//===-- InstrSelectionSupport.cpp -----------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// Target-independent instruction selection code. See SparcInstrSelection.cpp
// for usage.
#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/InstrForest.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/MachineRegInfo.h"
+#include "llvm/Target/TargetRegInfo.h"
+#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Constants.h"
-#include "llvm/Function.h"
-#include "llvm/Type.h"
-#include "llvm/iMemory.h"
-using std::vector;
-
-//*************************** Local Functions ******************************/
+#include "llvm/BasicBlock.h"
+#include "llvm/DerivedTypes.h"
+#include "../SparcInstrSelectionSupport.h"
+namespace llvm {
// Generate code to load the constant into a TmpInstruction (virtual reg) and
// returns the virtual register.
InsertCodeToLoadConstant(Function *F,
Value* opValue,
Instruction* vmInstr,
- vector<MachineInstr*>& loadConstVec,
+ std::vector<MachineInstr*>& loadConstVec,
TargetMachine& target)
{
// Create a tmp virtual register to hold the constant.
- TmpInstruction* tmpReg = new TmpInstruction(opValue);
MachineCodeForInstruction &mcfi = MachineCodeForInstruction::get(vmInstr);
- mcfi.addTemp(tmpReg);
+ TmpInstruction* tmpReg = new TmpInstruction(mcfi, opValue);
target.getInstrInfo().CreateCodeToLoadConst(target, F, opValue, tmpReg,
loadConstVec, mcfi);
}
-//---------------------------------------------------------------------------
-// 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.
-//---------------------------------------------------------------------------
-
-uint64_t
-GetConstantValueAsUnsignedInt(const Value *V,
- bool &isValidConstant)
+MachineOperand::MachineOperandType
+ChooseRegOrImmed(int64_t intValue,
+ bool isSigned,
+ MachineOpCode opCode,
+ const TargetMachine& target,
+ bool canUseImmed,
+ unsigned int& getMachineRegNum,
+ int64_t& getImmedValue)
{
- 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;
-}
+ MachineOperand::MachineOperandType opType=MachineOperand::MO_VirtualRegister;
+ getMachineRegNum = 0;
+ getImmedValue = 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;
+ 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) {
+ opType = MachineOperand::MO_MachineRegister;
+ getMachineRegNum = target.getRegInfo().getZeroRegNum();
}
- return 0;
-}
-
-
-//---------------------------------------------------------------------------
-// Function: FoldGetElemChain
-//
-// Purpose:
-// Fold a chain of GetElementPtr instructions containing only
-// constant offsets into an equivalent (Pointer, IndexVector) pair.
-// Returns the pointer Value, and stores the resulting IndexVector
-// in argument chainIdxVec. This is a helper function for
-// FoldConstantIndices that does the actual folding.
-//---------------------------------------------------------------------------
-
-static Value*
-FoldGetElemChain(InstrTreeNode* ptrNode, vector<Value*>& chainIdxVec)
-{
- InstructionNode* gepNode = dyn_cast<InstructionNode>(ptrNode);
- if (gepNode == NULL)
- return NULL; // ptr value is not computed in this tree
-
- GetElementPtrInst* gepInst =
- dyn_cast<GetElementPtrInst>(gepNode->getInstruction());
- if (gepInst == NULL) // ptr value does not come from GEP instruction
- return NULL;
-
- // Return NULL if we don't fold any instructions in.
- Value* ptrVal = NULL;
-
- // Remember if the last instruction had a leading [0] index.
- bool hasLeadingZero = false;
-
- // Now chase the chain of getElementInstr instructions, if any.
- // Check for any non-constant indices and stop there.
- //
- InstructionNode* ptrChild = gepNode;
- while (ptrChild && (ptrChild->getOpLabel() == Instruction::GetElementPtr ||
- ptrChild->getOpLabel() == GetElemPtrIdx))
- {
- // Child is a GetElemPtr instruction
- gepInst = cast<GetElementPtrInst>(ptrChild->getValue());
- User::op_iterator OI, firstIdx = gepInst->idx_begin();
- User::op_iterator lastIdx = gepInst->idx_end();
- bool allConstantOffsets = true;
-
- // 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 = gepInst->getPointerOperand();
-
- // Check for a leading [0] index, if any. It will be discarded later.
- ConstantUInt* CV = dyn_cast<ConstantUInt>((Value*) *firstIdx);
- hasLeadingZero = bool(CV && CV->getValue() == 0);
-
- // Insert its index vector at the start, skipping any leading [0]
- chainIdxVec.insert(chainIdxVec.begin(),
- firstIdx + hasLeadingZero, lastIdx);
-
- // Mark the folded node so no code is generated for it.
- ((InstructionNode*) ptrChild)->markFoldedIntoParent();
- }
- else // cannot fold this getElementPtr instr. or any further ones
- break;
-
- ptrChild = dyn_cast<InstructionNode>(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 && hasLeadingZero)
- chainIdxVec.insert(chainIdxVec.begin(), ConstantUInt::get(Type::UIntTy,0));
-
- 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.
