LCOM1920-T02G10

/*        $NetBSD: fenv.h,v 1.2 2014/02/12 23:04:43 dsl Exp $        */

/*-

 * Copyright (c) 2004-2005 David Schultz <das (at) 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.

 */

#ifndef        _X86_FENV_H_

#define        _X86_FENV_H_

#ifndef _KERNEL

#include <sys/stdint.h>

#endif

/* Default x87 control word. */

#define __INITIAL_NPXCW__       0x037f  

/* Modern NetBSD uses the default control word.. */

#define __NetBSD_NPXCW__        __INITIAL_NPXCW__

/* NetBSD before 6.99.26 forced IEEE double precision. */

#define __NetBSD_COMPAT_NPXCW__ 0x127f

/* Default values for the mxcsr. All traps masked. */

#define __INITIAL_MXCSR__       0x1f80

#ifndef _KERNEL

/*

 * Each symbol representing a floating point exception expands to an integer

 * constant expression with values, such that bitwise-inclusive ORs of _all

 * combinations_ of the constants result in distinct values.

 *

 * We use such values that allow direct bitwise operations on FPU/SSE registers.

 */

#define        FE_INVALID        0x01        /* 000000000001 */

#define        FE_DENORMAL        0x02        /* 000000000010 */

#define        FE_DIVBYZERO        0x04        /* 000000000100 */

#define        FE_OVERFLOW        0x08        /* 000000001000 */

#define        FE_UNDERFLOW        0x10        /* 000000010000 */

#define        FE_INEXACT        0x20        /* 000000100000 */

/*

 * The following symbol is simply the bitwise-inclusive OR of all floating-point

 * exception constants defined above.

 */

#define FE_ALL_EXCEPT        (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \

                         FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)

/*

 * Each symbol representing the rounding direction, expands to an integer

 * constant expression whose value is distinct non-negative value.

 *

 * We use such values that allow direct bitwise operations on FPU/SSE registers.

 */

#define        FE_TONEAREST        0x000        /* 000000000000 */

#define        FE_DOWNWARD        0x400        /* 010000000000 */

#define        FE_UPWARD        0x800        /* 100000000000 */

#define        FE_TOWARDZERO        0xC00        /* 110000000000 */

/*

 * As compared to the x87 control word, the SSE unit's control has the rounding

 * control bits offset by 3 and the exception mask bits offset by 7

 */

#define        __X87_ROUND_MASK        0xC00                /* 110000000000 */

#define        __SSE_ROUND_SHIFT        3

#define        __SSE_EMASK_SHIFT        7

/*

 * fenv_t represents the entire floating-point environment

 */

typedef struct {

        struct {

                uint16_t control;        /* Control word register */

                uint16_t unused1;

                uint16_t status;        /* Status word register */

                uint16_t unused2;

                uint16_t tag;                /* Tag word register */

                uint16_t unused3;

                uint32_t others[4];        /* EIP, Pointer Selector, etc */

        } x87;

        uint32_t mxcsr;                        /* Control and status register */

} fenv_t;

/*

 * The following constant 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  fenv_t                __fe_dfl_env;

#define FE_DFL_ENV      ((const fenv_t *) &__fe_dfl_env)

/*

 * fexcept_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 uint32_t fexcept_t;

#endif

#endif        /* ! _X86_FENV_H_ */