Arch Linux

Ranguvar

Member

Registered: 2008-08-12

Posts: 2,577

Re: Intel C Compiler

If you're talking benchmarking x264 that has been compiled with ICC (as opposed to GCC x264 on an ICC kernel), I can spare you the wait.

1.) x264 has handwritten x86 (and some PPC) assembly for almost every CPU-intensive function. Don't expect more than a percent or two difference when using a different compiler. It has a configure switch to disable its ASM and use compiled C for everything, so you can compare compilers, but expect performance to go down the tubes.
2.) ICC is the exception, that and MSVC -- but performance SUCKS, it isn't better. The reason is that ICC and MSVC do not preserve stack alignment -- I don't remember well, it was something like that. And to compensate for that, a lot of expensive hacks must be made.

More info on forum.doom9.org.

Wintershade

Member

From: Croatia

Registered: 2008-02-18

Posts: 175

Website

Re: Intel C Compiler

Interesting point, I agree. However, it would be nice to see the numbers, in order to make some objective comparation - if nothing else, than to see which apps and in what manner lose their performance if not compiled with gcc.

---

Only the best is good enough.

Ranguvar

Member

Registered: 2008-08-12

Posts: 2,577

Re: Intel C Compiler

ffmpeg's decoding (libavcodec?) appears to have issues with this, too: http://wiki.multimedia.cx/index.php?tit … er#Caveats

More info on x264: http://forum.doom9.org/archive/index.php/t-143153.html

Obviously not all apps suffer from this or have lots of custom ASM, I know many apps experience a small but appreciated boost

Some related news, you may find GCC getting better soon thanks to Intel:
http://www.h-online.com/open/Intel-want … ews/113065
http://www.phoronix.com/scan.php?page=n … &px=NzE5Nw

Thaidog

Member

Registered: 2009-03-16

Posts: 6

Re: Intel C Compiler

Hi my name is Tyler McAdams. I am the project founder for LinuxDNA. Let me know if there is anything I can do to clarify our project or the kernel please let me know.

FALK

Member

From: Denmark

Registered: 2008-03-24

Posts: 95

Re: Intel C Compiler

Hi my name is Tyler McAdams. I am the project founder for LinuxDNA. Let me know if there is anything I can do to clarify our project or the kernel please let me know.

Could you point me at some benchmarks? Want to know if it's worth the hassle for everyday use.

Cool project btw

mothersh1p

Member

Registered: 2009-04-05

Posts: 2

Re: Intel C Compiler

For the problem with compiling:

make[1]: *** [kernel/bounds.s] Error 1

open ./arch/x86/kernel/acpi/realmode/Makefile
find $(obj)/wakeup.elf: $(obj)/
wakeup.lds $(WAKEUP_OBJS) FORCE
add  /opt/intel/cc/10.1.018/lib/libirc_s.a after it.

sxe

Member

Registered: 2009-06-04

Posts: 103

Re: Intel C Compiler

Hey guys,

i installed the last ICC version (a preview PKGBUILD can be found in the comments of the ICC pkgbuild in AUR).

I'm trying to install wine but it throws an error and i have no clue what happens. Maybe someone here can help me.

http://pastebin.ca/1552761

I'm using the following flags cause i read that this should work with wine.

CC="icc" CFLAGS="-no-cxxlib -pch -O2 -static-libgcc -wd144 -wd177 -wd181 -wd188 -wd191 -wd193 -wd556 -wd593 -wd810 -wd869 -wd981 -wd1287 -wd1292 -wd1418 -wd10156" ./configure -v --prefix=/usr

Thx..

Andy

Wintershade

Member

From: Croatia

Registered: 2008-02-18

Posts: 175

Website

Re: Intel C Compiler

Some things just won't compile with ICC. And yes, I believe WINE was one of them. Since it has many build-time dependencies which won't compile with ICC either, it shouldn't be a big surprise.

And don't worry about that; WINE is one of those applications where you wouldn't notice any performance gain by compiling with ICC.

---

Only the best is good enough.