1; This testcase is distilled from the GNU rx package.  The loop should be
2; removed but causes a problem when ADCE does.  The source function is:
3; int rx_bitset_empty (int size, rx_Bitset set) {
4;  int x;
5;  RX_subset s;
6;  s = set[0];
7;  set[0] = 1;
8;  for (x = rx_bitset_numb_subsets(size) - 1; !set[x]; --x)
9;    ;
10;  set[0] = s;
11;  return !s;
12;}
13;
14; RUN: opt < %s -adce
15
16define i32 @rx_bitset_empty(i32 %size, i32* %set) {
17bb1:
18        %reg110 = load i32* %set                ; <i32> [#uses=2]
19        store i32 1, i32* %set
20        %cast112 = sext i32 %size to i64                ; <i64> [#uses=1]
21        %reg113 = add i64 %cast112, 31          ; <i64> [#uses=1]
22        %reg114 = lshr i64 %reg113, 5           ; <i64> [#uses=2]
23        %cast109 = trunc i64 %reg114 to i32             ; <i32> [#uses=1]
24        %reg129 = add i32 %cast109, -1          ; <i32> [#uses=1]
25        %reg114-idxcast = trunc i64 %reg114 to i32              ; <i32> [#uses=1]
26        %reg114-idxcast-offset = add i32 %reg114-idxcast, 1073741823            ; <i32> [#uses=1]
27        %reg114-idxcast-offset.upgrd.1 = zext i32 %reg114-idxcast-offset to i64         ; <i64> [#uses=1]
28        %reg124 = getelementptr i32* %set, i64 %reg114-idxcast-offset.upgrd.1           ; <i32*> [#uses=1]
29        %reg125 = load i32* %reg124             ; <i32> [#uses=1]
30        %cond232 = icmp ne i32 %reg125, 0               ; <i1> [#uses=1]
31        br i1 %cond232, label %bb3, label %bb2
32
33bb2:            ; preds = %bb2, %bb1
34        %cann-indvar = phi i32 [ 0, %bb1 ], [ %add1-indvar, %bb2 ]              ; <i32> [#uses=2]
35        %reg130-scale = mul i32 %cann-indvar, -1                ; <i32> [#uses=1]
36        %reg130 = add i32 %reg130-scale, %reg129                ; <i32> [#uses=1]
37        %add1-indvar = add i32 %cann-indvar, 1          ; <i32> [#uses=1]
38        %reg130-idxcast = bitcast i32 %reg130 to i32            ; <i32> [#uses=1]
39        %reg130-idxcast-offset = add i32 %reg130-idxcast, 1073741823            ; <i32> [#uses=1]
40        %reg130-idxcast-offset.upgrd.2 = zext i32 %reg130-idxcast-offset to i64         ; <i64> [#uses=1]
41        %reg118 = getelementptr i32* %set, i64 %reg130-idxcast-offset.upgrd.2           ; <i32*> [#uses=1]
42        %reg119 = load i32* %reg118             ; <i32> [#uses=1]
43        %cond233 = icmp eq i32 %reg119, 0               ; <i1> [#uses=1]
44        br i1 %cond233, label %bb2, label %bb3
45
46bb3:            ; preds = %bb2, %bb1
47        store i32 %reg110, i32* %set
48        %cast126 = zext i32 %reg110 to i64              ; <i64> [#uses=1]
49        %reg127 = add i64 %cast126, -1          ; <i64> [#uses=1]
50        %reg128 = lshr i64 %reg127, 63          ; <i64> [#uses=1]
51        %cast120 = trunc i64 %reg128 to i32             ; <i32> [#uses=1]
52        ret i32 %cast120
53}
54
55