2011/6/21 Georg-Johann Lay <a...@gjlay.de>: > Denis Chertykov schrieb: >> 2011/6/21 Georg-Johann Lay: > >>> Ok. d_register_operand or satisfies_constraint_d would do. But I >>> preferred to introduce a new constraint for 4 and avoid splitting >>> *extzv altogether to keep it simple. Complexity of splitting is not a >>> real advantage over writing things down directly. >>> >>> As avr is running out of constraint letters, I started 3-letter >>> constraints 'Y**' in the style of bfin. Would be nice if 'K' was not >>> already occupied or could be deprecated (is'n not really useful in >>> inline asm)... >> >> Better to choose starting letter different to pointer register names X,Y,Z. >> May be better to use underscore '_' ? >> >> Denis. > > My preference would be to change 'K' to 'K02' and thus deprecate 'K'. > > Other letters are 'A', 'B', 'C', D', 'R', 'S', 'T', 'U', 'W', 'Z'. > I do not like '_' as constraint. > 'R' might be needed in the future for more register constraints (r24, > r24-r25, r22-25, ...) and 'R' is a nice prefix. > 'C' looks appealing for constant.
I'm vote for 'C'. Denis.
