CFLAGS determination script

[ollie]

[bsolar]

[xunil]

[Arafaen]

[raid517]

How about this for a total n00b... How exactly do you get that script to work? I've seen executable scripts before, but runing those is easy. What do I do? Make a text file or something and paste the script into it? Also can that script be adapted so that it actually creates a unique make.conf file for each users individual systems? I know some guys are working on a Gentoo installer and would probably appreciate this.

Q

[ChadRock!]

I had the same thoughts Raid517. I'm a nube. How do you make scripts?

Good questions:

1. "What do I do? Make a text file or something and paste the script into it?"
2. "Can that script be adapted so that it actually creates a unique make.conf file for each users individual systems?"

[s3ntient]

Basically past it all into a file called say cflag_script , put that file into /usr/bin then do
chmod +x /usr/bin/cflag_script
then you can just type cflag_script in a console and i'll execute giving you the output of the script.
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[gandalf2041]

I've followed the instructions in this thread to get the script up and running; however, I get either:

RAND bin # ./cflags_script
:bad interpreter: No such file or directory OR

RAND bin #bash cflags_script
:command not found 2:
:command not found 4:
:command not found 7:
:command not found 10:
:command not found 12:
cflags_script: line 21: syntax error near unexpected token 'elif'
'flags_script: line 21: ' elif [ "$name" == "cpu family" ]; then

this is a BRAND new Gentoo 1.4 install on a Wintel P4 1.8 GHz (I haven't even installed X). Any help would be greatly appreciated.

[maxilion]

[gandalf2041]

That did it. Looks like I had an extra return at the end. Thanks!

BTW: Output ---> -march=pentium4 -mfpmath=sse -msse2 -mmmx

[ChadRock!]

Thanks for the patience people. I took a Redhat Linux course and learned some basics, like chmod and scipts, so I know how to make scripts now.

The class did not go into compiling yet, so I'm afraid Gentoo is a little over my head still.

I compiled Gentoo ok following the ix86 install instructions and got a bootable system. The problem is, I understood what was going on up until compiling the kernel. That was the point at which the instructions lose beginners like me.

It did not specify exactly what to do step by step, so I could understand, and thus I was lost from that point on. I was not sure what to pick in the kernel. Also, I was not sure that if I chose some options, whether or not the defaults apply along with what you change or if they don't apply at all if I make any changes.

I was following along fine until that point. My system booted up but I did not have basic apps and commands working. Maybe it was a pathing problem. I did not know if I had all of the packages I wanted or needed. I did not know what to chose from. I guess that's the way it is huh? It seems like the instructions were step by step dummy proof up until the kernel compile.

I just don't seem to be geek enough to figure it out like you guys do yet. But hopefully in a year or two I will be.

[rinnan]

Cut-n-paste it into Kate, from Konqueror, which works but will preserve the HTML encoding as control characters. To eliminate them, so that the script can be run, follow these instructions.

First, choose "Select All" from the "Edit" menu in Kate. Then, select "Clean Indentation" from Kate's "Tool" menu. This eliminates the starting blank character on each line. Next we have to change the indents to something that doesn't confuse /bin/sh. On line #15 of the script is "unset IFS", if you cut-n-pasted it exactly from the first text line. It's the middle line in the following list of lines:

[fastus eddius]

(hope i got all the relevant keywords in there other than epia)

i successfully completed a stage3 install of gentoo 1.4. emerge -u world worked without a hitch and the system seems stable. audio and X work thanks to various members in this forum.

related cpu/compiler settings are as follows:

gcc version 3.2.3 20030422 (Gentoo Linux 1.4 3.2.3-r1, propolice)

CHOST="i686-pc-linux-gnu"
CFLAGS="-march=pentium3 -mfpmath=sse -msse -mmmx -O3 -pipe -fomit-frame-pointer
-fprefetch-loop-arrays -fforce-addr -falign-functions=4"

Eden C3-2/Nehemiah (Via M10000)

$ cat /proc/cpuinfo
processor : 0
vendor_id : CentaurHauls
cpu family : 6

model : 9
model name : VIA Nehemiah
stepping : 1
cpu MHz : 999.550
cache size : 64 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu de tsc msr mtrr pge cmov mmx fxsr sse
bogomips : 1992.29

fwiw, the cflags script gave the following output for this cpu - i just added the rest to see if i could get away with it:
-march=pentium3 -mfpmath=sse -msse -mmmx

[regeya]

[Autie]

i get errors after is set my echo from that script in my make.conf.

