Fix bug: InstCombine/2005-05-07-UDivSelectCrash.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21152 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-04-08 04:03:26 +00:00
parent b37246d65e
commit bf70b838e7

View File

@ -1068,23 +1068,25 @@ Instruction *InstCombiner::visitDiv(BinaryOperator &I) {
I.setOperand(1, SFO); I.setOperand(1, SFO);
return &I; return &I;
} else if (SFO->getValue() == 0) { } else if (SFO->getValue() == 0) {
I.setOperand(1, STO); I.setOperand(2, STO);
return &I; return &I;
} }
if (uint64_t TSA = Log2(STO->getValue())) uint64_t TVA = STO->getValue(), FVA = SFO->getValue();
if (uint64_t FSA = Log2(SFO->getValue())) { unsigned TSA = 0, FSA = 0;
Constant *TC = ConstantUInt::get(Type::UByteTy, TSA); if ((TVA == 1 || (TSA = Log2(TVA))) && // Log2 fails for 0 & 1.
Instruction *TSI = new ShiftInst(Instruction::Shr, Op0, (FVA == 1 || (FSA = Log2(FVA)))) {
TC, SI->getName()+".t"); Constant *TC = ConstantUInt::get(Type::UByteTy, TSA);
TSI = InsertNewInstBefore(TSI, I); Instruction *TSI = new ShiftInst(Instruction::Shr, Op0,
TC, SI->getName()+".t");
Constant *FC = ConstantUInt::get(Type::UByteTy, FSA); TSI = InsertNewInstBefore(TSI, I);
Instruction *FSI = new ShiftInst(Instruction::Shr, Op0,
FC, SI->getName()+".f"); Constant *FC = ConstantUInt::get(Type::UByteTy, FSA);
FSI = InsertNewInstBefore(FSI, I); Instruction *FSI = new ShiftInst(Instruction::Shr, Op0,
return new SelectInst(SI->getOperand(0), TSI, FSI); FC, SI->getName()+".f");
} FSI = InsertNewInstBefore(FSI, I);
return new SelectInst(SI->getOperand(0), TSI, FSI);
}
} }
// 0 / X == 0, we don't need to preserve faults! // 0 / X == 0, we don't need to preserve faults!