gcc/testsuite/gcc.dg/autopar/reduc-6.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -ftree-parallelize-loops=4 -fdump-tree-parloops2-details -fdump-tree-optimized" } */
   3
   4 #include <stdarg.h>
   5 #include <stdlib.h>
   6
   7 #define N 1600
   8 #define DIFF 2558402
   9
  10
  11 __attribute__ ((noinline))
  12 int main1 (float x, float max_result)
  13 {
  14   int i;
  15   float b[N];
  16   float c[N];
  17   float diff = 2;
  18   float max = x;
  19   float min = 10;
  20
  21   for (i=0; i<N; i++)
  22     {
  23       b[i] = i * 3;
  24       c[i] = i;
  25     }
  26
  27   for (i = 0; i < N; i++) {
  28     diff += (b[i] - c[i]);
  29   }
  30
  31   for (i = 0; i < N; i++) {
  32     max = max < c[i] ? c[i] : max;
  33   }
  34
  35   for (i = 0; i < N; i++) {
  36     min = min > c[i] ? c[i] : min;
  37   }
  38
  39   /* check results:  */
  40   if (diff != DIFF)
  41     abort ();
  42   if (max != max_result)
  43     abort ();
  44   if (min != 0)
  45     abort ();
  46
  47   return 0;
  48 }
  49
  50 int main (void)
  51 {
  52   main1 (2000, 2000);
  53   main1 (0, 1599);
  54   return 0;
  55 }
  56
  57
  58 /* need -ffast-math to  parallelize these loops.  */
  59 /* { dg-final { scan-tree-dump-times "Detected reduction" 0 "parloops2" } } */
  60 /* { dg-final { scan-tree-dump-times "SUCCESS: may be parallelized" 1 "parloops2" } } */
  61 /* { dg-final { scan-tree-dump-times "FAILED: it is not a part of reduction" 3 "parloops2" } } */