[PATCH] Split helper classification macros from mathcalls.h

["Gabriel F. T. Gomes" <gftg at linux dot vnet dot ibm dot com>]

In https://sourceware.org/ml/libc-alpha/2016-11/msg00366.html, Joseph
suggested that mathcalls.h could need to be split, in order to allow
the declaration of helper functions (e.g. __signbitf128) when not
declaring functions protected by a __GLIBC_USE conditional for
TS-18661-3 (e.g. sinf128).  This patch does the split in preparation
for the float128 work.

-- 8< --
The classification macros: finite, fpclassify, isnan, isinf, and
signbit are defined by ISO C11 and declared in mathcalls.h for each of
the floating-point types: float, double, and long double.

TS 18661-3 does not mention these macros for float128, however support
for them must be present when _Float128 is present.  This is true,
even when the feature test macro __STDC_WANT_IEC_60559_TYPES_EXT__ is
false.  Other function declarations in mathcalls.h, on the other hand,
depend on __STDC_WANT_IEC_60559_TYPES_EXT__.

This patch splits the helper functions (__finite, __fpclassify,
__isnan, __isinf, and __signbit) from mathcalls.h, so that these
helper functions can be declared for _Float128, even when
__STDC_WANT_IEC_60559_TYPES_EXT__ is false.

Tested for powerpc64le and x86_64.

2017-03-06  Gabriel F. T. Gomes  <gftg@linux.vnet.ibm.com>

	* include/bits/mathcalls-helper-functions.h: New file.
	* math/Makefile (headers): Add bits/mathcalls-helper-functions.h.
	* math/bits/mathcalls.h (__finite, __fpclassify, __isnan)
	(__isinf, __signbit): Move declarations to
	math/bits/mathcalls-helper-functions.h.
	* math/bits/mathcalls-helper-functions.h: New file.
	* math/math.h: Include bits/mathcalls-helper-functions.h for
	float, double, and long double.
---
 include/bits/mathcalls-helper-functions.h |  1 +
 math/Makefile                             |  2 +-
 math/bits/mathcalls-helper-functions.h    | 54 +++++++++++++++++++++++++++++++
 math/bits/mathcalls.h                     | 21 ------------
 math/math.h                               |  3 ++
 5 files changed, 59 insertions(+), 22 deletions(-)
 create mode 100644 include/bits/mathcalls-helper-functions.h
 create mode 100644 math/bits/mathcalls-helper-functions.h

diff --git a/include/bits/mathcalls-helper-functions.h b/include/bits/mathcalls-helper-functions.h
new file mode 100644
index 0000000..bb71f7f
--- /dev/null
+++ b/include/bits/mathcalls-helper-functions.h
@@ -0,0 +1 @@
+#include <math/bits/mathcalls-helper-functions.h>
diff --git a/math/Makefile b/math/Makefile
index 29e7436..97080a7 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -29,7 +29,7 @@ headers		:= math.h bits/mathcalls.h bits/mathinline.h bits/huge_val.h \
 		   bits/math-finite.h bits/math-vector.h \
 		   bits/libm-simd-decl-stubs.h bits/iscanonical.h \
 		   bits/flt-eval-method.h bits/fp-fast.h bits/fp-logb.h \
-		   bits/long-double.h
+		   bits/long-double.h bits/mathcalls-helper-functions.h
 
