1; RUN: opt -loop-load-elim -S < %s | FileCheck %s
2
3; Simple st->ld forwarding derived from a lexical forward dep.
4;
5;   for (unsigned i = 0; i < 100; i++) {
6;     A[i+1] = B[i] + 2;
7;     C[i] = A[i] * 2;
8;   }
9
10target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
11
12define void @f(i32* %A, i32* %B, i32* %C, i64 %N) {
13
14; CHECK:   for.body.lver.check:
15; CHECK:     %found.conflict{{.*}} =
16; CHECK-NOT: %found.conflict{{.*}} =
17
18entry:
19; for.body.ph:
20; CHECK: %load_initial = load i32, i32* %A
21  br label %for.body
22
23for.body:                                         ; preds = %for.body, %entry
24; CHECK: %store_forwarded = phi i32 [ %load_initial, %for.body.ph ], [ %a_p1, %for.body ]
25  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
26  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
27
28  %Aidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
29  %Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
30  %Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
31  %Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
32
33  %b = load i32, i32* %Bidx, align 4
34  %a_p1 = add i32 %b, 2
35  store i32 %a_p1, i32* %Aidx_next, align 4
36
37  %a = load i32, i32* %Aidx, align 4
38; CHECK: %c = mul i32 %store_forwarded, 2
39  %c = mul i32 %a, 2
40  store i32 %c, i32* %Cidx, align 4
41
42  %exitcond = icmp eq i64 %indvars.iv.next, %N
43  br i1 %exitcond, label %for.end, label %for.body
44
45for.end:                                          ; preds = %for.body
46  ret void
47}
48