2005-08-08 Paolo Bonzini <bonzini@gnu.org>

2005-08-08  Paolo Bonzini  <bonzini@gnu.org>
	    Dale Johannesen  <dalej@apple.com>

	PR target/19653
	* regclass.c (struct reg_pref): Update documentation.
	(regclass): Set prefclass to NO_REGS if memory is the best option.
	(record_reg_classes): Cope with a prefclass set to NO_REGS.
	* reload.c (find_reloads): Take PREFERRED_OUTPUT_RELOAD_CLASS
	into account.  For non-registers, equate an empty preferred
	reload class to a `!' in the constraint; move the if clause to
	do so after those that reject the insn.
	(push_reload): Allow PREFERRED_*_RELOAD_CLASS to liberally
	return NO_REGS.
	(find_dummy_reload): Likewise.
	* doc/tm.texi (Register Classes): Document what it means
	if PREFERRED_*_RELOAD_CLASS return NO_REGS.
	* config/i386/i386.c (ix86_preferred_reload_class): Force
	using SSE registers (and return NO_REGS for floating-point
	constants) if math is done with SSE.
	(ix86_preferred_output_reload_class): New.
	* config/i386/i386-protos.h (ix86_preferred_output_reload_class): New.
	* config/i386/i386.h (PREFERRED_OUTPUT_RELOAD_CLASS): New.
	* config/i386/i386.md: Remove # register preferences.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@112637 138bc75d-0d04-0410-961f-82ee72b054a4