Tim Peters wrote: > pymalloc ensures 8-byte alignment. This is one plausible reason to > keep the current int free list: an int object struct holds 3 4-byte > members on most boxes (type pointer, refcount, and the int's value), > and the int freelist code uses exactly 12 bytes for each on most > boxes. To keep 8-byte alignment, pymalloc would have to hand out a > 16-byte chunk per int object, wasting a fourth of the space (pymalloc > always rounds up a requested size to a multiple of 8, and ensures the > address returned is 8-byte aligned).
Given the background information Python's long implementation could probably optimized. In 3.0 a long has 3 4-byte members (ref count, ob_size and *ob_type) plus one to many unsigned shorts (2 bytes each) to hold the value. If pymalloc aligns the objects at 8 byte address boundaries wouldn't it be better and slightly faster to use unsigned ints instead of unsigned shorts? Christian _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
