Support _Float128 in tgmath.h.

This patch adds tgmath.h support for _Float128, so eliminating the
awkward caveat in NEWS about the type not being supported there.  This
does inevitably increase the size of macro expansions (which grows
particularly fast when you have nested calls to tgmath.h macros), but
only when _Float128 is supported and the declarations of _Float128
interfaces are visible; otherwise the expansions are unchanged.

Tested for x86_64 and arm.

	* math/tgmath.h: Include <bits/libc-header-start.h> and
	<bits/floatn.h>.
	(__TGMATH_F128): New macro.
	(__TGMATH_CF128): Likewise.
	(__TGMATH_UNARY_REAL_ONLY): Use __TGMATH_F128.
	(__TGMATH_UNARY_REAL_RET_ONLY): Likewise.
	(__TGMATH_BINARY_FIRST_REAL_ONLY): Likewise.
	(__TGMATH_BINARY_FIRST_REAL_STD_ONLY): New macro.
	(__TGMATH_BINARY_REAL_ONLY): Use __TGMATH_F128.
	(__TGMATH_BINARY_REAL_STD_ONLY): New macro.
	(__TGMATH_BINARY_REAL_RET_ONLY): Use __TGMATH_F128.
	(__TGMATH_TERNARY_FIRST_SECOND_REAL_ONLY): Likewise.
	(__TGMATH_TERNARY_REAL_ONLY): Likewise.
	(__TGMATH_TERNARY_FIRST_REAL_RET_ONLY): Likewise.
	(__TGMATH_UNARY_REAL_IMAG): Use __TGMATH_CF128.
	(__TGMATH_UNARY_IMAG): Use __TGMATH_F128.
	(__TGMATH_UNARY_REAL_IMAG_RET_REAL): Use __TGMATH_CF128.
	(__TGMATH_BINARY_REAL_IMAG): Likewise.
	(nexttoward): Use __TGMATH_BINARY_FIRST_REAL_STD_ONLY.
	[__USE_MISC] (scalb): Use __TGMATH_BINARY_REAL_STD_ONLY.
	* math/gen-tgmath-tests.py (Type.init_types): Enable _FloatN and
	_FloatNx types if the corresponding HUGE_VAL macros are defined.

4 files changed, 160 insertions, 40 deletions

diff --git a/ChangeLog b/ChangeLog
index a6fbb36ac1..8334e48c13 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,28 @@
 2017-06-28  Joseph Myers  <joseph@codesourcery.com>
 
+	* math/tgmath.h: Include <bits/libc-header-start.h> and
+	<bits/floatn.h>.
+	(__TGMATH_F128): New macro.
+	(__TGMATH_CF128): Likewise.
+	(__TGMATH_UNARY_REAL_ONLY): Use __TGMATH_F128.
+	(__TGMATH_UNARY_REAL_RET_ONLY): Likewise.
+	(__TGMATH_BINARY_FIRST_REAL_ONLY): Likewise.
+	(__TGMATH_BINARY_FIRST_REAL_STD_ONLY): New macro.
+	(__TGMATH_BINARY_REAL_ONLY): Use __TGMATH_F128.
+	(__TGMATH_BINARY_REAL_STD_ONLY): New macro.
+	(__TGMATH_BINARY_REAL_RET_ONLY): Use __TGMATH_F128.
+	(__TGMATH_TERNARY_FIRST_SECOND_REAL_ONLY): Likewise.
+	(__TGMATH_TERNARY_REAL_ONLY): Likewise.
+	(__TGMATH_TERNARY_FIRST_REAL_RET_ONLY): Likewise.
+	(__TGMATH_UNARY_REAL_IMAG): Use __TGMATH_CF128.
+	(__TGMATH_UNARY_IMAG): Use __TGMATH_F128.
+	(__TGMATH_UNARY_REAL_IMAG_RET_REAL): Use __TGMATH_CF128.
+	(__TGMATH_BINARY_REAL_IMAG): Likewise.
+	(nexttoward): Use __TGMATH_BINARY_FIRST_REAL_STD_ONLY.
+	[__USE_MISC] (scalb): Use __TGMATH_BINARY_REAL_STD_ONLY.
+	* math/gen-tgmath-tests.py (Type.init_types): Enable _FloatN and
+	_FloatNx types if the corresponding HUGE_VAL macros are defined.
+
 	* math/tgmath.h [__USE_GNU] (log10): Use clog10 not __clog10.
 	* math/gen-tgmath-tests.py (Tests.add_all_tests): Test log10 for
 	complex arguments.
diff --git a/NEWS b/NEWS
index ba3e77b66a..84c69bf056 100644
--- a/NEWS
+++ b/NEWS
@@ -135,10 +135,10 @@ Version 2.26
 * Support is added, on powerpc64le, x86_64, x86 and ia64, for interfaces
   supporting the _Float128 type from ISO/IEC TS 18661-3:2015.  Most of the
   interfaces are taken from TS 18661-3.  The type-generic macros in <math.h>
-  support this type, but those in <tgmath.h> do not.  The GNU C Library now
-  requires GCC 6.2 or later to build for powerpc64le.  When used with GCC
-  versions before GCC 7, these interfaces may be used with the type under
-  the non-standard name __float128.
+  and <tgmath.h> support this type.  The GNU C Library now requires GCC 6.2
+  or later to build for powerpc64le.  When used with GCC versions before GCC
+  7, these interfaces may be used with the type under the non-standard name
+  __float128.
 
