Fix constant folding relational operators with undef operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17077 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-10-17 04:01:51 +00:00
parent a78a9027f5
commit 35f92ae3af

View File

@ -830,7 +830,9 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
// If we successfully folded the expression, return it now.
if (C) return C;
if (SetCondInst::isRelational(Opcode))
if (SetCondInst::isRelational(Opcode)) {
if (isa<UndefValue>(V1) || isa<UndefValue>(V2))
return UndefValue::get(Type::BoolTy);
switch (evaluateRelation(V1, V2)) {
default: assert(0 && "Unknown relational!");
case Instruction::BinaryOpsEnd:
@ -871,17 +873,12 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
if (Opcode == Instruction::SetNE) return ConstantBool::True;
break;
}
}
if (isa<UndefValue>(V1) || isa<UndefValue>(V2)) {
switch (Opcode) {
case Instruction::Add:
case Instruction::Sub:
case Instruction::SetEQ:
case Instruction::SetNE:
case Instruction::SetLT:
case Instruction::SetLE:
case Instruction::SetGT:
case Instruction::SetGE:
case Instruction::Xor:
return UndefValue::get(V1->getType());