winsup/cygwin/ChangeLog:

	* Makefile.in (DLL_OFILES): Add new fenv.o module.
	(fenv_CFLAGS): New flags definition for fenv.o compile.
	* autoload.cc (std_dll_init): Use fenv.h functions instead of direct
	manipulation of x87 FPU registers.
	* crt0.c (mainCRTStartup): Likewise.
	* cygwin.din (feclearexcept, fegetexceptflag, feraiseexcept,
	fesetexceptflag, fetestexcept, fegetround, fesetround, fegetenv,
	feholdexcept, fesetenv, feupdateenv, fegetprec, fesetprec,
	feenableexcept, fedisableexcept, fegetexcept, _feinitialise,
	_fe_dfl_env, _fe_nomask_env): Export new functions and data items.
	* fenv.cc: New file.
	* posix.sgml: Update status of newly-implemented APIs.
	* include/fenv.h: Likewise related header.
	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.

1 files changed, 176 insertions, 0 deletions

diff --git a/winsup/cygwin/include/fenv.h b/winsup/cygwin/include/fenv.h
new file mode 100755
index 000000000..89e3d48c4
--- /dev/null
+++ b/winsup/cygwin/include/fenv.h
@@ -0,0 +1,176 @@
+/* fenv.h
+
+   Copyright 2010 Red Hat, Inc.
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#ifndef _FENV_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Primary sources:
+
+     The Open Group Base Specifications Issue 6:
+   http://www.opengroup.org/onlinepubs/000095399/basedefs/fenv.h.html
+
+     C99 Language spec (draft n1256):
+   <url unknown>
+
+     Intel® 64 and IA-32 Architectures Software Developer’s Manuals:
+   http://www.intel.com/products/processor/manuals/
+
+     GNU C library manual pages:
+   http://www.gnu.org/software/libc/manual/html_node/Control-Functions.html
+   http://www.gnu.org/software/libc/manual/html_node/Rounding.html
+   http://www.gnu.org/software/libc/manual/html_node/FP-Exceptions.html
+   http://www.gnu.org/software/libc/manual/html_node/Status-bit-operations.html
+
+     Linux online man page(s):
+   http://linux.die.net/man/3/fegetexcept
+
+    The documentation quotes these sources for reference.  All definitions and
+   code have been developed solely based on the information from these specs.
+
+*/
+
+/*  Represents the entire floating-point environment. The floating-point
+   environment refers collectively to any floating-point status flags and
+   control modes supported by the implementation.
+    In this implementation, the struct contains the state information from
+   the fstenv/fnstenv instructions and a copy of the SSE MXCSR, since GCC
+   uses SSE for a lot of floating-point operations.  (Cygwin assumes i686
+   or above these days, as does the compiler.)  */
+
+typedef struct _fenv_t
+{
+  struct _fpu_env_info {
+    unsigned int _fpu_cw;	/* low 16 bits only. */
+    unsigned int _fpu_sw;	/* low 16 bits only. */
+    unsigned int _fpu_tagw;	/* low 16 bits only. */
+    unsigned int _fpu_ipoff;
+    unsigned int _fpu_ipsel;
+    unsigned int _fpu_opoff;
+    unsigned int _fpu_opsel;	/* low 16 bits only. */
+  } _fpu;
+  unsigned int _sse_mxcsr;
+} fenv_t;
+
+/*  Represents the floating-point status flags collectively, including
+   any status the implementation associates with the flags. A floating-point
+   status flag is a system variable whose value is set (but never cleared)
+   when a floating-point exception is raised, which occurs as a side effect
+   of exceptional floating-point arithmetic to provide auxiliary information.
+    A floating-point control mode is a system variable whose value may be
+   set by the user to affect the subsequent behavior of floating-point
+   arithmetic.  */
+
+typedef struct _fexcept_t
+{
+  unsigned short _fpu_exceptions;
+  unsigned short _sse_exceptions;
+} fexcept_t;
+
+/*  The <fenv.h> header shall define the following constants if and only
