Re: [PATCH] x86: Add optimized popcnt variants

From: Borislav Petkov
Date: Thu Mar 18 2010 - 07:17:19 EST


From: "H. Peter Anvin" <hpa@xxxxxxxxx>
Date: Sat, Feb 27, 2010 at 12:00:26PM -0800

> On 02/27/2010 12:28 AM, Borislav Petkov wrote:
> >
> >> I guess, on the other hand, if it ends up not getting merged until .35
> >> it's not a huge deal either.
> >
> > Yeah, let's give it another round of testing and queue it for .35 -
> > AFAIR Ingo runs also a wide testing effort so it spending another cycle
> > in -tip and being hammered on by us could give us a bit more certainty.
> >
>
> Yes, if we can get into -tip then we'll get more test coverage, so I'll
> queue it up for .35 as soon as the merge window closes. Please remind
> me if I forget.

Ok, I've been pretty busy lately and this got pushed back on the todo
list. I finally got around to do some build-testing with a bunch of
compilers and -fcall-saved* seem to get accepted. I haven't stared at
their asm output though, yet:


command:
make CC=gcc-<version> HOSTCC=gcc-<version> -j4

compile stats (64bit only):

not ok:
- gcc-3.3 (GCC) 3.3.5 (Debian 1:3.3.5-13): OOM KILLER goes off, gcc-3.3 leak maybe

ok:
- gcc-3.4 (GCC) 3.4.4 20050314 (prerelease) (Debian 3.4.3-13sarge1)
- gcc-4.1 (GCC) 4.1.3 20080704 (prerelease) (Debian 4.1.2-27)
- gcc-4.3 (Debian 4.3.4-6) 4.3.4
- gcc (Debian 4.4.2-6) 4.4.2
- gcc (Debian 4.4.3-3) 4.4.3

- gcc-3.4.6 (GCC) 3.4.6 (Gentoo 3.4.6-r2 p1.6, ssp-3.4.6-1.0, pie-8.7.10)
- gcc-4.1.2 (GCC) 4.1.2 (Gentoo 4.1.2 p1.3)

I'm attaching the versions of the patches I'm using. The first one by
PeterZ touches a bunch of arches and Andrew hasn't picked it up yet so
the question of getting the second (popcnt) patch to see wider testing
in some tree is still unresolved. Suggestions, ideas?

Thanks.

--
Regards/Gruss,
Boris.

--
Advanced Micro Devices, Inc.
Operating Systems Research Center
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