_PyLong_Format. In longobject.c, changed long_format to
_PyLong_Format. In intobject.c, changed uses of PyOS_snprintf to
_PyInt_Format instead.
_PyLong_Format is similar to py3k's routine of the same name, except
it has 2 additional parameters: addL and newstyle. addL was existing
in long_format, and controls adding the trailing "L". This is
unneeded in py3k. newstyle is used to control whether octal prepends
"0" (the pre-2.6 style), or "0o" (the 3.0 sytle).
PyNumber_ToBase is needed for PEP 3127 (Integer Literal Support and
Syntax) and PEP 3101 (Advanced String Formatting).
This changeset does not need merging into py3k.
First chapter of the Python 3.0 io framework back port: _fileio
The next step depends on a working bytearray type which itself depends on a backport of the nwe buffer API.
round included:
* Revert round to its 2.6 behavior (half away from 0).
* Because round, floor, and ceil always return float again, it's no
longer necessary to have them delegate to __xxx___, so I've ripped
that out of their implementations and the Real ABC. This also helps
in implementing types that work in both 2.6 and 3.0: you return int
from the __xxx__ methods, and let it get enabled by the version
upgrade.
* Make pow(-1, .5) raise a ValueError again.
the complex_pow part), r56649, r56652, r56715, r57296, r57302, r57359, r57361,
r57372, r57738, r57739, r58017, r58039, r58040, and r59390, and new
documentation. The only significant difference is that round(x) returns a float
to preserve backward-compatibility. See http://bugs.python.org/issue1689.
predictable to being completely predictable. The value of hash(n)
is unchanged for any n that's small enough to be representable as an
int, and also unchanged for the vast majority of long integers n of
reasonable size.
- Reenable modules on x64 that had been disabled aeons ago for Itanium.
- Cleared up confusion about compilers for 64 bit windows. There is only Itanium and x64. Added macros MS_WINI64 and MS_WINX64 for those rare cases where it matters, such as the disabling of modules above.
- Set target platform (_WIN32_WINNT and WINVER) to 0x0501 (XP) for x64, and 0x0400 (NT 4.0) otherwise, which are the targeted minimum platforms.
- Fixed thread_nt.h. The emulated InterlockedCompareExchange function didn´t work on x64, probaby due to the lack of a "volatile" specifier. Anyway, win95 is no longer a target platform.
- Itertools module used wrong constant to check for overflow in count()
- PyInt_AsSsize_t couldn't deal with attribute error when accessing the __long__ member.
- PyLong_FromSsize_t() incorrectly specified that the operand were unsigned.
With these changes, the x64 passes the testsuite, for those modules present.
of some of the common builtin types.
Use a bit in tp_flags for each common builtin type. Check the bit
to determine if any instance is a subclass of these common types.
The check avoids a function call and O(n) search of the base classes.
The check is done in the various Py*_Check macros rather than calling
PyType_IsSubtype().
All the bits are set in tp_flags when the type is declared
in the Objects/*object.c files because PyType_Ready() is not called
for all the types. Should PyType_Ready() be called for all types?
If so and the change is made, the changes to the Objects/*object.c files
can be reverted (remove setting the tp_flags). Objects/typeobject.c
would also have to be modified to add conditions
for Py*_CheckExact() in addition to each the PyType_IsSubtype check.
* unified the way intobject, longobject and mystrtoul handle
values around -sys.maxint-1.
* in general, trying to entierely avoid overflows in any computation
involving signed ints or longs is extremely involved. Fixed a few
simple cases where a compiler might be too clever (but that's all
guesswork).
* more overflow checks against bad data in marshal.c.
* 2.5 specific: fixed a number of places that were still confusing int
and Py_ssize_t. Some of them could potentially have caused
"real-world" breakage.
* list.pop(x): fixing overflow issues on x was messy. I just reverted
to PyArg_ParseTuple("n"), which does the right thing. (An obscure
test was trying to give a Decimal to list.pop()... doesn't make
sense any more IMHO)
* trying to write a few tests...
I modified this patch some by fixing style, some error checking, and adding
XXX comments. This patch requires review and some changes are to be expected.
