[llvm] [DSE] Apply initializes attribute to DSE (PR #107282)

[Jan Voung via llvm-commits]

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@@ -0,0 +1,159 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=dse -enable-dse-initializes-attr-improvement -S | FileCheck %s
+
+declare void @p1_write_only(ptr nocapture noundef writeonly initializes((0, 2)) dead_on_unwind)
+declare void @p1_write_then_read(ptr nocapture noundef initializes((0, 2)) dead_on_unwind)
+declare void @p2_same_range(ptr nocapture noundef initializes((0, 2)) dead_on_unwind, ptr nocapture noundef initializes((0, 2)) dead_on_unwind)
+declare void @p2_no_init(ptr nocapture noundef initializes((0, 2)) dead_on_unwind, ptr nocapture noundef dead_on_unwind)
+declare void @p2_no_dead_on_unwind(ptr nocapture noundef initializes((0, 2)) dead_on_unwind, ptr nocapture noundef initializes((0, 2)))
+
+; Function Attrs: mustprogress nounwind uwtable
+define i16 @p1_write_only_caller() {
+; CHECK-LABEL: @p1_write_only_caller(
+; CHECK-NEXT:    %ptr = alloca i16, align 2
+; CHECK-NEXT:    call void @p1_write_only(ptr %ptr)
+; CHECK-NEXT:    %l = load i16, ptr %ptr
+; CHECK-NEXT:    ret i16 %l
+;
+  %ptr = alloca i16
+  store i16 0, ptr %ptr
+  call void @p1_write_only(ptr %ptr)
+  %l = load i16, ptr %ptr
+  ret i16 %l
+}
+
+; Function Attrs: mustprogress nounwind uwtable
+define i16 @p1_write_then_read_caller() {
+; CHECK-LABEL: @p1_write_then_read_caller(
+; CHECK-NEXT:    %ptr = alloca i16, align 2
+; CHECK-NEXT:    call void @p1_write_then_read(ptr %ptr)
+; CHECK-NEXT:    %l = load i16, ptr %ptr
+; CHECK-NEXT:    ret i16 %l
+;
+  %ptr = alloca i16
+  store i16 0, ptr %ptr
+  call void @p1_write_then_read(ptr %ptr)
+  %l = load i16, ptr %ptr
+  ret i16 %l
+}
+
+; Function Attrs: mustprogress nounwind uwtable
+define i16 @p2_same_range_nonalias_caller() {
+; CHECK-LABEL: @p2_same_range_nonalias_caller(
+; CHECK-NEXT:    %ptr1 = alloca i16, align 2
+; CHECK-NEXT:    %ptr2 = alloca i16, align 2
+; CHECK-NEXT:    call void @p2_same_range(ptr %ptr1, ptr %ptr2)
+; CHECK-NEXT:    %l = load i16, ptr %ptr1
+; CHECK-NEXT:    ret i16 %l
+;
+  %ptr1 = alloca i16
+  %ptr2 = alloca i16
+  store i16 0, ptr %ptr1
+  store i16 0, ptr %ptr2
+  call void @p2_same_range(ptr %ptr1, ptr %ptr2)
+  %l = load i16, ptr %ptr1
+  ret i16 %l
+}
+
+; Function Attrs: mustprogress nounwind uwtable
+define i16 @p2_same_range_alias_caller() {
+; CHECK-LABEL: @p2_same_range_alias_caller(
+; CHECK-NEXT:    %ptr = alloca i16, align 2
+; CHECK-NEXT:    call void @p2_same_range(ptr %ptr, ptr %ptr)
+; CHECK-NEXT:    %l = load i16, ptr %ptr
+; CHECK-NEXT:    ret i16 %l
+;
+  %ptr = alloca i16
+  store i16 0, ptr %ptr
+  call void @p2_same_range(ptr %ptr, ptr %ptr)
+  %l = load i16, ptr %ptr
+  ret i16 %l
+}
+
+; Function Attrs: mustprogress nounwind uwtable
+define i16 @p2_no_init_alias_caller() {
+; CHECK-LABEL: @p2_no_init_alias_caller(
+; CHECK-NEXT:    %ptr = alloca i16, align 2
+; CHECK-NEXT:    store i16 0, ptr %ptr
+; CHECK-NEXT:    call void @p2_no_init(ptr %ptr, ptr %ptr)
+; CHECK-NEXT:    %l = load i16, ptr %ptr
+; CHECK-NEXT:    ret i16 %l
+;
+  %ptr = alloca i16
+  store i16 0, ptr %ptr
+  call void @p2_no_init(ptr %ptr, ptr %ptr)
+  %l = load i16, ptr %ptr
+  ret i16 %l
+}
+
+; Function Attrs: mustprogress nounwind uwtable
+define i16 @p2_no_dead_on_unwind_alias_caller() {
+; CHECK-LABEL: @p2_no_dead_on_unwind_alias_caller(
+; CHECK-NEXT:    %ptr = alloca i16, align 2
+; CHECK-NEXT:    store i16 0, ptr %ptr
+; CHECK-NEXT:    call void @p2_no_dead_on_unwind(ptr %ptr, ptr %ptr)
+; CHECK-NEXT:    %l = load i16, ptr %ptr
+; CHECK-NEXT:    ret i16 %l
+;
+  %ptr = alloca i16
+  store i16 0, ptr %ptr
+  call void @p2_no_dead_on_unwind(ptr %ptr, ptr %ptr)
+  %l = load i16, ptr %ptr
+  ret i16 %l
+}
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jvoung wrote:

maybe a version where the function has nounwind ?

https://github.com/llvm/llvm-project/pull/107282