[InstSimplify][NFC] Reorganize simplifyUnsignedRangeCheck() to emphasize and/or symmetry
Only a single `X >= Y && Y == 0 --> Y == 0` fold appears to be missing.
llvm-svn: 372490
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index cfb37f4..5c8bf8f 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -1443,25 +1443,28 @@
isKnownNonZero(X, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT))
return IsAnd ? UnsignedICmp : ZeroICmp;
+ // X >= Y && Y == 0 --> Y == 0 FIXME
+ // X >= Y || Y == 0 --> X >= Y
+ if (UnsignedPred == ICmpInst::ICMP_UGE && EqPred == ICmpInst::ICMP_EQ &&
+ !IsAnd)
+ return UnsignedICmp;
+
// X > Y && Y == 0 --> Y == 0 iff X != 0
// X > Y || Y == 0 --> X > Y iff X != 0
if (UnsignedPred == ICmpInst::ICMP_UGT && EqPred == ICmpInst::ICMP_EQ &&
isKnownNonZero(X, Q.DL, /*Depth=*/0, Q.AC, Q.CxtI, Q.DT))
return IsAnd ? ZeroICmp : UnsignedICmp;
- // X >= Y || Y != 0 --> true
- // X >= Y || Y == 0 --> X >= Y
- if (UnsignedPred == ICmpInst::ICMP_UGE && !IsAnd) {
- if (EqPred == ICmpInst::ICMP_NE)
- return getTrue(UnsignedICmp->getType());
- return UnsignedICmp;
- }
-
// X < Y && Y == 0 --> false
if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_EQ &&
IsAnd)
return getFalse(UnsignedICmp->getType());
+ // X >= Y || Y != 0 --> true
+ if (UnsignedPred == ICmpInst::ICMP_UGE && EqPred == ICmpInst::ICMP_NE &&
+ !IsAnd)
+ return getTrue(UnsignedICmp->getType());
+
return nullptr;
}