i386-protos.h (x86_maybe_negate_const_int): Declare.

	* config/i386/i386-protos.h (x86_maybe_negate_const_int): Declare.
	* config/i386/i386.c (x86_maybe_negate_const_int): New.
	(x86_output_mi_thunk): Use x86_maybe_negate_const_int.
	* config/i386/i386.md (*add<mode>_1, *addsi_1_zext, *addhi_1,
	*addhi_1_lea, *addqi_1, *addqi_1_lea, *addqi_1_slp, *add<mode>_2,
	*addsi_2_zext, *addhi_2, *addqi_2, *add<mode>_3, *addsi_3_zext,
	*addhi_3, *addqi_3,*add<mode>_5, *addhi_5, *addqi_5):
	Use x86_maybe_negate_const_int to output insn mnemonic.
	(*adddi_4, *addsi_4, *addhi_4, *addqi_4): Ditto.  Remove overflow
	check from instruction predicate.  Update comments.
	* config/i386/sync.md (sync_add<mode>): Use
	x86_maybe_negate_const_int to output insn mnemonic.

From-SVN: r158013