/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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.
 */

#include <sys/types.h>
#include <machine/fpu.h>

#include "fenv.h"

const fenv_t __fe_dfl_env = {
        { 0xffff0000 | __INITIAL_FPUCW__,
          0xffff0000,
          0xffffffff,
          { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
        },
        __INITIAL_MXCSR__
};

int
(feclearexcept)(int excepts)
{
        return (__feclearexcept_int(excepts));
}

int
(fegetexceptflag)(fexcept_t *flagp, int excepts)
{
        return (__fegetexceptflag_int(flagp, excepts));
}

int
fesetexceptflag(const fexcept_t *flagp, int excepts)
{
        fenv_t env;

        __fnstenv(&env.__x87);
        env.__x87.__status &= ~excepts;
        env.__x87.__status |= *flagp & excepts;
        __fldenv(&env.__x87);

        __stmxcsr(&env.__mxcsr);
        env.__mxcsr &= ~excepts;
        env.__mxcsr |= *flagp & excepts;
        __ldmxcsr(&env.__mxcsr);

        return (0);
}

int
feraiseexcept(int excepts)
{
        fexcept_t ex = excepts;

        fesetexceptflag(&ex, excepts);
        __fwait();
        return (0);
}

int
(fetestexcept)(int excepts)
{
        return (__fetestexcept_int(excepts));
}

int
(fegetround)(void)
{
        return (__fegetround_int());
}

int
(fesetround)(int round)
{
        return (__fesetround_int(round));
}

int
fegetenv(fenv_t *envp)
{

        __fnstenv(&envp->__x87);
        __stmxcsr(&envp->__mxcsr);
        /*
         * fnstenv masks all exceptions, so we need to restore the
         * control word to avoid this side effect.
         */
        __fldcw(&envp->__x87.__control);
        return (0);
}

int
feholdexcept(fenv_t *envp)
{
        __uint32_t mxcsr;

        __stmxcsr(&mxcsr);
        __fnstenv(&envp->__x87);
        __fnclex();
        envp->__mxcsr = mxcsr;
        mxcsr &= ~FE_ALL_EXCEPT;
        mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
        __ldmxcsr(&mxcsr);
        return (0);
}

int
(fesetenv)(const fenv_t *envp)
{
        return (__fesetenv_int(envp));
}

int
feupdateenv(const fenv_t *envp)
{
        __uint32_t mxcsr;
        __uint16_t status;

        __fnstsw(&status);
        __stmxcsr(&mxcsr);
        fesetenv(envp);
        feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
        return (0);
}

int
__feenableexcept(int mask)
{
        __uint32_t mxcsr, omask;
        __uint16_t control;

        mask &= FE_ALL_EXCEPT;
        __fnstcw(&control);
        __stmxcsr(&mxcsr);
        omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
        control &= ~mask;
        __fldcw(&control);
        mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
        __ldmxcsr(&mxcsr);
        return (omask);
}

int
__fedisableexcept(int mask)
{
        __uint32_t mxcsr, omask;
        __uint16_t control;

        mask &= FE_ALL_EXCEPT;
        __fnstcw(&control);
        __stmxcsr(&mxcsr);
        omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
        control |= mask;
        __fldcw(&control);
        mxcsr |= mask << _SSE_EMASK_SHIFT;
        __ldmxcsr(&mxcsr);
        return (omask);
}

__weak_reference(__feenableexcept, feenableexcept);
__weak_reference(__fedisableexcept, fedisableexcept);