I'm checking in now to get the greatest possible review and establish a
baseline for moving forward. I don't want this to hold up release if possible.
a new comment) suggests there are almost certainly large input
integers in all non-binary input bases for which one Python digit
too few is initally allocated to hold the final result. Instead
of assert-failing when that happens, allocate more space. Alas,
I estimate it would take a few days to find a specific such case,
so this isn't backed up by a new test (not to mention that such
a case may take hours to run, since conversion time is quadratic
in the number of digits, and preliminary attempts suggested that
the smallest such inputs contain at least a million digits).
The SIGCHECK macro defined here has always been bizarre, but
it apparently causes compiler warnings on "Sun Studio 11".
I believe the warnings are bogus, but it doesn't hurt to make
the macro definition saner.
Bugfix candidate (but I'm not going to bother).
both mystrtoul.c and longobject.c. Share the table instead. Also
cut its size by 64 entries (they had been used for an inscrutable
trick originally, but the code no longer tries to use that trick).
longobject.c: also fix an ssize_t problem
<a> could have been NULL, so hoist the size calc to not use <a>.
_ssl.c: under fail: self is DECREF'd, but it would have been NULL.
_elementtree.c: delete self if there was an error.
_csv.c: I'm not sure if lineterminator could have been anything other than
a string. However, other string method calls are checked, so check this
one too.
to avoid confusing situations like:
>>> int("")
ValueError: invalid literal for int():
>>> int("2\n\n2")
ValueError: invalid literal for int(): 2
2
Also report the base used, to avoid:
ValueError: invalid literal for int(): 2
They now report:
>>> int("")
ValueError: invalid literal for int() with base 10: ''
>>> int("2\n\n2")
ValueError: invalid literal for int() with base 10: '2\n\n2'
>>> int("2", 2)
ValueError: invalid literal for int() with base 2: '2'
(Reporting the base could be avoided when base is 10, which is the default,
but hrm.) Another effect of these changes is that the errormessage can be
longer; before, it was cut off at about 250 characters. Now, it can be up to
four times as long, as the unrepr'ed string is cut off at 200 characters,
instead.
No tests were added or changed, since testing for exact errormsgs is (pardon
the pun) somewhat errorprone, and I consider not testing the exact text
preferable. The actually changed code is tested frequent enough in the
test_builtin test as it is (120 runs for each of ints and longs.)
PyTypeObject structures, I had to make prototypes for the functions, and
move the structure definition ahead of the functions. I'd dearly like a better
way to do this - to change this would make for a massive set of changes to
the codebase.
There's still some warnings - this is purely to get rid of errors first.
to protect against actual uninitialized usage.
Objects/longobject.c: In function ‘PyLong_AsDouble’:
Objects/longobject.c:655: warning: ‘e’ may be used uninitialized in this function
Objects/longobject.c: In function ‘long_true_divide’:
Objects/longobject.c:2263: warning: ‘aexp’ may be used uninitialized in this function
Objects/longobject.c:2263: warning: ‘bexp’ may be used uninitialized in this function
In C++, it's an error to pass a string literal to a char* function
without a const_cast(). Rather than require every C++ extension
module to put a cast around string literals, fix the API to state the
const-ness.
I focused on parts of the API where people usually pass literals:
PyArg_ParseTuple() and friends, Py_BuildValue(), PyMethodDef, the type
slots, etc. Predictably, there were a large set of functions that
needed to be fixed as a result of these changes. The most pervasive
change was to make the keyword args list passed to
PyArg_ParseTupleAndKewords() to be a const char *kwlist[].
One cast was required as a result of the changes: A type object
mallocs the memory for its tp_doc slot and later frees it.
PyTypeObject says that tp_doc is const char *; but if the type was
created by type_new(), we know it is safe to cast to char *.
In addition, long_pow() skipped a necessary (albeit extremely unlikely
to trigger) error check when converting an int modulus to long.
Alas, I was unable to write a test case that crashed due to either
cause.
