clang/test/Profile/misexpect-switch-default.c

   1 // Test that misexpect detects mis-annotated switch statements for default case
   2
   3 // RUN: llvm-profdata merge %S/Inputs/misexpect-switch-default.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 sum(int *buff, int size);
  11 int random_sample(int *buff, int size);
  12 int rand();
  13 void init_arry();
  14
  15 int arry[arry_size] = {0};
  16
  17 int main() {
  18   init_arry();
  19   int val = 0;
  20   int j;
  21   for (j = 0; j < outer_loop * inner_loop; ++j) {
  22     unsigned condition = rand() % 5;
  23     switch (__builtin_expect(condition, 6)) { // 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     case 4:
  32       val += random_sample(arry, arry_size);
  33       break;
  34     default:
  35       __builtin_unreachable();
  36     } // end switch
  37   }   // end outer_loop
  38
  39   return 0;
  40 }