gcc/testsuite/gcc.dg/vect/no-vfa-vect-depend-1.c

   1 /* { dg-require-effective-target vect_int } */
   2
   3 #include <stdarg.h>
   4 #include "tree-vect.h"
   5
   6 #define N 17
   7
   8 int ia[N] = {0,3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48};
   9 int ib[N] = {0,3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48};
  10 int res[N] = {12,24,36,48,60,72,84,96,108,120,132,144,156,168,180,192,48};
  11
  12 __attribute__ ((noinline))
  13 int main1 ()
  14 {
  15   int i;
  16
  17   /* Not vectorizable due to data dependence: dependence distance 1.  */
  18   for (i = 0; i < N - 1; i++)
  19     {
  20       ia[i+1] = ia[i] * 4;
  21     }
  22
  23   /* check results:  */
  24 #pragma GCC novector
  25   for (i = 0; i < N - 1; i++)
  26     {
  27       if (ia[i] != 0)
  28         abort ();
  29     }
  30
  31   /* Vectorizable. Dependence distance -1.  */
  32   for (i = 0; i < N - 1; i++)
  33     {
  34       ib[i] = ib[i+1] * 4;
  35     }
  36
  37   /* check results:  */
  38 #pragma GCC novector
  39   for (i = 0; i < N - 1; i++)
  40     {
  41       if (ib[i] != res[i])
  42         abort ();
  43     }
  44
  45   return 0;
  46 }
  47
  48 int main (void)
  49 {
  50   check_vect();
  51
  52   return main1 ();
  53 }
  54
  55 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" {xfail { vect_no_align && { ! vect_hw_misalign } } } } } */
  56 /* { dg-final { scan-tree-dump-times "dependence distance negative" 1 "vect"  } } */
  57