volatile-1.c

来自「linux下编程用 编译软件」· C语言 代码 · 共 15 行

/* PR optimization/11381 */
/* Originator: <[e-mail]> */
/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
/* { dg-options "-O" } */

/* Verify that the comparison is not optimized away. */

void foo(volatile unsigned int *vaddr)
{
  while (*vaddr != *vaddr)
    ;
}

/* { dg-final { scan-assembler "cmp" } } */