GCC-4.0 status

[Polymorphic]

Huzzah! GCC-4.0 is finally out, with some pretty nasty optimization code, according to the CHANGELOG and all the hooplah about it. I am wanting to through it into use by building a custom distro around it (not the first time i've done this, but last time was with 2.95.2). Does anyone have any firsthand experience comiling an entire system with this, or any real-world testing experience with this new release? preferably just the full 4.0.0 release - i know the old prerelease versions werent so great. Also, a listing of what CFLAGS/CXXFLAGS you used would be great.

My host system is a slackware 10.1 system nested inside a real slackware 10.1 system using vmware. The system i'm building at first is a cross-compile of sorts, my P4 will be compiling highly optimised code for a P-100 laptop (optimized for a P100 that is of course). this will be later copied to the physical disk drive for the laptop.

--Poly

 

[horndude]

Around here???Good luck, doubtful many on this forum even know what your talking about from what ive seen.

Interesting project,but based on my experience, you can optimize the compiler flags all you want and your still talking about miniscule differences in execution speed in the final result, you get much better results using better code to start with.

Ive never built a toolchain and system with gcc 4.0, ive used 3.3 though without too many problems,hardest part is always compiling the compiler LOL.Gcc 2.95.x was probably the best at compiling kernels and using as something to build a toolchain, not sure if gcc 4.0 is any better, doubtful would be my guess.

As far as what flags to use, set the architecture,cpu type, and anything else you may think is relavent, I havent had real good experiences with agressive flag settings.

 

[Polymorphic]

my experience has been that (with 2.xx series and 3.xx *shudder*) that intelligent use of opt flags can result in significant speed increases,a albeit obviously not as high speed increases over more efficient code ;-).

From what I've heard, OS X Tiger was all compiled with gcc-4 and ships with it. i've also heard of a couple bsd boxen compiled with 4.0.0

--Poly

 

[horndude]

Ya thats what I thought when I tried gentoo, UNTIL I actually did some testing.I tested a whole range of apps where I could get actual results that could be quantified on the same system, only difference was a stock 10.1 slackware install vs a stage 1 gentoo install, the differences were barely worth talking about, im talking 20-30seconds worth of difference on an app that takes 2hrs to run.The only apps Ive ever seen actual worthwhile speed increases were those that had options in the code to take advantage of mmx or sse instructions,like encoding apps for video for example, other than that, it was a waste of my time.Ive even spent weeks rebuilding versions of the firefox browser with different flags and settings only to be prettymuch disappointed with the results, its a slow pig no matter what you do to it except for removing features.Every major program Ive tried this on has had similar results.C while being relatively fast, still isnt assembly,and some of the libraries for GUI apps in use by linux arent exactly speedy thats for sure.Ive seen lots of claims of speed increases from people, but rarely any real numbers, I can see a decent difference between something left as a base 486 precompiled binary being slower than one compiled for 686 Im running on, but speed changes due to other flag settings in my experience have been tiny.Might be worth it on a huge app made up of a whole bunch of libraries, but even then, so far, I havent seen anything worthwhile about it,nothing to get real enthusiastic over anyway.

 

[Polymorphic]

This is where GCC-4.0 supposedly has it's greatest benefit. The whole library format has been redesigned, along with the precompile stages, so that C++ code is MUCH faster, and instead of the current way optimization has been done, which is to compile to an intermediate code similar to assembly, THEN optimize, the new method is more like graph theoriticians suggest, where the optimization is done more at a higher level, keeping the "whole picture" in mind and producing more optimized code on the algorithm level instead of the opcode level.

Now about Firefox.. lynx is for REAL speed-demons ;-)

 

[horndude]

I hope c++ has gotten faster, cause it compiles like a snail with gcc 3.3 or 3.4 LOL, took my system about 14hrs to compile and build KDE from source, if gcc 4.0.0 helps then im all for it.

That would be interesting trial, I may have to try a KDE build again with GCC 4.0.0 and see what happens, Im not a big KDE fan,but its worth a try to see what happens with it.

I read slashdot pretty regularly and the new GCC got mixed feelings, if its less buggy than previous versions Im all for it, the changelog has a boatload of changes and fixes thats for sure, but ive never really had too many problems with gcc 3.3 either cept for c++ compiling be god awful slow.

What do think, how many slackware versions till KDE 3.4 and GCC 4.0.0 are included?Im guessing maybe 2 or 3 more, I know the new 2.6 series kernel is slated for the next slackware version with no more 2.4 series, slackware current seems pretty stable as is.

 

[Polymorphic]

haha we'll not know prolly till slackware 12 or 13 when they FINALLY feel its time to throw it in. ;-)

I dig your not being a huge KDE fan. I currently runXFCE cuz it is such a nice break speed-wise from the big desktops - although at least kde isnt gnome, speed-wise... gnome is disgusting in its lack of performance from launch of X to actually running simple programs, nevermind bohemoths like Mozilla, Nautilus, etc.

I try not to place too much thought to what the slashdorks bicker about. Most /.ers dont know grep from awk, nevermind the slightest thing about compiler stability or optimization algorithms. Although i do admit i love to lurk and read the flamewars heh.

I do agree KDE would be a pretty nice test. I'm actually thinking of making 3 or 4 generations of GCC-4.0.0 compiled by the generation before it, with the same optimizations set, and comparing the binary images, sans all time-stamping and other volitile data. hmmm... :-/

 

[horndude]

I tried xfce for awhile, then blackbox, and finally stuck with fluxbox.After using fluxbox for almost a year now I dont really have any complaints, it works, its speedy, and its easy enough to configure I guess, heck I use the plain console or a terminal in X as much as anything anymore.If someone had told me Id be doing that at this point 3 years ago Id have told them they were nuts, seems like most linux users end up this way though, must be the control freak in all of us.

I have mixed feelings about /. , ive seen some interesting posts from guys at the forefront of open source lately, which I find pretty fascinating and way cool, and a healthy dose of idiots too, Im not a linux guru by any stretch, but im always learning, probably never stop I hope, been a linux user for several years and im still not clear about alot of things.

3-4 generations then compared, oooooooooh man, you know though, you might end up suprised, it may be a pretty good result, worth a shot just for sheots and giggles.

Ive got so many little projects going on I dont know what to do, I need to get focused and get some stuff done and get it out of the way.

You know, I think your the first guy/gal Ive chatted with on here in recent history that seems like you know what your doing, glad to see it, I was beginning to wonder if I might ever get some help around here, and im not even a moderator

 

[Polymorphic]

Fluxbox and blackbox are really nice, but i like the CDE-like feel of xfce, even though the xterm icon reaally gets almost all the use. heh c'est la vie i suppose..

heh thanks - good to hear. I've been using Linux heavily (often exclusively) since about 96-97, HP-UX before that. Also worked heavily in Open Net and FreeBSD, have trained in vanilla AT&T SVR4 2.1a, and test driven a bunch more NIX and non-NIX OSes. Between C, C++, C# (yech), Java(double yech), assembly, SQL, etc etc etc I definitely have enough projects to kdeep me more than busy. I know what you mean about focus, it does get quite difficult to stick to one topic.