xref: /llvm-project/llvm/test/Transforms/MemCpyOpt/pr54682.ll (revision a11faeed446882a81e79d780125d93e7199df645)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S -passes=memcpyopt < %s | FileCheck %s
3
4; The memcpy here is *not* dead, because it reads memory written in a previous
5; loop iteration.
6
7define void @test(i1 %c, ptr nocapture noundef readonly %path, ptr noundef writeonly %name) {
8; CHECK-LABEL: @test(
9; CHECK-NEXT:  entry:
10; CHECK-NEXT:    [[TMP:%.*]] = alloca [260 x i8], align 16
11; CHECK-NEXT:    br label [[WHILE_BODY:%.*]]
12; CHECK:       while.body:
13; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[WHILE_BODY]] ], [ 259, [[ENTRY:%.*]] ]
14; CHECK-NEXT:    [[IV_NEXT]] = add nsw i64 [[IV]], -1
15; CHECK-NEXT:    [[TMP_IV:%.*]] = getelementptr inbounds [260 x i8], ptr [[TMP]], i64 0, i64 [[IV]]
16; CHECK-NEXT:    store i8 42, ptr [[TMP_IV]], align 1
17; CHECK-NEXT:    br i1 [[C:%.*]], label [[WHILE_BODY]], label [[EXIT:%.*]]
18; CHECK:       exit:
19; CHECK-NEXT:    [[TMP_IV_1:%.*]] = getelementptr inbounds i8, ptr [[TMP_IV]], i64 1
20; CHECK-NEXT:    [[LEN:%.*]] = sub nsw i64 259, [[IV]]
21; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr align 1 [[NAME:%.*]], ptr nonnull align 1 [[TMP_IV_1]], i64 [[LEN]], i1 false)
22; CHECK-NEXT:    ret void
23;
24entry:
25  %tmp = alloca [260 x i8], align 16
26  br label %while.body
27
28while.body:
29  %iv = phi i64 [ %iv.next, %while.body ], [ 259, %entry ]
30  %iv.next = add nsw i64 %iv, -1
31  %tmp.iv = getelementptr inbounds [260 x i8], ptr %tmp, i64 0, i64 %iv
32  store i8 42, ptr %tmp.iv, align 1
33  br i1 %c, label %while.body, label %exit
34
35exit:
36  %tmp.iv.1 = getelementptr inbounds i8, ptr %tmp.iv, i64 1
37  %len = sub nsw i64 259, %iv
38  call void @llvm.memcpy.p0.p0.i64(ptr align 1 %name, ptr nonnull align 1 %tmp.iv.1, i64 %len, i1 false)
39  ret void
40}
41
42declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly %0, ptr noalias nocapture readonly %1, i64 %2, i1 immarg %3)
43