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Created on 2006-06-01 20:03 by collinwinter, last changed 2022-04-11 14:56 by admin. This issue is now closed.
| Files | ||||
|---|---|---|---|---|
| File name | Uploaded | Description | Edit | |
| optimise_in_const_ops.patch | collinwinter, 2006-06-01 20:03 | Optimise "in" ops on constant tuples, against r46597 | ||
| Messages (2) | |||
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| msg50407 - (view) | Author: Collin Winter (collinwinter) *  |
Date: 2006-06-01 20:03 | |
The following patch adds a peephole optimisation to the compiler that optimises expressions like x in (5, 6, 7) to x in frozenset([5, 6, 7]) That is, any "in" operation on tuples of constants will be optimised to "in" operations on frozensets. Note that the patch does not handle lists, as "in [constant list]" is already optimised to "in (constant tuple)". Additional tests for Lib/test/test_peepholer.py are included. This patch is against r46597. Some benchmarks (all times in usecs per loop): ./python -mtimeit '5 in (5, 6, 7, 8, 9)' Unoptimised: 0.376 Optimised: 0.437 ./python -mtimeit '9 in (5, 6, 7, 8, 9)' Unoptimised: 1.14 Optimised: 0.436 ./python -mtimeit '89 in (5, 6, 7, 8, 9)' Unoptimised: 1.32 Optimised: 0.498 |
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| msg50408 - (view) | Author: Raymond Hettinger (rhettinger) * |
Date: 2006-06-03 08:22 | |
Logged In: YES
user_id=80475
Sorry, this enticing idea has already been explored and
rejected. This is issue is that the transformation is not
semanatically neutral. Currently, writing "{} in (1,2,3)"
returns False, but after the transformation would raise an
exception, "TypeError: dict objects are unhashable".
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:56:17 | admin | set | github: 43447 |
| 2006-06-01 20:03:07 | collinwinter | create | |