| Xin Tong | ec6f90b | 2017-02-23 23:42:19 +0000 | [diff] [blame] | 1 | ; RUN: opt < %s -loop-unswitch -verify-loop-info -S < %s 2>&1 | FileCheck %s |
| 2 | |
| 3 | ; There are 1 case and 1 default case in the switch. after we unswitch, we know the |
| 4 | ; %a is definitely not 0 in one of the unswitched loop, make sure we take advantage |
| 5 | ; of that and simplify the branches in the loop. |
| 6 | ; |
| 7 | ; CHECK: define void @simplify_with_nonvalness( |
| 8 | |
| 9 | ; This is the loop in which we know %a is definitely 0. |
| 10 | ; CHECK: sw.bb.us: |
| 11 | ; CHECK: br i1 true, label %if.then.us, label %if.end.us |
| 12 | |
| 13 | ; This is the loop in which we do not know what %a is but we know %a is definitely NOT 0. |
| 14 | ; Make sure we use that information to simplify. |
| 15 | ; The icmp eq i32 %a, 0 in one of the unswitched loop is simplified to false. |
| 16 | ; CHECK: sw.bb.split: |
| 17 | ; CHECK: br i1 false, label %if.then, label %if.end |
| 18 | |
| 19 | define void @simplify_with_nonvalness(i32 %a) #0 { |
| 20 | entry: |
| 21 | br label %for.cond |
| 22 | |
| 23 | for.cond: |
| 24 | %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ] |
| 25 | %cmp = icmp slt i32 %i.0, 1024 |
| 26 | br i1 %cmp, label %for.body, label %for.end |
| 27 | |
| 28 | for.body: |
| 29 | switch i32 %a, label %sw.default [ |
| 30 | i32 0, label %sw.bb |
| 31 | ] |
| 32 | |
| 33 | sw.bb: |
| 34 | %cmp1 = icmp eq i32 %a, 0 |
| 35 | br i1 %cmp1, label %if.then, label %if.end |
| 36 | |
| 37 | if.then: |
| 38 | call void (...) @bar() |
| 39 | br label %if.end |
| 40 | |
| 41 | if.end: |
| 42 | br label %sw.epilog |
| 43 | |
| 44 | sw.default: |
| 45 | br label %sw.epilog |
| 46 | |
| 47 | sw.epilog: |
| 48 | br label %for.inc |
| 49 | |
| 50 | for.inc: |
| 51 | %inc = add nsw i32 %i.0, 1 |
| 52 | br label %for.cond |
| 53 | |
| 54 | for.end: |
| 55 | ret void |
| 56 | } |
| 57 | |
| 58 | declare void @bar(...) |