diff --git a/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll b/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Transforms/DeadStoreElimination/store-after-loop.ll @@ -0,0 +1,60 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -passes=dse -S | FileCheck %s + +target datalayout = "E-m:e-p:32:32-i64:32-f64:32:64-a:0:32-n32-S32" + +%struct.ilist = type { i32, %struct.ilist* } + +; There is no dead store in this test. Make sure no store is deleted by DSE. +; Test case related to bug report PR52774. +; NOTE: Showing actual (broken) DSE behavior. + +define %struct.ilist* @test() { +; CHECK-LABEL: @test( +; CHECK-NEXT: br label [[LOOP:%.*]] +; CHECK: loop: +; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[TMP0:%.*]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ] +; CHECK-NEXT: [[LIST_NEXT:%.*]] = phi %struct.ilist* [ null, [[TMP0]] ], [ [[LIST_NEW_ILIST_PTR:%.*]], [[LOOP]] ] +; CHECK-NEXT: [[LIST_NEW_I8_PTR:%.*]] = tail call align 8 dereferenceable_or_null(8) i8* @malloc(i32 8) +; CHECK-NEXT: [[LIST_NEW_ILIST_PTR]] = bitcast i8* [[LIST_NEW_I8_PTR]] to %struct.ilist* +; CHECK-NEXT: [[GEP_NEW_VALUE:%.*]] = getelementptr inbounds [[STRUCT_ILIST:%.*]], %struct.ilist* [[LIST_NEW_ILIST_PTR]], i32 0, i32 0 +; CHECK-NEXT: store i32 42, i32* [[GEP_NEW_VALUE]], align 8 +; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1 +; CHECK-NEXT: [[COND:%.*]] = icmp eq i32 [[IV_NEXT]], 10 +; CHECK-NEXT: br i1 [[COND]], label [[EXIT:%.*]], label [[LOOP]] +; CHECK: exit: +; CHECK-NEXT: [[LIST_LAST_ILIST_PTR:%.*]] = bitcast i8* [[LIST_NEW_I8_PTR]] to %struct.ilist* +; CHECK-NEXT: [[GEP_LIST_LAST_NEXT:%.*]] = getelementptr inbounds [[STRUCT_ILIST]], %struct.ilist* [[LIST_LAST_ILIST_PTR]], i32 0, i32 1 +; CHECK-NEXT: store %struct.ilist* null, %struct.ilist** [[GEP_LIST_LAST_NEXT]], align 4 +; CHECK-NEXT: [[GEP_LIST_NEXT_NEXT:%.*]] = getelementptr inbounds [[STRUCT_ILIST]], %struct.ilist* [[LIST_NEXT]], i32 0, i32 1 +; CHECK-NEXT: [[LOADED_PTR:%.*]] = load %struct.ilist*, %struct.ilist** [[GEP_LIST_NEXT_NEXT]], align 4 +; CHECK-NEXT: ret %struct.ilist* [[LOADED_PTR]] +; + br label %loop + +loop: + %iv = phi i32 [ 0, %0 ], [ %iv.next, %loop ] + %list.next = phi %struct.ilist* [ null, %0 ], [ %list.new.ilist.ptr, %loop ] + %list.new.i8.ptr = tail call align 8 dereferenceable_or_null(8) i8* @malloc(i32 8) + %list.new.ilist.ptr = bitcast i8* %list.new.i8.ptr to %struct.ilist* + %gep.new.value = getelementptr inbounds %struct.ilist, %struct.ilist* %list.new.ilist.ptr, i32 0, i32 0 + store i32 42, i32* %gep.new.value, align 8 + %gep.new.next = getelementptr inbounds %struct.ilist, %struct.ilist* %list.new.ilist.ptr, i32 0, i32 1 + store %struct.ilist* %list.next, %struct.ilist** %gep.new.next, align 4 + %iv.next = add nuw nsw i32 %iv, 1 + %cond = icmp eq i32 %iv.next, 10 + br i1 %cond, label %exit, label %loop + +exit: + %list.last.ilist.ptr = bitcast i8* %list.new.i8.ptr to %struct.ilist* + %gep.list.last.next = getelementptr inbounds %struct.ilist, %struct.ilist* %list.last.ilist.ptr, i32 0, i32 1 + store %struct.ilist* null, %struct.ilist** %gep.list.last.next, align 4 + %gep.list.next.next = getelementptr inbounds %struct.ilist, %struct.ilist* %list.next, i32 0, i32 1 + %loaded_ptr = load %struct.ilist*, %struct.ilist** %gep.list.next.next, align 4 + ret %struct.ilist* %loaded_ptr ; use loaded pointer +} + +; Function Attrs: inaccessiblememonly nounwind +declare noalias noundef align 8 i8* @malloc(i32 noundef) local_unnamed_addr #0 + +attributes #0 = { inaccessiblememonly nounwind}