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1; Test to make sure llvm.invariant.start calls are not treated as clobbers.
2; RUN: opt < %s -gvn -S | FileCheck %s
3
4
5declare {}* @llvm.invariant.start.p0i8(i64, i8* nocapture) nounwind readonly
6declare void @llvm.invariant.end.p0i8({}*, i64, i8* nocapture) nounwind
7
8; We forward store to the load across the invariant.start intrinsic
9define i8 @forward_store() {
10; CHECK-LABEL: @forward_store
11; CHECK: call {}* @llvm.invariant.start.p0i8(i64 1, i8* %a)
12; CHECK-NOT: load
13; CHECK: ret i8 0
14  %a = alloca i8
15  store i8 0, i8* %a
16  %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %a)
17  %r = load i8, i8* %a
18  ret i8 %r
19}
20
21declare i8 @dummy(i8* nocapture) nounwind readonly
22
23; We forward store to the load in the non-local analysis case,
24; i.e. invariant.start is in another basic block.
25define i8 @forward_store_nonlocal(i1 %cond) {
26; CHECK-LABEL: forward_store_nonlocal
27; CHECK: call {}* @llvm.invariant.start.p0i8(i64 1, i8* %a)
28; CHECK: ret i8 0
29; CHECK: ret i8 %val
30  %a = alloca i8
31  store i8 0, i8* %a
32  %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %a)
33  br i1 %cond, label %loadblock, label %exit
34
35loadblock:
36  %r = load i8, i8* %a
37  ret i8 %r
38
39exit:
40  %val = call i8 @dummy(i8* %a)
41  ret i8 %val
42}
43
44; We should not value forward %foo to the invariant.end corresponding to %bar.
45define i8 @forward_store1() {
46; CHECK-LABEL: forward_store1
47; CHECK: %foo = call {}* @llvm.invariant.start.p0i8
48; CHECK-NOT: load
49; CHECK: %bar = call {}* @llvm.invariant.start.p0i8
50; CHECK: call void @llvm.invariant.end.p0i8({}* %bar, i64 1, i8* %a)
51; CHECK: ret i8 0
52  %a = alloca i8
53  store i8 0, i8* %a
54  %foo = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %a)
55  %r = load i8, i8* %a
56  %bar = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %a)
57  call void @llvm.invariant.end.p0i8({}* %bar, i64 1, i8* %a)
58  ret i8 %r
59}
60