H8300: genrecog issues warnings

Ralf Gütlein ralf.guetlein@aranea.de
Fri Jan 14 05:27:00 GMT 2000

I digged through the ChangeLogs and found the 

Thu Oct 14 01:49:54 1999  Richard Henderson  <rth@cygnus.com>

	* genrecog.c (special_mode_pred_table): New.
	(find_operand): New.
	(validate_pattern): New argument `insn'.  Warn for assignment to
	any predicate accepting non-lvalues.  Conditionaly warn for
	match_operand without a mode.  Try much harder to match source
	and destination modes on a set.
	* tm.texi (SPECIAL_MODE_PREDICATES): Document.

Apparently this causes the warnings.
The generated compiler seems to work as supposed to do, but
someone should walk through the *.md files trying to correct
the suspicious define_xxx's

I tried to do this for h8300, but to no avail. Please, give hints
of what to do.

Also, I want to direct your attention to fact that correcting the
*.md files may improve the code generation (see original message

> Von: Paul Clarke <paulc@senet.com.au>
> An: Ralf Gütlein <ralf.guetlein@rodgau.netsurf.de>
> Cc: Ralf Gütlein <ralf.guetlein@aranea.de>
> Betreff: Re: H8300: genrecog issues warnings
> Datum: Donnerstag, 13. Januar 2000 20:07
> Ralf Gütlein wrote:
> > When interpreting h8300.md genrecog issues several warnings
> >
> > "destination operand allows non-lvalue"
> >
> > Changing some operator constraints in h8300.md from "r" to "=r"
> > leads to slightly better code (this should be investigated!!),
> > but doesn't eliminate the warnings.
> >
> > Regards,
> > Ralf
> >
> > --
> HI Ralf,
> Looks like you have been busy on the H8 compiler.
> I have looked at the h8300.md file after reading this
> email and cannot see anywhere that the constraints
> should be modified.
> Can you give a better description of the changes
> you have made and when/how the error message
> occurs? (I haven't recompiled gcc lately is this
> when it occurs?)
> Paul

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