lkml.org 
[lkml]   [2017]   [Jul]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subject[PATCH 0/3] lib/int_sqrt: Fix, optimize and document
Hi,

Here are a few patches that should improve things lib/int_sqrt. As stated
elsewhere; I'm looking at using int_sqrt() to calculate the stdev on a normal
distribution and am expecting the input values to be smallish.

In any case, these optimizations should work fine for large numbers too. And
if you have a find-last-set or count-leading-zeros instruction they rock ;-)

I can post the tool used to generate the numbers or do a patch to add it to
tools/testing/ if people care. The cold numbers are fairly sensitive to code
layout (GCC version, random changes etc..), so I expect the branch predictor of
my SKL is only partially confused or there's other things at play. However the
general trend in the numbers seems fairly stable.

\
 
 \ /
  Last update: 2017-07-24 17:38    [W:0.098 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site