lkml.org 
[lkml]   [2005]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: memcpy(a,b,CONST) is not inlined by gcc 3.4.1 in Linux kernel
Date
> 
> On Tue, Mar 29, 2005 at 05:37:06PM +0300, Denis Vlasenko wrote:
> > /*
> > * This looks horribly ugly, but the compiler can optimize it totally,
> > * as the count is constant.
> > */
> > static inline void * __constant_memcpy(void * to, const void * from, size_t n)
> > {
> > if (n <= 128)
> > return __builtin_memcpy(to, from, n);
> The problem is that in GCC < 4.0 there is no constant propagation
> pass before expanding builtin functions, so the __builtin_memcpy
> call above sees a variable rather than a constant.

or change "size_t n" to "const size_t n" will also fix the issue.
As we do some (well very little and with inlining and const values)
const progation before 4.0.0 on the trees before expanding the builtin.

-- Pinski
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-04-06 13:31    [W:0.089 / U:1.520 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site