Re: [Linux-fbdev-devel] [PATCH 1/1 2.6.13] framebuffer: bit_putcs() optimization for 8x* fonts

[Roman Zippel <zippel@linux-m68k.org>]

Hi,

On Wed, 31 Aug 2005, Knut Petersen wrote:

> I added the multiply back because gcc (v. 3.3.4) does generate the fastest
> code
> if I write it this way.

The multiply is not generally faster, so your version may be the fastest, 
but in other situations it will be a lot slower. My version is generally 
fast.

> The special case for s_pitch == 2 saves about 270 ms system time (2120 ->
> 1850ms)
> with a 16x30 font.

Compared to what? How much is the function call overhead?

> It´s as fast/slow as your previous version, the measurements are almost
> identical.

The generated code is a bit smaller, so it mostly depends on the icache to 
see a difference.

bye, Roman