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[varLib.featureVars] Optimize popCount()

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While might look like unjustified micro-optimizing, for featureVars_test.py with
n=100, speeds up 10%.  From 2.5s to 2.2s.
This commit is contained in:
Behdad Esfahbod 2018-11-09 14:34:15 -05:00
parent 0283b1fd1d
commit 0be1636176
1 changed files with 7 additions and 7 deletions
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14
Lib/fontTools/varLib/featureVars.py
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@ -73,13 +73,13 @@ class hashdict(dict):
return result
def popCount(v):
# TODO Speed up
i = 0
while v:
if v & 1:
i += 1
v = v >> 1
return i
if v > 0xFFFFFFFF:
return popCount(v >> 32) + popCount(v & 0xFFFFFFFF)
# HACKMEM 169
y = (v >> 1) & 033333333333
y = v - y - ((y >> 1) & 033333333333)
return (((y + (y >> 3)) & 030707070707) % 077)
def addFeatureVariations(font, conditionalSubstitutions):