| 1 | // RUN: %clang_cc1 %s -O3 -emit-llvm -o - | FileCheck %s |
|---|
| 2 | // |
|---|
| 3 | // PR13214 |
|---|
| 4 | // No assumption may be made about the order that a frontend emits branch |
|---|
| 5 | // targets (basic blocks). However, the backend's basic block layout makes an |
|---|
| 6 | // attempt to preserve source order of control flow, and any bias toward source |
|---|
| 7 | // order must start with the frontend. |
|---|
| 8 | // |
|---|
| 9 | // Note that the frontend inverts branches to simplify the condition, so the |
|---|
| 10 | // order of a branch instruction's labels cannot be used as a source order bias. |
|---|
| 11 | |
|---|
| 12 | void calla(); |
|---|
| 13 | void callb(); |
|---|
| 14 | void callc(); |
|---|
| 15 | |
|---|
| 16 | // CHECK: @test1 |
|---|
| 17 | // CHECK: @calla |
|---|
| 18 | // CHECK: @callb |
|---|
| 19 | // CHECK: @callc |
|---|
| 20 | // CHECK: ret void |
|---|
| 21 | void test1(int a) { |
|---|
| 22 | if (a) |
|---|
| 23 | calla(); |
|---|
| 24 | else |
|---|
| 25 | callb(); |
|---|
| 26 | callc(); |
|---|
| 27 | } |
|---|
| 28 | |
|---|
| 29 | // CHECK: @test2 |
|---|
| 30 | // CHECK: @callb |
|---|
| 31 | // CHECK: @calla |
|---|
| 32 | // CHECK: @callc |
|---|
| 33 | // CHECK: ret void |
|---|
| 34 | void test2(int a) { |
|---|
| 35 | if (!a) |
|---|
| 36 | callb(); |
|---|
| 37 | else |
|---|
| 38 | calla(); |
|---|
| 39 | callc(); |
|---|
| 40 | } |
|---|
| 41 | |
|---|