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Swiping PADTMPs
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From:
Father Chrysostomos
Date:
November 21, 2013 00:28
Subject:
Swiping PADTMPs
Message ID:
20131121002813.7978.qmail@lists-nntp.develooper.com
Simplistic benchmarks show that swipe (stealing a string buffer from
one SV and giving it to another, instead of copying the string) is
faster than copy-on-write (sharing the buffer). That makes sense,
because copy-on-write has a later overhead.
I have tried to speed things up by allowing strings belonging to
PADTMPs (operator targets; used by ops to return values without real-
locating a new SV ieach time) to be swiped.
However, it seems to slow things down, based on a simple
mktables test.
At sprout/theft^^:
$ time ./miniperl -Ilib lib/unicore/mktables -C lib/unicore -P pod -maketest -makelist -p -w
real0m26.063s
user0m25.404s
sys0m0.438s
At the tip of sprout/theft:
real0m26.063s0m27.534s
user0m25.404s0m26.536s
sys0m0.438s0m0.452s
And I get consistent results. That means it is 3-4% slower. Yet I
cannot understand why.
Could this be noise? Could someone who actually knows something about
benchmarks have a try? :-)
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Swiping PADTMPs
by Father Chrysostomos