Bugfix candidate.
conversion using the proper magic slot (e.g., __int__()). Also move conversion
code out of PyNumber_*() functions in the C API into the nb_* function.
Applied patch #1109424. Thanks Walter Doewald.
This checkin is adapted from part 2 (of 3) of Trevor Perrin's patch set.
BACKWARD INCOMPATIBILITY: SHIFT must now be divisible by 5. AFAIK,
nobody will care. long_pow() could be complicated to worm around that,
if necessary.
long_pow():
- BUGFIX: This leaked the base and power when the power was negative
(and so the computation delegated to float pow).
- Instead of doing right-to-left exponentiation, do left-to-right. This
is more efficient for small bases, which is the common case.
- In addition, if the exponent is large (more than FIVEARY_CUTOFF
digits), precompute [a**i % c for i in range(32)], and go left to
right 5 bits at a time.
l_divmod():
- The signature changed so that callers who don't want the quotient,
or don't want the remainder, can pass NULL in the slot they don't
want. This saves them from having to declare a vrbl for unwanted
stuff, and remembering to decref it.
long_mod(), long_div(), long_classic_div():
- Adjust to new l_divmod() signature, and simplified as a result.
This checkin is adapted from part 1 (of 3) of Trevor Perrin's patch set.
x_mul()
- sped a little by optimizing the C
- sped a lot (~2X) if it's doing a square; note that long_pow() squares
often
k_mul()
- more cache-friendly now if it's doing a square
KARATSUBA_CUTOFF
- boosted; gradeschool mult is quicker now, and it may have been too low
for many platforms anyway
KARATSUBA_SQUARE_CUTOFF
- new
- since x_mul is a lot faster at squaring now, the point at which
Karatsuba pays for squaring is much higher than for general mult
Some version of gcc in the "RTEMS port running on the Coldfire (m5200)
processor" generates bad code for a loop in long_from_binary_base(),
comparing the wrong half of an int to a short. The patch changes the
decl of the short temp to be an int temp instead. This "simplifies"
the code enough that gcc no longer blows it.
New functions:
unsigned long PyInt_AsUnsignedLongMask(PyObject *);
unsigned PY_LONG_LONG) PyInt_AsUnsignedLongLongMask(PyObject *);
unsigned long PyLong_AsUnsignedLongMask(PyObject *);
unsigned PY_LONG_LONG) PyLong_AsUnsignedLongLongMask(PyObject *);
New and changed format codes:
b unsigned char 0..UCHAR_MAX
B unsigned char none **
h unsigned short 0..USHRT_MAX
H unsigned short none **
i int INT_MIN..INT_MAX
I * unsigned int 0..UINT_MAX
l long LONG_MIN..LONG_MAX
k * unsigned long none
L long long LLONG_MIN..LLONG_MAX
K * unsigned long long none
Notes:
* New format codes.
** Changed from previous "range-and-a-half" to "none"; the
range-and-a-half checking wasn't particularly useful.
New test test_getargs2.py, to verify all this.
wasn't used outside the assert (and hence caused a compiler warning
about an unused variable in NDEBUG mode). The assert wasn't very
useful any more.
_PyLong_NumBits(): moved the calculation of ndigits after asserting
that v != NULL.
Assorted code cleanups; e.g., sizeof(char) is 1 by definition, so there's
no need to do things like multiply by sizeof(char) in hairy malloc
arguments. Fixed an undetected-overflow bug in readline_file().
longobject.c: Fixed a really stupid bug in the new _PyLong_NumBits.
pickle.py: Fixed stupid bug in save_long(): When proto is 2, it
wrote LONG1 or LONG4, but forgot to return then -- it went on to
append the proto 1 LONG opcode too.
Fixed equally stupid cancelling bugs in load_long1() and
load_long4(): they *returned* the unpickled long instead of pushing
it on the stack. The return values were ignored. Tests passed
before only because save_long() pickled the long twice.
Fixed bugs in encode_long().
Noted that decode_long() is quadratic-time despite our hopes,
because long(string, 16) is still quadratic-time in len(string).
