* i386.c (ix86_attr_length_default): Handle TYPE_STR and TYPE_CLD.
	* i386.md (FIRST_PSEUDO_REGISTER): Set to 20.
	(FIXED_REGISTERS): Set dirflag as fixed.
	(CALL_USED_REGISTERS): Set dirflag as used.
	(REG_ALLOC_ORDER): Set dirflag as last one.
	(DIRFLAG_REG): New macro.
	(MD_ASM_CLOBBERS): Asm clobber dirflag for backward compatibility.
	(HI_REGISTER_NAMES): Add dirflag.
	(DEBUF_PRINT_REG): Handle dirflag.
	* i386.md (type attribute): New cld and str types.
	(length_opcode attribute): Set cld and str to 1.
	(memory attribute): Set str to unknown - it is not clear from the
	patterns.
	(pent_np function unit): Prefixed string operations takes 12 cycles
	minimally; cld takes 2 cycles.
	(ppro_uops attribute): Str is "many" and cld is "few".
	(ppro_p0 unit): Handle cld here.
	(k6_alux unit): Handle cld and str types.
	(k6_load unit): It is ocupied by str opcodes.
	(k6_store unit): It is ocupied by str opcodes.
	(athlon_decode): Str is vector decoded.
	(athlon_ieu): Handle str and cld.
	(cld pattern): New.
	(movstrsi, clrstr, cmpstr, strlen expander): Emit cld instruction
	(movstrsi_1, clrstrsi_1, cmpstrsi_1, strlensi_1,
	cmpstrsi_nz_1 insn): Do not output cld instruction

From-SVN: r31326