fpu_regs.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef __X86EMU_FPU_REGS_H
#define __X86EMU_FPU_REGS_H

#ifdef X86_FPU_SUPPORT

#ifdef PACK
#pragma PACK
#endif

/* Basic 8087 register can hold any of the following values: */

union x86_fpu_reg_u
{
    s8 tenbytes[10];
    double dval;
    float fval;
    s16 sval;
    s32 lval;
};

struct x86_fpu_reg
{
    union x86_fpu_reg_u reg;
    char tag;
};

/*
 * Since we are not going to worry about the problems of aliasing
 * registers, every time a register is modified, its result type is
 * set in the tag fields for that register.  If some operation
 * attempts to access the type in a way inconsistent with its current
 * storage format, then we flag the operation.  If common, we'll
 * attempt the conversion.
 */

#define X86_FPU_VALID 0x80
#define X86_FPU_REGTYP(r) ((r) &0x7F)

#define X86_FPU_WORD 0x0
#define X86_FPU_SHORT 0x1
#define X86_FPU_LONG 0x2
#define X86_FPU_FLOAT 0x3
#define X86_FPU_DOUBLE 0x4
#define X86_FPU_LDBL 0x5
#define X86_FPU_BSD 0x6

#define X86_FPU_STKTOP 0

struct x86_fpu_registers
{
    struct x86_fpu_reg x86_fpu_stack[8];
    int x86_fpu_flags;
    int x86_fpu_config; /* rounding modes, etc. */
    short x86_fpu_tos, x86_fpu_bos;
};

#ifdef END_PACK
#pragma END_PACK
#endif

/*
 * There are two versions of the following macro.
 *
 * One version is for opcode D9, for which there are more than 32
 * instructions encoded in the second byte of the opcode.
 *
 * The other version, deals with all the other 7 i87 opcodes, for
 * which there are only 32 strings needed to describe the
 * instructions.
 */

#endif /* X86_FPU_SUPPORT */

#ifdef DEBUG
#define DECODE_PRINTINSTR32(t, mod, rh, rl) DECODE_PRINTF(t[(mod << 3) + (rh)]);
#define DECODE_PRINTINSTR256(t, mod, rh, rl) \
    DECODE_PRINTF(t[(mod << 6) + (rh << 3) + (rl)]);
#else
#define DECODE_PRINTINSTR32(t, mod, rh, rl)
#define DECODE_PRINTINSTR256(t, mod, rh, rl)
#endif

#endif /* __X86EMU_FPU_REGS_H */