   New <stdlib.h> functions from ISO/IEC TS 18661-3:
 
diff --git a/math/gen-tgmath-tests.py b/math/gen-tgmath-tests.py
index 31a3bd2e2c..04492cd3d5 100755
--- a/math/gen-tgmath-tests.py
+++ b/math/gen-tgmath-tests.py
@@ -165,25 +165,25 @@ class Type(object):
         """Initialize all the known types."""
         Type.create_type('_Float16', 'f16', 'FLT16_MANT_DIG',
                          complex_name='__CFLOAT16',
-                         condition='0', order=(0, 0))
+                         condition='defined HUGE_VAL_F16', order=(0, 0))
         Type.create_type('float', 'f', 'FLT_MANT_DIG', order=(1, 1))
         Type.create_type('_Float32', 'f32', 'FLT32_MANT_DIG',
                          complex_name='__CFLOAT32',
-                         condition='0', order=(2, 2))
+                         condition='defined HUGE_VAL_F32', order=(2, 2))
         Type.create_type('_Float32x', 'f32x', 'FLT32X_MANT_DIG',
                          complex_name='__CFLOAT32X',
-                         condition='0', order=(3, 3))
+                         condition='defined HUGE_VAL_F32X', order=(3, 3))
         Type.create_type('double', '', 'DBL_MANT_DIG', order=(4, 4))
         Type.create_type('long double', 'l', 'LDBL_MANT_DIG', order=(5, 7))
         Type.create_type('_Float64', 'f64', 'FLT64_MANT_DIG',
                          complex_name='__CFLOAT64',
-                         condition='0', order=(6, 5))
+                         condition='defined HUGE_VAL_F64', order=(6, 5))
         Type.create_type('_Float64x', 'f64x', 'FLT64X_MANT_DIG',
                          complex_name='__CFLOAT64X',
-                         condition='0', order=(7, 6))
+                         condition='defined HUGE_VAL_F64X', order=(7, 6))
         Type.create_type('_Float128', 'f128', 'FLT128_MANT_DIG',
                          complex_name='__CFLOAT128',
-                         condition='0', order=(8, 8))
+                         condition='defined HUGE_VAL_F128', order=(8, 8))
         Type.create_type('char', integer=True)
         Type.create_type('signed char', integer=True)
         Type.create_type('unsigned char', integer=True)
@@ -202,10 +202,12 @@ class Type(object):
         # whether long double has the same format as double.
         Type.create_type('long_double_Float64', 'LDBL_MANT_DIG',
                          complex_name='complex_long_double_Float64',
-                         condition='0', order=(6, 7), internal=True)
+                         condition='defined HUGE_VAL_F64', order=(6, 7),
+                         internal=True)
         Type.create_type('long_double_Float64x', 'FLT64X_MANT_DIG',
                          complex_name='complex_long_double_Float64x',
-                         condition='0', order=(7, 7), internal=True)
+                         condition='defined HUGE_VAL_F64X', order=(7, 7),
+                         internal=True)
 
