[PATCH] Improves __ieee754_exp() performance by greater than 5x on sparc/x86.

Siddhesh Poyarekar siddhesh@gotplt.org
Mon Dec 11 17:53:00 GMT 2017


On Monday 11 December 2017 10:29 PM, Patrick McGehearty wrote:
> log, log10, pow, cbrt are on my short list of functions to investigate
> as these all show significant performance advantage (1.8x or greater)
> using the Solaris Studio libm functions vs the Linux libm functions in
> the preliminary testing I did months ago. I intend to take these one
> at a time, first with a trial port and extensive accuracy and perf tests.
> 
> Assuming the performance advantage applies across multiple platforms
> and accuracy does not suffer to an unacceptable degree, I will
> propose each in turn for patching. "log" is my next target, likely
> with log10 following close behind. I'll also look at the 32 bit functions
> to see if they offer similar opportunities, but I haven't written/run those
> tests yet. I don't have plans to work on 80 bit or 128 bit (long double)
> functions at this time.
> 
> As always, the above is not a formal commitment as my management
> may redirect efforts to meet other corporate goals.
> My background project right now is supporting Vladimir Mezentsev's
> work on improving accuracy and range of complex divide.
> By range, I mean the range of input values which currently cause
> overflow/underflow but don't need to with appropriate scaling.

Sure, I won't hold you to it :)

Thanks,
Siddhesh



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