-//---------------------------------------------------------------------------
-
-
-// Check for a constant (uint) 0.
-inline bool
-IsZero(Value* idx)
-{
- return (isa<ConstantInt>(idx) && cast<ConstantInt>(idx)->isNullValue());
-}
-
-Value*
-GetMemInstArgs(const InstructionNode* memInstrNode,
- vector<Value*>& idxVec,
- bool& allConstantIndices)
-{
- allConstantIndices = true;
- Instruction* memInst = memInstrNode->getInstruction();
-
- // 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();
-
- // GEP is the only indexed memory instruction. gepI is used below.
- GetElementPtrInst* gepI = dyn_cast<GetElementPtrInst>(memInst);
- // If memInst is a GEP, check if all indices are constant for this instruction
- if (gepI)
- 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;
- if (allConstantIndices)
- if (Value* newPtr = FoldGetElemChain(ptrChild, idxVec))
- {
- ptrVal = newPtr;
- foldedGEPs = true;
- assert((!gepI || IsZero(*gepI->idx_begin())) && "1st index not 0");
- }
-
- // Append the index vector of the current instruction, if any.
- // Skip the leading [0] index if preceding GEPs were folded into this.
- if (gepI)
- idxVec.insert(idxVec.end(), gepI->idx_begin() +foldedGEPs, gepI->idx_end());
-
- return ptrVal;
-}
-
-//------------------------------------------------------------------------
-// Function Set2OperandsFromInstr
-// Function Set3OperandsFromInstr
-//
-// For the common case of 2- and 3-operand arithmetic/logical instructions,
-// set the m/c instr. operands directly from the VM instruction's operands.
-// Check whether the first or second operand is 0 and can use a dedicated "0"
-// register.
-// Check whether the second operand should use an immediate field or register.
-// (First and third operands are never immediates for such instructions.)
-//
-// Arguments:
-// canDiscardResult: Specifies that the result operand can be discarded
-// by using the dedicated "0"
-//
-// op1position, op2position and resultPosition: Specify in which position
-// in the machine instruction the 3 operands (arg1, arg2
-// and result) should go.
-//
-//------------------------------------------------------------------------
-
-void
-Set2OperandsFromInstr(MachineInstr* minstr,
- InstructionNode* vmInstrNode,
- const TargetMachine& target,
- bool canDiscardResult,
- int op1Position,
- int resultPosition)
-{
- Set3OperandsFromInstr(minstr, vmInstrNode, target,
- canDiscardResult, op1Position,
- /*op2Position*/ -1, resultPosition);
-}
-
-
-void
-Set3OperandsFromInstr(MachineInstr* minstr,
- InstructionNode* vmInstrNode,
- const TargetMachine& target,
- bool canDiscardResult,
- int op1Position,
- int op2Position,
- int resultPosition)
-{
- assert(op1Position >= 0);
- assert(resultPosition >= 0);
-
- // operand 1
- minstr->SetMachineOperandVal(op1Position, MachineOperand::MO_VirtualRegister,
- vmInstrNode->leftChild()->getValue());
-
- // operand 2 (if any)
- if (op2Position >= 0)
- minstr->SetMachineOperandVal(op2Position, MachineOperand::MO_VirtualRegister,
- vmInstrNode->rightChild()->getValue());
-
- // result operand: if it can be discarded, use a dead register if one exists
- if (canDiscardResult && target.getRegInfo().getZeroRegNum() >= 0)
- minstr->SetMachineOperandReg(resultPosition,
- target.getRegInfo().getZeroRegNum());
- else
- minstr->SetMachineOperandVal(resultPosition,
- MachineOperand::MO_VirtualRegister, vmInstrNode->getValue());
+ return opType;
}
unsigned int& getMachineRegNum,
int64_t& getImmedValue)
{
- 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 (!CPB->getValue() && target.getRegInfo().getZeroRegNum() >= 0)
- {
- getMachineRegNum = target.getRegInfo().getZeroRegNum();
- return MachineOperand::MO_MachineRegister;
- }
+ // To use reg or immed, constant needs to be integer, bool, or a NULL pointer
+ // TargetInstrInfo::ConvertConstantToIntType() does the right conversions:
+ bool isValidConstant;
+ uint64_t valueToUse =
+ target.getInstrInfo().ConvertConstantToIntType(target, val, val->getType(),
+ isValidConstant);
+ if (! isValidConstant)
+ return MachineOperand::MO_VirtualRegister;
- getImmedValue = 1;
- return MachineOperand::MO_SignExtendedImmed;
- }
-
- // Otherwise it needs to be an integer or a NULL pointer
- if (! CPV->getType()->isInteger() &&
- ! (isa<PointerType>(CPV->getType()) &&
- CPV->isNullValue()))
- return opType;
-
- // 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
- // unsigned constants to signed).
+ // Now check if the constant value fits in the IMMED field.
