diff --git a/clang/test/CodeGen/branch-target-layout.c b/clang/test/CodeGen/branch-target-layout.c new file mode 100644 index 000000000000..b93a0c7a4bc7 --- /dev/null +++ b/clang/test/CodeGen/branch-target-layout.c @@ -0,0 +1,40 @@ +// RUN: %clang_cc1 %s -O3 -emit-llvm -o - | FileCheck %s +// +// PR13214 +// No assumption may be made about the order that a frontend emits branch +// targets (basic blocks). However, the backend's basic block layout makes an +// attempt to preserve source order of control flow, and any bias toward source +// order must start with the frontend. +// +// Note that the frontend inverts branches to simplify the condition, so the +// order of a branch instruction's labels cannot be used as a source order bias. + +void calla(); +void callb(); +void callc(); + +// CHECK: @test +// CHECK: @calla() +// CHECK: @callb() +// CHECK: @callc() +// CHECK: ret void +void test1(int a) { + if (a) + calla(); + else + callb(); + callc(); +} + +// CHECK: @test +// CHECK: @callb() +// CHECK: @calla() +// CHECK: @callc() +// CHECK: ret void +void test2(int a) { + if (!a) + callb(); + else + calla(); + callc(); +}