diff options
| -rw-r--r-- | lib/Analysis/MemoryBuiltins.cpp | 4 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/objsize.ll | 17 |
2 files changed, 21 insertions, 0 deletions
diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp index c0cc27b6ec..e77d2ff9e4 100644 --- a/lib/Analysis/MemoryBuiltins.cpp +++ b/lib/Analysis/MemoryBuiltins.cpp @@ -473,6 +473,10 @@ ObjectSizeOffsetVisitor::visitExtractValueInst(ExtractValueInst&) { } SizeOffsetType ObjectSizeOffsetVisitor::visitGEPOperator(GEPOperator &GEP) { + // Ignore self-referencing GEPs, they can occur in unreachable code. + if (&GEP == GEP.getPointerOperand()) + return unknown(); + SizeOffsetType PtrData = compute(GEP.getPointerOperand()); if (!bothKnown(PtrData) || !GEP.hasAllConstantIndices()) return unknown(); diff --git a/test/Transforms/InstCombine/objsize.ll b/test/Transforms/InstCombine/objsize.ll index dbb0ffcd67..d7e292155c 100644 --- a/test/Transforms/InstCombine/objsize.ll +++ b/test/Transforms/InstCombine/objsize.ll @@ -238,3 +238,20 @@ xpto: return: ret i32 42 } + +; CHECK: @PR13621 +define i32 @PR13621(i1 %bool) nounwind { +entry: + %cond = or i1 %bool, true + br i1 %cond, label %return, label %xpto + +; technically reachable, but this malformed IR may appear as a result of constant propagation +xpto: + %gep = getelementptr i8* %gep, i32 1 + %o = call i32 @llvm.objectsize.i32(i8* %gep, i1 true) +; CHECK: ret i32 undef + ret i32 %o + +return: + ret i32 7 +} |