepNode->markFoldedIntoParent();
+ }
+
+ // If there are no indices, return the current pointer.
+ // Else extract the pointer from the GEP and fold the indices.
+ return (gepNode)? GetGEPInstArgs(gepNode, idxVec, allConstantIndices)
+ : ptrVal;
+}
+
//------------------------------------------------------------------------
// Function Set2OperandsFromInstr
// in the machine instruction the 3 operands (arg1, arg2
// and result) should go.
//
-// RETURN VALUE: unsigned int flags, where
-// flags & 0x01 => operand 1 is constant and needs a register
-// flags & 0x02 => operand 2 is constant and needs a register
//------------------------------------------------------------------------
void
MachineOperand::MachineOperandType
-ChooseRegOrImmed(Value* val,
+ChooseRegOrImmed(int64_t intValue,
+ bool isSigned,
MachineOpCode opCode,
const TargetMachine& target,
bool canUseImmed,
unsigned int& getMachineRegNum,
int64_t& getImmedValue)
{
- MachineOperand::MachineOperandType opType =
- MachineOperand::MO_VirtualRegister;
+ MachineOperand::MachineOperandType opType=MachineOperand::MO_VirtualRegister;
getMachineRegNum = 0;
getImmedValue = 0;
-
- // Check for the common case first: argument is not constant
- //
- Constant *CPV = dyn_cast<Constant>(val);
- if (!CPV) return opType;
- if (ConstantBool *CPB = dyn_cast<ConstantBool>(CPV))
+ if (canUseImmed &&
+ target.getInstrInfo().constantFitsInImmedField(opCode, intValue))
+ {
+ opType = isSigned? MachineOperand::MO_SignExtendedImmed
+ : MachineOperand::MO_UnextendedImmed;
+ getImmedValue = intValue;
+ }
+ else if (intValue == 0 && target.getRegInfo().getZeroRegNum() >= 0)
{
- if (!CPB->getValue() && target.getRegInfo().getZeroRegNum() >= 0)
- {
- getMachineRegNum = target.getRegInfo().getZeroRegNum();
- return MachineOperand::MO_MachineRegister;
- }
-
- getImmedValue = 1;
- return MachineOperand::MO_SignExtendedImmed;
+ opType = MachineOperand::MO_MachineRegister;
+ getMachineRegNum = target.getRegInfo().getZeroRegNum();
}
-
- // Otherwise it needs to be an integer or a NULL pointer
- if (! CPV->getType()->isIntegral() &&
- ! (isa<PointerType>(CPV->getType()) &&
- CPV->isNullValue()))
- return opType;
-
+
+ return opType;
+}
+
+
+MachineOperand::MachineOperandType
+ChooseRegOrImmed(Value* val,
+ MachineOpCode opCode,
+ const TargetMachine& target,
+ bool canUseImmed,
+ unsigned int& getMachineRegNum,
+ int64_t& getImmedValue)
+{
+ getMachineRegNum = 0;
+ getImmedValue = 0;
+
+ // To use reg or immed, constant needs to be integer, bool, or a NULL pointer
+ Constant *CPV = dyn_cast<Constant>(val);
+ if (CPV == NULL ||
+ (! CPV->getType()->isIntegral() &&
+ ! (isa<PointerType>(CPV->getType()) && CPV->isNullValue())))
+ return MachineOperand::MO_VirtualRegister;
+
// Now get the constant value and check if it fits in the IMMED field.
