1; RUN: opt -basicaa -gvn -S < %s | FileCheck %s
2
3target datalayout = "e-p:64:64:64"
4
5; GVN should ignore the store to p[1] to see that the load from p[0] is
6; fully redundant.
7
8; CHECK-LABEL: @yes(
9; CHECK: if.then:
10; CHECK-NEXT: store i32 0, i32* %q
11; CHECK-NEXT: ret void
12
13define void @yes(i1 %c, i32* %p, i32* %q) nounwind {
14entry:
15  store i32 0, i32* %p
16  %p1 = getelementptr inbounds i32, i32* %p, i64 1
17  store i32 1, i32* %p1
18  br i1 %c, label %if.else, label %if.then
19
20if.then:
21  %t = load i32, i32* %p
22  store i32 %t, i32* %q
23  ret void
24
25if.else:
26  ret void
27}
28
29; GVN should ignore the store to p[1] to see that the first load from p[0] is
30; fully redundant. However, the second load is larger, so it's not a simple
31; redundancy.
32
33; CHECK-LABEL: @watch_out_for_size_change(
34; CHECK: if.then:
35; CHECK-NEXT: store i32 0, i32* %q
36; CHECK-NEXT: ret void
37; CHECK: if.else:
38; CHECK: load i64, i64* %pc
39; CHECK: store i64
40
41define void @watch_out_for_size_change(i1 %c, i32* %p, i32* %q) nounwind {
42entry:
43  store i32 0, i32* %p
44  %p1 = getelementptr inbounds i32, i32* %p, i64 1
45  store i32 1, i32* %p1
46  br i1 %c, label %if.else, label %if.then
47
48if.then:
49  %t = load i32, i32* %p
50  store i32 %t, i32* %q
51  ret void
52
53if.else:
54  %pc = bitcast i32* %p to i64*
55  %qc = bitcast i32* %q to i64*
56  %t64 = load i64, i64* %pc
57  store i64 %t64, i64* %qc
58  ret void
59}
60