K6 optimization && compiler builtins

[Oleg Krivosheev]

hi,

On Mon, 15 Dec 1997, Ronald Wahl wrote:

> Date: Mon, 15 Dec 1997 23:36:17 +0100 (CET)
> From: Ronald Wahl <Ronald.Wahl@informatik.tu-chemnitz.de>
> Reply-To: egcs@cygnus.com
> To: egcs@cygnus.com
> Subject: K6 optimization && compiler builtins
> 
> Hi,
> 
> At the moment I'm playing with the string/memory routines of libc which
> are written in assembler. On a K6 (somtimes PPro also, Pentium not testet)
> I can get a performance gain of 10-40% (!). Now my question: If I use one
> of the string/memory functions (e.g. memcmp) in my programs, which one
> will be uses - the compiler builtin or the one in the libc? 

i believe compiler built-in will be used if known
number of bytes to be copied. I checked once 
what's going on while memcpy double.
Gcc substituted few inlined assembelr instructions
instead of function calls. It was on SPARC though...
Sorry, don't know about x86.

> If the builtin
> is used - is it possible to include my optimized versions (if ready)?

do you have patch against latest snapshot ?

OK