Peter Maydell <peter.mayd...@linaro.org> writes: > On 5 February 2016 at 16:17, Alex Bennée <alex.ben...@linaro.org> wrote: >> >> Peter Maydell <peter.mayd...@linaro.org> writes: >>> I haven't measured, no, but since there are only 3 arguments the >>> third argument is going to be in a register on any host architecture >>> we care about, which means the overhead is just going to be a single >>> "load constant 0 or 1 into register before the call". I think that's >>> going to be lost in the noise compared to actually having to make >>> the function call at all, the work the function call does, and then >>> the second function call later to do the read or write. >> >> I was thinking of knock on effects on spilling other registers in the >> TCG code. I guess this depends on how complex the code is around system >> register access. > > The register in question is going to be caller-saves anyway, so no > effect on spilling in the TCG code I think.
Well my only remaining objection is the additional line-wrapping looks ugly which I don't think is a valid objection ;-) Reviewed-by: Alex Bennée <alex.ben...@linaro.org> > > thanks > -- PMM -- Alex Bennée