It's hex() that's linear-time. I don't know a way to make decode_long()
linear-time in Python, short of maybe transforming the 256's-complement
bytes into marshal's funky internal format, and letting marshal decode
that. It would be more valuable to make long(string, 16) linear time.
pickletester.py: Added a global "protocols" vector so tests can try
all the protocols in a sane way. Changed test_ints() and test_unicode()
to do so. Added a new test_long(), but the tail end of it is disabled
because it "takes forever" under pickle.py (but runs very quickly under
cPickle: cPickle proto 2 for longs is linear-time).
needs of pickling longs. Backed off to a definition that's much easier
to understand. The pickler will have to work a little harder, but other
uses are more likely to be correct <0.5 wink>.
_PyLong_Sign(): New teensy function to characterize a long, as to <0, ==0,
or >0.
types. The special handling for these can now be removed from save_newobj().
Add some testing for this.
Also add support for setting the 'fast' flag on the Python Pickler class,
which suppresses use of the memo.
start for the C implemention of new pickle LONG1 and LONG4 opcodes (the
linear-time way to pickle a long is to call _PyLong_AsByteArray, but
the caller has no idea how big an array to allocate, and correct
calculation is a bit subtle).
globals, _Py_Ticker and _Py_CheckInterval. This also implements Jeremy's
shortcut in Py_AddPendingCall that zeroes out _Py_Ticker. This allows the
test in the main loop to only test a single value.
The gory details are at
http://python.org/sf/602191
SHIFT and MASK, and widen digit. One problem is that code of the form
digit << small_integer
implicitly assumes that the result fits in an int or unsigned int
(platform-dependent, but "int sized" in any case), since digit is
promoted "just" to int or unsigned via the usual integer promotions.
But if digit is typedef'ed as unsigned int, this loses information.
The cure for this is just to cast digit to twodigits first.
rigorous instead of hoping for testing not to turn up counterexamples.
Call me heretical, but despite that I'm wholly confident in the proof,
and have done it two different ways now, I still put more faith in
testing ...
ah*bh and al*bl. This is much easier than explaining why that's true
for (ah+al)*(bh+bl), and follows directly from the simple part of the
(ah+al)*(bh+bl) explanation.
space is no longer needed, so removed the code. It was only possible when
a degenerate (ah->ob_size == 0) split happened, but after that fix went
in I added k_lopsided_mul(), which saves the body of k_mul() from seeing
a degenerate split. So this removes code, and adds a honking long comment
block explaining why spilling out of bounds isn't possible anymore. Note:
ff we end up spilling out of bounds anyway <wink>, an assert in v_iadd()
is certain to trigger.
k_mul() when inputs have vastly different sizes, and a little more
efficient when they're close to a factor of 2 out of whack.
I consider this done now, although I'll set up some more correctness
tests to run overnight.
cases, overflow the allocated result object by 1 bit. In such cases,
it would have been brought back into range if we subtracted al*bl and
ah*bh from it first, but I don't want to do that because it hurts cache
behavior. Instead we just ignore the excess bit when it appears -- in
effect, this is forcing unsigned mod BASE**(asize + bsize) arithmetic
in a case where that doesn't happen all by itself.
algorithm. MSVC 6 wasn't impressed <wink>.
Something odd: the x_mul algorithm appears to get substantially worse
than quadratic time as the inputs grow larger:
bits in each input x_mul time k_mul time
------------------ ---------- ----------
15360 0.01 0.00
30720 0.04 0.01
61440 0.16 0.04
122880 0.64 0.14
245760 2.56 0.40
491520 10.76 1.23
983040 71.28 3.69
1966080 459.31 11.07
That is, x_mul is perfectly quadratic-time until a little burp at
2.56->10.76, and after that goes to hell in a hurry. Under Karatsuba,
doubling the input size "should take" 3 times longer instead of 4, and
that remains the case throughout this range. I conclude that my "be nice
to the cache" reworkings of k_mul() are paying.
correct now, so added some final comments, did some cleanup, and enabled
it for all long-int multiplies. The KARAT envar no longer matters,
although I left some #if 0'ed code in there for my own use (temporary).
k_mul() is still much slower than x_mul() if the inputs have very
differenent sizes, and that still needs to be addressed.
