| Hans Wennborg | 45172ac | 2014-11-25 17:23:05 +0000 | [diff] [blame] | 1 | ; RUN: opt -jump-threading -S %s | FileCheck %s |
| 2 | |
| 3 | ; Check that we thread arg2neg -> checkpos -> end. |
| 4 | ; |
| 5 | ; LazyValueInfo would previously fail to analyze the value of %arg in arg2neg |
| 6 | ; because its predecessing blocks (checkneg) hadn't been processed yet (PR21238) |
| 7 | |
| 8 | ; CHECK-LABEL: @test_jump_threading |
| 9 | ; CHECK: arg2neg: |
| 10 | ; CHECK-NEXT: br i1 %arg1, label %end, label %checkpos.thread |
| 11 | ; CHECK: checkpos.thread: |
| 12 | ; CHECK-NEXT: br label %end |
| 13 | |
| 14 | define i32 @test_jump_threading(i1 %arg1, i32 %arg2) { |
| 15 | checkneg: |
| 16 | %cmp = icmp slt i32 %arg2, 0 |
| 17 | br i1 %cmp, label %arg2neg, label %checkpos |
| 18 | |
| 19 | arg2neg: |
| 20 | br i1 %arg1, label %end, label %checkpos |
| 21 | |
| 22 | checkpos: |
| 23 | %cmp2 = icmp sgt i32 %arg2, 0 |
| 24 | br i1 %cmp2, label %arg2pos, label %end |
| 25 | |
| 26 | arg2pos: |
| 27 | br label %end |
| 28 | |
| 29 | end: |
| 30 | %0 = phi i32 [ 1, %arg2neg ], [ 2, %checkpos ], [ 3, %arg2pos ] |
| 31 | ret i32 %0 |
| 32 | } |
| 33 | |
| 34 | |
| 35 | ; arg2neg has an edge back to itself. If LazyValueInfo is not careful when |
| 36 | ; visiting predecessors, it could get into an infinite loop. |
| 37 | |
| 38 | ; CHECK-LABEL: test_infinite_loop |
| 39 | |
| 40 | define i32 @test_infinite_loop(i1 %arg1, i32 %arg2) { |
| 41 | checkneg: |
| 42 | %cmp = icmp slt i32 %arg2, 0 |
| 43 | br i1 %cmp, label %arg2neg, label %checkpos |
| 44 | |
| 45 | arg2neg: |
| 46 | br i1 %arg1, label %arg2neg, label %checkpos |
| 47 | |
| 48 | checkpos: |
| 49 | %cmp2 = icmp sgt i32 %arg2, 0 |
| 50 | br i1 %cmp2, label %arg2pos, label %end |
| 51 | |
| 52 | arg2pos: |
| 53 | br label %end |
| 54 | |
| 55 | end: |
| 56 | %0 = phi i32 [ 2, %checkpos ], [ 3, %arg2pos ] |
| 57 | ret i32 %0 |
| 58 | } |