STINNER Victor added the comment: FYI.
> Peephole optimizer of Python 2.7 (...) only optimizes 2**100, but not > 2**(2**100). This optimizer is dummy, it's only able to replace "LOAD_CONST x; LOAD_CONST y; OPERATION" with the result, whereas the optimizer replaces the bytecode with "NOP; NOP; NOP; NOP; LOAD_CONST z". So "LOAD_CONST x; LOAD_CONST y; LOAD_CONST z; OPERATION1; OPERATION2" cannot be optimized. But it's enough to optimize 1+2+3 or 1*2*3 for example. Python 3 peephole optimize does better thanks to a better design: --- changeset: 68375:14205d0fee45 user: Antoine Pitrou <solip...@pitrou.net> date: Fri Mar 11 17:27:02 2011 +0100 files: Lib/test/test_peepholer.py Misc/NEWS Python/peephole.c description: Issue #11244: The peephole optimizer is now able to constant-fold arbitrarily complex expressions. This also fixes a 3.2 regression where operations involving negative numbers were not constant-folded. --- It uses a stack for constants, so it's able to optimize more cases. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue25828> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