(it's possible, but should be harmless -- this requires more thought,
and allocating enough space in advance to prevent it requires exactly
as much thought, to know exactly how much that is -- the end result
certainly fits in the allocated space -- hmm, but that's really all
the thought it needs! borrows/carries out of the high digits really
are harmless).
k_mul(): This didn't allocate enough result space when one input had
more than twice as many bits as the other. This was partly hidden by
that x_mul() didn't normalize its result.
The Karatsuba recurrence is pretty much hosed if the inputs aren't
roughly the same size. If one has at least twice as many bits as the
other, we get a degenerate case where the "high half" of the smaller
input is 0. Added a special case for that, for speed, but despite that
it helped, this can still be much slower than the "grade school" method.
It seems to take a really wild imbalance to trigger that; e.g., a
2**22-bit input times a 1000-bit input on my box runs about twice as slow
under k_mul than under x_mul. This still needs to be addressed.
I'm also not sure that allocating a->ob_size + b->ob_size digits is
enough, given that this is computing k = (ah+al)*(bh+bl) instead of
k = (ah-al)*(bl-bh); i.e., it's certainly enough for the final result,
but it's vaguely possible that adding in the "artificially" large k may
overflow that temporarily. If so, an assert will trigger in the debug
build, but we'll probably compute the right result anyway(!).
addition and subtraction. Reworked the tail end of k_mul() to use them.
This saves oodles of one-shot longobject allocations (this is a triply-
recursive routine, so saving one allocation in the body saves 3**n
allocations at depth n; we actually save 2 allocations in the body).
SF 560379: Karatsuba multiplication.
Lots of things were changed from that. This needs a lot more testing,
for correctness and speed, the latter especially when bit lengths are
unbalanced. For now, the Karatsuba code gets invoked if and only if
envar KARAT exists.
The staticforward define was needed to support certain broken C
compilers (notably SCO ODT 3.0, perhaps early AIX as well) botched the
static keyword when it was used with a forward declaration of a static
initialized structure. Standard C allows the forward declaration with
static, and we've decided to stop catering to broken C compilers. (In
fact, we expect that the compilers are all fixed eight years later.)
I'm leaving staticforward and statichere defined in object.h as
static. This is only for backwards compatibility with C extensions
that might still use it.
XXX I haven't updated the documentation.
many types were subclassable but had a xxx_dealloc function that
called PyObject_DEL(self) directly instead of deferring to
self->ob_type->tp_free(self). It is permissible to set tp_free in the
type object directly to _PyObject_Del, for non-GC types, or to
_PyObject_GC_Del, for GC types. Still, PyObject_DEL was a tad faster,
so I'm fearing that our pystone rating is going down again. I'm not
sure if doing something like
void xxx_dealloc(PyObject *self)
{
if (PyXxxCheckExact(self))
PyObject_DEL(self);
else
self->ob_type->tp_free(self);
}
is any faster than always calling the else branch, so I haven't
attempted that -- however those types whose own dealloc is fancier
(int, float, unicode) do use this pattern.
Generalize PyLong_AsLongLong to accept int arguments too. The real point
is so that PyArg_ParseTuple's 'L' code does too. That code was
undocumented (AFAICT), so documented it.
Both int and long multiplication are changed to be more careful in
their assumptions about when one of the arguments is a sequence: the
assumption that at least one of the arguments must be an int (or long,
respectively) is still held, but the assumption that these don't smell
like sequences is no longer true: a subtype of int or long may well
have a sequence-repeat thingie!
Eric Smith
Christian Heimes
Jeffrey Yasskin
Facundo Batista
Martin v. Löwis
Kristján Valur Jónsson
Georg Brandl
Neal Norwitz
Armin Rigo
Tim Peters
Bob Ippolito
Skip Montanaro
Thomas Wouters
Anthony Baxter
Guido van Rossum
Hye-Shik Chang
Jeremy Hylton
Raymond Hettinger
Brett Cannon
Thomas Heller
Neil Schemenauer
Walter Dörwald