//
- int64_t intValue;
- if (isa<PointerType>(CPV->getType()))
- {
- intValue = 0;
- }
- else if (CPV->getType()->isSigned())
- {
- intValue = cast<ConstantSInt>(CPV)->getValue();
- }
- else
- {
- uint64_t V = cast<ConstantUInt>(CPV)->getValue();
- if (V >= INT64_MAX) return opType;
- intValue = (int64_t)V;
- }
-
- if (intValue == 0 && target.getRegInfo().getZeroRegNum() >= 0)
- {
- opType = MachineOperand::MO_MachineRegister;
- getMachineRegNum = target.getRegInfo().getZeroRegNum();
- }
- else if (canUseImmed &&
- target.getInstrInfo().constantFitsInImmedField(opCode, intValue))
- {
- opType = CPV->getType()->isSigned()
- ? MachineOperand::MO_SignExtendedImmed
- : MachineOperand::MO_UnextendedImmed;
- getImmedValue = intValue;
- }
-
- return opType;
+ return ChooseRegOrImmed((int64_t) valueToUse, val->getType()->isSigned(),
+ opCode, target, canUseImmed,
+ getMachineRegNum, getImmedValue);
}
-
//---------------------------------------------------------------------------
// Function: FixConstantOperandsForInstr
//
// fall under case 3; these must be inserted before `minstr'.
//---------------------------------------------------------------------------
-vector<MachineInstr*>
+std::vector<MachineInstr*>
FixConstantOperandsForInstr(Instruction* vmInstr,
MachineInstr* minstr,
TargetMachine& target)
{
- vector<MachineInstr*> loadConstVec;
-
- const MachineInstrDescriptor& instrDesc =
- target.getInstrInfo().getDescriptor(minstr->getOpCode());
+ std::vector<MachineInstr*> MVec;
+ MachineOpCode opCode = minstr->getOpcode();
+ const TargetInstrInfo& instrInfo = target.getInstrInfo();
+ int resultPos = instrInfo.getResultPos(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 (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) {
+ 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;
+ }
+ } else {
+ //
+ // If the operand is from the constant pool, don't try to change it.
+ //
+ if (mop.getType() == MachineOperand::MO_ConstantPoolIndex) {
continue;
}
-
- Value* opValue = mop.getVRegValue();
- bool constantThatMustBeLoaded = false;
-
- if (Constant *opConst = dyn_cast<Constant>(opValue))
- {
- 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.isImmediate());
+ 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.isHiBits32() || mop.isLoBits32() ||
+ mop.isHiBits64() || mop.isLoBits64())
+ continue;
+
+ opType = ChooseRegOrImmed(mop.getImmedValue(), isSigned,
+ opCode, target, (immedPos == (int)op),
+ machineRegNum, immedValue);
+
+ if (opType == MachineOperand::MO_SignExtendedImmed ||
+ opType == MachineOperand::MO_UnextendedImmed) {
+ // The optype is an immediate value
+ // This means we need to change the opcode, e.g. ADDr -> ADDi
+ unsigned newOpcode = convertOpcodeFromRegToImm(opCode);
+ minstr->setOpcode(newOpcode);
}
-
- if (constantThatMustBeLoaded || isa<GlobalValue>(opValue))
- { // opValue is a constant that must be explicitly loaded into a reg.
- TmpInstruction* tmpReg = InsertCodeToLoadConstant(F, opValue,vmInstr,
- loadConstVec,
- target);
+
+ 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 (opType == MachineOperand::MO_MachineRegister)
+ minstr->SetMachineOperandReg(op, machineRegNum);
+ else if (opType == MachineOperand::MO_SignExtendedImmed ||
+ opType == MachineOperand::MO_UnextendedImmed) {
+ minstr->SetMachineOperandConst(op, opType, immedValue);
+ // The optype is or has become an immediate
+ // This means we need to change the opcode, e.g. ADDr -> ADDi
+ unsigned newOpcode = convertOpcodeFromRegToImm(opCode);
+ minstr->setOpcode(newOpcode);
+ } 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,
+ MVec, target);
minstr->SetMachineOperandVal(op, MachineOperand::MO_VirtualRegister,
tmpReg);
}
}
- //
// Also, check for implicit operands used by the machine instruction
// (no need to check those defined since they cannot be constants).
// These include:
// have no immediate fields, so the constant always needs to be loaded
// into a register.
//
- bool isCall = target.getInstrInfo().isCall(minstr->getOpCode());
+ bool isCall = instrInfo.isCall(opCode);
unsigned lastCallArgNum = 0; // unused if not a call
CallArgsDescriptor* argDesc = NULL; // unused if not a call
if (isCall)
{
Value* oldVal = minstr->getImplicitRef(i);
TmpInstruction* tmpReg =
- InsertCodeToLoadConstant(F, oldVal, vmInstr, loadConstVec, target);
+ InsertCodeToLoadConstant(F, oldVal, vmInstr, MVec, 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);
- }
+ 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;
+ return MVec;
}
-
+} // End llvm namespace
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