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Remove the code that tried to evaluate whether (A pred B) is known 

by determining if (B pred (B-A)) is known, as it doesn't handle
overflow correctly.

llvm-svn: 76504
This commit is contained in:
Dan Gohman 2009-07-20 23:53:35 +00:00
parent a2d2adfa4e
commit 00c1aaec5a
1 changed files with 0 additions and 42 deletions
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42
llvm/lib/Analysis/ScalarEvolution.cpp
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@ -4274,20 +4274,6 @@ bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
return true;
if (LHSRange.getSignedMin().sge(RHSRange.getSignedMax()))
return false;
const SCEV *Diff = getMinusSCEV(LHS, RHS);
ConstantRange DiffRange = getUnsignedRange(Diff);
if (isKnownNegative(Diff)) {
if (DiffRange.getUnsignedMax().ult(LHSRange.getUnsignedMin()))
return true;
if (DiffRange.getUnsignedMin().uge(LHSRange.getUnsignedMax()))
return false;
} else if (isKnownPositive(Diff)) {
if (LHSRange.getUnsignedMax().ult(DiffRange.getUnsignedMin()))
return true;
if (LHSRange.getUnsignedMin().uge(DiffRange.getUnsignedMax()))
return false;
}
break;
}
case ICmpInst::ICMP_SGE:
@ -4300,20 +4286,6 @@ bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
return true;
if (LHSRange.getSignedMin().sgt(RHSRange.getSignedMax()))
return false;
const SCEV *Diff = getMinusSCEV(LHS, RHS);
ConstantRange DiffRange = getUnsignedRange(Diff);
if (isKnownNonPositive(Diff)) {
if (DiffRange.getUnsignedMax().ule(LHSRange.getUnsignedMin()))
return true;
if (DiffRange.getUnsignedMin().ugt(LHSRange.getUnsignedMax()))
return false;
} else if (isKnownNonNegative(Diff)) {
if (LHSRange.getUnsignedMax().ule(DiffRange.getUnsignedMin()))
return true;
if (LHSRange.getUnsignedMin().ugt(DiffRange.getUnsignedMax()))
return false;
}
break;
}
case ICmpInst::ICMP_UGT:
@ -4326,13 +4298,6 @@ bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
return true;
if (LHSRange.getUnsignedMin().uge(RHSRange.getUnsignedMax()))
return false;
const SCEV *Diff = getMinusSCEV(LHS, RHS);
ConstantRange DiffRange = getUnsignedRange(Diff);
if (LHSRange.getUnsignedMax().ult(DiffRange.getUnsignedMin()))
return true;
if (LHSRange.getUnsignedMin().uge(DiffRange.getUnsignedMax()))
return false;
break;
}
case ICmpInst::ICMP_UGE:
@ -4345,13 +4310,6 @@ bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
return true;
if (LHSRange.getUnsignedMin().ugt(RHSRange.getUnsignedMax()))
return false;
const SCEV *Diff = getMinusSCEV(LHS, RHS);
ConstantRange DiffRange = getUnsignedRange(Diff);
if (LHSRange.getUnsignedMax().ule(DiffRange.getUnsignedMin()))
return true;
if (LHSRange.getUnsignedMin().ugt(DiffRange.getUnsignedMax()))
return false;
break;
}
case ICmpInst::ICMP_NE: {