 # FPU support code.
 aux		:= setfpucw fpu_control
diff --git a/math/bits/mathcalls-helper-functions.h b/math/bits/mathcalls-helper-functions.h
new file mode 100644
index 0000000..3fae4d0
--- /dev/null
+++ b/math/bits/mathcalls-helper-functions.h
@@ -0,0 +1,54 @@
+/* Prototype declarations for math classification macros helpers.
+   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/>.  */
+
+
+#if defined __USE_XOPEN_EXTENDED || defined __USE_ISOC99
+__BEGIN_NAMESPACE_C99
+#endif
+
+#ifdef __USE_ISOC99
+
+/* Classify given number.  */
+__MATHDECL_1 (int, __fpclassify,, (_Mdouble_ __value))
+     __attribute__ ((__const__));
+
+/* Test for negative number.  */
+__MATHDECL_1 (int, __signbit,, (_Mdouble_ __value))
+     __attribute__ ((__const__));
+
+#endif /* __USE_ISOC99.  */
+
+#if defined __USE_XOPEN_EXTENDED || defined __USE_ISOC99
+__END_NAMESPACE_C99
+#endif
+
+
+_Mdouble_BEGIN_NAMESPACE
+
+/* Return 0 if VALUE is finite or NaN, +1 if it
+   is +Infinity, -1 if it is -Infinity.  */
+__MATHDECL_1 (int, __isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
+
+/* Return nonzero if VALUE is finite and not NaN.  Used by isfinite macro.  */
+__MATHDECL_1 (int, __finite,, (_Mdouble_ __value)) __attribute__ ((__const__));
+
+_Mdouble_END_NAMESPACE
+
+
+/* Return nonzero if VALUE is not a number.  */
+__MATHDECL_1 (int, __isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
diff --git a/math/bits/mathcalls.h b/math/bits/mathcalls.h
index 3d3b414..8dfbf34 100644
--- a/math/bits/mathcalls.h
+++ b/math/bits/mathcalls.h
@@ -187,14 +187,6 @@ __MATHCALLX (floor,, (_Mdouble_ __x), (__const__));
 
 /* Floating-point modulo remainder of X/Y.  */
 __MATHCALL (fmod,, (_Mdouble_ __x, _Mdouble_ __y));
-
-
-/* Return 0 if VALUE is finite or NaN, +1 if it
-   is +Infinity, -1 if it is -Infinity.  */
-__MATHDECL_1 (int,__isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
-
-/* Return nonzero if VALUE is finite and not NaN.  */
-__MATHDECL_1 (int,__finite,, (_Mdouble_ __value)) __attribute__ ((__const__));
 _Mdouble_END_NAMESPACE
 
 #ifdef __USE_MISC
@@ -232,9 +224,6 @@ __END_NAMESPACE_C99
 #endif
 
 
-/* Return nonzero if VALUE is not a number.  */
-__MATHDECL_1 (int,__isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
-
 #if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 # if (!defined __cplusplus \
       || __cplusplus < 201103L /* isnan conflicts with C++11.  */ \
@@ -366,16 +355,6 @@ __MATHCALLX (fmax,, (_Mdouble_ __x, _Mdouble_ __y), (__const__));
 /* Return minimum numeric value from X and Y.  */
 __MATHCALLX (fmin,, (_Mdouble_ __x, _Mdouble_ __y), (__const__));
 
-
-/* Classify given number.  */
-__MATHDECL_1 (int, __fpclassify,, (_Mdouble_ __value))
-     __attribute__ ((__const__));
-
-/* Test for negative number.  */
-__MATHDECL_1 (int, __signbit,, (_Mdouble_ __value))
-     __attribute__ ((__const__));
-
-
 /* Multiply-add function computed as a ternary operation.  */
 __MATHCALL (fma,, (_Mdouble_ __x, _Mdouble_ __y, _Mdouble_ __z));
 #endif /* Use ISO C99.  */
diff --git a/math/math.h b/math/math.h
index 09f0ce8..fde3070 100644
--- a/math/math.h
+++ b/math/math.h
@@ -210,6 +210,7 @@ enum
 #define __MATH_DECLARING_DOUBLE  1
 #define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_STD
 #define _Mdouble_END_NAMESPACE   __END_NAMESPACE_STD
+#include <bits/mathcalls-helper-functions.h>
 #include <bits/mathcalls.h>
 #undef	_Mdouble_
 #undef _Mdouble_BEGIN_NAMESPACE
@@ -231,6 +232,7 @@ enum
 # define __MATH_DECLARING_DOUBLE  0
 # define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
 # define _Mdouble_END_NAMESPACE   __END_NAMESPACE_C99
+# include <bits/mathcalls-helper-functions.h>
 # include <bits/mathcalls.h>
 # undef	_Mdouble_
 # undef _Mdouble_BEGIN_NAMESPACE
@@ -278,6 +280,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #  define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
 #  define _Mdouble_END_NAMESPACE   __END_NAMESPACE_C99
 #  define __MATH_DECLARE_LDOUBLE   1
+#  include <bits/mathcalls-helper-functions.h>
 #  include <bits/mathcalls.h>
 #  undef _Mdouble_
 #  undef _Mdouble_BEGIN_NAMESPACE
-- 
2.4.11