diff --git a/llvm/test/Transforms/GVN/phi-translation-to-wrong-context.ll b/llvm/test/Transforms/GVN/phi-translation-to-wrong-context.ll new file mode 100644 index 00000000000000..93fc03ae3c06e3 --- /dev/null +++ b/llvm/test/Transforms/GVN/phi-translation-to-wrong-context.ll @@ -0,0 +1,60 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -S -gvn < %s | FileCheck %s + +; FIXME +; Phi translation of %gep.j cannot use %gep.i, which is located in a context +; where %i != 0, and would result in incorrect NoAlias results in a context +; where %i == 0 may hold. + +define i32 @test(i64 %i, i1 %c1, i1 %c2) { +; CHECK-LABEL: @test( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[PTR:%.*]] = alloca [2 x i32], align 4 +; CHECK-NEXT: br i1 [[C1:%.*]], label [[IF:%.*]], label [[ELSE:%.*]] +; CHECK: if: +; CHECK-NEXT: br i1 [[C2:%.*]], label [[IF2:%.*]], label [[ELSE2:%.*]] +; CHECK: if2: +; CHECK-NEXT: store i32 1, ptr [[PTR]], align 4 +; CHECK-NEXT: br label [[JOIN:%.*]] +; CHECK: else2: +; CHECK-NEXT: store i32 2, ptr [[PTR]], align 4 +; CHECK-NEXT: br label [[JOIN]] +; CHECK: join: +; CHECK-NEXT: [[J:%.*]] = phi i64 [ [[I:%.*]], [[IF2]] ], [ 0, [[ELSE2]] ] +; CHECK-NEXT: [[GEP_J:%.*]] = getelementptr inbounds i32, ptr [[PTR]], i64 [[J]] +; CHECK-NEXT: ret i32 2 +; CHECK: else: +; CHECK-NEXT: [[CMP:%.*]] = icmp ne i64 [[I]], 0 +; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) +; CHECK-NEXT: [[GEP_I:%.*]] = getelementptr inbounds i32, ptr [[PTR]], i64 [[I]] +; CHECK-NEXT: ret i32 0 +; +entry: + %ptr = alloca [2 x i32] + br i1 %c1, label %if, label %else + +if: + br i1 %c2, label %if2, label %else2 + +if2: + store i32 1, ptr %ptr + br label %join + +else2: + store i32 2, ptr %ptr + br label %join + +join: + %j = phi i64 [ %i, %if2 ], [ 0, %else2 ] + %gep.j = getelementptr inbounds i32, ptr %ptr, i64 %j + %v = load i32, ptr %gep.j + ret i32 %v + +else: + %cmp = icmp ne i64 %i, 0 + call void @llvm.assume(i1 %cmp) + %gep.i = getelementptr inbounds i32, ptr %ptr, i64 %i + ret i32 0 +} + +declare void @llvm.assume(i1)