     @staticmethod
     def can_combine_types(types):
diff --git a/math/tgmath.h b/math/tgmath.h
index 7afe41e859..f75e3dca78 100644
--- a/math/tgmath.h
+++ b/math/tgmath.h
@@ -22,7 +22,11 @@
 #ifndef _TGMATH_H
 #define _TGMATH_H	1
 
+#define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
+#include <bits/libc-header-start.h>
+
 /* Include the needed headers.  */
+#include <bits/floatn.h>
 #include <math.h>
 #include <complex.h>
 
@@ -66,6 +70,23 @@
   __tgmath_real_type_sub (__typeof__ ((__typeof__ (expr)) 0),		      \
 			  __floating_type (__typeof__ (expr)))
 
+/* Expand to text that checks if ARG_COMB has type _Float128, and if
+   so calls the appropriately suffixed FCT (which may include a cast),
+   or FCT and CFCT for complex functions, with arguments ARG_CALL.  */
+# if __HAVE_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)
+#  define __TGMATH_F128(arg_comb, fct, arg_call) \
+  __builtin_types_compatible_p (__typeof (arg_comb), _Float128)	\
+  ? fct ## f128 arg_call :
+#  define __TGMATH_CF128(arg_comb, fct, cfct, arg_call)			\
+  __builtin_types_compatible_p (__typeof (__real__ (arg_comb)), _Float128) \
+  ? (sizeof (__real__ (arg_comb)) == sizeof (arg_comb)			\
+     ? fct ## f128 arg_call						\
+     : cfct ## f128 arg_call) :
+# else
+#  define __TGMATH_F128(arg_comb, fct, arg_call) /* Nothing.  */
+#  define __TGMATH_CF128(arg_comb, fct, cfct, arg_call) /* Nothing.  */
+# endif
+
 
 /* We have two kinds of generic macros: to support functions which are
    only defined on real valued parameters and those which are defined
@@ -76,7 +97,9 @@
 		     ? (__tgmath_real_type (Val)) Fct (Val)		      \
 		     : (sizeof (Val) == sizeof (float))			      \
 		     ? (__tgmath_real_type (Val)) Fct##f (Val)		      \
-		     : (__tgmath_real_type (Val)) __tgml(Fct) (Val)))
+		     : __TGMATH_F128 ((Val), (__tgmath_real_type (Val)) Fct,  \
+				      (Val))				      \
+		     (__tgmath_real_type (Val)) __tgml(Fct) (Val)))
 
 # define __TGMATH_UNARY_REAL_RET_ONLY(Val, Fct) \
      (__extension__ ((sizeof (Val) == sizeof (double)			      \
@@ -84,7 +107,8 @@
 		     ? Fct (Val)					      \
 		     : (sizeof (Val) == sizeof (float))			      \
 		     ? Fct##f (Val)					      \
-		     : __tgml(Fct) (Val)))
+		     : __TGMATH_F128 ((Val), Fct, (Val))		      \
+		     __tgml(Fct) (Val)))
 
 # define __TGMATH_BINARY_FIRST_REAL_ONLY(Val1, Val2, Fct) \
      (__extension__ ((sizeof (Val1) == sizeof (double)			      \
@@ -92,14 +116,47 @@
 		     ? (__tgmath_real_type (Val1)) Fct (Val1, Val2)	      \
 		     : (sizeof (Val1) == sizeof (float))		      \
 		     ? (__tgmath_real_type (Val1)) Fct##f (Val1, Val2)	      \
+		     : __TGMATH_F128 ((Val1), (__tgmath_real_type (Val1)) Fct, \
+				    (Val1, Val2))			      \
+		     (__tgmath_real_type (Val1)) __tgml(Fct) (Val1, Val2)))
+
+# define __TGMATH_BINARY_FIRST_REAL_STD_ONLY(Val1, Val2, Fct) \
+     (__extension__ ((sizeof (Val1) == sizeof (double)			      \
+		      || __builtin_classify_type (Val1) != 8)		      \
+		     ? (__tgmath_real_type (Val1)) Fct (Val1, Val2)	      \
+		     : (sizeof (Val1) == sizeof (float))		      \
+		     ? (__tgmath_real_type (Val1)) Fct##f (Val1, Val2)	      \
 		     : (__tgmath_real_type (Val1)) __tgml(Fct) (Val1, Val2)))
 
