slackbuild guidance needed

mcnalu · 05-10-2008, 03:52 PM

First off, thanks to the folks at slackbuilds.org for all their efforts, especially the HOWTOs, FAQ and other very clear docs.

I've succeeded in making a slackbuild for kphotoalbum but have come across conflicting advice.
http://www.slackbuilds.com/guidelines/ tells me to include these lines:

Code:

if [ "$ARCH" = "i486" ]; then
       SLKCFLAGS="-O2 -march=i486 -mtune=i686"
    elif [ "$ARCH" = "i686" ]; then
       SLKCFLAGS="-O2 -march=i686 -mtune=i686"
    elif [ "$ARCH" = "x86_64" ]; then
       SLKCFLAGS="-O2 -fPIC"
    fi

but the tutorial http://www.slackwiki.org/Writing_A_SlackBuild_Script says

Code:

if [ "$ARCH" = "i386" ]; then
  SLKCFLAGS="-O2 -march=i386 -mtune=i686"
 elif [ "$ARCH" = "i486" ]; then
  SLKCFLAGS="-O2 -march=i486 -mtune=i686"
 elif [ "$ARCH" = "x86_64" ]; then
  SLKCFLAGS="-O2 -fPIC"
fi

Which is preferred?

Emerson · 05-10-2008, 04:03 PM

You know what ARCH you are building it for, right? Or you are building a generic build for using in multiple machines?

mcnalu · 05-10-2008, 04:12 PM

The latter - hopefully I won't be only the person to use it

dugan · 05-10-2008, 04:18 PM

I recommend asking this on the SlackBuilds.org mailing list.

Emerson · 05-10-2008, 04:54 PM

Use i486 and add warning it is not intended for i386 use.

shadowsnipes · 05-10-2008, 11:19 PM

Quote:

Originally Posted by dugan

I recommend asking this on the SlackBuilds.org mailing list.

Agreed. That is by far the best place for such a question.

But to answer your question (remember my answer isn't the official slackBuilds.org answer), the first code snippet is generally used. Just take a look at a lot of the other slackBuilds and you will see this.

All of them, as far as I know, either by default build for i486 or noarch (unless they repackage binaries). I typically choose i686 for my builds if applicable.

mcnalu · 05-11-2008, 04:21 AM

Thanks for the replies.

I did a quick survey of a few slackbuilds from slackbuilds.org and the first snippet is the most common, but of course, that doesn't mean it's the best choice.

I'll go explain to my inbox that I'm joining another mailing list

titopoquito · 05-11-2008, 06:45 AM

EDIT: Forget what I posted before. I just read Carlos' answer on the mailing list. In short: The first one is preferred, the second makes no sense anymore for Slackware versions > 9.0.

http://lists.slackbuilds.org/piperma...ay/002620.html

Emerson · 05-11-2008, 09:44 AM

You can use your own, will work whatever ARCH is set. Something like this:

Code:

    if [ "$ARCH" = "i386" ]; then
       SLKCFLAGS="-O2 -march=i386"
    elif [ "$ARCH" = "i486" ]; then
       SLKCFLAGS="-O2 -march=i486"
    elif [ "$ARCH" = "i586" ]; then
       SLKCFLAGS="-O2 -march=pentium-mmx"
    elif [ "$ARCH" = "i686" ]; then
       SLKCFLAGS="-O2 -march=i686"
    elif [ "$ARCH" = "x86_64" ]; then
       SLKCFLAGS="-O2 -fPIC"
    fi

march option implies also mtune in recent GCC versions. With GCC-4.2 and newer you can omit it all and just use march=native.

jong357 · 05-11-2008, 11:40 AM

Starting with glibc-2.6, i486 is the minimum supported arch so it really doesn't make a whole lot of sense to build anything else at i386...

I ussually don't even include CFLAGS in my build scripts. I set it globaly on my login shell and then forget about it. Reduces the clutter in your build scripts.

jong357 · 05-11-2008, 12:07 PM

Also, putting -march=native would optimize for your machine only ( -mtune=native is implied). The use of mtune is still as applicable as it's ever been. -march=i486 -mtune=generic would be the better option IMO. If you just want to build for your machine then -march=native is fine.