PR target/50910
	* config/avr/avr.opt (-mbranch-cost=): New option.
	* config/avr/avr.h (BRANCH_COST): Define to avr_branch_cost.
	* config/avr/avr.c (avr_rtx_costs_1): Adjust [U]DIV/[U]MOD costs.
	* config/avr/avr.md (*addqi3.lt0, *addhi3.lt0, *addsi3.lt0): New insns.
	(*addhi3_zero_extend1): Remov % in constraint of operand 1.
	(*addhi3.sign_extend1, *subhi3.sign_extend2): New insns.

From-SVN: r180739