1; RUN: llc < %s -march=arm | FileCheck %s
2
3; This loop is rewritten with an indvar which counts down, which
4; frees up a register from holding the trip count.
5
6define void @test(i32* %P, i32 %A, i32 %i) nounwind {
7entry:
8; CHECK: str r1, [{{r.*}}, {{r.*}}, lsl #2]
9        icmp eq i32 %i, 0               ; <i1>:0 [#uses=1]
10        br i1 %0, label %return, label %bb
11
12bb:             ; preds = %bb, %entry
13        %indvar = phi i32 [ 0, %entry ], [ %indvar.next, %bb ]          ; <i32> [#uses=2]
14        %i_addr.09.0 = sub i32 %i, %indvar              ; <i32> [#uses=1]
15        %tmp2 = getelementptr i32* %P, i32 %i_addr.09.0         ; <i32*> [#uses=1]
16        store i32 %A, i32* %tmp2
17        %indvar.next = add i32 %indvar, 1               ; <i32> [#uses=2]
18        icmp eq i32 %indvar.next, %i            ; <i1>:1 [#uses=1]
19        br i1 %1, label %return, label %bb
20
21return:         ; preds = %bb, %entry
22        ret void
23}
24
25; This loop has a non-address use of the count-up indvar, so
26; it'll remain. Now the original store uses a negative-stride address.
27
28define void @test_with_forced_iv(i32* %P, i32 %A, i32 %i) nounwind {
29entry:
30; CHECK: str r1, [{{r.*}}, -{{r.*}}, lsl #2]
31        icmp eq i32 %i, 0               ; <i1>:0 [#uses=1]
32        br i1 %0, label %return, label %bb
33
34bb:             ; preds = %bb, %entry
35        %indvar = phi i32 [ 0, %entry ], [ %indvar.next, %bb ]          ; <i32> [#uses=2]
36        %i_addr.09.0 = sub i32 %i, %indvar              ; <i32> [#uses=1]
37        %tmp2 = getelementptr i32* %P, i32 %i_addr.09.0         ; <i32*> [#uses=1]
38        store i32 %A, i32* %tmp2
39        store i32 %indvar, i32* null
40        %indvar.next = add i32 %indvar, 1               ; <i32> [#uses=2]
41        icmp eq i32 %indvar.next, %i            ; <i1>:1 [#uses=1]
42        br i1 %1, label %return, label %bb
43
44return:         ; preds = %bb, %entry
45        ret void
46}
47
48