Commit Graph

4 Commits

Author SHA1 Message Date
Victor Stinner b3b98082c5
bpo-41617: Add _Py__has_builtin() macro (GH-23260)
Fix building pycore_bitutils.h internal header on old clang version
without __builtin_bswap16() (ex: Xcode 4.6.3 on Mac OS X 10.7).

Add a new private _Py__has_builtin() macro to check for availability
of a preprocessor builtin function.

Co-Authored-By: Joshua Root <jmr@macports.org>

Co-authored-by: Joshua Root <jmr@macports.org>
2020-11-13 15:38:17 +01:00
Victor Stinner e6905e4c82
bpo-41617: Fix pycore_bitutils.h to support clang 3.0 (GH-22042)
__builtin_bswap16() is not available in LLVM clang 3.0.
2020-09-01 18:25:14 +02:00
Niklas Fiekas 794e7d1ab2
bpo-29782: Consolidate _Py_Bit_Length() (GH-20739)
In GH-2866, _Py_Bit_Length() was added to pymath.h for lack of a better
location. GH-20518 added a more appropriate header file for bit utilities. It
also shows how to properly use intrinsics. This allows reconsidering bpo-29782.

* Move the function to the new header.
* Changed return type to match __builtin_clzl() and reviewed usage.
* Use intrinsics where available.
* Pick a fallback implementation suitable for inlining.
2020-06-15 14:33:48 +02:00
Victor Stinner c6b292cdee
bpo-29882: Add _Py_popcount32() function (GH-20518)
* Rename pycore_byteswap.h to pycore_bitutils.h.
* Move popcount_digit() to pycore_bitutils.h as _Py_popcount32().
* _Py_popcount32() uses GCC and clang builtin function if available.
* Add unit tests to _Py_popcount32().
2020-06-08 16:30:33 +02:00