[New-bugs-announce] [issue46640] Python can now use the C99 NAN constant

[STINNER Victor]

New submission from STINNER Victor <vstinner at python.org>:

While debugging a GCC regression (*) on "HUGE_VAL * 0" used by Py_NAN macro, I noticed that Python can now C99 "NAN" constant.

(*) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104389

In bpo-45440, I already removed legacy code for pre-C99 support and old platforms:

"Building Python now requires a C99 <math.h> header file providing the following functions: copysign(), hypot(), isfinite(), isinf(), isnan(), round()."

Attached patch modifies Py_NAN to simply reuse NAN.

mathmodule.c and cmathmodule.c m_nan() still use _Py_dg_stdnan() by default (if PY_NO_SHORT_FLOAT_REPR is not defined).

----------
components: Interpreter Core
messages: 412531
nosy: vstinner
priority: normal
severity: normal
status: open
title: Python can now use the C99 NAN constant
versions: Python 3.11

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<https://bugs.python.org/issue46640>
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