source: branches/libc-0.6/src/emx/include/386/npx.h

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *      from: @(#)npx.h 5.3 (Berkeley) 1/18/91
 * $FreeBSD: src/sys/i386/include/npx.h,v 1.26 2002/09/23 05:55:10 peter Exp $
 */

/*
 * 287/387 NPX Coprocessor Data Structures and Constants
 * W. Jolitz 1/90
 */

/** @file
 * FreeBSD 5.1
 */

#ifndef _MACHINE_NPX_H_
#define _MACHINE_NPX_H_

/* Environment information of floating point unit */
struct env87 {
        long    en_cw;          /* control word (16bits) */
        long    en_sw;          /* status word (16bits) */
        long    en_tw;          /* tag word (16bits) */
        long    en_fip;         /* floating point instruction pointer */
        u_short en_fcs;         /* floating code segment selector */
        u_short en_opcode;      /* opcode last executed (11 bits ) */
        long    en_foo;         /* floating operand offset */
        long    en_fos;         /* floating operand segment selector */
};

/* Contents of each floating point accumulator */
struct fpacc87 {
#ifdef dontdef /* too unportable */
        u_long  fp_mantlo;      /* mantissa low (31:0) */
        u_long  fp_manthi;      /* mantissa high (63:32) */
        int     fp_exp:15;      /* exponent */
        int     fp_sgn:1;       /* mantissa sign */
#else
        u_char  fp_bytes[10];
#endif
};

/* Floating point context */
struct save87 {
        struct  env87 sv_env;   /* floating point control/status */
        struct  fpacc87 sv_ac[8];       /* accumulator contents, 0-7 */
        u_char  sv_pad0[4];     /* padding for (now unused) saved status word */
        /*
         * Bogus padding for emulators.  Emulators should use their own
         * struct and arrange to store into this struct (ending here)
         * before it is inspected for ptracing or for core dumps.  Some
         * emulators overwrite the whole struct.  We have no good way of
         * knowing how much padding to leave.  Leave just enough for the
         * GPL emulator's i387_union (176 bytes total).
         */
        u_char  sv_pad[64];     /* padding; used by emulators */
};

struct  envxmm {
        u_int16_t       en_cw;          /* control word (16bits) */
        u_int16_t       en_sw;          /* status word (16bits) */
        u_int16_t       en_tw;          /* tag word (16bits) */
        u_int16_t       en_opcode;      /* opcode last executed (11 bits ) */
        u_int32_t       en_fip;         /* floating point instruction pointer */
        u_int16_t       en_fcs;         /* floating code segment selector */
        u_int16_t       en_pad0;        /* padding */
        u_int32_t       en_foo;         /* floating operand offset */
        u_int16_t       en_fos;         /* floating operand segment selector */
        u_int16_t       en_pad1;        /* padding */
        u_int32_t       en_mxcsr;       /* SSE sontorol/status register */
        u_int32_t       en_pad2;        /* padding */
};

/* Contents of each SSE extended accumulator */
struct  xmmacc {
        u_char  xmm_bytes[16];
};

struct  savexmm {
        struct  envxmm  sv_env;
        struct {
                struct fpacc87  fp_acc;
                u_char          fp_pad[6];      /* padding */
        } sv_fp[8];
        struct xmmacc   sv_xmm[8];
        u_char sv_pad[224];
} __aligned(16);

union   savefpu {
        struct  save87  sv_87;
        struct  savexmm sv_xmm;
};

/*
 * The hardware default control word for i387's and later coprocessors is
 * 0x37F, giving:
 *
 *      round to nearest
 *      64-bit precision
 *      all exceptions masked.
 *
 * We modify the affine mode bit and precision bits in this to give:
 *
 *      affine mode for 287's (if they work at all) (1 in bitfield 1<<12)
 *      53-bit precision (2 in bitfield 3<<8)
 *
 * 64-bit precision often gives bad results with high level languages
 * because it makes the results of calculations depend on whether
 * intermediate values are stored in memory or in FPU registers.
 */
#define __INITIAL_NPXCW__       0x127F

#ifdef _KERNEL
int     npxdna(void);
void    npxdrop(void);
void    npxexit(struct thread *td);
int     npxformat(void);
int     npxgetregs(struct thread *td, union savefpu *addr);
void    npxinit(u_short control);
void    npxsave(union savefpu *addr);
void    npxsetregs(struct thread *td, union savefpu *addr);
int     npxtrap(void);
#endif

#endif /* !_MACHINE_NPX_H_ */