clang/test/Profile/misexpect-switch.c

   1 // Test that misexpect detects mis-annotated switch statements
   2
   3 // RUN: llvm-profdata merge %S/Inputs/misexpect-switch.proftext -o %t.profdata
   4 // RUN: %clang_cc1 %s -O2 -o - -emit-llvm -fprofile-instrument-use-path=%t.profdata -verify -Wmisexpect -debug-info-kind=line-tables-only
   5
   6 #define inner_loop 1000
   7 #define outer_loop 20
   8 #define arry_size 25
   9
  10 int arry[arry_size] = {0};
  11
  12 int rand();
  13 int sum(int *buff, int size);
  14 int random_sample(int *buff, int size);
  15
  16 int main() {
  17   int val = 0;
  18
  19   int j, k;
  20   for (j = 0; j < outer_loop; ++j) {
  21     for (k = 0; k < inner_loop; ++k) {
  22       unsigned condition = rand() % 10000;
  23       switch (__builtin_expect(condition, 0)) { // expected-warning-re {{potential performance regression from use of __builtin_expect(): annotation was correct on {{.+}}% ({{[0-9]+ / [0-9]+}}) of profiled executions}}
  24       case 0:
  25         val += sum(arry, arry_size);
  26         break;
  27       case 1:
  28       case 2:
  29       case 3:
  30         break;
  31       default:
  32         val += random_sample(arry, arry_size);
  33         break;
  34       } // end switch
  35     }   // end inner_loop
  36   }     // end outer_loop
  37
  38   return 0;
  39 }