gnu/dist/gcc4/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-vars" } */
   5
   6 /* Size of this structure should be sufficiently weird so that no memory
   7    addressing mode applies.  */
   8
   9 struct bla
  10 {
  11   char x[187];
  12   int y;
  13   char z[253];
  14 } arr_base[100];
  15
  16 void xxx(void)
  17 {
  18   int iter;
  19
  20   for (iter = 0; iter < 100; iter++)
  21     arr_base[iter].y = 17 * iter;
  22 }
  23
  24 /* Access to arr_base[iter].y should be strength reduced, i.e., there should
  25    be no multiplication.  */
  26
  27 /* { dg-final { scan-tree-dump-times " \\* \[^\\n\\r\]*=" 0 "vars" } } */
  28 /* { dg-final { scan-tree-dump-times "\[^\\n\\r\]*= \\* " 0 "vars" } } */
  29 /* { dg-final { scan-tree-dump-times "MEM" 1 "vars" } } */
  30
  31 /* 17 * iter should be strength reduced.  */
  32
  33 /* { dg-final { scan-tree-dump-times " \\* 17" 0 "vars" } } */
  34 /* { dg-final { scan-tree-dump-times " \\+ 17" 1 "vars" } } */
  35
  36 /* The induction variable comparison with 99 should be eliminated
  37    and replaced by comparison of one of the newly created ivs.  */
  38
  39 /* { dg-final { scan-tree-dump-times "iter" 0 "vars" } } */
  40 /* { dg-final { scan-tree-dump-times "99" 0 "vars" } } */
  41 /* { dg-final { scan-tree-dump-times "100" 0 "vars" } } */
  42
  43 /* { dg-final { cleanup-tree-dump "vars" } } */