Implement light-weight DImode support.

Implement light-weight DImode support.

gcc/
	Implement light-weight DImode support.
	* config/avr/avr-dimode.md: New file.
	* config/avr/avr.md: Include it.
	(adjust_len): Add plus64, compare64.
	(HIDI): Remove code iterator.
	(code_stdname): New code attribute.
	(rotx, rotsmode): Remove DI.
	(rotl<mode>3, *rotw<mode>, *rotb<mode>): Use HISI instead of HIDI
	as code iterator.
	* config/avr/avr-protos.h (avr_have_dimode): New.
	(avr_out_plus64, avr_out_compare64): New.
	* config/avr/avr.c (avr_out_compare): Handle DImode.
	(avr_have_dimode): New variable definition and initialization.
	(avr_out_compare64, avr_out_plus64): New functions.
	(avr_out_plus_1): Use simplify_unary_operation to negate xval.
	(adjust_insn_length): Handle ADJUST_LEN_COMPARE64, ADJUST_LEN_PLUS64.
	(avr_compare_pattern): Skip DImode comparisons.

libgcc/
	Implement light-weight DImode support.
	* config/avr/t-avr (LIB1ASMFUNCS): Add _adddi3, _adddi3_s8,
	_subdi3, _cmpdi2, _cmpdi2_s8, _rotldi3.
	* config/avr/lib1funcs.S (__adddi3, __adddi3_s8, __subdi3,
	__cmpdi2, __cmpdi2_s8, __rotldi3): New functions.

From-SVN: r182794