llvm-mirror/lib/CodeGen/MachineInstr.cpp
Chris Lattner 9329758c8c Eliminate lots of unnecessary #includes and forward decls
there are probably more to kill

llvm-svn: 261
2001-07-21 23:24:48 +00:00

333 lines
9.5 KiB
C++

// $Id$
//***************************************************************************
// File:
// MachineInstr.cpp
//
// Purpose:
//
//
// Strategy:
//
// History:
// 7/2/01 - Vikram Adve - Created
//**************************************************************************/
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/ConstPoolVals.h"
#include "llvm/Instruction.h"
#include <strstream>
//************************ Class Implementations **************************/
bool
MachineInstrInfo::constantFitsInImmedField(int64_t intValue) const
{
// First, check if opCode has an immed field.
bool isSignExtended;
uint64_t maxImmedValue = this->maxImmedConstant(isSignExtended);
if (maxImmedValue != 0)
{
// Now check if the constant fits
if (intValue <= (int64_t) maxImmedValue &&
intValue >= -((int64_t) maxImmedValue+1))
return true;
}
return false;
}
MachineInstr::MachineInstr(MachineOpCode _opCode,
OpCodeMask _opCodeMask)
: opCode(_opCode),
opCodeMask(_opCodeMask),
operands(TargetMachineInstrInfo[_opCode].numOperands)
{
}
MachineInstr::~MachineInstr()
{
}
void
MachineInstr::SetMachineOperand(unsigned int i,
MachineOperand::MachineOperandType operandType,
Value* _val)
{
assert(i < TargetMachineInstrInfo[opCode].numOperands);
operands[i].Initialize(operandType, _val);
}
void
MachineInstr::SetMachineOperand(unsigned int i,
MachineOperand::MachineOperandType operandType,
int64_t intValue)
{
assert(i < TargetMachineInstrInfo[opCode].numOperands);
operands[i].InitializeConst(operandType, intValue);
}
void
MachineInstr::SetMachineOperand(unsigned int i,
unsigned int regNum)
{
assert(i < TargetMachineInstrInfo[opCode].numOperands);
operands[i].InitializeReg(regNum);
}
void
MachineInstr::dump(unsigned int indent)
{
for (unsigned i=0; i < indent; i++)
cout << " ";
cout << *this;
}
ostream&
operator<< (ostream& os, const MachineInstr& minstr)
{
os << TargetMachineInstrInfo[minstr.opCode].opCodeString;
for (unsigned i=0, N=minstr.getNumOperands(); i < N; i++)
os << "\t" << minstr.getOperand(i);
return os;
}
ostream&
operator<< (ostream& os, const MachineOperand& mop)
{
strstream regInfo;
if (mop.machineOperandType == MachineOperand::MO_Register)
{
if (mop.vregType == MachineOperand::MO_VirtualReg)
regInfo << "(val " << mop.value << ")" << ends;
else
regInfo << "(" << mop.regNum << ")" << ends;
}
else if (mop.machineOperandType == MachineOperand::MO_CCRegister)
regInfo << "(val " << mop.value << ")" << ends;
switch(mop.machineOperandType)
{
case MachineOperand::MO_Register:
os << "%reg" << regInfo.str();
free(regInfo.str());
break;
case MachineOperand::MO_CCRegister:
os << "%ccreg" << regInfo.str();
free(regInfo.str());
break;
case MachineOperand::MO_SignExtendedImmed:
os << mop.immedVal;
break;
case MachineOperand::MO_UnextendedImmed:
os << mop.immedVal;
break;
case MachineOperand::MO_PCRelativeDisp:
os << "%disp(label " << mop.value << ")";
break;
default:
assert(0 && "Unrecognized operand type");
break;
}
return os;
}
//---------------------------------------------------------------------------
// Target-independent utility routines for creating machine instructions
//---------------------------------------------------------------------------
//------------------------------------------------------------------------
// 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.
//
// 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
Set2OperandsFromInstr(MachineInstr* minstr,
InstructionNode* vmInstrNode,
const TargetMachine& targetMachine,
bool canDiscardResult,
int op1Position,
int resultPosition)
{
Set3OperandsFromInstr(minstr, vmInstrNode, targetMachine,
canDiscardResult, op1Position,
/*op2Position*/ -1, resultPosition);
}
unsigned
Set3OperandsFromInstrJUNK(MachineInstr* minstr,
