[InstSimplify] simplifyUnsignedRangeCheck(): X >= Y && Y == 0 --> Y == 0
https://rise4fun.com/Alive/v9Y4
llvm-svn: 372491
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 5c8bf8f..67b06ea 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -1443,11 +1443,10 @@
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 --> Y == 0
// X >= Y || Y == 0 --> X >= Y
- if (UnsignedPred == ICmpInst::ICMP_UGE && EqPred == ICmpInst::ICMP_EQ &&
- !IsAnd)
- return UnsignedICmp;
+ if (UnsignedPred == ICmpInst::ICMP_UGE && EqPred == ICmpInst::ICMP_EQ)
+ return IsAnd ? ZeroICmp : UnsignedICmp;
// X > Y && Y == 0 --> Y == 0 iff X != 0
// X > Y || Y == 0 --> X > Y iff X != 0