Re: [RFC] div64_64 support

From: Chuck Ebbert
Date: Wed Mar 07 2007 - 11:36:11 EST


Sami Farin wrote:
> On Tue, Mar 06, 2007 at 23:53:49 +0200, Sami Farin wrote:
> ...
>> And I found bug in gcc-4.1.2, it gave 0 for ncubic results
>> when doing 1000 loops test... gcc-4.0.3 works.
>
> Found it.
>
> --- cbrt-test.c~ 2007-03-07 00:20:54.735248105 +0200
> +++ cbrt-test.c 2007-03-07 00:21:03.964864343 +0200
> @@ -209,7 +209,7 @@
>
> __asm__("bsrl %1,%0\n\t"
> "cmovzl %2,%0"
> - : "=&r" (r) : "rm" (x), "rm" (-1));
> + : "=&r" (r) : "rm" (x), "rm" (-1) : "memory");
> return r+1;
> }
>
> Now Linux 2.6 does not have "memory" in fls, maybe it causes
> some gcc funnies some people are seeing.

Can you post the difference in the generated code with that change?

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