 # define __TGMATH_BINARY_REAL_ONLY(Val1, Val2, Fct) \
      (__extension__ (((sizeof (Val1) > sizeof (double)			      \
 		       || sizeof (Val2) > sizeof (double))		      \
 		      && __builtin_classify_type ((Val1) + (Val2)) == 8)      \
+		     ? __TGMATH_F128 ((Val1) + (Val2),			      \
+				      (__typeof				      \
+				       ((__tgmath_real_type (Val1)) 0	      \
+					+ (__tgmath_real_type (Val2)) 0)) Fct, \
+				      (Val1, Val2))			      \
+		     (__typeof ((__tgmath_real_type (Val1)) 0		      \
+				+ (__tgmath_real_type (Val2)) 0))	      \
+		     __tgml(Fct) (Val1, Val2)				      \
+		     : (sizeof (Val1) == sizeof (double)		      \
+			|| sizeof (Val2) == sizeof (double)		      \
+			|| __builtin_classify_type (Val1) != 8		      \
+			|| __builtin_classify_type (Val2) != 8)		      \
 		     ? (__typeof ((__tgmath_real_type (Val1)) 0		      \
 				   + (__tgmath_real_type (Val2)) 0))	      \
+		       Fct (Val1, Val2)					      \
+		     : (__typeof ((__tgmath_real_type (Val1)) 0		      \
+				   + (__tgmath_real_type (Val2)) 0))	      \
+		       Fct##f (Val1, Val2)))
+
+# define __TGMATH_BINARY_REAL_STD_ONLY(Val1, Val2, Fct) \
+     (__extension__ (((sizeof (Val1) > sizeof (double)			      \
+		       || sizeof (Val2) > sizeof (double))		      \
+		      && __builtin_classify_type ((Val1) + (Val2)) == 8)      \
+		     ? (__typeof ((__tgmath_real_type (Val1)) 0		      \
+				  + (__tgmath_real_type (Val2)) 0))	      \
 		       __tgml(Fct) (Val1, Val2)				      \
 		     : (sizeof (Val1) == sizeof (double)		      \
 			|| sizeof (Val2) == sizeof (double)		      \
@@ -116,7 +173,8 @@
      (__extension__ (((sizeof (Val1) > sizeof (double)			      \
 		       || sizeof (Val2) > sizeof (double))		      \
 		      && __builtin_classify_type ((Val1) + (Val2)) == 8)      \
-		     ? __tgml(Fct) (Val1, Val2)				      \
+		     ? __TGMATH_F128 ((Val1) + (Val2), Fct, (Val1, Val2))     \
+		     __tgml(Fct) (Val1, Val2)				      \
 		     : (sizeof (Val1) == sizeof (double)		      \
 			|| sizeof (Val2) == sizeof (double)		      \
 			|| __builtin_classify_type (Val1) != 8		      \
@@ -128,9 +186,14 @@
      (__extension__ (((sizeof (Val1) > sizeof (double)			      \
 		       || sizeof (Val2) > sizeof (double))		      \
 		      && __builtin_classify_type ((Val1) + (Val2)) == 8)      \
-		     ? (__typeof ((__tgmath_real_type (Val1)) 0		      \
-				   + (__tgmath_real_type (Val2)) 0))	      \
-		       __tgml(Fct) (Val1, Val2, Val3)			      \
+		     ? __TGMATH_F128 ((Val1) + (Val2),			      \
+				      (__typeof				      \
+				       ((__tgmath_real_type (Val1)) 0	      \
+					+ (__tgmath_real_type (Val2)) 0)) Fct, \
+				      (Val1, Val2, Val3))		      \
+		     (__typeof ((__tgmath_real_type (Val1)) 0		      \
+				+ (__tgmath_real_type (Val2)) 0))	      \
+		     __tgml(Fct) (Val1, Val2, Val3)			      \
 		     : (sizeof (Val1) == sizeof (double)		      \
 			|| sizeof (Val2) == sizeof (double)		      \
 			|| __builtin_classify_type (Val1) != 8		      \
@@ -148,9 +211,15 @@
 		       || sizeof (Val3) > sizeof (double))		      \
 		      && __builtin_classify_type ((Val1) + (Val2) + (Val3))   \
 			 == 8)						      \
-		     ? (__typeof ((__tgmath_real_type (Val1)) 0		      \
-				   + (__tgmath_real_type (Val2)) 0	      \
-				   + (__tgmath_real_type (Val3)) 0))	      \
+		     ? __TGMATH_F128 ((Val1) + (Val2) + (Val3),		      \
+				      (__typeof				      \
+				       ((__tgmath_real_type (Val1)) 0	      \
+					+ (__tgmath_real_type (Val2)) 0	      \
+					+ (__tgmath_real_type (Val3)) 0)) Fct, \
+				      (Val1, Val2, Val3))		      \
+		     (__typeof ((__tgmath_real_type (Val1)) 0		      \
+				+ (__tgmath_real_type (Val2)) 0		      \
+				+ (__tgmath_real_type (Val3)) 0))	      \
 		       __tgml(Fct) (Val1, Val2, Val3)			      \
 		     : (sizeof (Val1) == sizeof (double)		      \
 			|| sizeof (Val2) == sizeof (double)		      \
@@ -173,7 +242,8 @@
 		     ? Fct (Val1, Val2, Val3)				\
 		     : (sizeof (Val1) == sizeof (float))		\
 		     ? Fct##f (Val1, Val2, Val3)			\
-		     : __tgml(Fct) (Val1, Val2, Val3)))
+		     : __TGMATH_F128 ((Val1), Fct, (Val1, Val2, Val3))	\
+		     __tgml(Fct) (Val1, Val2, Val3)))
 
