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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76504 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 04ddc4e..2b97a8c 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -4274,20 +4274,6 @@
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 @@
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 @@
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 @@
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: {