InstructionNode* vmInstrNode,
const TargetMachine& targetMachine,
bool canDiscardResult,
int op1Position,
int op2Position,
int resultPosition)
{
assert(op1Position >= 0);
assert(resultPosition >= 0);
unsigned returnFlags = 0x0;
// Check if operand 1 is 0 and if so, try to use the register that gives 0, if any.
Value* op1Value = vmInstrNode->leftChild()->getValue();
bool isValidConstant;
int64_t intValue = GetConstantValueAsSignedInt(op1Value, isValidConstant);
if (isValidConstant && intValue == 0 && targetMachine.zeroRegNum >= 0)
minstr->SetMachineOperand(op1Position, /*regNum*/ targetMachine.zeroRegNum);
else
{
if (op1Value->getValueType() == Value::ConstantVal)
{// value is constant and must be loaded from constant pool
returnFlags = returnFlags | (1 << op1Position);
}
minstr->SetMachineOperand(op1Position, MachineOperand::MO_Register,
op1Value);
}
// Check if operand 2 (if any) fits in the immediate field of the instruction,
// of if it is 0 and can use a dedicated machine register
if (op2Position >= 0)
{
Value* op2Value = vmInstrNode->rightChild()->getValue();
int64_t immedValue;
MachineOperand::VirtualRegisterType vregType;
unsigned int machineRegNum;
MachineOperand::MachineOperandType
op2type = ChooseRegOrImmed(op2Value, minstr->getOpCode(),targetMachine,
/*canUseImmed*/ true,
vregType, machineRegNum, immedValue);
if (op2type == MachineOperand::MO_Register)
{
if (vregType == MachineOperand::MO_MachineReg)
minstr->SetMachineOperand(op2Position, machineRegNum);
else
{
if (op2Value->getValueType() == Value::ConstantVal)
{// value is constant and must be loaded from constant pool
returnFlags = returnFlags | (1 << op2Position);
}
minstr->SetMachineOperand(op2Position, op2type, op2Value);
}
}
else
minstr->SetMachineOperand(op2Position, op2type, immedValue);
}
// If operand 3 (result) can be discarded, use a dead register if one exists
if (canDiscardResult && targetMachine.zeroRegNum >= 0)
minstr->SetMachineOperand(resultPosition, targetMachine.zeroRegNum);
else
minstr->SetMachineOperand(resultPosition, MachineOperand::MO_Register,
vmInstrNode->getValue());
return returnFlags;
}
void
Set3OperandsFromInstr(MachineInstr* minstr,
InstructionNode* vmInstrNode,
const TargetMachine& targetMachine,
bool canDiscardResult,
int op1Position,
int op2Position,
int resultPosition)
{
assert(op1Position >= 0);
assert(resultPosition >= 0);
// operand 1
minstr->SetMachineOperand(op1Position, MachineOperand::MO_Register,
vmInstrNode->leftChild()->getValue());
// operand 2 (if any)
if (op2Position >= 0)
minstr->SetMachineOperand(op2Position, MachineOperand::MO_Register,
vmInstrNode->rightChild()->getValue());
// result operand: if it can be discarded, use a dead register if one exists
if (canDiscardResult && targetMachine.zeroRegNum >= 0)
minstr->SetMachineOperand(resultPosition, targetMachine.zeroRegNum);
else
minstr->SetMachineOperand(resultPosition, MachineOperand::MO_Register,
vmInstrNode->getValue());
}
MachineOperand::MachineOperandType
ChooseRegOrImmed(Value* val,
MachineOpCode opCode,
const TargetMachine& targetMachine,
bool canUseImmed,
MachineOperand::VirtualRegisterType& getVRegType,
unsigned int& getMachineRegNum,
int64_t& getImmedValue)
{
MachineOperand::MachineOperandType opType = MachineOperand::MO_Register;
getVRegType = MachineOperand::MO_VirtualReg;
getMachineRegNum = 0;
getImmedValue = 0;
// Check for the common case first: argument is not constant
//
if (val->getValueType() != Value::ConstantVal)
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).
//
bool isValidConstant;
int64_t intValue = GetConstantValueAsSignedInt(val, isValidConstant);
if (isValidConstant)
{
if (intValue == 0 && targetMachine.zeroRegNum >= 0)
{
getVRegType = MachineOperand::MO_MachineReg;
getMachineRegNum = targetMachine.zeroRegNum;
}
else if (canUseImmed &&
targetMachine.machineInstrInfo[opCode].constantFitsInImmedField(intValue))
{
opType = MachineOperand::MO_SignExtendedImmed;
getImmedValue = intValue;
}
}
return opType;
}