 /* XXX This definition has to be changed as soon as the compiler understands
    the imaginary keyword.  */
@@ -187,9 +257,12 @@
 		     ? ((sizeof (__real__ (Val)) == sizeof (Val))	      \
 			? (__tgmath_real_type (Val)) Fct##f (Val)	      \
 			: (__tgmath_real_type (Val)) Cfct##f (Val))	      \
-		     : ((sizeof (__real__ (Val)) == sizeof (Val))	      \
-			? (__tgmath_real_type (Val)) __tgml(Fct) (Val)	      \
-			: (__tgmath_real_type (Val)) __tgml(Cfct) (Val))))
+		     : __TGMATH_CF128 ((Val), (__tgmath_real_type (Val)) Fct, \
+				       (__tgmath_real_type (Val)) Cfct,       \
+				       (Val))				      \
+		     ((sizeof (__real__ (Val)) == sizeof (Val))		      \
+		      ? (__tgmath_real_type (Val)) __tgml(Fct) (Val)	      \
+		      : (__tgmath_real_type (Val)) __tgml(Cfct) (Val))))
 
 # define __TGMATH_UNARY_IMAG(Val, Cfct) \
      (__extension__ ((sizeof (__real__ (Val)) == sizeof (double)	      \
@@ -199,8 +272,12 @@
 		     : (sizeof (__real__ (Val)) == sizeof (float))	      \
 		     ? (__typeof__ ((__tgmath_real_type (Val)) 0	      \
 				    + _Complex_I)) Cfct##f (Val)	      \
-		     : (__typeof__ ((__tgmath_real_type (Val)) 0	      \
-				    + _Complex_I)) __tgml(Cfct) (Val)))
+		     : __TGMATH_F128 (__real__ (Val),			      \
+				      (__typeof__			      \
+				       ((__tgmath_real_type (Val)) 0	      \
+					+ _Complex_I)) Cfct, (Val))	      \
+		     (__typeof__ ((__tgmath_real_type (Val)) 0		      \
+				  + _Complex_I)) __tgml(Cfct) (Val)))
 
