From 2c3acb0e273a50a9b4eeaf9d5544f6168bda85a6 Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Sat, 18 Feb 2012 03:29:25 +0000 Subject: [PATCH] Fix a rather nasty regression from r150690: LHS != RHS does not imply LHS->stripPointerCasts() != RHS->stripPointerCasts(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150863 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 3 ++- test/Transforms/InstSimplify/compare.ll | 10 ++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 9d5b74c8cf2..88a2c53e806 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -1593,10 +1593,11 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // the compare, and if only one of them is then we moved it to RHS already. Value *LHSPtr = LHS->stripPointerCasts(); Value *RHSPtr = RHS->stripPointerCasts(); + if (LHSPtr == RHSPtr) + return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred)); if (isa(LHSPtr) && (isa(RHSPtr) || isa(RHSPtr) || isa(RHSPtr))) - // We already know that LHS != RHS. return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred)); // If we are comparing with zero then try hard since this is a common case. diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll index 60f5990840b..92b8fc7e3a9 100644 --- a/test/Transforms/InstSimplify/compare.ll +++ b/test/Transforms/InstSimplify/compare.ll @@ -30,6 +30,16 @@ define i1 @gep() { ; CHECK-NEXT: ret i1 false } +define i1 @gep2() { +; CHECK: @gep2 + %a = alloca [3 x i8], align 8 + %x = getelementptr inbounds [3 x i8]* %a, i32 0, i32 0 + %y = getelementptr inbounds [3 x i8]* %a, i32 0, i32 0 + %cmp = icmp eq i8* %x, %y + ret i1 %cmp +; CHECK-NEXT: ret i1 true +} + define i1 @zext(i32 %x) { ; CHECK: @zext %e1 = zext i32 %x to i64 -- 2.34.1