float128: Add public _Float128 declarations to libm.

This introduces the machine-dependent bits/floatn.h to control
the inclusion of _Float128 ABI.

	* bits/floatn.h: New file.
	* bits/huge_val_flt128.h: Likewise.

	* bits/libm-simd-decl-stubs.h (__DECL_SIMD_cosf128): New macro.
	(__DECL_SIMD_sinf128): Likewise.
	(__DECL_SIMD_sincosf128): Likewise.
	(__DECL_SIMD_logf128): Likewise.
	(__DECL_SIMD_expf128): Likewise.
	(__DECL_SIMD_powf128): Likewise.

	* math/Makefile (headers): Install bits/floatn.h and
	bits/huge_val_flt128.h.

	* math/bits/cmathcalls.h (_Mdouble_complex_): Only define if not
	defined.

	* math/bits/mathcalls.h (pow10, isinf, finite, drem, significand)
	(isnan, gamma, nexttoward, scalb): Only define if not
	__MATH_DECLARING_FLOATN.
	(nextdown, nextup, llogb, roundeven, fromfp, ufromfp, fromfpx)
	(ufromfpx, fmaxmag, fminmag, totalorder, totalordermag)
	(canonicalize, getpayload, setpayload, setpayloadsig): Declare for
	_FloatN even if	__STDC_WANT_IEC_60559_BFP_EXT__ is not defined.

	* math/complex.h: Include bits/libc-header-start.h and bits/floatn.h.
	Include bits/cmathcalls.h to get the declarations of _Float128
	versions of complex functions.
	[__HAVE_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)] (CMPLXF128):
	Define macro.

	* math/math.h: Include bits/floatn.h and bits/huge_val_flt128.h.
	Include bits/mathcalls-helper-functions.h and bits/mathcalls.h to
	get the declarations of _Float128 versions of math functions.
	(__MATH_DECLARING_FLOATN): New macro to control declaration of
	_FloatN types.
	[__GNUC_PREREQ (6,0)] (signbit): Since GCC 6.0, __builtin_signbit
	is type-generic, so use it without __MATH_TG.
	[__HAVE_DISTINCT_FLOAT128] (isinf): This builtin is broken for
	_Float128 type on GCC < 7.0.  Explicitly call __isinff128 for
	_Float128 type and GCC < 7.0, otherwise use the builtin.
	[__HAVE_FLOAT128 && defined __USE_GNU] (M_Ef128, M_LOG2Ef128)
	(M_LOG10Ef128, M_LN2f128, M_LN10f128, M_PIf128, M_PI_2f128)
	(M_PI_4f128, M_1_PIf128, M_2_PIf128, M_SQRT2f128, M_SQRT1_2f128):
	New _GNU_SOURCE enabled macros.

1 files changed, 27 insertions, 1 deletions

diff --git a/math/complex.h b/math/complex.h
index 59ce30e297..1ae4ec2409 100644
--- a/math/complex.h
+++ b/math/complex.h
@@ -22,11 +22,15 @@
 #ifndef _COMPLEX_H
 #define _COMPLEX_H	1
 
-#include <features.h>
+#define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
+#include <bits/libc-header-start.h>
 
 /* Get general and ISO C99 specific information.  */
 #include <bits/mathdef.h>
 
+/* Gather machine-dependent _FloatN type support.  */
+#include <bits/floatn.h>
+
 __BEGIN_DECLS
 
 /* We might need to add support for more compilers here.  But since ISO
@@ -55,6 +59,10 @@ __BEGIN_DECLS
 # define CMPLXL(x, y) __builtin_complex ((long double) (x), (long double) (y))
 #endif
 
+#if __HAVE_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)
+# define CMPLXF128(x, y) __builtin_complex ((_Float128) (x), (_Float128) (y))
+#endif
+
 /* The file <bits/cmathcalls.h> contains the prototypes for all the
    actual math functions.  These macros are used for those prototypes,
    so we can easily declare each function as both `name' and `__name',
@@ -84,6 +92,24 @@ __BEGIN_DECLS
 #undef	_Mdouble_
 #undef	__MATH_PRECNAME
 
+#if (__HAVE_DISTINCT_FLOAT128 || (__HAVE_FLOAT128 && !defined _LIBC)) \
+     && __GLIBC_USE (IEC_60559_TYPES_EXT)
+# ifndef _Mfloat128_
+#  define _Mfloat128_		_Float128
+# endif
+/* GCC < 7 requires extra convincing to expose a complex float128 type.  */
+# ifdef __CFLOAT128
+#  undef _Mdouble_complex_
+#  define _Mdouble_complex_	__CFLOAT128
+# endif
+# define _Mdouble_		_Mfloat128_
+# define __MATH_PRECNAME(name)	name##f128
+# include <bits/cmathcalls.h>
+# undef _Mdouble_
+# undef __MATH_PRECNAME
+# undef _Mdouble_complex_
+#endif
+
 /* And the long double versions.  It is non-critical to define them
    here unconditionally since `long double' is required in ISO C99.  */
 #if !(defined __NO_LONG_DOUBLE_MATH && defined _LIBC)	\