 /* XXX This definition has to be changed as soon as the compiler understands
    the imaginary keyword.  */
@@ -218,11 +295,19 @@
 			  Fct##f (Val)					      \
 			: (__typeof__ (__real__ (__tgmath_real_type (Val)) 0))\
 			  Cfct##f (Val))				      \
-		     : ((sizeof (__real__ (Val)) == sizeof (Val))	      \
-			? (__typeof__ (__real__ (__tgmath_real_type (Val)) 0))\
-			  __tgml(Fct) (Val)				      \
-			: (__typeof__ (__real__ (__tgmath_real_type (Val)) 0))\
-			  __tgml(Cfct) (Val))))
+		     : __TGMATH_CF128 ((Val), \
+				       (__typeof__			      \
+					(__real__			      \
+					 (__tgmath_real_type (Val)) 0)) Fct,  \
+				       (__typeof__			      \
+					(__real__			      \
+					 (__tgmath_real_type (Val)) 0)) Cfct, \
+				       (Val))				      \
+		     ((sizeof (__real__ (Val)) == sizeof (Val))		      \
+		      ? (__typeof__ (__real__ (__tgmath_real_type (Val)) 0))  \
+		      __tgml(Fct) (Val)					      \
+		      : (__typeof__ (__real__ (__tgmath_real_type (Val)) 0))  \
+		      __tgml(Cfct) (Val))))
 
 /* XXX This definition has to be changed as soon as the compiler understands
    the imaginary keyword.  */
@@ -231,14 +316,24 @@
 		       || sizeof (__real__ (Val2)) > sizeof (double))	      \
 		      && __builtin_classify_type (__real__ (Val1)	      \
 						  + __real__ (Val2)) == 8)    \
-		     ? ((sizeof (__real__ (Val1)) == sizeof (Val1)	      \
-			 && sizeof (__real__ (Val2)) == sizeof (Val2))	      \
-			? (__typeof ((__tgmath_real_type (Val1)) 0	      \
+		     ? __TGMATH_CF128 ((Val1) + (Val2),			      \
+				       (__typeof			      \
+					((__tgmath_real_type (Val1)) 0	      \
+					 + (__tgmath_real_type (Val2)) 0))    \
+				       Fct,				      \
+				       (__typeof			      \
+					((__tgmath_real_type (Val1)) 0	      \
+					 + (__tgmath_real_type (Val2)) 0))    \
+				       Cfct,				      \
+				       (Val1, Val2))			      \
+		     ((sizeof (__real__ (Val1)) == sizeof (Val1)	      \
+		       && sizeof (__real__ (Val2)) == sizeof (Val2))	      \
+		      ? (__typeof ((__tgmath_real_type (Val1)) 0	      \
 				   + (__tgmath_real_type (Val2)) 0))	      \
-			  __tgml(Fct) (Val1, Val2)			      \
-			: (__typeof ((__tgmath_real_type (Val1)) 0	      \
+		      __tgml(Fct) (Val1, Val2)				      \
+		      : (__typeof ((__tgmath_real_type (Val1)) 0	      \
 				   + (__tgmath_real_type (Val2)) 0))	      \
-			  __tgml(Cfct) (Val1, Val2))			      \
+		      __tgml(Cfct) (Val1, Val2))			      \
 		     : (sizeof (__real__ (Val1)) == sizeof (double)	      \
 			|| sizeof (__real__ (Val2)) == sizeof (double)	      \
 			|| __builtin_classify_type (__real__ (Val1)) != 8     \
@@ -422,14 +517,14 @@
 /* Return X + epsilon if X < Y, X - epsilon if X > Y.  */
 #define nextafter(Val1, Val2) __TGMATH_BINARY_REAL_ONLY (Val1, Val2, nextafter)
 #define nexttoward(Val1, Val2) \
-     __TGMATH_BINARY_FIRST_REAL_ONLY (Val1, Val2, nexttoward)
+     __TGMATH_BINARY_FIRST_REAL_STD_ONLY (Val1, Val2, nexttoward)
 
 /* Return the remainder of integer divison X / Y with infinite precision.  */
 #define remainder(Val1, Val2) __TGMATH_BINARY_REAL_ONLY (Val1, Val2, remainder)
 
 /* Return X times (2 to the Nth power).  */
 #ifdef __USE_MISC
-# define scalb(Val1, Val2) __TGMATH_BINARY_REAL_ONLY (Val1, Val2, scalb)
+# define scalb(Val1, Val2) __TGMATH_BINARY_REAL_STD_ONLY (Val1, Val2, scalb)
 #endif
 
 /* Return X times (2 to the Nth power).  */