Re: [3.4 patch] Fix PR16314, undefined reference to `__subdf3' forarm-softfloat

[Vladimir Ivanov <vladitx at nucleusys dot com>]

On Tue, 31 Aug 2004, Daniel Jacobowitz wrote:

> On Tue, Aug 31, 2004 at 02:12:16PM +0300, Vladimir Ivanov wrote:
> > On Tue, 31 Aug 2004, Richard Earnshaw wrote:
> >
> > > On Tue, 2004-08-31 at 11:25, Vladimir Ivanov wrote:
> > > > What about defining more targets, like "t-linux-crunch" and
> > > > "t-linux-softfp"? This could solve some of the current ABI differences.
> > >
> > > Not really.  I suspect folks really want a single compiler that supports
> > > both hard and soft float.  Separate t-* files only come into play with
> > > separate configurations of the compiler.  Besides that it becomes a
> > > maintenance nightmare.
> >
> > Then we're back to the single "t-linux". Here's what I've been using:
>
> > LIB1ASMSRC = arm/lib1funcs.asm
> > LIB1ASMFUNCS = _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_lnx \
> > 	_negdf2 _addsubdf3 _muldivdf3 _cmpdf2 _unorddf2 _fixdfsi _fixunsdfsi
> > 	\
> > 	_truncdfsf2 _negsf2 _addsubsf3 _muldivsf3 _cmpsf2 _unordsf2 \
> > 	_fixsfsi _fixunssfsi
>
> So, let's think about Richard's point.  Does the -mcpu=ep9312 version
> _work_?  It probably doesn't - calls to divdf3 will always return using
> the soft float convention and the compiler would expect them to return
> using the Crunch registers.

Yes, it works, although not exactly in the official gcc 3.4.x (but that's 
because of other things).
Due to using multilibs, when "-mcpu=ep9312" is specified a version of 
divdf3 is used which returns result in FP register. So, for me the 
multilib approach solves this problem - I can have arm-linux compiler 
which produces hard-float, soft-float and crunch (ep9312) code, together 
with appropriate libgcc.

What I've been asking was connected to TARGET_LIBGCC2_CFLAGS - is there a 
way to put specific options per multilib. And also, does someone know how 
to link against different glibc's based on the multilib options (but 
that's perhaps slightly [OT]).

> Hopefully we can support using the soft-float ABI for libcalls soon.

That's a different story.

  -- Vladimir