float128: Add private _Float128 declarations for libm.

Add the necessary bits to the private headers to support
building the _Float128 libm functions.

A local override for float.h is provided to include the
missing *FLT128 macros implied by TS 18661-3 for this
type when compiling prior to GCC 7.

	* include/complex.h (__kernel_casinhf128): New declaration.
	* include/float.h: New file.
	* include/math.h (__finitef128): Add a hidden def.
	(__isinff128): Likewise.
	(__isnanf128): Likewise.
	(__fpclassify): Likewise.
	(__issignalling): Likewise.
	(__expf128): Likewise.
	(__expm1f128): Likewise.

	* sysdeps/generic/fix-fp-int-convert-overflow.h:
	(FIX_FLT128_LONG_CONVERT_OVERFLOW): New macro.
	(FIX_FLT128_LLONG_CONVERT_OVERFLOW): Likewise.

	* sysdeps/generic/math-type-macros-float128.h: New file.

	* sysdeps/generic/math_private.h: Include bits/floatn.h and
	math_private_calls.h for _Float128.
	(__isinff128): New inline implementation used when GCC < 7.0,
	since in this case __builtin_isinf_sign is broken.
	(fabsf128): New inline implementation that calls the builtin.
	(__EXPR_FLT128): New macro.
	(min_of_type): Optionally include _Float128 types too.

	* sysdeps/generic/math_private_calls.h (__kernel_sincos):
	Declare for _Float128.
	(__kernel_rem_pio2): Likewise.

	* sysdeps/ieee754/ldbl-opt/s_sin.c:
	(__DECL_SIMD_sincos_disablef128): New macro.

4 files changed, 93 insertions, 3 deletions

diff --git a/sysdeps/generic/fix-fp-int-convert-overflow.h b/sysdeps/generic/fix-fp-int-convert-overflow.h
index f53eaf00b2..4b0cd9159f 100644
--- a/sysdeps/generic/fix-fp-int-convert-overflow.h
+++ b/sysdeps/generic/fix-fp-int-convert-overflow.h
@@ -29,5 +29,7 @@
 #define FIX_DBL_LLONG_CONVERT_OVERFLOW 0
 #define FIX_LDBL_LONG_CONVERT_OVERFLOW 0
 #define FIX_LDBL_LLONG_CONVERT_OVERFLOW 0
+#define FIX_FLT128_LONG_CONVERT_OVERFLOW 0
+#define FIX_FLT128_LLONG_CONVERT_OVERFLOW 0
 
 #endif /* fix-fp-int-convert-overflow.h */
diff --git a/sysdeps/generic/math-type-macros-float128.h b/sysdeps/generic/math-type-macros-float128.h
new file mode 100644
index 0000000000..dcb8560548
--- /dev/null
+++ b/sysdeps/generic/math-type-macros-float128.h
@@ -0,0 +1,39 @@
+/* Helper macros for _Float128 variants of type generic functions of libm.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _MATH_TYPE_MACROS_FLOAT128
+#define _MATH_TYPE_MACROS_FLOAT128
+
+#include <math.h>
+#include <complex.h>
+
+#define M_LIT(c) __f128 (c)
+#define M_PFX FLT128
+#define M_SUF(c) c ## f128
+#define FLOAT _Float128
+#define M_STRTO_NAN __strtof128_nan
+
+#define CFLOAT __CFLOAT128
+
+#define M_MLIT(c) c ## f128
+
+
+/* Supply the generic macros.  */
+#include <math-type-macros.h>
+
+#endif
diff --git a/sysdeps/generic/math_private.h b/sysdeps/generic/math_private.h
index 4d8a35ff87..6ea5e25e5a 100644
--- a/sysdeps/generic/math_private.h
+++ b/sysdeps/generic/math_private.h
@@ -23,6 +23,9 @@
 #include <float.h>
 #include <get-rounding-mode.h>
 
