gcc/testsuite/gcc.dg/vect/bb-slp-pr81635-2.c

   1 /* { dg-do compile } */
   2 /* { dg-additional-options "-fno-tree-loop-vectorize -fno-tree-dominator-opts" } */
   3 /* { dg-require-effective-target lp64 } */
   4
   5 double p[1000];
   6 double q[1000];
   7
   8 void
   9 f1 (double *p, double *q)
  10 {
  11   p = (double *) __builtin_assume_aligned (p, sizeof (double) * 2);
  12   q = (double *) __builtin_assume_aligned (q, sizeof (double) * 2);
  13   for (unsigned int i = 2; i < ~0U - 4; i += 4)
  14     {
  15       double a = q[i + 2] + p[i + 2];
  16       double b = q[i + 3] + p[i + 3];
  17       q[i + 2] = a;
  18       q[i + 3] = b;
  19     }
  20 }
  21
  22 void
  23 f2 (double *p, double *q)
  24 {
  25   p = (double *) __builtin_assume_aligned (p, sizeof (double) * 2);
  26   q = (double *) __builtin_assume_aligned (q, sizeof (double) * 2);
  27   for (unsigned int i = 0; i < ~0U - 3; i += 4)
  28     {
  29       double a = q[i + 4] + p[i + 4];
  30       double b = q[i + 5] + p[i + 5];
  31       q[i + 4] = a;
  32       q[i + 5] = b;
  33     }
  34 }
  35
  36 void
  37 f3 (double *p, double *q)
  38 {
  39   p = (double *) __builtin_assume_aligned (p, sizeof (double) * 2);
  40   q = (double *) __builtin_assume_aligned (q, sizeof (double) * 2);
  41   for (unsigned int i = 0; i < 1000; i += 4)
  42     {
  43       double a = q[i - 2] + p[i - 2];
  44       double b = q[i - 1] + p[i - 1];
  45       q[i - 2] = a;
  46       q[i - 1] = b;
  47     }
  48 }
  49
  50 void
  51 f4 (double *p, double *q)
  52 {
  53   p = (double *) __builtin_assume_aligned (p, sizeof (double) * 2);
  54   q = (double *) __builtin_assume_aligned (q, sizeof (double) * 2);
  55   for (unsigned int i = 2; i < 1000; i += 4)
  56     {
  57       double a = q[i - 4] + p[i - 4];
  58       double b = q[i - 3] + p[i - 3];
  59       q[i - 4] = a;
  60       q[i - 3] = b;
  61     }
  62 }
  63
  64 /* { dg-final { scan-tree-dump-not "optimized: basic block" "slp1" } } */