Re: [gentoo-sparc] GLIBC Issues

[Mike Frysinger]

On 19 Jan 2016 16:23, Alex McWhirter wrote:
> On 01/19/2016 04:05 PM, Mike Frysinger wrote:
> > if you delete that CHOST override, do the *_OPT values end up being
> > sparc-* ? if not, put `set -x` at the top of setup_env and `set +x` at
> > the bottom of setup_env and send that log over. sparc is the only one
> > that sets CTARGET_OPT in this sub-case, so there might be a bug in
> > there. unfortunately we can't get away from overriding the tuple for
> > glibc since user's can't really change it and glibc itself does no
> > probing :(. my preference otherwise would be to delete this block of
> > code entirely. -mike
>
> No it doesn't seem to make any difference. multilib_env doesn't set
> CTARGET or CHOST, it just sets the _$ABI variants. It seems to be a
> backup in case they aren't set in the profile.
>
> In my profile ABI and DEFAULT_ABI are set to sparc64 and glibc changes
> that to sparc32 when building multilib which is correct. The question i
> have is, where is CTARGET set? glibc's ebuild doesn't seem to do it and
> my profile doesn't either. multlib_env only sets CTARGET_$ABI which
> isn't use here.

CTARGET is set to CHOST by default by glibc itself.  we might only be
doing that at a higher level though, so we might have to reset it in
there.

> For what it's worth glibc will probe for which assembly to use based on
> the value of -mpcu. I've built enough LFS builds on sparc to know what
> happens when you pass glibc -mpcu=v9 and it need something more
> specific. But if you use -mcpu=ultrasparc,ultrasparc3,etc... glibc will
> pick the right assembly on it's own. At least the current version does
> anyways. So getting rid of *_OPT vars should be fine as long as people
> are something more specific than -mcpu=v9

i'm like 99% sure you're not looking at the right thing :).  the issue
isn't multiarch/ifunc (which works), or for some feature testing (which
works), or for code generation by gcc itself (which works), but for 
selection of subdirs which host different files.  example:

$ ../configure CC=sparc-unknown-linux-gnu-gcc \
	CFLAGS='-O2 -mcpu=niagara -pipe' \
	--prefix=/usr --host=sparcv9v-unknown-linux-gnu
$ grep ^config-sysdirs config.make
config-sysdirs =  sysdeps/unix/sysv/linux/sparc/sparc32/sparcv9/fpu/multiarch sysdeps/sparc/sparc32/sparcv9/fpu/multiarch sysdeps/sparc/sparc32/sparcv9/fpu sysdeps/sparc/sparc32/fpu sysdeps/unix/sysv/linux/sparc/sparc32/sparcv9/fpu sysdeps/unix/sysv/linux/sparc/sparc32/sparcv9 sysdeps/unix/sysv/linux/sparc/sparc32/fpu sysdeps/unix/sysv/linux/sparc/sparc32 sysdeps/ieee754/ldbl-64-128 sysdeps/ieee754/ldbl-opt sysdeps/unix/sysv/linux/sparc sysdeps/sparc/nptl sysdeps/unix/sysv/linux sysdeps/nptl sysdeps/pthread sysdeps/gnu sysdeps/unix/inet sysdeps/unix/sysv sysdeps/unix sysdeps/posix sysdeps/sparc/sparc32/sparcv9/multiarch sysdeps/sparc/sparc32/sparcv9 sysdeps/sparc/sparc32 sysdeps/wordsize-32 sysdeps/ieee754/ldbl-128 sysdeps/ieee754/dbl-64 sysdeps/ieee754/flt-32 sysdeps/sparc/sparc32/soft-fp sysdeps/sparc/fpu sysdeps/sparc sysdeps/ieee754 sysdeps/generic

$ ../configure CC=sparc-unknown-linux-gnu-gcc \
	CFLAGS='-O2 -mcpu=niagara -pipe' \
	--prefix=/usr --host=sparc-unknown-linux-gnu
$ grep ^config-sysdirs config.make
config-sysdirs =  sysdeps/unix/sysv/linux/sparc/sparc32/fpu sysdeps/sparc/sparc32/fpu sysdeps/unix/sysv/linux/sparc/sparc32 sysdeps/ieee754/ldbl-64-128 sysdeps/ieee754/ldbl-opt sysdeps/unix/sysv/linux/sparc sysdeps/sparc/nptl sysdeps/unix/sysv/linux sysdeps/nptl sysdeps/pthread sysdeps/gnu sysdeps/unix/inet sysdeps/unix/sysv sysdeps/unix sysdeps/posix sysdeps/sparc/sparc32 sysdeps/wordsize-32 sysdeps/ieee754/ldbl-128 sysdeps/ieee754/dbl-64 sysdeps/ieee754/flt-32 sysdeps/sparc/sparc32/soft-fp sysdeps/sparc/fpu sysdeps/sparc sysdeps/ieee754 sysdeps/generic

see how there is significant difference here ?
-mike