llvm-6502/lib/VMCore/iOperators.cpp
2002-09-01 19:46:40 +00:00

155 lines
5.0 KiB
C++

//===-- iOperators.cpp - Implement binary Operators ------------*- C++ -*--===//
//
// This file implements the nontrivial binary operator instructions.
//
//===----------------------------------------------------------------------===//
#include "llvm/iOperators.h"
#include "llvm/Type.h"
#include "llvm/Constants.h"
//===----------------------------------------------------------------------===//
// BinaryOperator Class
//===----------------------------------------------------------------------===//
BinaryOperator *BinaryOperator::create(BinaryOps Op, Value *S1, Value *S2,
const std::string &Name) {
switch (Op) {
// Binary comparison operators...
case SetLT: case SetGT: case SetLE:
case SetGE: case SetEQ: case SetNE:
return new SetCondInst(Op, S1, S2, Name);
default:
return new GenericBinaryInst(Op, S1, S2, Name);
}
}
BinaryOperator *BinaryOperator::createNeg(Value *Op, const std::string &Name) {
return new GenericBinaryInst(Instruction::Sub,
Constant::getNullValue(Op->getType()), Op, Name);
}
BinaryOperator *BinaryOperator::createNot(Value *Op, const std::string &Name) {
return new GenericBinaryInst(Instruction::Xor, Op,
ConstantIntegral::getAllOnesValue(Op->getType()),
Name);
}
// isConstantAllOnes - Helper function for several functions below
static inline bool isConstantAllOnes(const Value *V) {
return isa<ConstantIntegral>(V) &&cast<ConstantIntegral>(V)->isAllOnesValue();
}
bool BinaryOperator::isNeg(const Value *V) {
if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(V))
return Bop->getOpcode() == Instruction::Sub &&
isa<Constant>(Bop->getOperand(0)) && cast<Constant>(V)->isNullValue();
return false;
}
bool BinaryOperator::isNot(const Value *V) {
if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(V))
return (Bop->getOpcode() == Instruction::Xor &&
(isConstantAllOnes(Bop->getOperand(1)) ||
isConstantAllOnes(Bop->getOperand(0))));
return false;
}
Value *BinaryOperator::getNegArgument(BinaryOperator *Bop) {
assert(isNeg(Bop) && "getNegArgument from non-'neg' instruction!");
return Bop->getOperand(1);
}
const Value *BinaryOperator::getNegArgument(const BinaryOperator *Bop) {
return getNegArgument((BinaryOperator*)Bop);
}
Value *BinaryOperator::getNotArgument(BinaryOperator *Bop) {
assert(isNot(Bop) && "getNotArgument on non-'not' instruction!");
Value *Op0 = Bop->getOperand(0);
Value *Op1 = Bop->getOperand(1);
if (isConstantAllOnes(Op0)) return Op1;
assert(isConstantAllOnes(Op1));
return Op0;
}
const Value *BinaryOperator::getNotArgument(const BinaryOperator *Bop) {
return getNotArgument((BinaryOperator*)Bop);
}
// swapOperands - Exchange the two operands to this instruction. This
// instruction is safe to use on any binary instruction and does not
// modify the semantics of the instruction. If the instruction is
// order dependant (SetLT f.e.) the opcode is changed.
//
bool BinaryOperator::swapOperands() {
if (SetCondInst *SCI = dyn_cast<SetCondInst>(this)) {
iType = SCI->getSwappedCondition();
std::swap(Operands[0], Operands[1]);
return false;
}
switch (getOpcode()) {
// Instructions that don't need opcode modification
case Add: case Mul:
case And: case Xor:
case Or:
// Error on the side of caution
default:
return true;
}
std::swap(Operands[0], Operands[1]);
return false;
}
//===----------------------------------------------------------------------===//
// SetCondInst Class
//===----------------------------------------------------------------------===//
SetCondInst::SetCondInst(BinaryOps opType, Value *S1, Value *S2,
const std::string &Name)
: BinaryOperator(opType, S1, S2, Name) {
OpType = opType;
setType(Type::BoolTy); // setcc instructions always return bool type.
// Make sure it's a valid type...
assert(getOpcodeName() != 0);
}
// getInverseCondition - Return the inverse of the current condition opcode.
// For example seteq -> setne, setgt -> setle, setlt -> setge, etc...
//
Instruction::BinaryOps SetCondInst::getInverseCondition(BinaryOps Opcode) {
switch (Opcode) {
default:
assert(0 && "Unknown setcc opcode!");
case SetEQ: return SetNE;
case SetNE: return SetEQ;
case SetGT: return SetLE;
case SetLT: return SetGE;
case SetGE: return SetLT;
case SetLE: return SetGT;
}
}
// getSwappedCondition - Return the condition opcode that would be the result
// of exchanging the two operands of the setcc instruction without changing
// the result produced. Thus, seteq->seteq, setle->setge, setlt->setgt, etc.
//
Instruction::BinaryOps SetCondInst::getSwappedCondition(BinaryOps Opcode) {
switch (Opcode) {
default: assert(0 && "Unknown setcc instruction!");
case SetEQ: case SetNE: return Opcode;
case SetGT: return SetLT;
case SetLT: return SetGT;
case SetGE: return SetLE;
case SetLE: return SetGE;
}
}