diff options
| author | Raymond Hettinger <python@rcn.com> | 2007-12-18 21:24:09 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2007-12-18 21:24:09 (GMT) |
| commit | fd7ed407d79b797e20d0a6fe69e18f9ba9354979 (patch) | |
| tree | 3dc9abccf69e49db5c98aa0805dcbaab50fc90c3 /Misc | |
| parent | 3c887b2802e1b44b7e33cd14329541d0d22769d7 (diff) | |
| download | cpython-fd7ed407d79b797e20d0a6fe69e18f9ba9354979.zip cpython-fd7ed407d79b797e20d0a6fe69e18f9ba9354979.tar.gz cpython-fd7ed407d79b797e20d0a6fe69e18f9ba9354979.tar.bz2 | |
Give meaning to the oparg for BUILD_MAP: estimated size of the dictionary.
Allows dictionaries to be pre-sized (upto 255 elements) saving time lost
to re-sizes with their attendant mallocs and re-insertions.
Has zero effect on small dictionaries (5 elements or fewer), a slight
benefit for dicts upto 22 elements (because they had to resize once
anyway), and more benefit for dicts upto 255 elements (saving multiple
resizes during the build-up and reducing the number of collisions on
the first insertions). Beyond 255 elements, there is no addional benefit.
Diffstat (limited to 'Misc')
| -rw-r--r-- | Misc/NEWS | 4 |
1 files changed, 4 insertions, 0 deletions
@@ -12,6 +12,10 @@ What's New in Python 2.6 alpha 1? Core and builtins ----------------- +- Compiler now generates simpler and faster code for dictionary literals. + The oparg for BUILD_MAP now indicates an estimated dictionary size. + There is a new opcode, STORE_MAP, for adding entries to the dictionary. + - Issue #1638: %zd configure test fails on Linux - Issue #1620: New property decorator syntax was modifying the decorator |