gcc/testsuite/gcc.dg/tree-ssa/slsr-31.c

   1 /* Verify straight-line strength reduction for add candidates in
   2    which the stride is unknown and increments appear that differ
   3    only in sign.  Verify the increments are shared.  */
   4
   5 /* { dg-do compile } */
   6 /* { dg-options "-O3 -fdump-tree-optimized" } */
   7
   8 int
   9 f (int s, int c)
  10 {
  11   int a1, a2, a3, a4, x1, x2, x3, x4, x;
  12
  13   a1 = 2 * s;
  14   x1 = c + a1;
  15   a2 = 4 * s;  /* incr = +2  */
  16   x2 = c + a2;
  17   a3 = 7 * s;
  18   x3 = c + a3;
  19   a4 = 5 * s;  /* incr = -2  */
  20   x4 = c + a4;
  21   x = x1 + x2 + x3 + x4;
  22   return x;
  23 }
  24
  25 /* { dg-final { scan-tree-dump-times " \\* 2" 1 "optimized" } } */
  26 /* { dg-final { scan-tree-dump-times " \\* -2" 0 "optimized" } } */