+/* Gather machine dependent _Floatn support.  */
+#include <bits/floatn.h>
+
 /* The original fdlibm code used statements like:
 	n0 = ((*(int*)&one)>>29)^1;		* index of high word *
 	ix0 = *(n0+(int*)&x);			* high word of x *
@@ -211,6 +214,41 @@ do {								\
 #undef _MSUF_
 #undef _Mdouble_
 
+#if __HAVE_DISTINCT_FLOAT128
+# define _Mdouble_ _Float128
+# define _MSUF_ f128
+# define __MATH_DECLARING_FLOATN
+# include <math_private_calls.h>
+# undef __MATH_DECLARING_FLOATN
+# undef _MSUF_
+# undef _Mdouble_
+#endif
+
+#if __HAVE_DISTINCT_FLOAT128
+
+/* __builtin_isinf_sign is broken in GCC < 7 for float128.  */
+# if ! __GNUC_PREREQ (7, 0)
+#  include <ieee754_float128.h>
+extern inline int
+__isinff128 (_Float128 x)
+{
+  int64_t hx, lx;
+  GET_FLOAT128_WORDS64 (hx, lx, x);
+  lx |= (hx & 0x7fffffffffffffffLL) ^ 0x7fff000000000000LL;
+  lx |= -lx;
+  return ~(lx >> 63) & (hx >> 62);
+}
+# endif
+
+extern inline _Float128
+fabsf128 (_Float128 x)
+{
+  return __builtin_fabsf128 (x);
+}
+#endif
+
+
+
 /* fdlibm kernel function */
 extern double __kernel_standard (double,double,int);
 extern float __kernel_standard_f (float,float,int);
@@ -263,13 +301,24 @@ extern void __docos (double __x, double __dx, double __v[]);
    })
 #endif
 
+#if __HAVE_DISTINCT_FLOAT128
+# define __EXPR_FLT128(x, yes, no)				\
+  __builtin_choose_expr (__builtin_types_compatible_p		\
+			 (__typeof (x), long double), no, yes)
+#else
+# define __EXPR_FLT128(x, yes, no) no
+#endif
+
+
 #define fabs_tg(x) __MATH_TG ((x), (__typeof (x)) __builtin_fabs, (x))
+
 #define min_of_type(type) __builtin_choose_expr		\
   (__builtin_types_compatible_p (type, float),		\
    FLT_MIN,						\
    __builtin_choose_expr				\
    (__builtin_types_compatible_p (type, double),	\
-    DBL_MIN, LDBL_MIN))
+    DBL_MIN,						\
+    __EXPR_FLT128 (x, FLT128_MIN, LDBL_MIN)))
 
 /* If X (which is not a NaN) is subnormal, force an underflow
    exception.  */
diff --git a/sysdeps/generic/math_private_calls.h b/sysdeps/generic/math_private_calls.h
index 8c1d304a8f..34bbd5e684 100644
--- a/sysdeps/generic/math_private_calls.h
+++ b/sysdeps/generic/math_private_calls.h
@@ -64,12 +64,12 @@ extern _Mdouble_ __MSUF (__kernel_sin) (_Mdouble_, _Mdouble_, int);
 extern _Mdouble_ __MSUF (__kernel_cos) (_Mdouble_, _Mdouble_);
 extern _Mdouble_ __MSUF (__kernel_tan) (_Mdouble_, _Mdouble_, int);
 
-#if defined __MATH_DECLARING_LONG_DOUBLE
+#if defined __MATH_DECLARING_LONG_DOUBLE || defined __MATH_DECLARING_FLOATN
 extern void __MSUF (__kernel_sincos) (_Mdouble_, _Mdouble_,
 				      _Mdouble_ *, _Mdouble_ *, int);
 #endif
 
-#if !defined __MATH_DECLARING_LONG_DOUBLE
+#if !defined __MATH_DECLARING_LONG_DOUBLE || defined __MATH_DECLARING_FLOATN
 extern int __MSUF (__kernel_rem_pio2) (_Mdouble_ *, _Mdouble_ *, int,
 				       int, int, const int32_t *);
 #endif