mini benchmark vtim formatting

Poul-Henning Kamp phk at
Mon Oct 8 09:07:47 UTC 2018

In message <6e3db4b7-5817-4c60-8c20-f4dce1ebf9d1 at>, Nils Goroll writes:

>> 	printf("%ju.%06ju",
>> 		(uint64_t)floor(foo),
>> 		(uint64_t)floor((foo*1e6)) % 1000000UL);
>nice trick. On Linux, this gets us down to the same order of magnitude as a
>%lu.%06lu with uint64_t

The important thing here is the FP rendering, not the FP math, which is
instantaneous for all practical purposes.

It's kind of surprising to me that "%.<N>f" hasn't gotten specific
optimization, it is a lot simpler thing than the general FP formatting
problem, but if there is any code I'm not keen on wading into, it is
FP formatting code...

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.

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