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/*---------------------------------------------------------------------------+

 |  fpu_emu.h                                                                |

 |                                                                           |

 | Copyright (C) 1992,1993,1994                                              |

 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |

 |                       Australia.  E-mail   billm@vaxc.cc.monash.edu.au    |

 |                                                                           |

 +---------------------------------------------------------------------------*/

#ifndef _FPU_EMU_H_

#define _FPU_EMU_H_

/*

 * Define DENORM_OPERAND to make the emulator detect denormals

 * and use the denormal flag of the status word. Note: this only

 * affects the flag and corresponding interrupt, the emulator

 * will always generate denormals and operate upon them as required.

 */

#define DENORM_OPERAND

/*

 * Define PECULIAR_486 to get a closer approximation to 80486 behaviour,

 * rather than behaviour which appears to be cleaner.

 * This is a matter of opinion: for all I know, the 80486 may simply

 * be complying with the IEEE spec. Maybe one day I'll get to see the

 * spec...

 */

#define PECULIAR_486

#ifdef __ASSEMBLY__

#include "fpu_asm.h"

#define Const(x)        $##x

#else

#define Const(x)        x

#endif

#define EXP_BIAS        Const(0)

#define EXP_OVER        Const(0x4000)    /* smallest invalid large exponent */

#define EXP_UNDER       Const(-0x3fff)   /* largest invalid small exponent */

#define EXP_Infinity    EXP_OVER

#define EXP_NaN         EXP_OVER

#define SIGN_POS        Const(0)

#define SIGN_NEG        Const(1)

/* Keep the order TW_Valid, TW_Zero, TW_Denormal */

#define TW_Valid        Const(0)        /* valid */

#define TW_Zero         Const(1)        /* zero */

/* The following fold to 2 (Special) in the Tag Word */

/* #define TW_Denormal     Const(4) */       /* De-normal */

#define TW_Infinity     Const(5)        /* + or - infinity */

#define TW_NaN          Const(6)        /* Not a Number */

#define TW_Empty        Const(7)        /* empty */

#ifndef __ASSEMBLY__

#include <asm/sigcontext.h>     /* for struct _fpstate */

#include <asm/math_emu.h>

#include <linux/linkage.h>

/*

#define RE_ENTRANT_CHECKING

 */

#ifdef RE_ENTRANT_CHECKING

extern char emulating;

#  define RE_ENTRANT_CHECK_OFF emulating = 0

#  define RE_ENTRANT_CHECK_ON emulating = 1

#else

#  define RE_ENTRANT_CHECK_OFF

#  define RE_ENTRANT_CHECK_ON

#endif RE_ENTRANT_CHECKING

#define FWAIT_OPCODE 0x9b

#define OP_SIZE_PREFIX 0x66

#define ADDR_SIZE_PREFIX 0x67

#define PREFIX_CS 0x2e

#define PREFIX_DS 0x3e

#define PREFIX_ES 0x26

#define PREFIX_SS 0x36

#define PREFIX_FS 0x64

#define PREFIX_GS 0x65

#define PREFIX_REPE 0xf3

#define PREFIX_REPNE 0xf2

#define PREFIX_LOCK 0xf0

#define PREFIX_CS_ 1

#define PREFIX_DS_ 2

#define PREFIX_ES_ 3

#define PREFIX_FS_ 4

#define PREFIX_GS_ 5

#define PREFIX_SS_ 6

#define PREFIX_DEFAULT 7

struct address {

  unsigned int offset;

  unsigned short selector;

  unsigned short opcode:11,

                 empty:5;

};

typedef void (*FUNC)(void);

typedef struct fpu_reg FPU_REG;

typedef void (*FUNC_ST0)(FPU_REG *st0_ptr);

typedef struct { unsigned char address_size, operand_size, segment; }

        overrides;

/* This structure is 32 bits: */

typedef struct { overrides override;

                 unsigned char default_mode; } fpu_addr_modes;

/* PROTECTED has a restricted meaning in the emulator; it is used

   to signal that the emulator needs to do special things to ensure

   that protection is respected in a segmented model. */

#define PROTECTED 4

#define SIXTEEN   1         /* We rely upon this being 1 (true) */

#define VM86      SIXTEEN

#define PM16      (SIXTEEN | PROTECTED)

#define SEG32     PROTECTED

extern unsigned char const data_sizes_16[32];

#define st(x)   ( regs[((top+x) &7 )] )

#define STACK_OVERFLOW  (st_new_ptr = &st(-1), st_new_ptr->tag != TW_Empty)

#define NOT_EMPTY(i)    (st(i).tag != TW_Empty)

#define NOT_EMPTY_ST0   (st0_tag ^ TW_Empty)

#define pop()   { regs[(top++ & 7 )].tag = TW_Empty; }

#define poppop() { regs[((top + 1) & 7 )].tag \

                     = regs[(top & 7 )].tag = TW_Empty; \

                   top += 2; }

/* push() does not affect the tags */

#define push()  { top--; }

#define reg_move(x, y) { \

                 *(short *)&((y)->sign) = *(const short *)&((x)->sign); \

                 *(long *)&((y)->exp) = *(const long *)&((x)->exp); \

                 *(long long *)&((y)->sigl) = *(const long long *)&((x)->sigl); }

#define significand(x) ( ((unsigned long long *)&((x)->sigl))[0] )

/*----- Prototypes for functions written in assembler -----*/

/* extern void reg_move(FPU_REG *a, FPU_REG *b); */

asmlinkage void normalize(FPU_REG *x);

asmlinkage void normalize_nuo(FPU_REG *x);

asmlinkage int reg_div(FPU_REG const *arg1, FPU_REG const *arg2,

                       FPU_REG *answ, unsigned int control_w);

asmlinkage int reg_u_sub(FPU_REG const *arg1, FPU_REG const *arg2,

                         FPU_REG *answ, unsigned int control_w);

asmlinkage int reg_u_mul(FPU_REG const *arg1, FPU_REG const *arg2,

                         FPU_REG *answ, unsigned int control_w);

asmlinkage int reg_u_div(FPU_REG const *arg1, FPU_REG const *arg2,

                         FPU_REG *answ, unsigned int control_w);

asmlinkage int reg_u_add(FPU_REG const *arg1, FPU_REG const *arg2,

                         FPU_REG *answ, unsigned int control_w);

asmlinkage int wm_sqrt(FPU_REG *n, unsigned int control_w);

asmlinkage unsigned     shrx(void *l, unsigned x);

asmlinkage unsigned     shrxs(void *v, unsigned x);

asmlinkage unsigned long div_small(unsigned long long *x, unsigned long y);

asmlinkage void round_reg(FPU_REG *arg, unsigned int extent,

                      unsigned int control_w);

#ifndef MAKING_PROTO

#include "fpu_proto.h"

#endif

#endif __ASSEMBLY__

#endif _FPU_EMU_H_