Add missing long double functions to Cygwin

This patch adds the long double functions missing in newlib to Cygwin.
Apart from some self-written additions (exp10l, finite{f,l}, isinf{f,l},
isnan{f,l}, pow10l) the files are taken from the Mingw-w64 math lib.
Minor changes were required, e.g. substitue _WIN64 with __x86_64__ and
fixing __FLT_RPT_DOMAIN/__FLT_RPT_ERANGE for Cygwin.

Cygwin:
	* math: New subdir with math functions.
	* Makefile.in (VPATH): Add math subdir.
	(MATH_OFILES): List of object files collected from building files in
	math subdir.
	(DLL_OFILES): Add $(MATH_OFILES).
	${CURDIR}/libm.a: Add $(MATH_OFILES) to build.
	* common.din: Add new functions from math subdir.
	* i686.din: Align to new math subdir.  Remove functions now commonly
	available.
	* x86_64.din: Ditto.
	* math.h: math.h wrapper to define mingw structs used in some files in
	math subdir.
	* include/cygwin/version.h: Bump API minor version.

newlib:
	* libc/include/complex.h: Add prototypes for complex long double
	functions.  Only define for Cygwin.
	* libc/include/math.h: Additionally enable prototypes of long double
	functions for Cygwin.  Add Cygwin-only prototypes for dreml, sincosl,
	exp10l and pow10l.  Explain why we don't add them to newlib.
	* libc/include/tgmath.h: Enable long double handling on Cygwin.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

1 files changed, 22 insertions, 4 deletions

diff --git a/newlib/libc/include/math.h b/newlib/libc/include/math.h
index eeedeba92..e5d612367 100644
--- a/newlib/libc/include/math.h
+++ b/newlib/libc/include/math.h
@@ -421,8 +421,12 @@ extern float log2f _PARAMS((float));
 extern float hypotf _PARAMS((float, float));
 #endif /* ! defined (_REENT_ONLY) */
 
-/* On platforms where long double equals double.  */
-#ifdef _LDBL_EQ_DBL
+/* Newlib doesn't fully support long double math functions so far.
+   On platforms where long double equals double the long double functions
+   simply call the double functions.  On Cygwin the long double functions
+   are implemented independently from newlib to be able to use optimized
+   assembler functions despite using the Microsoft x86_64 ABI. */
+#if defined (_LDBL_EQ_DBL) || defined (__CYGWIN__)
 /* Reentrant ANSI C functions.  */
 #ifndef __math_68881
 extern long double atanl _PARAMS((long double));
@@ -492,7 +496,7 @@ extern long double lgammal _PARAMS((long double));
 extern long double erfl _PARAMS((long double));
 extern long double erfcl _PARAMS((long double));
 #endif /* ! defined (_REENT_ONLY) */
-#else /* !_LDBL_EQ_DBL */
+#else /* !_LDBL_EQ_DBL && !__CYGWIN__ */
 extern long double hypotl _PARAMS((long double, long double));
 extern long double sqrtl _PARAMS((long double));
 #ifdef __i386__
@@ -501,13 +505,16 @@ extern _LONG_DOUBLE rintl _PARAMS((_LONG_DOUBLE));
 extern long int lrintl _PARAMS((_LONG_DOUBLE));
 extern long long int llrintl _PARAMS((_LONG_DOUBLE));
 #endif /* __i386__ */
-#endif /* !_LDBL_EQ_DBL */
+#endif /* !_LDBL_EQ_DBL && !__CYGWIN__ */
 
 #endif /* __ISO_C_VISIBLE >= 1999 */
 
 #if __MISC_VISIBLE
 extern double drem _PARAMS((double, double));
 extern float dremf _PARAMS((float, float));
+#ifdef __CYGWIN__
+extern float dreml _PARAMS((long double, long double));
+#endif /* __CYGWIN__ */
 extern double gamma_r _PARAMS((double, int *));
 extern double lgamma_r _PARAMS((double, int *));
 extern float gammaf_r _PARAMS((float, int *));
@@ -536,6 +543,9 @@ extern float jnf _PARAMS((int, float));
 #if __GNU_VISIBLE
 extern void sincos _PARAMS((double, double *, double *));
 extern void sincosf _PARAMS((float, float *, float *));
+#ifdef __CYGWIN__
+extern void sincosl _PARAMS((long double, long double *, long double *));
+#endif /* __CYGWIN__ */
 # ifndef exp10
 extern double exp10 _PARAMS((double));
 # endif
@@ -548,6 +558,14 @@ extern float exp10f _PARAMS((float));
 # ifndef pow10f
 extern float pow10f _PARAMS((float));
 # endif
+#ifdef __CYGWIN__
+# ifndef exp10l
+extern float exp10l _PARAMS((float));
+# endif
+# ifndef pow10l
+extern float pow10l _PARAMS((float));
+# endif
+#endif /* __CYGWIN__ */
 #endif /* __GNU_VISIBLE */
 
 #if __MISC_VISIBLE || __XSI_VISIBLE