[MIPS] PR target/22209: Support TImode arithmetic on MIPS

[Richard Sandiford]

> 2006-02-05  Roger Sayle  <roger@eyesopen.com>
>
> 	PR target/22209
> 	* config/mips/mips.h (MIN_UNITS_PER_WORD): Don't define for libgcc.
> 	* config/mips/_tilib.c: Remove.
> 	* config/fixtfdi.c: New libgcc source file.
> 	* config/fixunstfdi.c: New source file.
> 	* config/floatditf.c: New source file.
> 	* config/floatunditf.c: New souce file.
> 	* config/mips/t-iris6 (LIB2FUNCS_EXTRA): Include the new source
> 	files above instead of config/mips/_tilib.c.
> 	* config/mips/t-linux64 (LIB2FUNCS_EXTRA): Likewise.

Thanks for looking at this.  As before, I don't have access to any
64-bit OS targets at the moment, so I can't really help much, either
with testing or with conceptual stuff (in the latter case because it's
hard to get configury right without access to a running system).

Still, the MIPS parts of your patch look good to me.  I suppose not
defining MIN_UNITS_PER_WORD make sense for libgcc2.c, which is always
compiled with a fixed word size.  But that makes me wonder why we use
MIN_UNITS_PER_WORD rather than UNITS_PER_WORD at all in libgcc2.c.
Why doesn't the same logic apply for all targets?

Since you have access to an affected system, I'm happy for you to use
your discretion and middle-end approval rights to apply this patch to
whatever branches you see fit.

Richard