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Implement InstCombine/select.ll:test[7-10] 

llvm-svn: 12769
This commit is contained in:
Chris Lattner 2004-04-08 04:43:23 +00:00
parent ac42fd5912
commit 1c631e813d
1 changed files with 28 additions and 13 deletions
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41
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -2027,25 +2027,41 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
if (TrueVal == FalseVal)
return ReplaceInstUsesWith(SI, TrueVal);
if (SI.getType() == Type::BoolTy)
if (ConstantBool *C = dyn_cast<ConstantBool>(TrueVal)) {
if (C == ConstantBool::True) {
// Change: A = select B, true, C --> A = or B, C
return BinaryOperator::create(Instruction::Or, CondVal, FalseVal);
} else {
// Change: A = select B, false, C --> A = and !B, C
Value *NotCond =
InsertNewInstBefore(BinaryOperator::createNot(CondVal,
"not."+CondVal->getName()), SI);
return BinaryOperator::create(Instruction::And, NotCond, FalseVal);
}
} else if (ConstantBool *C = dyn_cast<ConstantBool>(FalseVal)) {
if (C == ConstantBool::False) {
// Change: A = select B, C, false --> A = and B, C
return BinaryOperator::create(Instruction::And, CondVal, TrueVal);
} else {
// Change: A = select B, C, true --> A = or !B, C
Value *NotCond =
InsertNewInstBefore(BinaryOperator::createNot(CondVal,
"not."+CondVal->getName()), SI);
return BinaryOperator::create(Instruction::Or, NotCond, TrueVal);
}
}
// Selecting between two constants?
if (Constant *TrueValC = dyn_cast<Constant>(TrueVal))
if (Constant *FalseValC = dyn_cast<Constant>(FalseVal)) {
if (SI.getType() == Type::BoolTy &&
isa<ConstantBool>(TrueValC) && isa<ConstantBool>(FalseValC)) {
// select C, true, false -> C
if (TrueValC == ConstantBool::True)
return ReplaceInstUsesWith(SI, CondVal);
// select C, false, true -> !C
return BinaryOperator::createNot(CondVal);
}
// If the true constant is a 1 and the false is a zero, turn this into a
// cast from bool.
if (FalseValC->isNullValue() && isa<ConstantInt>(TrueValC) &&
cast<ConstantInt>(TrueValC)->getRawValue() == 1)
return new CastInst(CondVal, SI.getType());
}
return 0;
}
@ -2177,9 +2193,8 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) {
if ((*AI)->getType() == ParamTy) {
Args.push_back(*AI);
} else {
Instruction *Cast = new CastInst(*AI, ParamTy, "tmp");
InsertNewInstBefore(Cast, *Caller);
Args.push_back(Cast);
Args.push_back(InsertNewInstBefore(new CastInst(*AI, ParamTy, "tmp"),
*Caller));
}
}