| Eric Christopher | cee313d | 2019-04-17 04:52:47 +0000 | [diff] [blame] | 1 | ; RUN: opt %s -simplifycfg -S | FileCheck %s |
| 2 | |
| 3 | declare i32 @f(i32) |
| 4 | |
| 5 | define i32 @basic(i32 %x) { |
| 6 | ; CHECK-LABEL: @basic |
| 7 | ; CHECK: x.off = add i32 %x, -5 |
| 8 | ; CHECK: %switch = icmp ult i32 %x.off, 3 |
| 9 | ; CHECK: br i1 %switch, label %a, label %default |
| 10 | |
| 11 | entry: |
| 12 | switch i32 %x, label %default [ |
| 13 | i32 5, label %a |
| 14 | i32 6, label %a |
| 15 | i32 7, label %a |
| 16 | ] |
| 17 | default: |
| 18 | %0 = call i32 @f(i32 0) |
| 19 | ret i32 %0 |
| 20 | a: |
| 21 | %1 = call i32 @f(i32 1) |
| 22 | ret i32 %1 |
| 23 | } |
| 24 | |
| 25 | |
| 26 | define i32 @unreachable(i32 %x) { |
| 27 | ; CHECK-LABEL: @unreachable |
| 28 | ; CHECK: x.off = add i32 %x, -5 |
| 29 | ; CHECK: %switch = icmp ult i32 %x.off, 3 |
| 30 | ; CHECK: br i1 %switch, label %a, label %b |
| 31 | |
| 32 | entry: |
| 33 | switch i32 %x, label %unreachable [ |
| 34 | i32 5, label %a |
| 35 | i32 6, label %a |
| 36 | i32 7, label %a |
| 37 | i32 10, label %b |
| 38 | i32 20, label %b |
| 39 | i32 30, label %b |
| 40 | i32 40, label %b |
| 41 | ] |
| 42 | unreachable: |
| 43 | unreachable |
| 44 | a: |
| 45 | %0 = call i32 @f(i32 0) |
| 46 | ret i32 %0 |
| 47 | b: |
| 48 | %1 = call i32 @f(i32 1) |
| 49 | ret i32 %1 |
| 50 | } |
| 51 | |
| 52 | |
| 53 | define i32 @unreachable2(i32 %x) { |
| 54 | ; CHECK-LABEL: @unreachable2 |
| 55 | ; CHECK: x.off = add i32 %x, -5 |
| 56 | ; CHECK: %switch = icmp ult i32 %x.off, 3 |
| 57 | ; CHECK: br i1 %switch, label %a, label %b |
| 58 | |
| 59 | entry: |
| 60 | ; Note: folding the most popular case destination into the default |
| 61 | ; would prevent switch-to-icmp here. |
| 62 | switch i32 %x, label %unreachable [ |
| 63 | i32 5, label %a |
| 64 | i32 6, label %a |
| 65 | i32 7, label %a |
| 66 | i32 10, label %b |
| 67 | i32 20, label %b |
| 68 | ] |
| 69 | unreachable: |
| 70 | unreachable |
| 71 | a: |
| 72 | %0 = call i32 @f(i32 0) |
| 73 | ret i32 %0 |
| 74 | b: |
| 75 | %1 = call i32 @f(i32 1) |
| 76 | ret i32 %1 |
| 77 | } |