[EarlyCSE] Add tests showing loss of alignment info for ptr loads.

Precommit tests for #109131.

Author: fhahn

llvm/test/Transforms/EarlyCSE/materialize-align-assumptions.ll

@@ -0,0 +1,100 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes='early-cse<memssa>' -S %s | FileCheck %s
+
+declare void @foo(ptr)
+
+define ptr @align_replacement_does_not_have_align_metadata(ptr noalias %p) {
+; CHECK-LABEL: define ptr @align_replacement_does_not_have_align_metadata(
+; CHECK-SAME: ptr noalias [[P:%.*]]) {
+; CHECK-NEXT:    [[L_1:%.*]] = load ptr, ptr [[P]], align 8
+; CHECK-NEXT:    call void @foo(ptr [[L_1]])
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i8, ptr [[L_1]], i64 4
+; CHECK-NEXT:    store ptr [[GEP]], ptr [[P]], align 8
+; CHECK-NEXT:    ret ptr [[GEP]]
+;
+  %l.1 = load ptr, ptr %p, align 8
+  call void @foo(ptr %l.1)
+  %l.2 = load ptr, ptr %p, align 8
+  %gep = getelementptr i8, ptr %l.2, i64 4
+  store ptr %gep, ptr %p, align 8
+  %l.3 = load ptr, ptr %p, align 8, !align !0
+  ret ptr %l.3
+}
+
+define ptr @align_replacement_does_not_have_align_metadata2(ptr noalias %p) {
+; CHECK-LABEL: define ptr @align_replacement_does_not_have_align_metadata2(
+; CHECK-SAME: ptr noalias [[P:%.*]]) {
+; CHECK-NEXT:    [[L_1:%.*]] = load ptr, ptr [[P]], align 8
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i8, ptr [[L_1]], i64 4
+; CHECK-NEXT:    store ptr [[GEP]], ptr [[P]], align 8
+; CHECK-NEXT:    ret ptr [[GEP]]
+;
+  %l.1 = load ptr, ptr %p, align 8
+  %gep = getelementptr i8, ptr %l.1, i64 4
+  store ptr %gep, ptr %p, align 8
+  %l.2 = load ptr, ptr %p, align 8, !align !0
+  ret ptr %l.2
+}
+
+define ptr @align_replacement_has_same_alignment(ptr noalias %p) {
+; CHECK-LABEL: define ptr @align_replacement_has_same_alignment(
+; CHECK-SAME: ptr noalias [[P:%.*]]) {
+; CHECK-NEXT:    [[L_1:%.*]] = load ptr, ptr [[P]], align 8, !align [[META0:![0-9]+]]
+; CHECK-NEXT:    call void @foo(ptr [[L_1]])
+; CHECK-NEXT:    ret ptr [[L_1]]
+;
+  %l.1 = load ptr, ptr %p, align 8, !align !0
+  call void @foo(ptr %l.1)
+  %l.2 = load ptr, ptr %p, align 8, !align !0
+  ret ptr %l.2
+}
+
+define ptr @align_replacement_has_smaller_alignment(ptr noalias %p) {
+; CHECK-LABEL: define ptr @align_replacement_has_smaller_alignment(
+; CHECK-SAME: ptr noalias [[P:%.*]]) {
+; CHECK-NEXT:    [[L_1:%.*]] = load ptr, ptr [[P]], align 8, !align [[META0]]
+; CHECK-NEXT:    call void @foo(ptr [[L_1]])
+; CHECK-NEXT:    ret ptr [[L_1]]
+;
+  %l.1 = load ptr, ptr %p, align 8, !align !0
+  call void @foo(ptr %l.1)
+  %l.2 = load ptr, ptr %p, align 8, !align !1
+  ret ptr %l.2
+}
+
+define ptr @align_replacement_has_larger_alignment(ptr %p) {
+; CHECK-LABEL: define ptr @align_replacement_has_larger_alignment(
+; CHECK-SAME: ptr [[P:%.*]]) {
+; CHECK-NEXT:    [[L_1:%.*]] = load ptr, ptr [[P]], align 8, !align [[META1:![0-9]+]]
+; CHECK-NEXT:    call void @foo(ptr [[L_1]])
+; CHECK-NEXT:    [[L_2:%.*]] = load ptr, ptr [[P]], align 8, !align [[META0]]
+; CHECK-NEXT:    ret ptr [[L_2]]
+;
+  %l.1 = load ptr, ptr %p, align 8, !align !1
+  call void @foo(ptr %l.1)
+  %l.2 = load ptr, ptr %p, align 8, !align !0
+  ret ptr %l.2
+}
+
+define ptr @align_1(ptr %p) {
+; CHECK-LABEL: define ptr @align_1(
+; CHECK-SAME: ptr [[P:%.*]]) {
+; CHECK-NEXT:    [[L_1:%.*]] = load ptr, ptr [[P]], align 8
+; CHECK-NEXT:    call void @foo(ptr [[L_1]])
+; CHECK-NEXT:    [[L_2:%.*]] = load ptr, ptr [[P]], align 8, !align [[META2:![0-9]+]]
+; CHECK-NEXT:    ret ptr [[L_2]]
+;
+  %l.1 = load ptr, ptr %p, align 8
+  call void @foo(ptr %l.1)
+  %l.2 = load ptr, ptr %p, align 8, !align !2
+  ret ptr %l.2
+}
+
+!0 = !{i64 4}
+!1 = !{i64 8}
+!2 = !{i64 1}
+;.
+; CHECK: [[META0]] = !{i64 4}
+; CHECK: [[META1]] = !{i64 8}
+; CHECK: [[META2]] = !{i64 1}
+;.