cpython/Modules/_decimal
Mark Shannon 7559f5fda9
GH-101291: Rearrange the size bits in PyLongObject (GH-102464)
* Eliminate all remaining uses of Py_SIZE and Py_SET_SIZE on PyLongObject, adding asserts.

* Change layout of size/sign bits in longobject to support future addition of immortal ints and tagged medium ints.

* Add functions to hide some internals of long object, and for setting sign and digit count.

* Replace uses of IS_MEDIUM_VALUE macro with _PyLong_IsCompact().
2023-03-22 14:49:51 +00:00
..
libmpdec gh-77532: Minor tweaks to allow compiling with PlatformToolset=ClangCL on Windows (GH-101352) 2023-01-27 14:45:08 +00:00
tests gh-92584: test_decimal uses shutil.which() (#92640) 2022-05-11 01:42:09 +02:00
_decimal.c GH-101291: Rearrange the size bits in PyLongObject (GH-102464) 2023-03-22 14:49:51 +00:00
docstrings.h gh-91291: Accept attributes as keyword arguments in decimal.localcontext (#32242) 2022-04-21 21:27:15 -07:00
README.txt Remove trailing whitespace. 2013-01-16 15:16:10 +01:00


About
=====

_decimal.c is a wrapper for the libmpdec library. libmpdec is a fast C
library for correctly-rounded arbitrary precision decimal floating point
arithmetic. It is a complete implementation of Mike Cowlishaw/IBM's
General Decimal Arithmetic Specification.


Build process for the module
============================

As usual, the build process for _decimal.so is driven by setup.py in the top
level directory. setup.py autodetects the following build configurations:

   1) x64         - 64-bit Python, x86_64 processor (AMD, Intel)

   2) uint128     - 64-bit Python, compiler provides __uint128_t (gcc)

   3) ansi64      - 64-bit Python, ANSI C

   4) ppro        - 32-bit Python, x86 CPU, PentiumPro or later

   5) ansi32      - 32-bit Python, ANSI C

   6) ansi-legacy - 32-bit Python, compiler without uint64_t

   7) universal   - Mac OS only (multi-arch)


It is possible to override autodetection by exporting:

   PYTHON_DECIMAL_WITH_MACHINE=value, where value is one of the above options.


NOTE
====

decimal.so is not built from a static libmpdec.a since doing so led to
failures on AIX (user report) and Windows (mixing static and dynamic CRTs
causes locale problems and more).