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Fix logic error optimizing "icmp pred (urem X, Y), Y" where pred is signed.

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Fixes PR16605.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186229 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nick Lewycky
2013-07-12 23:42:57 +00:00
parent 434c0bd2a5
commit 8a23270ce6
2 changed files with 16 additions and 5 deletions
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11
lib/Analysis/InstructionSimplify.cpp
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@ -2246,6 +2246,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
}
}
// icmp pred (urem X, Y), Y
if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
bool KnownNonNegative, KnownNegative;
switch (Pred) {
@ -2253,7 +2254,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
break;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE:
ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
if (!KnownNonNegative)
break;
// fall-through
@ -2263,7 +2264,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
return getFalse(ITy);
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE:
ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
if (!KnownNonNegative)
break;
// fall-through
@ -2273,6 +2274,8 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
return getTrue(ITy);
}
}
// icmp pred X, (urem Y, X)
if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
bool KnownNonNegative, KnownNegative;
switch (Pred) {
@ -2280,7 +2283,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
break;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE:
ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
if (!KnownNonNegative)
break;
// fall-through
@ -2290,7 +2293,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
return getTrue(ITy);
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE:
ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
if (!KnownNonNegative)
break;
// fall-through