On Thu, Sep 10, 2009 at 9:59 AM, Roland McGrath <roland@xxxxxxxxxx> wrote: > The latest GCC has a better way than "for (;;)" to indicate that a code > path cannot be reached due to reasons the compiler doesn't understand (such > as code in an asm). These patches provide UNREACHABLE() as a macro to hide > the details of this, and then use it for the BUG() macro on x86, saving > some dead code otherwise generated. > > Other arch's BUG() may want to this too instead of "for (;;)" or __builtin_trap. > > There are numerous matches from "git grep -n 'for *(;;) *;'" but it takes > someone who knows each bit of code to know where that means UNREACHABLE() > and where it really wants an infinite loop. Looks good! Reviewed-by: WANG Cong <xiyou.wangcong@xxxxxxxxx> Just curious, what different asm code will gcc generate for this? Comparing it to for(;;) ? I am sorry that I don't have gcc 4.5 on hand. Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
