Re: crosstool bloat

[David Karlton <dkarlton at themediamall dot com>]

Dave Korn wrote:
> ----Original Message----
>
> > From: David Karlton
> > Sent: 18 September 2005 22:24
>
>
> > The build seems
> > to work, but when I compile anything with the resulting compiler, all my
> > output files are suddenly quite huge -- anything that would have
> > compiled very small with 0.28 (eg. a 5k binary under 0.28) is now right
> > around 68k, consistently, with 0.38.  I simply ran "sh ./demo-mipsel.sh"
> > after editing the script to create the desired build.
> >
> > Any idea what may be causing the executables to be so large?
>
>
>   Lots of things *could* cause it, all the way down the toolchain starting
> at the compiler and ending with the linker.
>
>
> > I can't
> > recall what I had done in the installation for 0.28 to make the binaries
> > be "normal".  Is there an easy way to figure out what is getting
> > included into my builds?
>
>
>   Yep, it's called objdump.  Compile a 'hello world' program with the old
> and new compiler, and see what's different.

Being as far from a guru at this stuff as humanly possible, the best I 
could figure out was that the bloated programs have an additional 
section header named ".MIPS.stubs".  I'm not sure how else to use 
objdump effectively.  Forgive my inexperience with compilers and such... 
 Is there another arg I should try to compare?

One thing I noticed was that if I compress the two programs (like with 
zip), then the zipped size is almost identical (and small) for each 
binary, even though unzipped they're 5k and 68k.  Am I being naive by 
assuming that there's a lot of "dead air" in the bloated file and/or a 
lot of repeated values or something?

>   My first guess would be that the new compiler is linking statically
> against large chunks of glibc when the old one was linking against a shared
> glibc.  Maybe a '--enable-shared' got left out of configure options
> somewhere?

I don't see anything obvious within the setup for the crosstool build, 
nor any reference in the documentation that implies I need to do more 
than run the demo-mipsel.sh script.  :-/

>     cheers,
>       DaveK

Thanks for the help so far!

dk


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