* Deprecating config-ml.in multilib selection options
@ 2011-03-21 14:37 Joseph S. Myers
2011-03-21 14:42 ` Richard Earnshaw
2011-03-21 18:45 ` Richard Sandiford
0 siblings, 2 replies; 4+ messages in thread
From: Joseph S. Myers @ 2011-03-21 14:37 UTC (permalink / raw)
To: gcc
Cc: newlib, nickc, richard.earnshaw, paul, ramana.radhakrishnan, law,
schwab, echristo, rdsandiford, geoffk, dje.gcc
The toplevel config-ml.in configure fragment has some code for a few
targets that allows modifying the set of multilibs built, based on
configure options, to be different from that given by $CC -print-multi-lib.
The options in question are described in GCC's install.texi (but the
lists there may not be accurate):
Some targets provide finer-grained control over which multilibs are built
(e.g., @option{--disable-softfloat}):
@table @code
@item arm-*-*
fpu, 26bit, underscore, interwork, biendian, nofmult.
@item m68*-*-*
softfloat, m68881, m68000, m68020.
@item mips*-*-*
single-float, biendian, softfloat.
@item powerpc*-*-*, rs6000*-*-*
aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian,
sysv, aix.
@end table
(The option handling for arc-*-elf* is to be removed for GCC 4.7 as part
of the ARC target removal.)
I'd like to deprecate these options - or more specifically, their
implementations in config-ml.in. I don't think this script is a sensible
place to hardcode multilib selections for a few particular targets, and I
think the preferred way of doing such configuration is by options that
actually take effect on GCC when it is configured so that -print-multi-lib
gives the desired set of multilibs. The options could in principle be
used when building target libraries other than GCC's (in particular,
newlib), but if you want to build a set of newlib multilibs different from
GCC multilibs I still don't think such target-specific config-ml.in
options are the right way to do it (though a generic system to specify
multilibs to build / add / remove might be).
Comments? What I am proposing is a release-notes-only deprecation - that
is, state in gcc-4.6/changes.html that these options are deprecated,
without any change to the code, with a view to removing them later in the
GCC 4.7 development cycle (to give time for maintainers to reimplement any
options they still want, in config.gcc or elsewhere in the gcc/ directory)
rather than immediately. If we can't deprecate all of them, deprecating
some would still be good.
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Deprecating config-ml.in multilib selection options
2011-03-21 14:37 Deprecating config-ml.in multilib selection options Joseph S. Myers
@ 2011-03-21 14:42 ` Richard Earnshaw
2011-03-21 15:23 ` Andreas Schwab
2011-03-21 18:45 ` Richard Sandiford
1 sibling, 1 reply; 4+ messages in thread
From: Richard Earnshaw @ 2011-03-21 14:42 UTC (permalink / raw)
To: Joseph S. Myers
Cc: gcc, newlib, nickc, paul, ramana.radhakrishnan, law, schwab,
echristo, rdsandiford, geoffk, dje.gcc
On Mon, 2011-03-21 at 14:36 +0000, Joseph S. Myers wrote:
> Some targets provide finer-grained control over which multilibs are
> built
> (e.g., @option{--disable-softfloat}):
> @table @code
> @item arm-*-*
> fpu, 26bit, underscore, interwork, biendian, nofmult.
I'd expect that code to be very bit-rotten for ARM. The evidence of
this is that 26-bit mode hasn't been supported by gcc for about 5 years
now, but nobody has cleaned up this bit of code...
R.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Deprecating config-ml.in multilib selection options
2011-03-21 14:42 ` Richard Earnshaw
@ 2011-03-21 15:23 ` Andreas Schwab
0 siblings, 0 replies; 4+ messages in thread
From: Andreas Schwab @ 2011-03-21 15:23 UTC (permalink / raw)
To: Richard Earnshaw
Cc: Joseph S. Myers, gcc, newlib, nickc, paul, ramana.radhakrishnan,
law, echristo, rdsandiford, geoffk, dje.gcc
Richard Earnshaw <rearnsha@arm.com> writes:
> On Mon, 2011-03-21 at 14:36 +0000, Joseph S. Myers wrote:
>> Some targets provide finer-grained control over which multilibs are
>> built
>> (e.g., @option{--disable-softfloat}):
>> @table @code
>> @item arm-*-*
>> fpu, 26bit, underscore, interwork, biendian, nofmult.
>
> I'd expect that code to be very bit-rotten for ARM. The evidence of
> this is that 26-bit mode hasn't been supported by gcc for about 5 years
> now, but nobody has cleaned up this bit of code...
Probably because that part just turned into a no-op without creating any
problems.
Andreas.
--
Andreas Schwab, schwab@redhat.com
GPG Key fingerprint = D4E8 DBE3 3813 BB5D FA84 5EC7 45C6 250E 6F00 984E
"And now for something completely different."
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Deprecating config-ml.in multilib selection options
2011-03-21 14:37 Deprecating config-ml.in multilib selection options Joseph S. Myers
2011-03-21 14:42 ` Richard Earnshaw
@ 2011-03-21 18:45 ` Richard Sandiford
1 sibling, 0 replies; 4+ messages in thread
From: Richard Sandiford @ 2011-03-21 18:45 UTC (permalink / raw)
To: Joseph S. Myers
Cc: gcc, newlib, nickc, richard.earnshaw, paul, ramana.radhakrishnan,
law, schwab, echristo, geoffk, dje.gcc
"Joseph S. Myers" <joseph@codesourcery.com> writes:
> @item mips*-*-*
> single-float, biendian, softfloat.
FWIW, I've no objection from a MIPS point of view. Like Richard was
saying for ARM, single-float has long since stopped working for MIPS,
because no target has single-float multilibs.
Richard
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-03-21 18:45 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-03-21 14:37 Deprecating config-ml.in multilib selection options Joseph S. Myers
2011-03-21 14:42 ` Richard Earnshaw
2011-03-21 15:23 ` Andreas Schwab
2011-03-21 18:45 ` Richard Sandiford
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).