diff options
author | Nick Lewycky <nicholas@mxc.ca> | 2012-02-25 20:19:07 +0000 |
---|---|---|
committer | Nick Lewycky <nicholas@mxc.ca> | 2012-02-25 20:19:07 +0000 |
commit | 28e215ba63164f201292f8c77bf038b4282aa052 (patch) | |
tree | 39f1ffa20bb69ab0f1d72207445d08f400eff7cf | |
parent | 6bfb9d6a13261948c07599922246ac80e2ba66d0 (diff) | |
download | llvm-28e215ba63164f201292f8c77bf038b4282aa052.tar.gz llvm-28e215ba63164f201292f8c77bf038b4282aa052.tar.bz2 llvm-28e215ba63164f201292f8c77bf038b4282aa052.tar.xz |
An argument and a local identified object (eg. a noalias call) could turn out
equal if both are null. In the test, scope type %t and global @y by adding a
'gep' prefix to them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151452 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Analysis/InstructionSimplify.cpp | 25 | ||||
-rw-r--r-- | test/Transforms/InstSimplify/compare.ll | 38 |
2 files changed, 37 insertions, 26 deletions
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 11afa85159..93f55684c2 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -1626,21 +1626,22 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, LHSPtr = stripPointerAdjustments(LHSPtr); if (llvm::isIdentifiedObject(LHSPtr)) { RHSPtr = stripPointerAdjustments(RHSPtr); - // If both sides are different identified objects, they aren't equal unless - // they're null. - if (LHSPtr != RHSPtr && llvm::isIdentifiedObject(RHSPtr) && - (llvm::isKnownNonNull(LHSPtr) || llvm::isKnownNonNull(RHSPtr))) - return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred)); + if (llvm::isKnownNonNull(LHSPtr) || llvm::isKnownNonNull(RHSPtr)) { + // If both sides are different identified objects, they aren't equal + // unless they're null. + if (LHSPtr != RHSPtr && llvm::isIdentifiedObject(RHSPtr)) + return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred)); + + // A local identified object (alloca or noalias call) can't equal any + // incoming argument, unless they're both null. + if ((isa<Instruction>(LHSPtr) && isa<Argument>(RHSPtr)) || + (isa<Instruction>(RHSPtr) && isa<Argument>(LHSPtr))) + return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred)); + } - // Assume that the null is on the right. + // Assume that the constant null is on the right. if (llvm::isKnownNonNull(LHSPtr) && isa<ConstantPointerNull>(RHSPtr)) return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred)); - - // A local instruction (alloca or noalias call) can't equal any incoming - // argument. - if ((isa<Instruction>(LHSPtr) && isa<Argument>(RHSPtr)) || - (isa<Instruction>(RHSPtr) && isa<Argument>(LHSPtr))) - 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 85aea19e69..ea43f5fa45 100644 --- a/test/Transforms/InstSimplify/compare.ll +++ b/test/Transforms/InstSimplify/compare.ll @@ -41,14 +41,15 @@ define i1 @gep2() { } ; PR11238 -%t = type { i32, i32 } -@y = global %t zeroinitializer, align 8 +%gept = type { i32, i32 } +@gepy = global %gept zeroinitializer, align 8 +@gepz = extern_weak global %gept define i1 @gep3() { ; CHECK: @gep3 - %x = alloca %t, align 8 - %a = getelementptr %t* %x, i64 0, i32 0 - %b = getelementptr %t* %x, i64 0, i32 1 + %x = alloca %gept, align 8 + %a = getelementptr %gept* %x, i64 0, i32 0 + %b = getelementptr %gept* %x, i64 0, i32 1 %equal = icmp eq i32* %a, %b ret i1 %equal ; CHECK-NEXT: ret i1 false @@ -56,9 +57,9 @@ define i1 @gep3() { define i1 @gep4() { ; CHECK: @gep4 - %x = alloca %t, align 8 - %a = getelementptr %t* @y, i64 0, i32 0 - %b = getelementptr %t* @y, i64 0, i32 1 + %x = alloca %gept, align 8 + %a = getelementptr %gept* @gepy, i64 0, i32 0 + %b = getelementptr %gept* @gepy, i64 0, i32 1 %equal = icmp eq i32* %a, %b ret i1 %equal ; CHECK-NEXT: ret i1 false @@ -66,24 +67,33 @@ define i1 @gep4() { define i1 @gep5() { ; CHECK: @gep5 - %x = alloca %t, align 8 - %a = getelementptr inbounds %t* %x, i64 0, i32 1 - %b = getelementptr %t* @y, i64 0, i32 0 + %x = alloca %gept, align 8 + %a = getelementptr inbounds %gept* %x, i64 0, i32 1 + %b = getelementptr %gept* @gepy, i64 0, i32 0 %equal = icmp eq i32* %a, %b ret i1 %equal ; CHECK-NEXT: ret i1 false } -define i1 @gep6(%t* %x) { +define i1 @gep6(%gept* %x) { ; Same as @gep3 but potentially null. ; CHECK: @gep6 - %a = getelementptr %t* %x, i64 0, i32 0 - %b = getelementptr %t* %x, i64 0, i32 1 + %a = getelementptr %gept* %x, i64 0, i32 0 + %b = getelementptr %gept* %x, i64 0, i32 1 %equal = icmp eq i32* %a, %b ret i1 %equal ; CHECK-NEXT: ret i1 false } +define i1 @gep7(%gept* %x) { +; CHECK: @gep7 + %a = getelementptr %gept* %x, i64 0, i32 0 + %b = getelementptr %gept* @gepz, i64 0, i32 0 + %equal = icmp eq i32* %a, %b + ret i1 %equal +; CHECK: ret i1 %equal +} + define i1 @zext(i32 %x) { ; CHECK: @zext %e1 = zext i32 %x to i64 |