[Patch, AVR]: Fix PR33049 (implement extzv)

[Denis Chertykov]

2011/6/20 Georg-Johann Lay <avr@gjlay.de>:
> This is an optimization patch that implements extzv for 1-bit extracts.


> +(define_insn_and_split "*extzv"
> +  [(set (match_operand:QI 0 "register_operand"                    "=*d,*d,*d,r")
> +        (zero_extract:QI (match_operand:QI 1 "register_operand"     "0,r,0,r")
> +                         (const_int 1)
> +                         (match_operand:QI 2 "const_0_to_7_operand" "L,L,P,n")))]
> +  ""
> +  "@
> +	andi %0,1
> +	mov %0,%1\;andi %0,1
> +	lsr %0\;andi %0,1
> +	bst %1,%2\;clr %0\;bld %0,0"

Why you have a second constraint alternative (*d,r,L) ?
IMHO it's unnecessary.

> +   && REGNO (operands[0]) >= 16"

It's not a good practice to refer to register as number.

Denis.