Messages in this thread | | | From | Denys Vlasenko <> | Subject | Re: [PATCHv3 1/2] lib: vsprintf: optimised put_dec() function | Date | Thu, 12 Aug 2010 00:43:34 +0200 |
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On Wednesday 11 August 2010 23:58, Michal Nazarewicz wrote: > +static noinline_for_stack > +char *put_dec(char *buf, unsigned long long n) > +{ > + uint32_t d3, d2, d1, q; > + > + if (n < 10) { > + *buf++ = '0' + (unsigned)n; > + return buf; > + }
I looked at it and discovered that 0 is already special-cased at put_dec() callsite. You can drop the above if() block (or better comment it out, explaining that caller does it), and while at it, improve special-case code in number(): replace
/* generate full string in tmp[], in reverse order */ i = 0; if (num == 0) tmp[i++] = '0';
with
if (num <= 7) tmp[i++] = '0' + num;
(7, not 9, because it can be an octal conversion).
> + q = q / 10000; > + buf = put_dec_full4(buf, q % 10000);
Bug. You need to use temporary variable to store q / 10000 result.
-- vda
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