gcc/testsuite/gcc.dg/vect/vect-reduc-in-order-2.c

   1 /* { dg-xfail-run-if "" { { i?86-*-* x86_64-*-* } && ia32 } } */
   2 /* { dg-require-effective-target vect_double } */
   3 /* { dg-add-options ieee } */
   4 /* { dg-additional-options "-fno-fast-math" } */
   5
   6 #include "tree-vect.h"
   7
   8 #define N (VECTOR_BITS * 17)
   9
  10 double __attribute__ ((noinline, noclone))
  11 reduc_plus_double (double *restrict a, int n)
  12 {
  13   double res = 0.0;
  14   for (int i = 0; i < n; i++)
  15     for (int j = 0; j < N; j++)
  16       res += a[i];
  17   return res;
  18 }
  19
  20 int __attribute__ ((optimize (1)))
  21 main ()
  22 {
  23   int n = 19;
  24   double a[N];
  25   double r = 0;
  26   for (int i = 0; i < N; i++)
  27     {
  28       a[i] = (i * 0.1) * (i & 1 ? 1 : -1);
  29       asm volatile ("" ::: "memory");
  30     }
  31   for (int i = 0; i < n; i++)
  32     for (int j = 0; j < N; j++)
  33       {
  34         r += a[i];
  35         asm volatile ("" ::: "memory");
  36       }
  37   double res = reduc_plus_double (a, n);
  38   if (res != r)
  39     __builtin_abort ();
  40   return 0;
  41 }
  42
  43 /* { dg-final { scan-tree-dump {in-order double reduction not supported} "vect" } } */
  44 /* { dg-final { scan-tree-dump-times {using an in-order \(fold-left\) reduction} 1 "vect" } } */