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.
#require test-repo
$ . "$TESTDIR/helpers-testrepo.sh"
$ cd "$TESTDIR"/..
$ hg files 'set:(**.py)' | sed 's|\\|/|g' | xargs python contrib/check-py3-compat.py
contrib/python-zstandard/setup.py not using absolute_import
contrib/python-zstandard/setup_zstd.py not using absolute_import
contrib/python-zstandard/tests/common.py not using absolute_import
contrib/python-zstandard/tests/test_cffi.py not using absolute_import
contrib/python-zstandard/tests/test_compressor.py not using absolute_import
contrib/python-zstandard/tests/test_data_structures.py not using absolute_import
contrib/python-zstandard/tests/test_decompressor.py not using absolute_import
contrib/python-zstandard/tests/test_estimate_sizes.py not using absolute_import
contrib/python-zstandard/tests/test_module_attributes.py not using absolute_import
contrib/python-zstandard/tests/test_roundtrip.py not using absolute_import
contrib/python-zstandard/tests/test_train_dictionary.py not using absolute_import
hgext/fsmonitor/pywatchman/__init__.py not using absolute_import
hgext/fsmonitor/pywatchman/__init__.py requires print_function
hgext/fsmonitor/pywatchman/capabilities.py not using absolute_import
hgext/fsmonitor/pywatchman/pybser.py not using absolute_import
i18n/check-translation.py not using absolute_import
setup.py not using absolute_import
tests/test-demandimport.py not using absolute_import
#if py3exe
$ hg files 'set:(**.py) - grep(pygments)' | sed 's|\\|/|g' \
> | xargs $PYTHON3 contrib/check-py3-compat.py \
> | sed 's/[0-9][0-9]*)$/*)/'
hgext/convert/transport.py: error importing: <ImportError> No module named 'svn.client' (error at transport.py:*)
hgext/fsmonitor/pywatchman/capabilities.py: error importing: <ImportError> No module named 'pybser' (error at __init__.py:*)
hgext/fsmonitor/pywatchman/pybser.py: error importing: <ImportError> No module named 'pybser' (error at __init__.py:*)
hgext/fsmonitor/watchmanclient.py: error importing: <ImportError> No module named 'pybser' (error at __init__.py:*)
hgext/mq.py: error importing: <TypeError> __import__() argument 1 must be str, not bytes (error at extensions.py:*)
mercurial/scmwindows.py: error importing: <ImportError> No module named 'msvcrt' (error at win32.py:*)
mercurial/statprof.py: error importing: <TypeError> __slots__ items must be strings, not 'bytes' (error at statprof.py:*)
mercurial/win32.py: error importing: <ImportError> No module named 'msvcrt' (error at win32.py:*)
mercurial/windows.py: error importing: <ImportError> No module named 'msvcrt' (error at windows.py:*)
#endif
#if py3exe py3pygments
$ hg files 'set:(**.py) and grep(pygments)' | sed 's|\\|/|g' \
> | xargs $PYTHON3 contrib/check-py3-compat.py \
> | sed 's/[0-9][0-9]*)$/*)/'
#endif