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|
/*---------------------------------------------------------------------------+
| fpu_emu.h |
| |
| Copyright (C) 1992,1993,1994,1997 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@suburbia.net |
| |
+---------------------------------------------------------------------------*/
#ifndef _FPU_EMU_H_
#define _FPU_EMU_H_
/*
* 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_WAY_UNDER Const(-0x6000) /* Below the smallest denormal, but
still a 16 bit nr. */
#define EXP_Infinity EXP_OVER
#define EXP_NaN EXP_OVER
#define EXTENDED_Ebias Const(0x3fff)
#define EXTENDED_Emin (-0x3ffe) /* smallest valid exponent */
#define SIGN_POS Const(0)
#define SIGN_NEG Const(0x80)
#define SIGN_Positive Const(0)
#define SIGN_Negative Const(0x8000)
/* Keep the order TAG_Valid, TAG_Zero, TW_Denormal */
/* 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_Unsupported Const(7) /* Not supported by an 80486 */
#define TAG_Valid Const(0) /* valid */
#define TAG_Zero Const(1) /* zero */
#define TAG_Special Const(2) /* De-normal, + or - infinity,
or Not a Number */
#define TAG_Empty Const(3) /* empty */
#define TAG_Error Const(0x80) /* probably need to abort */
#define LOADED_DATA Const(10101) /* Special st() number to identify
loaded data (not on stack). */
/* A few flags (must be >= 0x10). */
#define REV 0x10
#define DEST_RM 0x20
#define LOADED 0x40
#define FPU_Exception Const(0x80000000) /* Added to tag returns. */
#ifndef __ASSEMBLY__
#include "fpu_system.h"
#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 u_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 int selector:16;
unsigned int opcode:11;
unsigned int empty:5;
};
struct fpu__reg {
unsigned sigl;
unsigned sigh;
short exp;
};
typedef void (*FUNC)(void);
typedef struct fpu__reg FPU_REG;
typedef void (*FUNC_ST0)(FPU_REG *st0_ptr, u_char st0_tag);
typedef struct { u_char address_size, operand_size, segment; }
overrides;
/* This structure is 32 bits: */
typedef struct { overrides override;
u_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 u_char const data_sizes_16[32];
#define register_base ((u_char *) registers )
#define fpu_register(x) ( * ((FPU_REG *)( register_base + 10 * (x & 7) )) )
#define st(x) ( * ((FPU_REG *)( register_base + 10 * ((top+x) & 7) )) )
#define STACK_OVERFLOW (FPU_stackoverflow(&st_new_ptr))
#define NOT_EMPTY(i) (!FPU_empty_i(i))
#define NOT_EMPTY_ST0 (st0_tag ^ TAG_Empty)
#define poppop() { FPU_pop(); FPU_pop(); }
/* push() does not affect the tags */
#define push() { top--; }
#define signbyte(a) (((u_char *)(a))[9])
#define getsign(a) (signbyte(a) & 0x80)
#define setsign(a,b) { if (b) signbyte(a) |= 0x80; else signbyte(a) &= 0x7f; }
#define copysign(a,b) { if (getsign(a)) signbyte(b) |= 0x80; \
else signbyte(b) &= 0x7f; }
#define changesign(a) { signbyte(a) ^= 0x80; }
#define setpositive(a) { signbyte(a) &= 0x7f; }
#define setnegative(a) { signbyte(a) |= 0x80; }
#define signpositive(a) ( (signbyte(a) & 0x80) == 0 )
#define signnegative(a) (signbyte(a) & 0x80)
static inline void reg_copy(FPU_REG const *x, FPU_REG *y)
{
*(short *)&(y->exp) = *(const short *)&(x->exp);
*(long long *)&(y->sigl) = *(const long long *)&(x->sigl);
}
#define exponent(x) (((*(short *)&((x)->exp)) & 0x7fff) - EXTENDED_Ebias)
#define setexponentpos(x,y) { (*(short *)&((x)->exp)) = \
((y) + EXTENDED_Ebias) & 0x7fff; }
#define exponent16(x) (*(short *)&((x)->exp))
#define setexponent16(x,y) { (*(short *)&((x)->exp)) = (y); }
#define addexponent(x,y) { (*(short *)&((x)->exp)) += (y); }
#define stdexp(x) { (*(short *)&((x)->exp)) += EXTENDED_Ebias; }
#define isdenormal(ptr) (exponent(ptr) == EXP_BIAS+EXP_UNDER)
#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 int FPU_normalize(FPU_REG *x);
asmlinkage int FPU_normalize_nuo(FPU_REG *x);
asmlinkage int FPU_u_sub(FPU_REG const *arg1, FPU_REG const *arg2,
FPU_REG *answ, unsigned int control_w, u_char sign,
int expa, int expb);
asmlinkage int FPU_u_mul(FPU_REG const *arg1, FPU_REG const *arg2,
FPU_REG *answ, unsigned int control_w, u_char sign,
int expon);
asmlinkage int FPU_u_div(FPU_REG const *arg1, FPU_REG const *arg2,
FPU_REG *answ, unsigned int control_w, u_char sign);
asmlinkage int FPU_u_add(FPU_REG const *arg1, FPU_REG const *arg2,
FPU_REG *answ, unsigned int control_w, u_char sign,
int expa, int expb);
asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2,
unsigned int control_w, u_char sign);
asmlinkage unsigned FPU_shrx(void *l, unsigned x);
asmlinkage unsigned FPU_shrxs(void *v, unsigned x);
asmlinkage unsigned long FPU_div_small(unsigned long long *x, unsigned long y);
asmlinkage int FPU_round(FPU_REG *arg, unsigned int extent, int dummy,
unsigned int control_w, u_char sign);
#ifndef MAKING_PROTO
#include "fpu_proto.h"
#endif
#endif /* __ASSEMBLY__ */
#endif /* _FPU_EMU_H_ */
|
