gcc/testsuite/gcc.dg/vect/vect-reduc-11.c

   1 /* { dg-do run } */
   2 /* { dg-require-effective-target vect_int } */
   3
   4 #include "tree-vect.h"
   5
   6 int x[1024], y[1024], z[1024];
   7
   8 int __attribute__((noinline,noclone))
   9 foo (int n)
  10 {
  11   int sum = 0;
  12   /* Can vectorize this.  */
  13   for (int i = 0; i < n; ++i)
  14     sum = (y[i] - (x[i] - sum));
  15   return sum;
  16 }
  17
  18 int __attribute__((noinline,noclone))
  19 bar (int n)
  20 {
  21   int sum = 0;
  22   /* Cannot vectorize this, sum is negated.  */
  23   for (int i = 0; i < n; ++i)
  24     sum = z[i] - (y[i] - (x[i] - sum));
  25   return sum;
  26 }
  27
  28 int
  29 main()
  30 {
  31   check_vect ();
  32   for (int i = 0; i < 1024; ++i)
  33     {
  34       x[i] = i;
  35       y[i] = i + 1;
  36       z[i] = 0;
  37       __asm__ volatile ("" : : : "memory");
  38     }
  39   if (foo (1024) != 1024)
  40     __builtin_abort ();
  41   if (bar (1023) != -1 || bar (1024) != 0)
  42     __builtin_abort ();
  43   return 0;
  44 }
  45
  46 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */