re PR target/49687 ([avr] Missed optimization for widening MUL)

re PR target/49687 ([avr] Missed optimization for widening MUL)

	PR target/49687
	* config/avr/t-avr (LIB1ASMFUNCS): Remove _xmulhisi3_exit.
	Add _muluhisi3, _mulshisi3, _usmulhisi3.
	* config/avr/libgcc.S (__mulsi3): Rewrite.
	(__mulhisi3): Rewrite.
	(__umulhisi3): Rewrite.
	(__usmulhisi3): New.
	(__muluhisi3): New.
	(__mulshisi3): New.
	(__mulohisi3): New.
	(__mulqi3, __mulqihi3, __umulqihi3, __mulhi3): Use DEFUN/ENDF to
	declare.
	* config/avr/predicates.md (pseudo_register_operand): Rewrite.
	(pseudo_register_or_const_int_operand): New.
	(combine_pseudo_register_operand): New.
	(u16_operand): New.
	(s16_operand): New.
	(o16_operand): New.
	* config/avr/avr.c (avr_rtx_costs): Handle costs for mult:SI.
	* config/avr/avr.md (QIHI, QIHI2): New mode iterators.
	(any_extend, any_extend2): New code iterators.
	(extend_prefix): New code attribute.
	(mulsi3): Rewrite. Turn insn to expander.
	(mulhisi3): Ditto.
	(umulhisi3): Ditto.
	(usmulhisi3): New expander.
	(*mulsi3): New insn-and-split.
	(mulu<mode>si3): New insn-and-split.
	(muls<mode>si3): New insn-and-split.
	(mulohisi3): New insn-and-split.
	(*uumulqihisi3, *uumulhiqisi3, *uumulhihisi3, *uumulqiqisi3,
	*usmulqihisi3, *usmulhiqisi3, *usmulhihisi3, *usmulqiqisi3,
	*sumulqihisi3, *sumulhiqisi3, *sumulhihisi3, *sumulqiqisi3,
	*ssmulqihisi3, *ssmulhiqisi3, *ssmulhihisi3, *ssmulqiqisi3): New
	insn-and-split.
	(*mulsi3_call): Rewrite.
	(*mulhisi3_call): Rewrite.
	(*umulhisi3_call): Rewrite.
	(*usmulhisi3_call): New insn.
	(*muluhisi3_call): New insn.
	(*mulshisi3_call): New insn.
	(*mulohisi3_call): New insn.
	(extendqihi2): Use combine_pseudo_register_operand as predicate
	for operand 1.
	(extendqisi2): Ditto.
	(zero_extendqihi2): Ditto.
	(zero_extendqisi2): Ditto.
	(zero_extendhisi2): Ditto.
	(extendhisi2): Ditto. Don't early-clobber operand 0.

From-SVN: r176862