(Request) Dolphin Compiled with AVX instructions

mfuhreck · 01-13-2011, 03:15 PM #1

New Sandy Bridge procs that just came out, plus upcoming bulldozer from amd use the avx instruction set.

Im pretty sure you currently need the intel compiler suite to pull this off which I happen to have, but Im having problems with my .net 3.5 and the only way I can fix it, is to reinstall windows which Im not going to do cause I have several terabytes of programs installed and its not worth it for just one dolphin build.

We need to test out the new instruction set, and see what it brings to the table for this emulator. It should give a least something, and although new procs are faster clock for clock, if you really want to see what they can do, were gonna need a avx compiled build.

Thanks in advance to the first person to compile one of these builds.

Someone will do it eventually, whether its a week or month, or longer.

**NaturalViolence** · (This post was last modified: 01-13-2011, 03:26 PM by NaturalViolence.)

Quote:New Sandy Bridge procs that just came out, plus upcoming bulldozer from amd use the avx instruction set.

Bulldozer won't be supporting all of the new avx instructions just so you know. Only some which they are merging into sse5. So software compiled for avx will still be strictly intel only (unless compilers have a second flag for "use amd compatible instructions only", but they rarely do). Developers will need to build software for three different code paths, sse2/sse3 for older cpus, ssse3/sse4.1/4.2/avx for newer intel cpus, and sse5 for the new amd cpus. At least sse5 will be getting some decent compiler support unlike sse4a.

**Squall Leonhart** · (This post was last modified: 01-13-2011, 04:17 PM by Squall Leonhart.)

No, infact VS2010 can compile with /arch:AVX specified.

However, these are compiler optimisations which probably won't optimise anything, and AVX is better off handwritten anyway.

Secondly, the most it will be good for is probably texture decoding which likely won't get much of an improvement over the SSE3-SSSE3 methods used currently.

However, until Win7 SP1, AVX's usefulness is very limited.

lamedude · 01-14-2011, 05:17 PM #4

I do make an AVX compile if someone is willing to install Win7 SP1 RC.

**Squall Leonhart** · (This post was last modified: 01-14-2011, 07:23 PM by Squall Leonhart.)

additionally, you cannot debug AVX optimised applications on pre sp1 Visual Studio 2010

also

simply setting the AVX flag WILL LIKELY ADD PENALTIES.

SSE and AVX suffer an upperbits penalty when mixed.

01-16-2011, 11:07 AM #6

(01-13-2011, 03:23 PM)NaturalViolence Wrote:
Quote:New Sandy Bridge procs that just came out, plus upcoming bulldozer from amd use the avx instruction set.

Bulldozer won't be supporting all of the new avx instructions just so you know. Only some which they are merging into sse5. So software compiled for avx will still be strictly intel only (unless compilers have a second flag for "use amd compatible instructions only", but they rarely do). Developers will need to build software for three different code paths, sse2/sse3 for older cpus, ssse3/sse4.1/4.2/avx for newer intel cpus, and sse5 for the new amd cpus. At least sse5 will be getting some decent compiler support unlike sse4a.

This is completely wrong, AMD scrapped SSE5 entirely after AVX was announced and decided instead to provide AVX support plus XOP. I think this will be the first time in AMD's history that they will have a CPU that is more feature-complete than its Intel's offering.

Read more here

**NaturalViolence** · 01-16-2011, 12:31 PM #7

Quote:I think this will be the first time in AMD's history that they will have a CPU that is more feature-complete than its Intel's offering.

What about athlon64?

Anyways I'm going to need more evidence before I believe that considering AMD revealed the details on bulldozer and sse5 after intel announced avx and all the major tech review/news had a copy word for word that said the same thing about it (tomshardware, anandtech, guru3d, icrontic, etc.). I guess time will tell, but I'm not holding my breath.

lamedude · 01-16-2011, 05:01 PM #8

K6-2 had 3DNow! but I can't blame you for trying to forget that CPU.

01-17-2011, 02:59 AM #9

(01-16-2011, 12:31 PM)NaturalViolence Wrote:
Quote:I think this will be the first time in AMD's history that they will have a CPU that is more feature-complete than its Intel's offering.

What about athlon64?

Anyways I'm going to need more evidence before I believe that considering AMD revealed the details on bulldozer and sse5 after intel announced avx and all the major tech review/news had a copy word for word that said the same thing about it (tomshardware, anandtech, guru3d, icrontic, etc.). I guess time will tell, but I'm not holding my breath.

SSE5 was announced in 2007, AVX was announced in 2008; all the articles stating that SSE5 will be implemented with Bulldozer are very outdated. AMD chose to support AVX and implement the features from SSE5 that weren't covered by Intel's AVX implementation using XOP, FMA4, and CVT16 extensions to AVX.

Edit: AMD announced the change in May 2009

**NaturalViolence** · (This post was last modified: 01-17-2011, 05:56 AM by NaturalViolence.)

We will see. I never saw an articles about sse5 or avx from before 2010, nor did I ever see amd or intel talk about them before 2010 at any keynote speak, press conference, or trade show.

Quote:K6-2 had 3DNow! but I can't blame you for trying to forget that CPU.

This made me lol. Yes, I pushed those memories to the far regions of my cerebrum.