gcc/testsuite/gcc.dg/tree-ssa/loop-interchange-9.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2 -floop-interchange -fdump-tree-linterchange-details" } */
   3 /* { dg-require-effective-target size20plus } */
   4 /* { dg-skip-if "too big data segment" { visium-*-* } } */
   5
   6 #define M 256
   7 int a[M][M], b[M][M], c[M], d[M];
   8 void __attribute__((noinline))
   9 simple_reduc_1 (int n)
  10 {
  11   for (int j = 0; j < n; j++)
  12     {
  13       int sum = c[j];
  14       for (int i = 0; i < n; i++)
  15         sum = sum + a[i][j]*b[i][j];
  16
  17       c[j] = sum;
  18     }
  19 }
  20
  21 void __attribute__((noinline))
  22 simple_reduc_2 (int n)
  23 {
  24   for (int j = 0; j < n; j++)
  25     {
  26       int sum = d[j];
  27       for (int i = 0; i < n; i++)
  28         sum = sum + a[i][j]*b[i][j];
  29
  30       asm volatile ("" ::: "memory");
  31       d[j] = sum;
  32     }
  33 }
  34
  35 extern void abort ();
  36
  37 static void __attribute__((noinline))
  38 init (int i)
  39 {
  40   c[i] = 0;
  41   d[i] = 0;
  42   for (int j = 0; j < M; j++)
  43     {
  44       a[i][j] = i;
  45       b[i][j] = j;
  46     }
  47 }
  48
  49 int main (void)
  50 {
  51   for (int i = 0; i < M; ++i)
  52     init (i);
  53
  54   simple_reduc_1 (M);
  55   simple_reduc_2 (M);
  56
  57   for (int i = 0; i < M; ++i)
  58     if (c[i] != d[i])
  59       abort ();
  60
  61   return 0;
  62 }
  63
  64 /* { dg-final { scan-tree-dump-times "Loop_pair<outer:., inner:.> is interchanged" 1 "linterchange" } } */