Richard Henderson <r...@twiddle.net> writes: > On 12/08/2016 09:19 AM, Alex Bennée wrote: >> >> Richard Henderson <r...@twiddle.net> writes: >> >>> This allows an output operand to match an input operand >>> only when the input operand needs a register. >>> >>> Signed-off-by: Richard Henderson <r...@twiddle.net> >> >> It's hard to offer anything more than a mechanical review for this as >> the constraints aren't intuitive to me (I guess not as a gcc hacker!). > > It's even more confusing for a gcc hacker, as we don't have a concept of > alternatives. You get one set of constraints. > >> Could we either expand the documentation of constraints in tcg/README >> with a summary of the global ones? > > There's only one global constraint: 'i'. So... sure, but I don't know how > much > that will help.
So what do 0..9 and & mean? Or do you mean they are only constraints applied by the backend? -- Alex Bennée
