Hal Finkel | a3f23e3 | 2014-10-14 16:04:49 +0000 | [diff] [blame^] | 1 | ; RUN: opt -S -jump-threading < %s | FileCheck %s |
| 2 | |
| 3 | declare i8* @escape() |
| 4 | declare void @llvm.assume(i1) |
| 5 | |
| 6 | define i1 @test1(i1 %cond) { |
| 7 | entry: |
| 8 | br i1 %cond, label %taken, label %not_taken |
| 9 | |
| 10 | ; CHECK-LABEL: @test1 |
| 11 | ; CHECK: br i1 %cond, label %no, label %yes |
| 12 | ; CHECK: ret i1 true |
| 13 | |
| 14 | taken: |
| 15 | %res1 = call i8* @escape() |
| 16 | %a = icmp eq i8* %res1, null |
| 17 | tail call void @llvm.assume(i1 %a) |
| 18 | br label %done |
| 19 | not_taken: |
| 20 | %res2 = call i8* @escape() |
| 21 | %b = icmp ne i8* %res2, null |
| 22 | tail call void @llvm.assume(i1 %b) |
| 23 | br label %done |
| 24 | |
| 25 | ; An assume that can be used to simplify this comparison dominates each |
| 26 | ; predecessor branch (although no assume dominates the cmp itself). Make sure |
| 27 | ; this still can be simplified. |
| 28 | |
| 29 | done: |
| 30 | %res = phi i8* [ %res1, %taken ], [ %res2, %not_taken ] |
| 31 | %cnd = icmp ne i8* %res, null |
| 32 | br i1 %cnd, label %yes, label %no |
| 33 | |
| 34 | yes: |
| 35 | ret i1 true |
| 36 | no: |
| 37 | ret i1 false |
| 38 | } |
| 39 | |