+2013-11-04 Joseph Myers <joseph@codesourcery.com>
+
+ * include/stdc-predef.h [__GCC_IEC_559] (__STDC_IEC_559__): Define
+ depending on [__GCC_IEC_559 > 0].
+ [__GCC_IEC_559_COMPLEX] (__STDC_IEC_559_COMPLEX__): Define
+ depending on [__GCC_IEC_559_COMPLEX > 0].
+
2013-11-03 Chris Leonard <cjl@sugarlabs.org>
* locale/iso-639.def: Add Quechua, Southern (quz) and Silesian (szl)
explicitly includes a system header. GCC knows the name of this
header in order to preinclude it. */
-/* We do support the IEC 559 math functionality, real and complex. */
-#define __STDC_IEC_559__ 1
-#define __STDC_IEC_559_COMPLEX__ 1
+/* glibc's intent is to support the IEC 559 math functionality, real
+ and complex. If the GCC (4.9 and later) predefined macros
+ specifying compiler intent are available, use them to determine
+ whether the overall intent is to support these features; otherwise,
+ presume an older compiler has intent to support these features and
+ define these macros by default. */
+
+#ifdef __GCC_IEC_559
+# if __GCC_IEC_559 > 0
+# define __STDC_IEC_559__ 1
+# endif
+#else
+# define __STDC_IEC_559__ 1
+#endif
+
+#ifdef __GCC_IEC_559_COMPLEX
+# if __GCC_IEC_559_COMPLEX > 0
+# define __STDC_IEC_559_COMPLEX__ 1
+# endif
+#else
+# define __STDC_IEC_559_COMPLEX__ 1
+#endif
/* wchar_t uses ISO/IEC 10646 (2nd ed., published 2011-03-15) /
Unicode 6.0. */