[ 1181301 ] make float packing copy bytes when they can
which hasn't been reviewed, despite numerous threats to check it in
anyway if noone reviews it. Please read the diff on the checkin list,
at least!
The basic idea is to examine the bytes of some 'probe values' to see if
the current platform is a IEEE 754-ish platform, and if so
_PyFloat_{Pack,Unpack}{4,8} just copy bytes around.
The rest is hair for testing, and tests.
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.
When an integer is compared to a float now, the int isn't coerced to float.
This avoids spurious overflow exceptions and insane results. This should
compute correct results, without raising spurious exceptions, in all cases
now -- although I expect that what happens when an int/long is compared to
a NaN is still a platform accident.
Note that we had potential problems here even with "short" ints, on boxes
where sizeof(long)==8. There's #ifdef'ed code here to handle that, but
I can't test it as intended. I tested it by changing the #ifdef to
trigger on my 32-bit box instead.
I suppose this is a bugfix candidate, but I won't backport it. It's
long-winded (for speed) and messy (because the problem is messy). Note
that this also depends on a previous 2.4 patch that introduced
_Py_SwappedOp[] as an extern.
recent gcc on Linux/x86)
[ 899109 ] 1==float('nan')
by implementing rich comparisons for floats.
Seems to make comparisons involving NaNs somewhat less surprising
when the underlying C compiler actually implements C99 semantics.
float_pow(): Don't let the platform pow() raise -1.0 to an integer power
anymore; at least glibc gets it wrong in some cases. Note that
math.pow() will continue to deliver wrong (but platform-native) results
in such cases.
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.
long but the double is too big to fit in a long. Prevent that. This
closes some recent bug or patch on SF, but SF is down now so I can't
say which.
Bugfix candidate.
comments everywhere that bugged me: /* Foo is inlined */ instead of
/* Inline Foo */. Somehow the "is inlined" phrase always confused me
for half a second (thinking, "No it isn't" until I added the missing
"here"). The new phrase is hopefully unambiguous.
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.
Another year in the quest to out-guess random C behavior.
Added macros Py_ADJUST_ERANGE1(X) and Py_ADJUST_ERANGE2(X, Y). The latter
is useful for functions with complex results. Two corrections to errno-
after-libm-call are attempted:
1. If the platform set errno to ERANGE due to underflow, clear errno.
Some unknown subset of libm versions and link options do this. It's
allowed by C89, but I never figured anyone would do it.
2. If the platform did not set errno but overflow occurred, force
errno to ERANGE. C89 required setting errno to ERANGE, but C99
doesn't. Some unknown subset of libm versions and link options do
it the C99 way now.
Bugfix candidate, but hold off until some Linux people actually try it,
with and without -lieee. I'll send a help plea to Python-Dev.
delivered bizarre results. Check float_divmod for a Py_NotImplemented
return and pass it along (instead of treating Py_NotImplemented as a
2-tuple).
CONVERT_TO_DOUBLE: Added comments; this macro is obscure.
pass the buffer length. Stop using it. It should be deprecated, but too
late in the release cycle to do that now.
New static format_float() does the same thing but requires passing the
buffer length too. Use it instead.
Try to ensure that divmod(-0.0, 1.0) -> (-0.0, +0.0) across platforms.
It always did on Windows, and still does. It didn't on Linux. Alas,
there's no platform-independent way to write a test case for this.
Bugfix candidate.
presence of NaNs. So pass the issue on to the platform libm fabs();
after all, fabs() is a std C function because you can't implement it
correctly in portable C89.
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.
requires that errno ever get set, and it looks like glibc is already
playing that game. New rules:
+ Never use HUGE_VAL. Use the new Py_HUGE_VAL instead.
+ Never believe errno. If overflow is the only thing you're interested in,
use the new Py_OVERFLOWED(x) macro. If you're interested in any libm
errors, use the new Py_SET_ERANGE_IF_OVERFLOW(x) macro, which attempts
to set errno the way C89 said it worked.
Unfortunately, none of these are reliable, but they work on Windows and I
*expect* under glibc too.
the fiddling is simply due to that no caller of PyLong_AsDouble ever
checked for failure (so that's fixing old bugs). PyLong_AsDouble is much
faster for big inputs now too, but that's more of a happy consequence
than a design goal.
PEP 238. Changes:
- add a new flag variable Py_DivisionWarningFlag, declared in
pydebug.h, defined in object.c, set in main.c, and used in
{int,long,float,complex}object.c. When this flag is set, the
classic division operator issues a DeprecationWarning message.
- add a new API PyRun_SimpleStringFlags() to match
PyRun_SimpleString(). The main() function calls this so that
commands run with -c can also benefit from -Dnew.
- While I was at it, I changed the usage message in main() somewhat:
alphabetized the options, split it in *four* parts to fit in under
512 bytes (not that I still believe this is necessary -- doc strings
elsewhere are much longer), and perhaps most visibly, don't display
the full list of options on each command line error. Instead, the
full list is only displayed when -h is used, and otherwise a brief
reminder of -h is displayed. When -h is used, write to stdout so
that you can do `python -h | more'.
Notes:
- I don't want to use the -W option to control whether the classic
division warning is issued or not, because the machinery to decide
whether to display the warning or not is very expensive (it involves
calling into the warnings.py module). You can use -Werror to turn
the warnings into exceptions though.
- The -Dnew option doesn't select future division for all of the
program -- only for the __main__ module. I don't know if I'll ever
change this -- it would require changes to the .pyc file magic
number to do it right, and a more global notion of compiler flags.
- You can usefully combine -Dwarn and -Dnew: this gives the __main__
module new division, and warns about classic division everywhere
else.
Michael W. Hudson
Brett Cannon
Tim Peters
Neal Norwitz
Martin v. Löwis
Skip Montanaro
Jack Jansen
Raymond Hettinger
Guido van Rossum
Walter Dörwald
Neil Schemenauer
Jeremy Hylton
Barry Warsaw