gcc/testsuite/gcc.dg/vect/vect-reduc-sad.c

   1 /* { dg-require-effective-target vect_usad_char } */
   2
   3 #include <stdarg.h>
   4 #include "tree-vect.h"
   5
   6 #define N 64
   7 #define SAD N*N/2
   8
   9 unsigned char X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
  10 unsigned char Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
  11 int abs (int);
  12
  13 /* Sum of absolute differences between arrays of unsigned char types.
  14    Detected as a sad pattern.
  15    Vectorized on targets that support sad for unsigned chars.  */
  16
  17 __attribute__ ((noinline)) int
  18 foo (int len)
  19 {
  20   int i;
  21   int result = 0;
  22
  23   for (i = 0; i < len; i++)
  24     result += abs (X[i] - Y[i]);
  25
  26   return result;
  27 }
  28
  29
  30 int
  31 main (void)
  32 {
  33   int i;
  34   int sad;
  35
  36   check_vect ();
  37
  38   for (i = 0; i < N; i++)
  39     {
  40       X[i] = i;
  41       Y[i] = N - i;
  42       __asm__ volatile ("");
  43     }
  44
  45   sad = foo (N);
  46   if (sad != SAD)
  47     abort ();
  48
  49   return 0;
  50 }
  51
  52 /* { dg-final { scan-tree-dump-times "vect_recog_sad_pattern: detected" 1 "vect" } } */
  53 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
  54