+   if the implementation supports the floating-point exception by means
+   of the floating-point functions feclearexcept(), fegetexceptflag(),
+   feraiseexcept(), fesetexceptflag(), and fetestexcept(). Each expands to
+   an integer constant expression with values such that bitwise-inclusive
+   ORs of all combinations of the constants result in distinct values.  */
+
+#define FE_DIVBYZERO	(1 << 2)
+#define FE_INEXACT	(1 << 5)
+#define FE_INVALID	(1 << 0)
+#define FE_OVERFLOW	(1 << 3)
+#define FE_UNDERFLOW	(1 << 4)
+
+/*  This is not defined by Posix, but since x87 supports it we provide
+   a definition according to the same naming scheme used above.  */
+#define FE_DENORMAL	(1 << 1)
+
+/*  The <fenv.h> header shall define the following constant, which is
+   simply the bitwise-inclusive OR of all floating-point exception
+   constants defined above:  */
+
+#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID \
+			| FE_OVERFLOW | FE_UNDERFLOW | FE_DENORMAL)
+
+/*  The <fenv.h> header shall define the following constants if and only
+   if the implementation supports getting and setting the represented
+   rounding direction by means of the fegetround() and fesetround()
+   functions. Each expands to an integer constant expression whose values
+   are distinct non-negative vales.  */
+
+#define FE_DOWNWARD	(1)
+#define FE_TONEAREST	(0)
+#define FE_TOWARDZERO	(3)
+#define FE_UPWARD	(2)
+
+/*  Precision bit values.  Not defined by Posix, but follow logically.  */
+#define FE_SINGLEPREC	(0)
+#define FE_RESERVEDPREC	(1)
+#define FE_DOUBLEPREC	(2)
+#define FE_EXTENDEDPREC	(3)
+
+/*  The <fenv.h> header shall define the following constant, which
+   represents the default floating-point environment (that is, the one
+   installed at program startup) and has type pointer to const-qualified
+   fenv_t. It can be used as an argument to the functions within the
+   <fenv.h> header that manage the floating-point environment.  */
+
+extern const fenv_t *_fe_dfl_env;
+#define FE_DFL_ENV (_fe_dfl_env)
+
+/*  Additional implementation-defined environments, with macro 
+   definitions beginning with FE_ and an uppercase letter,and having
+   type "pointer to const-qualified fenv_t",may also be specified by
+   the implementation.  */
+
+#ifdef _GNU_SOURCE
+/*  If possible, the GNU C Library defines a macro FE_NOMASK_ENV which
+   represents an environment where every exception raised causes a trap
+   to occur. You can test for this macro using #ifdef. It is only defined
+   if _GNU_SOURCE is defined.  */
+extern const fenv_t *_fe_nomask_env;
+#define FE_NOMASK_ENV (_fe_nomask_env)
+#endif /* _GNU_SOURCE */
+
+
+/*  The following shall be declared as functions and may also be
+   defined as macros. Function prototypes shall be provided.  */
+extern int feclearexcept (int excepts);
+extern int fegetexceptflag (fexcept_t *flagp, int excepts);
+extern int feraiseexcept (int excepts);
+extern int fesetexceptflag (const fexcept_t *flagp, int excepts);
+extern int fetestexcept (int excepts);
+extern int fegetround (void);
+extern int fesetround (int round);
+extern int fegetenv (fenv_t *envp);
+extern int feholdexcept (fenv_t *envp);
+extern int fesetenv (const fenv_t *envp);
+extern int feupdateenv (const fenv_t *envp);
+
+/* These are not defined in Posix, but make sense by obvious extension.  */
+extern int fegetprec (void);
+extern int fesetprec (int prec);
+
+/* This is Cygwin-custom, not from the standard, for use in the Cygwin CRT.  */
+extern void _feinitialise (void);
+
+/* These are GNU extensions defined in glibc.  */
+extern int feenableexcept (int excepts);
+extern int fedisableexcept (int excepts);
+extern int fegetexcept (void);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _FENV_H_ */