Dear Graeme Russ,
In message <CALButC+t=oul9xgqnfyadzmgpjrp7mdrwee9lkogyheg1d+...@mail.gmail.com>
you wrote:
>
> > If you want to support arbitrary buffer sizes, then just use
> >
> > #define CIRC_BUF_IDX(idx) ((idx) % CONFIG_SYS_TMP_CON_BUF_SZ)
>
> I know, but I was concerned that you wouldn't like the use of modulo
> arithmetic for every putc() - But I suppose thats cheaper than a compare
> plus branch...
Well, the difference of "i & (CONFIG_SYS_TMP_CON_BUF_SZ-1)" versus
"i % CONFIG_SYS_TMP_CON_BUF_SZ" is 1 versus 4 assembler instructions
on Power, and 2 versus 5 assembler instructions on ARM. I think we
can tolerate this.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
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