/*---------------------------------------------------------------------------+
| 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_
