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Eliminate floating point arithmatic in nre

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Integer division is already hard enough on your CPU, using floating
point here is WAY slower and can just as effectivly be done using
integers. This is important because matchImpl tends to be in the center
of very hot loops (like split()).
This commit is contained in:
Flaviu Tamas 2018-10-28 00:52:49 -04:00
commit 9ca1c2c930
1 changed files with 2 additions and 1 deletions
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lib/impure/nre.nim
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@ -469,7 +469,8 @@ proc matchImpl(str: string, pattern: Regex, start, endpos: int, flags: int): Opt
# 1x capture count as slack space for PCRE # 1x capture count as slack space for PCRE
let vecsize = (pattern.captureCount() + 1) * 3 let vecsize = (pattern.captureCount() + 1) * 3
# div 2 because each element is 2 cints long # div 2 because each element is 2 cints long
myResult.pcreMatchBounds = newSeq[HSlice[cint, cint]](ceil(vecsize / 2).int) # plus 1 because we need the ceiling, not the floor
myResult.pcreMatchBounds = newSeq[HSlice[cint, cint]]((vecsize div 2) + 1)
myResult.pcreMatchBounds.setLen(vecsize div 3) myResult.pcreMatchBounds.setLen(vecsize div 3)
let strlen = if endpos == int.high: str.len else: endpos+1 let strlen = if endpos == int.high: str.len else: endpos+1