gcc/testsuite/gcc.dg/tree-ssa/loop-2.c

   1 /* A test for strength reduction and induction variable elimination.  */
   2
   3 /* { dg-do compile } */
   4 /* { dg-options "-O1 -fdump-tree-optimized" } */
   5 /* { dg-require-effective-target size32plus } */
   6
   7 /* Size of this structure should be sufficiently weird so that no memory
   8    addressing mode applies.  */
   9
  10 struct bla
  11 {
  12   char x[187];
  13   int y;
  14   char z[253];
  15 } arr_base[100];
  16
  17 void xxx(void)
  18 {
  19   int iter;
  20
  21   for (iter = 0; iter < 100; iter++)
  22     arr_base[iter].y = 17 * iter;
  23 }
  24
  25 /* Access to arr_base[iter].y should be strength reduced, i.e., there should
  26    be no multiplication.  */
  27
  28 /* { dg-final { scan-tree-dump-times " \\* \[^\\n\\r\]*=" 0 "optimized" } } */
  29 /* { dg-final { scan-tree-dump-times "\[^\\n\\r\]*= \\* " 0 "optimized" } } */
  30 /* { dg-final { scan-tree-dump-times "MEM\\\[base" 1 "optimized" } } */
  31
  32 /* 17 * iter should be strength reduced.  */
  33
  34 /* { dg-final { scan-tree-dump-times " \\* 17" 0 "optimized" } } */
  35 /* { dg-final { scan-tree-dump-times " \\+ 17" 1 "optimized" } } */
  36
  37 /* The induction variable comparison with 99 should be eliminated
  38    and replaced by comparison of one of the newly created ivs.  */
  39
  40 /* { dg-final { scan-tree-dump-times "iter" 0 "optimized" } } */
  41 /* { dg-final { scan-tree-dump-times "= 99" 0 "optimized" } } */
  42 /* { dg-final { scan-tree-dump-times "< 100" 0 "optimized" } } */
  43