[LICM] Add test for #64897 (NFC)

Author: nikic

llvm/test/Transforms/LICM/pr64897.ll

@@ -0,0 +1,46 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -S -passes=licm < %s | FileCheck %s
+
+; FIXME: This is a miscompile.
+define void @test(i1 %c, i8 %x) {
+; CHECK-LABEL: define void @test(
+; CHECK-SAME: i1 [[C:%.*]], i8 [[X:%.*]]) {
+; CHECK-NEXT:  start:
+; CHECK-NEXT:    [[A:%.*]] = alloca [16 x i8], align 8
+; CHECK-NEXT:    [[P:%.*]] = getelementptr inbounds i8, ptr [[A]], i64 8
+; CHECK-NEXT:    [[P_COPY:%.*]] = getelementptr inbounds i8, ptr [[A]], i64 8
+; CHECK-NEXT:    [[P2:%.*]] = getelementptr inbounds i8, ptr [[A]], i64 12
+; CHECK-NEXT:    [[P2_PROMOTED:%.*]] = load i8, ptr [[P2]], align 1
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[TMP0:%.*]] = phi i8 [ 0, [[LOOP]] ], [ [[P2_PROMOTED]], [[START:%.*]] ]
+; CHECK-NEXT:    store i32 286331153, ptr [[P]], align 4
+; CHECK-NEXT:    store i32 34, ptr [[P_COPY]], align 4
+; CHECK-NEXT:    store i64 3689348814741910323, ptr [[P_COPY]], align 4
+; CHECK-NEXT:    call void @use(i8 [[TMP0]])
+; CHECK-NEXT:    br i1 [[C]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    store i8 0, ptr [[P2]], align 1
+; CHECK-NEXT:    ret void
+;
+start:
+  %a = alloca [16 x i8], align 8
+  %p = getelementptr inbounds i8, ptr %a, i64 8
+  %p.copy = getelementptr inbounds i8, ptr %a, i64 8
+  %p2 = getelementptr inbounds i8, ptr %a, i64 12
+  br label %loop
+
+loop:
+  store i32 u0x11111111, ptr %p
+  store i32 u0x22, ptr %p.copy
+  store i64 u0x3333333333333333, ptr %p.copy
+  %val = load i8, ptr %p2
+  call void @use(i8 %val)
+  store i8 0, ptr %p2
+  br i1 %c, label %loop, label %exit
+
+exit:
+  ret void
+}
+
+declare void @use(i8)