Define __STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__

TS 18661-1 and C2X specify predefined macros __STDC_IEC_60559_BFP__
and __STDC_IEC_60559_COMPLEX__, making __STDC_IEC_559__ and
__STDC_IEC_559_COMPLEX__ obsolescent (but still included in the
standard).  Now that we have all the functions from TS 18661-1, define
these macros in stdc-predef.h, under the same conditions in which the
older macros are defined, since support for the floating-point
features in TS 18661-1 is now at the same level as that for those in
C11 and before (all library functions and other library APIs present,
but no standard pragma support).

The macros are defined for now with their TS 18661-1 values.  C2X will
give them new values (listed as yyyymmL in the working drafts until
the final standard), at which point there will be the question of what
value to use in stdc-predef.h (where it could depend on
__STDC_VERSION__, but not on feature test macros defined by the user).
My inclination then would be to use the C2X value unconditionally
rather than using an older value to indicate TS support, and only have
any C standard version conditionals for the value when subsequent C
standard versions define further values.

(Note that I'm also inclined, when we implement the C2X change to the
return types of fromfp functions, to make that change unconditional
much like the change made to the types of totalorder functions, with
the old version only supported with compat symbols for already-linked
programs and not as an API for newly built objects.  So using the C2X
value would also accurately reflect not supporting the versions of
APIs in the TS where those ended up being incompatible with the first
version actually added to the standard.)

Tested for x86_64.

diff --git a/NEWS b/NEWS
index 889578bf39d3a8ffc56a504fa94699b6f6b7c23a..9ae04b2f2014439efc2a3625a960d09bcfbab9bc 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -32,6 +32,9 @@ Major new features:
   - ffma, ffmal, dfmal and corresponding fMfmafN, fMfmafNx, fMxfmafN and
     fMxfmafNx functions.
 
+* The __STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__ macros are
+  predefined as specified in TS 18661-1:2014.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * The r_version update in the debugger interface makes the glibc binary

diff --git a/include/stdc-predef.h b/include/stdc-predef.h
index e130c462a7b71f87956a6d4b2bd69a38c9d9cb32..ea9425277bbf23590b65abf2f3ff627017f679e8 100644 (file)
--- a/include/stdc-predef.h
+++ b/include/stdc-predef.h
@@ -36,17 +36,21 @@
 #ifdef __GCC_IEC_559
 # if __GCC_IEC_559 > 0
 #  define __STDC_IEC_559__             1
+#  define __STDC_IEC_60559_BFP__       201404L
 # endif
 #else
 # define __STDC_IEC_559__              1
+# define __STDC_IEC_60559_BFP__        201404L
 #endif
 
 #ifdef __GCC_IEC_559_COMPLEX
 # if __GCC_IEC_559_COMPLEX > 0
 #  define __STDC_IEC_559_COMPLEX__     1
+#  define __STDC_IEC_60559_COMPLEX__   201404L
 # endif
 #else
 # define __STDC_IEC_559_COMPLEX__      1
+# define __STDC_IEC_60559_COMPLEX__    201404L
 #endif
 
 /* wchar_t uses Unicode 10.0.0.  Version 10.0 of the Unicode Standard is