// Take advantage of the fact that the max unsigned value will rarely
// fit into any IMMED field and ignore that case (i.e., cast smaller
//
int64_t intValue;
if (isa<PointerType>(CPV->getType()))
- {
- intValue = 0;
- }
+ intValue = 0; // We checked above that it is NULL
+ else if (ConstantBool* CB = dyn_cast<ConstantBool>(CPV))
+ intValue = (int64_t) CB->getValue();
else if (CPV->getType()->isSigned())
- {
- intValue = cast<ConstantSInt>(CPV)->getValue();
- }
+ intValue = cast<ConstantSInt>(CPV)->getValue();
else
- {
- uint64_t V = cast<ConstantUInt>(CPV)->getValue();
- if (V >= INT64_MAX) return opType;
- intValue = (int64_t)V;
+ { // get the int value and sign-extend if original was less than 64 bits
+ intValue = (int64_t) cast<ConstantUInt>(CPV)->getValue();
+ switch(CPV->getType()->getPrimitiveID())
+ {
+ case Type::UByteTyID: intValue = (int64_t) (int8_t) intValue; break;
+ case Type::UShortTyID: intValue = (int64_t) (short) intValue; break;
+ case Type::UIntTyID: intValue = (int64_t) (int) intValue; break;
+ default: break;
+ }
}
- if (intValue == 0 && target.getRegInfo().getZeroRegNum() >= 0)
- {
- opType = MachineOperand::MO_MachineRegister;
- getMachineRegNum = target.getRegInfo().getZeroRegNum();
- }
- else if (canUseImmed &&
- target.getInstrInfo().constantFitsInImmedField(opCode, intValue))
- {
- opType = MachineOperand::MO_SignExtendedImmed;
- getImmedValue = intValue;
- }
-
- return opType;
+ return ChooseRegOrImmed(intValue, CPV->getType()->isSigned(),
+ opCode, target, canUseImmed,
+ getMachineRegNum, getImmedValue);
}
{
vector<MachineInstr*> loadConstVec;
- const MachineInstrDescriptor& instrDesc =
- target.getInstrInfo().getDescriptor(minstr->getOpCode());
-
+ MachineOpCode opCode = minstr->getOpCode();
+ const MachineInstrInfo& instrInfo = target.getInstrInfo();
+ const MachineInstrDescriptor& instrDesc = instrInfo.getDescriptor(opCode);
+ int immedPos = instrInfo.getImmedConstantPos(opCode);
+
Function *F = vmInstr->getParent()->getParent();
-
+
for (unsigned op=0; op < minstr->getNumOperands(); op++)
{
const MachineOperand& mop = minstr->getOperand(op);
- // skip the result position (for efficiency below) and any other
- // positions already marked as not a virtual register
- if (instrDesc.resultPos == (int) op ||
- mop.getOperandType() != MachineOperand::MO_VirtualRegister ||
- mop.getVRegValue() == NULL)
+ // Skip the result position, preallocated machine registers, or operands
+ // that cannot be constants (CC regs or PC-relative displacements)
+ if (instrDesc.resultPos == (int) op ||
+ mop.getType() == MachineOperand::MO_MachineRegister ||
+ mop.getType() == MachineOperand::MO_CCRegister ||
+ mop.getType() == MachineOperand::MO_PCRelativeDisp)
+ continue;
+
+ bool constantThatMustBeLoaded = false;
+ unsigned int machineRegNum = 0;
+ int64_t immedValue = 0;
+ Value* opValue = NULL;
+ MachineOperand::MachineOperandType opType =
+ MachineOperand::MO_VirtualRegister;
+
+ // Operand may be a virtual register or a compile-time constant
+ if (mop.getType() == MachineOperand::MO_VirtualRegister)
{
- continue;
+ assert(mop.getVRegValue() != NULL);
+ opValue = mop.getVRegValue();
+ if (Constant *opConst = dyn_cast<Constant>(opValue))
+ {
+ opType = ChooseRegOrImmed(opConst, opCode, target,
+ (immedPos == (int)op), machineRegNum, immedValue);
+ if (opType == MachineOperand::MO_VirtualRegister)
+ constantThatMustBeLoaded = true;
+ }
}
-
- Value* opValue = mop.getVRegValue();
- bool constantThatMustBeLoaded = false;
-
- if (Constant *opConst = dyn_cast<Constant>(opValue))
+ else
{
- unsigned int machineRegNum;
- int64_t immedValue;
- MachineOperand::MachineOperandType opType =
- ChooseRegOrImmed(opValue, minstr->getOpCode(), target,
- (target.getInstrInfo().getImmedConstantPos(minstr->getOpCode()) == (int) op),
- machineRegNum, immedValue);
-
- if (opType == MachineOperand::MO_MachineRegister)
- minstr->SetMachineOperandReg(op, machineRegNum);
- else if (opType == MachineOperand::MO_VirtualRegister)
- constantThatMustBeLoaded = true; // load is generated below
- else
- minstr->SetMachineOperandConst(op, opType, immedValue);
+ assert(mop.getType() == MachineOperand::MO_SignExtendedImmed ||
+ mop.getType() == MachineOperand::MO_UnextendedImmed);
+
+ bool isSigned = (mop.getType() ==
+ MachineOperand::MO_SignExtendedImmed);
+
+ // Bit-selection flags indicate an instruction that is extracting
+ // bits from its operand so ignore this even if it is a big constant.
