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, 26 insertions, 0 deletions

diff --git a/winsup/cygwin/math/roundl.c b/winsup/cygwin/math/roundl.c
new file mode 100644
index 000000000..9879a82cc
--- /dev/null
+++ b/winsup/cygwin/math/roundl.c
@@ -0,0 +1,26 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+#include <math.h>
+
+long double
+roundl (long double x)
+{
+  long double res = 0.0L;
+  if (x >= 0.0L)
+    {
+      res = ceill (x);
+      if (res - x > 0.5L)
+	res -= 1.0L;
+    }
+  else
+    {
+      res = ceill (-x);
+      if (res + x > 0.5L)
+	res -= 1.0L;
+      res = -res;
+    }
+  return res;
+}