[Autie]

i get errors after is set my echo from that script in my make.conf.

[Autie]

i get errors after is set my echo from that script in my make.conf.

[RikBlankestijn]

If I've done emerge -e world with these new flags and everything has been successfully compiled does mean your system will be ok? Or are there other things to think of?

[j11888]

am i the only one who nano will indent (untill it gets off teh screen) everything thats copyed into it from gnome-terminal?

anyways, i ran it on a celderon copermine and got:
-march=pentium3 -mfpmath=sse -msse -mmmx

im gonna use "-march=pentium3 -mfpmath=sse,387 -msse -mmmx -O3 -pipe -fomit-frame-pointer" unless anyone can think of a reason not to

being 2 lazy to recompile everything, ill just use the "emerge -Uu -v --oneshot `qpkg -I -nc`" from another topic and wind up recompiling everything sooner or later.

[fincoop]

I edited make.conf, and then emerged a new package (portage), and it didn't use the new settings. I copy/pasted the CFLAGS line from make.conf into my shell and then emerged another package and it worked. Do I need to have the CFLAGS variable loaded into memory for them to apply?

[bravecobra]

[vdboor]

Cool script! If this matures, I hope it will be in on the gentoo-install cd by default..

I was wondering if there is any way to specify what kind of usage one has in mind for their system. Because I have an AMD Athlon XP, I used to compile with -O3. Unfortunately, this takes ages to compile, and programs load slow (execute fast). Because I have a desktop, I want programs to load fast, so I use -Os.
There is one thing though, korganizer (kdepim package) seams to give a problem with -Os, this has been reported at bugs.kde.org as well.. That's why I use -O2 today: stable and safe.

Conclusion: could there be three options?

"What would you like to optimize your system for:"
- Slow application startup, fast execution (-O3)
- Small binaries (-Os)
- Safe and stable (-O2)
_________________
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[dalek]

I have a Athlon XP 2500+. Here is what it gave me in case you need to make a adjustment. Looks akay to me but what do I know??

[moocha]

In fact nobody should ever use the -mmmx, -msse etc etc flags. Just set -march and -mcpu (both, in case an ebuild filters -march out, then at leats you'll have -mcpu left) and let the compiler decide on the -m flags. It will usually make a better decision than you. Assuming you have at least GCC 3.3, of course.
-Os is useful for very old processors, without level 2 cache (or with a very small level 2 cache), and for SMP systems. For normal desktop usage it's slower than -O2 or -O3, and in most cases slower than -O1.
Avoid specifying -mfpmath. -mfpmath=sse always produces horrible code. -mfpmath=sse,387 produces marginally better but quite slow code (GCC's floating point optimizer can't yet make good use of a dual set of registers, SSE and the FP ones). Stick with -mfpmath=387, which is the default. In other words, don't fiddle with -mfpmath unless you're running the latest, bleeding edge CVS version of GCC (and if you do that you don't need anyone to tell you what to use )
Do NOT use -ffast-math. You're asking for it.
To summarize: Other than -march and -mcpu, stay away from the -m switches unless you know *exactly* what you're doing. Very few packages benefit from messing with them, and the corresponding ebuilds and/or configure scripts take care of them in those cases. You can fiddle with the -m flags, of course, but you'll usually end up with slower running code than if you'd just gone with the defaults.
_________________
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[vdboor]