On 12/07/11 11:35, Georg-Johann Lay wrote:
+(define_insn "*mulsu" + [(set (match_operand:HI 0 "register_operand" "=r") + (mult:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "a")) + (zero_extend:HI (match_operand:QI 2 "register_operand" "a"))))] + "AVR_HAVE_MUL" + "mulsu %1,%2 + movw %0,r0 + clr __zero_reg__" + [(set_attr "length" "3") + (set_attr "cc" "clobber")]) + +(define_insn "*mulus" + [(set (match_operand:HI 0 "register_operand" "=r") + (mult:HI (zero_extend:HI (match_operand:QI 1 "register_operand" "a")) + (sign_extend:HI (match_operand:QI 2 "register_operand" "a"))))] + "AVR_HAVE_MUL" + "mulsu %2,%1 + movw %0,r0 + clr __zero_reg__" + [(set_attr "length" "3") + (set_attr "cc" "clobber")])
1. You should name that "usmulqihi3" (no star), so the optimizers can see it.
2. There's no need to define both of these. For one thing, putting a '%' at the start of the constraint list for operand 1 does precisely this, but more importantly, I'm pretty sure one form or the other is the canonical form and the other should never occur. If it's not, maybe it should be?
Andrew