+ if (mop.opHiBits32() || mop.opLoBits32() ||
+ mop.opHiBits64() || mop.opLoBits64())
+ continue;
+
+ opType = ChooseRegOrImmed(mop.getImmedValue(), isSigned,
+ opCode, target, (immedPos == (int)op),
+ machineRegNum, immedValue);
+
+ if (opType == mop.getType())
+ continue; // no change: this is the most common case
+
+ if (opType == MachineOperand::MO_VirtualRegister)
+ {
+ constantThatMustBeLoaded = true;
+ opValue = isSigned
+ ? (Value*)ConstantSInt::get(Type::LongTy, immedValue)
+ : (Value*)ConstantUInt::get(Type::ULongTy,(uint64_t)immedValue);
+ }
}
-
- if (constantThatMustBeLoaded || isa<GlobalValue>(opValue))
- { // opValue is a constant that must be explicitly loaded into a reg.
+
+ if (opType == MachineOperand::MO_MachineRegister)
+ minstr->SetMachineOperandReg(op, machineRegNum);
+ else if (opType == MachineOperand::MO_SignExtendedImmed ||
+ opType == MachineOperand::MO_UnextendedImmed)
+ minstr->SetMachineOperandConst(op, opType, immedValue);
+ else if (constantThatMustBeLoaded ||
+ (opValue && isa<GlobalValue>(opValue)))
+ { // opValue is a constant that must be explicitly loaded into a reg
+ assert(opValue);
TmpInstruction* tmpReg = InsertCodeToLoadConstant(F, opValue, vmInstr,
- loadConstVec,
- target);
+ loadConstVec, target);
minstr->SetMachineOperandVal(op, MachineOperand::MO_VirtualRegister,
tmpReg);
}
}
- //
- // Also, check for implicit operands used (not those defined) by the
- // machine instruction. These include:
+ // Also, check for implicit operands used by the machine instruction
+ // (no need to check those defined since they cannot be constants).
+ // These include:
// -- arguments to a Call
// -- return value of a Return
// Any such operand that is a constant value needs to be fixed also.
// have no immediate fields, so the constant always needs to be loaded
// into a register.
//
+ bool isCall = instrInfo.isCall(opCode);
+ unsigned lastCallArgNum = 0; // unused if not a call
+ CallArgsDescriptor* argDesc = NULL; // unused if not a call
+ if (isCall)
+ argDesc = CallArgsDescriptor::get(minstr);
+
for (unsigned i=0, N=minstr->getNumImplicitRefs(); i < N; ++i)
if (isa<Constant>(minstr->getImplicitRef(i)) ||
isa<GlobalValue>(minstr->getImplicitRef(i)))
TmpInstruction* tmpReg =
InsertCodeToLoadConstant(F, oldVal, vmInstr, loadConstVec, target);
minstr->setImplicitRef(i, tmpReg);
+
+ if (isCall)
+ { // find and replace the argument in the CallArgsDescriptor
+ unsigned i=lastCallArgNum;
+ while (argDesc->getArgInfo(i).getArgVal() != oldVal)
+ ++i;
+ assert(i < argDesc->getNumArgs() &&
+ "Constant operands to a call *must* be in the arg list");
+ lastCallArgNum = i;
+ argDesc->getArgInfo(i).replaceArgVal(tmpReg);
+ }
}
return loadConstVec;