[pypy-svn] r17603 - pypy/dist/pypy/rpython

[arigo at codespeak.net]

Author: arigo
Date: Fri Sep 16 21:15:25 2005
New Revision: 17603

Modified:
   pypy/dist/pypy/rpython/rlist.py
Log:
This may be a good speed-up (untested): don't reallocate small lists too often
when items are removed.  This formula should make sure that e.g. popping from
2 to 1 doesn't reallocate from 4 to 4 (!).  It might have the side effect that
small lists with elements removed consume a tiny bit more memory, but well.


Modified: pypy/dist/pypy/rpython/rlist.py
==============================================================================
--- pypy/dist/pypy/rpython/rlist.py	(original)
+++ pypy/dist/pypy/rpython/rlist.py	Fri Sep 16 21:15:25 2005
@@ -341,7 +341,7 @@
     # Bypass realloc() when a previous overallocation is large enough
     # to accommodate the newsize.  If the newsize falls lower than half
     # the allocated size, then proceed with the realloc() to shrink the list.
-    if allocated >= newsize and newsize >= (allocated >> 1):
+    if allocated >= newsize and newsize >= ((allocated >> 1) - 5):
         # assert l.ob_item != NULL or newsize == 0
         l.length = newsize
         return