bdiff: don't check border condition in loop This is pretty much a copy of d500ddae7494, just to a different loop. The condition `p == plast` (`plast == a + len - 1`) was only true on the final iteration of the loop. So it was wasteful to check for it on every iteration. We decrease the iteration count by 1 and add an explicit check for `p == plast` after the loop. Again, we see modest wins. From the mozilla-unified repository: $ perfbdiff -m 3041e4d59df2 ! wall 0.035502 comb 0.040000 user 0.040000 sys 0.000000 (best of 100) ! wall 0.030480 comb 0.030000 user 0.030000 sys 0.000000 (best of 100) $ perfbdiff 0e9928989e9c --alldata --count 100 ! wall 4.097394 comb 4.100000 user 4.100000 sys 0.000000 (best of 3) ! wall 3.597798 comb 3.600000 user 3.600000 sys 0.000000 (best of 3) The 2nd example throws a total of ~3.3GB of data at bdiff. This change increases the throughput from ~811 MB/s to ~924 MB/s.

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#require symlink

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  $ origdir=`pwd`

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  $ hg init repo

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  $ cd repo

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  $ ln -s nothing dangling

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avoid tar warnings about old timestamp

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  $ hg ci -d '2000-01-01 00:00:00 +0000' -qAm 'add symlink'

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  $ hg archive -t files ../archive

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  $ hg archive -t tar -p tar ../archive.tar

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  $ hg archive -t zip -p zip ../archive.zip

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files

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  $ cd "$origdir"

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  $ cd archive

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  $ readlink.py dangling

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  dangling -> nothing

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tar

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  $ cd "$origdir"

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  $ tar xf archive.tar

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  $ cd tar

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  $ readlink.py dangling

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  dangling -> nothing

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#if unziplinks

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zip

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  $ cd "$origdir"

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  $ unzip archive.zip > /dev/null 2>&1

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  $ cd zip

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  $ readlink.py dangling

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  dangling -> nothing

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#endif

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  $ cd ..