This patch by Antoine Pitrou optimizes the bytecode for conditional branches by
merging the following "POP_TOP" instruction into the conditional jump. For
example, the list comprehension "[x for x in l if not x]" produced the
following bytecode:
1 0 BUILD_LIST 0
3 LOAD_FAST 0 (.0)
>> 6 FOR_ITER 23 (to 32)
9 STORE_FAST 1 (x)
12 LOAD_FAST 1 (x)
15 JUMP_IF_TRUE 10 (to 28)
18 POP_TOP
19 LOAD_FAST 1 (x)
22 LIST_APPEND 2
25 JUMP_ABSOLUTE 6
>> 28 POP_TOP
29 JUMP_ABSOLUTE 6
>> 32 RETURN_VALUE
but after the patch it produces the following bytecode:
1 0 BUILD_LIST 0
3 LOAD_FAST 0 (.0)
>> 6 FOR_ITER 18 (to 27)
9 STORE_FAST 1 (x)
12 LOAD_FAST 1 (x)
15 POP_JUMP_IF_TRUE 6
18 LOAD_FAST 1 (x)
21 LIST_APPEND 2
24 JUMP_ABSOLUTE 6
>> 27 RETURN_VALUE
Notice that not only the code is shorter, but the conditional jump
(POP_JUMP_IF_TRUE) jumps right to the start of the loop instead of going through
the JUMP_ABSOLUTE at the end. "continue" statements are helped
similarly.
Furthermore, the old jump opcodes (JUMP_IF_FALSE, JUMP_IF_TRUE) have been
replaced by two new opcodes:
- JUMP_IF_TRUE_OR_POP, which jumps if true and pops otherwise
- JUMP_IF_FALSE_OR_POP, which jumps if false and pops otherwise
svn+ssh://pythondev@svn.python.org/python/trunk
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r59544 | raymond.hettinger | 2007-12-18 01:13:45 +0100 (Tue, 18 Dec 2007) | 1 line
Add more namedtuple() test cases. Neaten the code and comments.
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r59545 | christian.heimes | 2007-12-18 04:38:03 +0100 (Tue, 18 Dec 2007) | 3 lines
Fixed for #1601: IDLE not working correctly on Windows (Py30a2/IDLE30a1)
Amaury's ideas works great. Should we build the Python core with WINVER=0x0500 and _WIN32_WINNT=0x0500, too?
........
r59546 | christian.heimes | 2007-12-18 10:00:13 +0100 (Tue, 18 Dec 2007) | 1 line
Make it a bit easier to test Tcl/Tk and idle from a build dir.
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r59547 | christian.heimes | 2007-12-18 10:12:10 +0100 (Tue, 18 Dec 2007) | 1 line
Removed several unused files from the PCbuild9 directory. They are relics from the past.
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r59548 | raymond.hettinger | 2007-12-18 19:26:18 +0100 (Tue, 18 Dec 2007) | 29 lines
Speed-up dictionary constructor by about 10%.
New opcode, STORE_MAP saves the compiler from awkward stack manipulations
and specializes for dicts using PyDict_SetItem instead of PyObject_SetItem.
Old disassembly:
0 BUILD_MAP 0
3 DUP_TOP
4 LOAD_CONST 1 (1)
7 ROT_TWO
8 LOAD_CONST 2 ('x')
11 STORE_SUBSCR
12 DUP_TOP
13 LOAD_CONST 3 (2)
16 ROT_TWO
17 LOAD_CONST 4 ('y')
20 STORE_SUBSCR
New disassembly:
0 BUILD_MAP 0
3 LOAD_CONST 1 (1)
6 LOAD_CONST 2 ('x')
9 STORE_MAP
10 LOAD_CONST 3 (2)
13 LOAD_CONST 4 ('y')
16 STORE_MAP
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r59549 | thomas.heller | 2007-12-18 20:00:34 +0100 (Tue, 18 Dec 2007) | 2 lines
Issue #1642: Fix segfault in ctypes when trying to delete attributes.
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r59551 | guido.van.rossum | 2007-12-18 21:10:42 +0100 (Tue, 18 Dec 2007) | 2 lines
Issue #1645 by Alberto Bertogli. Fix a comment.
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r59553 | raymond.hettinger | 2007-12-18 22:24:09 +0100 (Tue, 18 Dec 2007) | 12 lines
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.
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r59554 | christian.heimes | 2007-12-18 22:56:09 +0100 (Tue, 18 Dec 2007) | 1 line
Fixed#1649: IDLE error: dictionary changed size during iteration
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r59557 | raymond.hettinger | 2007-12-18 23:21:27 +0100 (Tue, 18 Dec 2007) | 1 line
Simplify and speedup _asdict() for named tuples.
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r59558 | christian.heimes | 2007-12-19 00:22:54 +0100 (Wed, 19 Dec 2007) | 3 lines
Applied patch #1635: Float patch for inf and nan on Windows (and other platforms).
The patch unifies float("inf") and repr(float("inf")) on all platforms.
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r59559 | raymond.hettinger | 2007-12-19 00:51:15 +0100 (Wed, 19 Dec 2007) | 1 line
Users demand iterable input for named tuples. The author capitulates.
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r59560 | raymond.hettinger | 2007-12-19 01:21:06 +0100 (Wed, 19 Dec 2007) | 1 line
Beef-up tests for dict literals
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r59561 | raymond.hettinger | 2007-12-19 01:27:21 +0100 (Wed, 19 Dec 2007) | 1 line
Zap a duplicate line
........
The compiler package hasn't been updated yet; test_compiler.py fails.
Otherwise all tests seem to be passing now. There are no occurrences
of __metaclass__ left in the standard library.
Docs have not been updated.
* Fix some docstrings and one Print -> print.
* Fix test_{class,code,descrtut,dis,extcall,parser,popen,pkg,subprocess,syntax,traceback}.
These were the ones that generated code with a print statement.
In most remaining failing tests there's an issue with the soft space.
This was started by Mike Bland and completed by Guido
(with help from Neal).
This still needs a __future__ statement added;
Thomas is working on Michael's patch for that aspect.
There's a small amount of code cleanup and refactoring
in ast.c, compile.c and ceval.c (I fixed the lltrace
behavior when EXT_POP is used -- however I had to make
lltrace a static global).
* Can now test for basic blocks.
* Optimize inverted comparisions.
* Optimize unary_not followed by a conditional jump.
* Added a new opcode, NOP, to keep code size constant.
* Applied NOP to previous transformations where appropriate.
Note, the NOP would not be necessary if other functions were
added to re-target jump addresses and update the co_lnotab mapping.
That would yield slightly faster and cleaner bytecode at the
expense of optimizer simplicity and of keeping it decoupled
from the line-numbering structure.
Jeffrey Yasskin
Antoine Pitrou
Georg Brandl
Benjamin Peterson
Thomas Wouters
Christian Heimes
Nick Coghlan
Guido van Rossum
Brett Cannon
Neal Norwitz
Raymond Hettinger
Walter Dörwald
Skip Montanaro