Anyone else using ICC?

CyberNinja · n00b Joined: 25 Jan 2003 Posts: 29

Hi,
I want to recompile my base system with ICC-7.1.006(latest in portage at the time of this post). My question is, how can i achive this with out tanking my system (1.4_rc4). Also is there an easy way to get the kernel to compile with ICC or is that a pipe dream. What flags can I use with my processors with out giving up to much stability.

Here is my /proc/cpuinfo :

Cheesefoam · Tux's lil' helper Joined: 02 Jan 2003 Posts: 89

AFAIK, you won't be able to get much compiled with ICC. There are very few packages that will actually work, so I suggest you just emerge those packages by hadn, after making sure you have the "ICC" flags in your USE flags. Otherwise, ICC will seriously b0rk the system, since it is not truly gcc compatible.

As for being binary compatible, you shouldn't have to worry. Since you are using P4-core Xeons, you are golden, since ICC 7.0 and above automatically assumes the "-tpp7" P4 optimizations as default. It should be able to figure out what you have and auto adjust its vectorization schemes to cope. However, you'll probably still want to add in "-xW" to give best optimization. Also, I'd suggest that if you use the "-ipo" option, throw in "-ipo_obj" to force the creation of object files.

Currently, ICC's biggest fault is shared librares. Though it can do it, getting the whole emerge system to do it isn't really doable right now. As an example, try emerging XMMS with GCC and with ICC. It will compile in both cases, but ICC will fail to make the libxmms.so and associated libraries. If I understand the compiler documentation correctly, we should be using xild to do all linking instead of ld to not only get proper linking, but also get more optimization. I haven't figured out how to do this yet.

CoronaLover · Posted: Sat May 03, 2003 11:47 am Post subject:

ICC support was added to libtool 1.5, but for some strange reason Gentoo is still using libtool 1.4.1

edit: I open a bug about it, https://bugs.gentoo.org/show_bug.cgi?id=20381

Cheesefoam · Tux's lil' helper Joined: 02 Jan 2003 Posts: 89

Well, I got emerges to find xild, xiar, and in some cases ifc by setting:

lousyd · Posted: Fri May 16, 2003 12:05 am Post subject: Re: Anyone else using ICC?

felicita · n00b Joined: 29 May 2003 Posts: 5

got 2 questions:
1. how to set the optimization parameters for icc w/ the new pentium-M CPU? ' -march=pentium4 -O2 -ipo -axW -xW'? or any else better?

2. I got a icc patch for kernel 2.5.45 here, and it works fine with 2.5.45 source code. wanna compile this kernel using icc, I changed linux-2.5.45/Makefile like this:

Cheesefoam · Tux's lil' helper Joined: 02 Jan 2003 Posts: 89

Well, with ICC/IFC it isn't really necessary to use -march or -mcpu. These options are handled by other ICC-specific flags, but ICC is still compatible with them. Here are the flags I use for ICC compiling:

felicita · n00b Joined: 29 May 2003 Posts: 5

thanks

it's cool to hear about -o3 works better in icc.
I read some articles that report gcc binaries w/ -O3 are sometimes faster than -O2, and depends diff. code may be bigger in size and runnig slower. then I switched from -O3 to -O2 in gcc. hehe
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Cheesefoam · Tux's lil' helper Joined: 02 Jan 2003 Posts: 89

For GCC on my laptop, I use -Os (with -fomit-frame-pointer, -funroll-loops, and a few others...). I haven't seen any reason under ICC to be as picky with -O3 vs -O2, etc.

I only wish there was a separate variable - maybe something called ICCFLAGS and ICXXFLAGS - which we could use to store separate ICC optimization variables. Kind of a pain to hand-tool it constantly.

mart_man00 · Apprentice Joined: 29 Jan 2003 Posts: 245

Cheesefoam · Tux's lil' helper Joined: 02 Jan 2003 Posts: 89

A full system emerge probably won't be doable for a good long while. Currently ICC has enough problems generating shared libraries in a manner consistent with what is expected from GCC & friends. Above and beyond that, while the compiler itself has improved a lot, many programs use GCC-specific coding extensions which Intel has not implemented yet. There's a very few programs that will compile "out of the box", much less actually link and run properly (Povray currently is the only 100% working one, AFAIK - mpqc is 90% functional, though there are linking problems).

What has been mentioned is that following the 1.4 release, there will be some work to make Gentoo more friendly to those of us who want to use ICC. It is going to be a tremendous amount of work to say the least, to get all of the foibles identified and dealt with.

avenj is the big cheese for this work, and deserves a lot of praise for even attempting it.

My few excursions into trying to get packages compiled with ICC/IFC met with very limited success - but some success is better than none. If you're really interested, take a crack at forcing a emerge to compile under ICC - a basic starting point is to export all necessary variables prior to starting (it's been posted in this thread before), and see what happens.

Try XMMS - I consider it a classic example of an "almost-but-not-quite" app. Compiles like a dream, and runs well - except no base plugin set, as the shared library never gets made.

Anyone ever try to compile gcc & glibc with icc?

Just kidding - though maybe one of these days I'll try it, just to see how badly I can b0rk my system.

wishkah · Guru Joined: 09 May 2003 Posts: 441 Location: de

Has anyone compiled the glibc with ICC? Cause I did some (amateur) tests on my notebook, and ICC produced significantly faster code (and quicker).
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voytas · Posted: Wed Dec 07, 2005 9:25 am Post subject:

big_gie · Apprentice Joined: 31 Aug 2004 Posts: 158

Is there some information about icc and gcc-config out there? I'd like to compile just certain apps with icc/ifc (not the whole system...) and right now I need to:
CC="icc" CXX="icc" F90="ifc" FC="ifc" CPP="icc" emerge mpich2
for example...
The wiki say:

nanoczar · Posted: Fri Jul 20, 2007 4:25 pm Post subject:

Anyone still interested in using ICC 10?
-nanoczar
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Don't fight the LaTeX. WORK with the LaTeX!! Become one with the LaTeX!!! - JIC

Zordas · n00b Joined: 10 Jun 2003 Posts: 19

nanoczar · Posted: Thu Aug 09, 2007 4:12 pm Post subject:

No, but I am sure we could modify the older ICC ebuild to get it.
How much of your system have your built using the ICC? I would really like to get my entire system running with it but have seen many posts showing that it does not compile certain things. What is your experience with it?
-nanoczar
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Don't fight the LaTeX. WORK with the LaTeX!! Become one with the LaTeX!!! - JIC

kEiNsTeiN · Guru Joined: 29 Apr 2005 Posts: 361 Location: Germany

I*m interested as well. Is it faster than gcc?

magawake · n00b Joined: 13 May 2010 Posts: 2

Anyone have a recipes for building GNU software with icc? This is a great thread to follow

magawake · n00b Joined: 13 May 2010 Posts: 2