Optimize mod division for ints

[1st1]

BPO	26315
Nosy	@mdickinson, @vstinner, @serhiy-storchaka, @1st1
Files	mod_div.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/1st1'
closed_at = <Date 2016-02-11.15:27:35.633>
created_at = <Date 2016-02-08.22:31:15.807>
labels = ['interpreter-core', 'performance']
title = 'Optimize mod division for ints'
updated_at = <Date 2016-02-11.15:27:35.632>
user = 'https://github.com/1st1'

bugs.python.org fields:

activity = <Date 2016-02-11.15:27:35.632>
actor = 'yselivanov'
assignee = 'yselivanov'
closed = True
closed_date = <Date 2016-02-11.15:27:35.633>
closer = 'yselivanov'
components = ['Interpreter Core']
creation = <Date 2016-02-08.22:31:15.807>
creator = 'yselivanov'
dependencies = []
files = ['41861']
hgrepos = []
issue_num = 26315
keywords = ['patch']
message_count = 4.0
messages = ['259897', '259898', '260045', '260111']
nosy_count = 5.0
nosy_names = ['mark.dickinson', 'vstinner', 'python-dev', 'serhiy.storchaka', 'yselivanov']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue26315'
versions = ['Python 3.6']

[1st1]

The attached patch implements fast path for modulo division of single digit longs.

Some timeit micro-benchmarks:

-m timeit -s "x=22331" "x%2;x%3;x%4;x%5;x%6;x%7;x%8;x%99;x%100;"
with patch: 0.213 usec
without patch: 0.602 usec

[vstinner]

See also issue bpo-21955.

[vstinner]

Is this patch is a subset of issue bpo-26289 patch?

[python-dev]

New changeset 37bacf3fa1f5 by Yury Selivanov in branch 'default':
Issues bpo-26289 and bpo-26315: Optimize floor/modulo div for single-digit longs
https://hg.python.org/cpython/rev/37bacf3fa1f5