[llvm] Attributor: Add baseline tests for propagating align to atomics (PR #134836)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/134836

>From 639fefd36f952b1863a2c732f7799c4f7e044790 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Tue, 8 Apr 2025 17:19:17 +0700
Subject: [PATCH] Attributor: Add baseline tests for propagating align to
 atomics

---
 .../Transforms/Attributor/align-atomic.ll     | 64 +++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 llvm/test/Transforms/Attributor/align-atomic.ll

diff --git a/llvm/test/Transforms/Attributor/align-atomic.ll b/llvm/test/Transforms/Attributor/align-atomic.ll
new file mode 100644
index 0000000000000..764ed7419a079
--- /dev/null
+++ b/llvm/test/Transforms/Attributor/align-atomic.ll
@@ -0,0 +1,64 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal  -attributor-annotate-decl-cs  -S < %s | FileCheck %s --check-prefixes=CHECK,TUNIT
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor-cgscc -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,CGSCC
+
+define i32 @atomicrmw_add_no_op(ptr align 4 %ptr, i32 %val) {
+; CHECK-LABEL: define i32 @atomicrmw_add_no_op(
+; CHECK-SAME: ptr nofree noundef nonnull align 4 captures(none) dereferenceable(4) [[PTR:%.*]], i32 [[VAL:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:    [[RESULT:%.*]] = atomicrmw add ptr [[PTR]], i32 [[VAL]] seq_cst, align 4
+; CHECK-NEXT:    ret i32 [[RESULT]]
+;
+  %result = atomicrmw add ptr %ptr, i32 %val seq_cst, align 4
+  ret i32 %result
+}
+
+; Check that the aligment increases to 8
+define i32 @atomicrmw_add_propagate(ptr align 8 %ptr, i32 %val) {
+; CHECK-LABEL: define i32 @atomicrmw_add_propagate(
+; CHECK-SAME: ptr nofree noundef nonnull align 8 captures(none) dereferenceable(4) [[PTR:%.*]], i32 [[VAL:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[RESULT:%.*]] = atomicrmw add ptr [[PTR]], i32 [[VAL]] seq_cst, align 2
+; CHECK-NEXT:    ret i32 [[RESULT]]
+;
+  %result = atomicrmw add ptr %ptr, i32 %val seq_cst, align 2
+  ret i32 %result
+}
+
+; Should increase alignment to 8, not 16.
+define ptr @atomicrmw_non_ptr_op_no_propagate(ptr %ptr, ptr align 16 %val) {
+; CHECK-LABEL: define ptr @atomicrmw_non_ptr_op_no_propagate(
+; CHECK-SAME: ptr nofree noundef nonnull align 2 captures(none) dereferenceable(8) [[PTR:%.*]], ptr nofree align 16 [[VAL:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[RESULT:%.*]] = atomicrmw xchg ptr [[PTR]], ptr [[VAL]] seq_cst, align 2
+; CHECK-NEXT:    ret ptr [[RESULT]]
+;
+  %result = atomicrmw xchg ptr %ptr, ptr %val seq_cst, align 2
+  ret ptr %result
+}
+
+define i32 @cmpxchg_propagate(ptr align 8 %ptr, i32 %cmp, i32 %val) {
+; CHECK-LABEL: define i32 @cmpxchg_propagate(
+; CHECK-SAME: ptr nofree noundef nonnull align 8 captures(none) dereferenceable(4) [[PTR:%.*]], i32 [[CMP:%.*]], i32 [[VAL:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[PAIR:%.*]] = cmpxchg ptr [[PTR]], i32 [[CMP]], i32 [[VAL]] seq_cst monotonic, align 2
+; CHECK-NEXT:    [[RESULT:%.*]] = extractvalue { i32, i1 } [[PAIR]], 0
+; CHECK-NEXT:    ret i32 [[RESULT]]
+;
+  %pair = cmpxchg ptr %ptr, i32 %cmp, i32 %val seq_cst monotonic, align 2
+  %result = extractvalue { i32, i1 } %pair, 0
+  ret i32 %result
+}
+
+; Should not increase alignment
+define ptr @cmpxchg_no_propagate(ptr %ptr, ptr align 16 %cmp, ptr align 32 %val) {
+; CHECK-LABEL: define ptr @cmpxchg_no_propagate(
+; CHECK-SAME: ptr nofree noundef nonnull align 2 captures(none) dereferenceable(8) [[PTR:%.*]], ptr nofree align 16 [[CMP:%.*]], ptr nofree align 32 [[VAL:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[PAIR:%.*]] = cmpxchg ptr [[PTR]], ptr [[CMP]], ptr [[VAL]] seq_cst monotonic, align 2
+; CHECK-NEXT:    [[RESULT:%.*]] = extractvalue { ptr, i1 } [[PAIR]], 0
+; CHECK-NEXT:    ret ptr [[RESULT]]
+;
+  %pair = cmpxchg ptr %ptr, ptr %cmp, ptr %val seq_cst monotonic, align 2
+  %result = extractvalue { ptr, i1 } %pair, 0
+  ret ptr %result
+}
+
+;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+; CGSCC: {{.*}}
+; TUNIT: {{.*}}