stdc_iec_559 -> iec_60559

Author: skirpichev

Doc/library/math.rst

@@ -848,7 +848,7 @@ Constants
 
    The :mod:`math` module consists mostly of thin wrappers around the platform C
    math library functions.  Behavior in exceptional cases follows Annex F of
-   the C99 standard, if :attr:`sys.float_info.stdc_iec_559` is true.
+   the C99 standard, if :attr:`sys.float_info.iec_60559` is true.
    The current implementation will raise
    :exc:`ValueError` for invalid operations like ``sqrt(-1.0)`` or ``log(0.0)``
    (where C99 Annex F recommends signaling invalid operation or divide-by-zero),

Doc/library/sys.rst

@@ -771,7 +771,7 @@ always available. Unless explicitly noted otherwise, all variables are read-only
           All other values for :c:macro:`!FLT_ROUNDS` characterize
           implementation-defined rounding behavior.
 
-      * - .. attribute:: float_info.stdc_iec_559
+      * - .. attribute:: float_info.iec_60559
         - :c:macro:`!__STDC_IEC_559__`
         - A boolean, indicating support the IEC 60559 floating-point standard.
           If true, the :class:`float` type characteristics and behavior matches

Misc/NEWS.d/next/Library/2025-09-12-07-30-13.gh-issue-138580.Qr_fSH.rst

@@ -1,2 +1,2 @@
 Add a boolean flag, indicating support the IEC 60559 floating-point standard
-(the Annex F of C99).  Patch by Sergey B Kirpichev.
+(as specified by the Annex F of C99).  Patch by Sergey B Kirpichev.

Objects/floatobject.c

@@ -68,8 +68,8 @@ static PyStructSequence_Field floatinfo_fields[] = {
     {"radix",           "FLT_RADIX -- radix of exponent"},
     {"rounds",          "FLT_ROUNDS -- rounding mode used for arithmetic "
                     "operations"},
-    {"stdc_iec_559", "test if implementation supports the IEC 60559 "
-                     "floating-point standard"},
+    {"iec_60559",   "test if implementation supports the IEC 60559 "
+                    "floating-point standard"},
     {0}
 };