/*-
 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#ifndef _FENV_H_
#define _FENV_H_

#include <stdint.h>
#include <sys/cdefs.h>
#include <sys/types.h>

typedef uint32_t        fenv_t;
typedef uint32_t        fexcept_t;

/* Exception flags */
#define FE_INVALID      0x0001
#define FE_DIVBYZERO    0x0002
#define FE_OVERFLOW     0x0004
#define FE_UNDERFLOW    0x0008
#define FE_INEXACT      0x0010
#define FE_ALL_EXCEPT   (FE_DIVBYZERO | FE_INEXACT | \
                         FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)

/* Rounding modes */
#define FE_TONEAREST    0x0000
#define FE_TOWARDZERO   0x0001
#define FE_UPWARD       0x0002
#define FE_DOWNWARD     0x0003
#define _ROUND_MASK     (FE_TONEAREST | FE_DOWNWARD | \
                         FE_UPWARD | FE_TOWARDZERO)
__BEGIN_DECLS

/* Default floating-point environment */
extern const fenv_t     __fe_dfl_env;
#define FE_DFL_ENV      (&__fe_dfl_env)

/* We need to be able to map status flag positions to mask flag positions */
#define _FPUSW_SHIFT    16
#define _ENABLE_MASK    (FE_ALL_EXCEPT << _FPUSW_SHIFT)

#ifdef  ARM_HARD_FLOAT
#define __rfs(__fpsr)   __asm __volatile("rfs %0" : "=r" (*(__fpsr)))
#define __wfs(__fpsr)   __asm __volatile("wfs %0" : : "r" (__fpsr))
#else
#define __rfs(__fpsr)
#define __wfs(__fpsr)
#endif

static __inline int
feclearexcept(int __excepts)
{
        fexcept_t __fpsr;

        __rfs(&__fpsr);
        __fpsr &= ~__excepts;
        __wfs(__fpsr);
        return (0);
}

static __inline int
fegetexceptflag(fexcept_t *__flagp, int __excepts)
{
        fexcept_t __fpsr;

        __rfs(&__fpsr);
        *__flagp = __fpsr & __excepts;
        return (0);
}

static __inline int
fesetexceptflag(const fexcept_t *__flagp, int __excepts)
{
        fexcept_t __fpsr;

        __rfs(&__fpsr);
        __fpsr &= ~__excepts;
        __fpsr |= *__flagp & __excepts;
        __wfs(__fpsr);
        return (0);
}

static __inline int
feraiseexcept(int __excepts)
{
        fexcept_t __ex = __excepts;

        fesetexceptflag(&__ex, __excepts);      /* XXX */
        return (0);
}

static __inline int
fetestexcept(int __excepts)
{
        fexcept_t __fpsr;

        __rfs(&__fpsr);
        return (__fpsr & __excepts);
}

static __inline int
fegetround(void)
{

        /*
         * Apparently, the rounding mode is specified as part of the
         * instruction format on ARM, so the dynamic rounding mode is
         * indeterminate.  Some FPUs may differ.
         */
        return (-1);
}

static __inline int
fesetround(int __round)
{

        return (-1);
}

static __inline int
fegetenv(fenv_t *__envp)
{

        __rfs(__envp);
        return (0);
}

static __inline int
feholdexcept(fenv_t *__envp)
{
        fenv_t __env;

        __rfs(&__env);
        *__envp = __env;
        __env &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
        __wfs(__env);
        return (0);
}

static __inline int
fesetenv(const fenv_t *__envp)
{

        __wfs(*__envp);
        return (0);
}

static __inline int
feupdateenv(const fenv_t *__envp)
{
        fexcept_t __fpsr;

        __rfs(&__fpsr);
        __wfs(*__envp);
        feraiseexcept(__fpsr & FE_ALL_EXCEPT);
        return (0);
}

#ifdef _DEFAULT_SOURCE

static __inline int
feenableexcept(int __mask)
{
        fenv_t __old_fpsr, __new_fpsr;

        __rfs(&__old_fpsr);
        __new_fpsr = __old_fpsr | (__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT;
        __wfs(__new_fpsr);
        return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
}

static __inline int
fedisableexcept(int __mask)
{
        fenv_t __old_fpsr, __new_fpsr;

        __rfs(&__old_fpsr);
        __new_fpsr = __old_fpsr & ~((__mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
        __wfs(__new_fpsr);
        return ((__old_fpsr >> _FPUSW_SHIFT) & FE_ALL_EXCEPT);
}

static __inline int
fegetexcept(void)
{
        fenv_t __fpsr;

        __rfs(&__fpsr);
        return ((__fpsr & _ENABLE_MASK) >> _FPUSW_SHIFT);
}

#endif /* _DEFAULT_SOURCE */

__END_DECLS

#endif  /* !_FENV_H_ */