Fix an off by one error in the peephole optimizer when checking for unreachable code beyond a return.
Do a bounds check within find_op so it can return before going past the end as a safety measure.
7db3c48833 (diff-a33329ae6ae0bb295d742f0caf93c137)
introduced this off by one error while fixing another one nearby.
This bug was shipped in all Python 3.6 and 3.7 releases.
The included unittest won't fail unless you do a clang msan build.
Constant folding was moved to AST optimizer.
But compiler may emit LOAD_CONSTs + BUILD_TUPLE.
For example, default arguments can be constant tuple
if all arguments are constant.
This commit makes peephole's tuple folding simple.
It doesn't support nested tuples because nested
tuples are folded by AST optimizer already.
Conversions like `not a is b -> a is not b` are implemented
in AST optimizer in previous commit (7ea143a).
So this commit removes them from peephole optimizer.
Issue #26107: The format of the co_lnotab attribute of code objects changes to
support negative line number delta.
Changes:
* assemble_lnotab(): if line number delta is less than -128 or greater than
127, emit multiple (offset_delta, lineno_delta) in co_lnotab
* update functions decoding co_lnotab to use signed 8-bit integers
- dis.findlinestarts()
- PyCode_Addr2Line()
- _PyCode_CheckLineNumber()
- frame_setlineno()
* update lnotab_notes.txt
* increase importlib MAGIC_NUMBER to 3361
* document the change in What's New in Python 3.6
* cleanup also PyCode_Optimize() to use better variable names
where the right hand operand is a set of constants, by turning the set into
a frozenset and pre-building it as a constant. The comparison operation
is made against the constant instead of building a new set each time it is
executed (a similar optimization already existed which turned a list of
constants into a pre-built tuple). Patch and additional tests by Dave
Malcolm.
svn+ssh://pythondev@svn.python.org/python/trunk
........
r72912 | benjamin.peterson | 2009-05-25 08:13:44 -0500 (Mon, 25 May 2009) | 5 lines
add a SETUP_WITH opcode
It speeds up the with statement and correctly looks up the special
methods involved.
........
r72920 | benjamin.peterson | 2009-05-25 15:12:57 -0500 (Mon, 25 May 2009) | 1 line
take into account the fact that SETUP_WITH pushes a finally block
........
r72940 | benjamin.peterson | 2009-05-26 07:49:59 -0500 (Tue, 26 May 2009) | 1 line
teach the peepholer about SETUP_WITH
........
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
PyUnicode_AsStringAndSize -> _PyUnicode_AsStringAndSize to mark
them for interpreter internal use only.
We'll have to rework these APIs or create new ones for the
purpose of accessing the UTF-8 representation of Unicode objects
for 3.1.
svn+ssh://pythondev@svn.python.org/python/trunk
........
r61834 | raymond.hettinger | 2008-03-24 07:07:49 +0100 (Mon, 24 Mar 2008) | 1 line
Tighten documentation for Random.triangular.
........
r61841 | raymond.hettinger | 2008-03-24 09:17:39 +0100 (Mon, 24 Mar 2008) | 1 line
Issue 2460: Make Ellipsis objects copyable.
........
r61842 | georg.brandl | 2008-03-24 10:34:34 +0100 (Mon, 24 Mar 2008) | 2 lines
#1700821: add a note to audioop docs about signedness of sample formats.
........
r61851 | christian.heimes | 2008-03-24 20:57:42 +0100 (Mon, 24 Mar 2008) | 1 line
Added quick hack for bzr
........
r61852 | christian.heimes | 2008-03-24 20:58:17 +0100 (Mon, 24 Mar 2008) | 1 line
Added quick hack for bzr
........
r61853 | amaury.forgeotdarc | 2008-03-24 22:04:10 +0100 (Mon, 24 Mar 2008) | 4 lines
Issue2469: Correct a typo I introduced at r61793: compilation error with UCS4 builds.
All buildbots compile with UCS2...
........
r61863 | neal.norwitz | 2008-03-25 05:17:38 +0100 (Tue, 25 Mar 2008) | 2 lines
Fix a bunch of UnboundLocalErrors when the tests fail.
........
r61864 | neal.norwitz | 2008-03-25 05:18:18 +0100 (Tue, 25 Mar 2008) | 2 lines
Try to fix a bunch of compiler warnings on Win64.
........
r61869 | neal.norwitz | 2008-03-25 07:35:10 +0100 (Tue, 25 Mar 2008) | 3 lines
Don't try to close a non-open file.
Don't let file removal cause the test to fail.
........
r61870 | neal.norwitz | 2008-03-25 08:00:39 +0100 (Tue, 25 Mar 2008) | 7 lines
Try to get this test to be more stable:
* disable gc during the test run because we are spawning objects and there
was an exception when calling Popen.__del__
* Always set an alarm handler so the process doesn't exit if the test fails
(should probably add assertions on the value of hndl_called in more places)
* Using a negative time causes Linux to treat it as zero, so disable that test.
........
r61874 | gregory.p.smith | 2008-03-25 08:31:28 +0100 (Tue, 25 Mar 2008) | 2 lines
Use a 32-bit unsigned int here, a long is not needed.
........
r61889 | georg.brandl | 2008-03-25 12:59:51 +0100 (Tue, 25 Mar 2008) | 2 lines
Move declarations to block start.
........
Victor Stinner
Gregory P. Smith
Serhiy Storchaka
INADA Naoki
Raymond Hettinger
Martin Panter
Victor Stinner
Yury Selivanov
Benjamin Peterson
Martin v. Löwis
Stefan Krah
Ezio Melotti
Mark Dickinson
Antoine Pitrou
Georg Brandl
Alexandre Vassalotti
Jeffrey Yasskin
Marc-André Lemburg
Christian Heimes
Amaury Forgeot d'Arc