clang/test/CodeGen/builtin-unpredictable.c

   1 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -disable-llvm-passes -o - %s -O1 | FileCheck %s
   2 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -disable-llvm-passes -o - -x c++ %s -O1 | FileCheck %s
   3 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s -O0 | FileCheck %s --check-prefix=CHECK_O0
   4
   5 // When optimizing, the builtin should be converted to metadata.
   6 // When not optimizing, there should be no metadata created for the builtin.
   7 // In both cases, the builtin should be removed from the code.
   8
   9 #ifdef __cplusplus
  10 extern "C" {
  11 #endif
  12
  13 void foo(void);
  14 void branch(int x) {
  15 // CHECK-LABEL: define{{.*}} void @branch(
  16
  17 // CHECK-NOT: builtin_unpredictable
  18 // CHECK: !unpredictable [[METADATA:.+]]
  19
  20 // CHECK_O0-NOT: builtin_unpredictable
  21 // CHECK_O0-NOT: !unpredictable
  22
  23   if (__builtin_unpredictable(x > 0))
  24     foo ();
  25 }
  26
  27 int unpredictable_switch(int x) {
  28 // CHECK-LABEL: @unpredictable_switch(
  29
  30 // CHECK-NOT: builtin_unpredictable
  31 // CHECK: !unpredictable [[METADATA:.+]]
  32
  33 // CHECK_O0-NOT: builtin_unpredictable
  34 // CHECK_O0-NOT: !unpredictable
  35
  36   switch(__builtin_unpredictable(x)) {
  37   default:
  38     return 0;
  39   case 0:
  40   case 1:
  41   case 2:
  42     return 1;
  43   case 5:
  44     return 5;
  45   };
  46
  47   return 0;
  48 }
  49
  50 #ifdef __cplusplus
  51 }
  52 #endif
  53
  54
  55 // CHECK: [[METADATA]] = !{}
  56