• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1; RUN: opt < %s -S -indvars | grep "= icmp" | count 3
2; PR4914.ll
3
4; Indvars should be able to do range analysis and eliminate icmps.
5; There are two here which cannot be eliminated.
6; There's one that icmp which can be eliminated and which indvars currently
7; cannot eliminate, because it requires analyzing more than just the
8; range of the induction variable.
9
10@0 = private constant [4 x i8] c"%d\0A\00", align 1 ; <[4 x i8]*> [#uses=1]
11
12define i32 @main() nounwind {
13bb:
14  br label %bb1
15
16bb1:                                              ; preds = %bb14, %bb
17  %t = phi i32 [ 0, %bb ], [ %t19, %bb14 ]        ; <i32> [#uses=5]
18  %t2 = phi i32 [ 0, %bb ], [ %t18, %bb14 ]       ; <i32> [#uses=1]
19  %t3 = icmp slt i32 %t, 0                        ; <i1> [#uses=1]
20  br i1 %t3, label %bb7, label %bb4
21
22bb4:                                              ; preds = %bb1
23  %t5 = icmp sgt i32 %t, 255                      ; <i1> [#uses=1]
24  %t6 = select i1 %t5, i32 255, i32 %t            ; <i32> [#uses=1]
25  br label %bb7
26
27bb7:                                              ; preds = %bb4, %bb1
28  %t8 = phi i32 [ %t6, %bb4 ], [ 0, %bb1 ]        ; <i32> [#uses=1]
29  %t9 = sub i32 0, %t                             ; <i32> [#uses=3]
30  %t10 = icmp slt i32 %t9, 0                      ; <i1> [#uses=1]
31  br i1 %t10, label %bb14, label %bb11
32
33bb11:                                             ; preds = %bb7
34  %t12 = icmp sgt i32 %t9, 255                    ; <i1> [#uses=1]
35  %t13 = select i1 %t12, i32 255, i32 %t9         ; <i32> [#uses=1]
36  br label %bb14
37
38bb14:                                             ; preds = %bb11, %bb7
39  %t15 = phi i32 [ %t13, %bb11 ], [ 0, %bb7 ]     ; <i32> [#uses=1]
40  %t16 = add nsw i32 %t2, 255                     ; <i32> [#uses=1]
41  %t17 = add nsw i32 %t16, %t8                    ; <i32> [#uses=1]
42  %t18 = add nsw i32 %t17, %t15                   ; <i32> [#uses=2]
43  %t19 = add nsw i32 %t, 1                        ; <i32> [#uses=2]
44  %t20 = icmp slt i32 %t19, 1000000000            ; <i1> [#uses=1]
45  br i1 %t20, label %bb1, label %bb21
46
47bb21:                                             ; preds = %bb14
48  %t22 = call i32 (i8*, ...)* @printf(i8* noalias getelementptr inbounds ([4 x i8]* @0, i32 0, i32 0), i32 %t18) nounwind
49  ret i32 0
50}
51
52declare i32 @printf(i8* noalias nocapture, ...) nounwind
53