loop-3.c

来自「Mac OS X 10.4.9 for x86 Source Code gcc」· C语言 代码 · 共 28 行

/* A test for strength reduction and induction variable elimination.
   Target is restricted to x86 type architectures, so that we may
   assume something about memory addressing modes.  */

/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
/* { dg-options "-O1 -fdump-tree-vars" } */

int arr_base[100];

int foo(int);

void xxx(void)
{
  int iter;

  for (iter = 0; iter < 100; iter++)
    arr_base[iter] = foo (iter);
}

/* Access to arr_base[iter].y should not be strength reduced, since
   we have a memory mode including multiplication by 4.  */

/* { dg-final { scan-tree-dump-times "arr_base.*=" 1 "vars" } } */

/* And original induction variable should be preserved.  */

/* { dg-final { scan-tree-dump-times "int iter" 1 "vars" } } */