Declare most TS 18661-1 interfaces for C2X.

C2X adds the interfaces from TS 18661-1, and all except a handful in
Annex F are unconditionally visible in C2X rather than only visible
when __STDC_WANT_IEC_60559_BFP_EXT__ is defined.  This patch updates
glibc headers accordingly: most uses of __GLIBC_USE
(IEC_60559_BFP_EXT) are changed to a new __GLIBC_USE
(IEC_60559_BFP_EXT_C2X).  (Regarding totalorder and totalordermag, the
type-generic macros in tgmath.h will go away when the functions are
changed to take pointer arguments.)

	* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_BFP_EXT): Update
	comment.
	(__GLIBC_USE_IEC_60559_BFP_EXT_C2X): New macro.
	* bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Change to
	[__GLIBC_USE (IEC_60559_BFP_EXT_C2X)].
	* include/limits.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* math/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* stdlib/bits/stdlib-ldbl.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* stdlib/stdint.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* stdlib/stdlib.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* sysdeps/aarch64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/alpha/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/arm/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/csky/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/hppa/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/ia64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/m68k/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/microblaze/bits/fenv.h [__GLIBC_USE
	(IEC_60559_BFP_EXT)]: Likewise.
	* sysdeps/mips/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/nios2/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/powerpc/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/riscv/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/s390/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/sh/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/sparc/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/x86/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise, except for totalorder, totalordermag, getpayload,
	setpayload and setpayloadsig.
	* math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise,
	except for totalorder and totalordermag.

2 files changed, 10 insertions, 2 deletions

diff --git a/bits/fenv.h b/bits/fenv.h
index c7ba575a87..d4870bf334 100644
--- a/bits/fenv.h
+++ b/bits/fenv.h
@@ -54,7 +54,7 @@ fenv_t;
 /* If the default argument is used we use this value.  */
 #define FE_DFL_ENV	((const fenv_t *) -1l)
 
-#if __GLIBC_USE (IEC_60559_BFP_EXT)
+#if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
 /* Type representing floating-point control modes.  */
 typedef unsigned int femode_t;
 
diff --git a/bits/libc-header-start.h b/bits/libc-header-start.h
index 72efab29f2..f2acc5333e 100644
--- a/bits/libc-header-start.h
+++ b/bits/libc-header-start.h
@@ -43,13 +43,21 @@
 #endif
 
 /* ISO/IEC TS 18661-1:2014 defines the __STDC_WANT_IEC_60559_BFP_EXT__
-   macro.  */
+   macro.  Most but not all symbols enabled by that macro in TS
+   18661-1 are enabled unconditionally in C2X; the symbols in Annex F
+   still require that macro in C2X.  */
 #undef __GLIBC_USE_IEC_60559_BFP_EXT
 #if defined __USE_GNU || defined __STDC_WANT_IEC_60559_BFP_EXT__
 # define __GLIBC_USE_IEC_60559_BFP_EXT 1
 #else
 # define __GLIBC_USE_IEC_60559_BFP_EXT 0
 #endif
+#undef __GLIBC_USE_IEC_60559_BFP_EXT_C2X
+#if __GLIBC_USE (IEC_60559_BFP_EXT) || __GLIBC_USE (ISOC2X)
+# define __GLIBC_USE_IEC_60559_BFP_EXT_C2X 1
+#else
+# define __GLIBC_USE_IEC_60559_BFP_EXT_C2X 0
+#endif
 
 /* ISO/IEC TS 18661-4:2015 defines the
    __STDC_WANT_IEC_60559_FUNCS_EXT__ macro.  */