[mirror_ubuntu-artful-kernel.git] / arch / x86 / math-emu / fpu_emu.h

/*---------------------------------------------------------------------------+
 |  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 <uapi/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) != 0) 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_ */
Commit	Line	Data
1da177e4 LT	1	/*---------------------------------------------------------------------------+
	2	\| fpu_emu.h \|
	3	\| \|
	4	\| Copyright (C) 1992,1993,1994,1997 \|
	5	\| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, \|
	6	\| Australia. E-mail billm@suburbia.net \|
	7	\| \|
	8	+---------------------------------------------------------------------------*/
	9
1da177e4 LT	10	#ifndef _FPU_EMU_H_
	11	#define _FPU_EMU_H_
	12
	13	/*
	14	* Define PECULIAR_486 to get a closer approximation to 80486 behaviour,
	15	* rather than behaviour which appears to be cleaner.
	16	* This is a matter of opinion: for all I know, the 80486 may simply
	17	* be complying with the IEEE spec. Maybe one day I'll get to see the
	18	* spec...
	19	*/
	20	#define PECULIAR_486
	21
	22	#ifdef __ASSEMBLY__
	23	#include "fpu_asm.h"
	24	#define Const(x) $##x
	25	#else
	26	#define Const(x) x
	27	#endif
	28
	29	#define EXP_BIAS Const(0)
3d0d14f9 IM	30	#define EXP_OVER Const(0x4000) /* smallest invalid large exponent */
	31	#define EXP_UNDER Const(-0x3fff) /* largest invalid small exponent */
	32	#define EXP_WAY_UNDER Const(-0x6000) /* Below the smallest denormal, but
	33	still a 16 bit nr. */
1da177e4 LT	34	#define EXP_Infinity EXP_OVER
	35	#define EXP_NaN EXP_OVER
	36
	37	#define EXTENDED_Ebias Const(0x3fff)
3d0d14f9	38	#define EXTENDED_Emin (-0x3ffe) /* smallest valid exponent */
1da177e4 LT	39
	40	#define SIGN_POS Const(0)
	41	#define SIGN_NEG Const(0x80)
	42
	43	#define SIGN_Positive Const(0)
	44	#define SIGN_Negative Const(0x8000)
	45
1da177e4 LT	46	/* Keep the order TAG_Valid, TAG_Zero, TW_Denormal */
1da177e4 LT	47	/* The following fold to 2 (Special) in the Tag Word */
3d0d14f9	48	#define TW_Denormal Const(4) /* De-normal */
1da177e4 LT	49	#define TW_Infinity Const(5) /* + or - infinity */
	50	#define TW_NaN Const(6) /* Not a Number */
	51	#define TW_Unsupported Const(7) /* Not supported by an 80486 */
	52
	53	#define TAG_Valid Const(0) /* valid */
	54	#define TAG_Zero Const(1) /* zero */
	55	#define TAG_Special Const(2) /* De-normal, + or - infinity,
	56	or Not a Number */
	57	#define TAG_Empty Const(3) /* empty */
d606f88f	58	#define TAG_Error Const(0x80) /* probably need to abort */
1da177e4 LT	59
	60	#define LOADED_DATA Const(10101) /* Special st() number to identify
	61	loaded data (not on stack). */
	62
	63	/* A few flags (must be >= 0x10). */
	64	#define REV 0x10
	65	#define DEST_RM 0x20
	66	#define LOADED 0x40
	67
3d0d14f9	68	#define FPU_Exception Const(0x80000000) /* Added to tag returns. */
1da177e4 LT	69
	70	#ifndef __ASSEMBLY__
	71
	72	#include "fpu_system.h"
	73
decb4c41	74	#include <uapi/asm/sigcontext.h> /* for struct _fpstate */
1da177e4 LT	75	#include <asm/math_emu.h>
	76	#include <linux/linkage.h>
	77
	78	/*
	79	#define RE_ENTRANT_CHECKING
	80	*/
	81
	82	#ifdef RE_ENTRANT_CHECKING
	83	extern u_char emulating;
	84	# define RE_ENTRANT_CHECK_OFF emulating = 0
	85	# define RE_ENTRANT_CHECK_ON emulating = 1
	86	#else
	87	# define RE_ENTRANT_CHECK_OFF
	88	# define RE_ENTRANT_CHECK_ON
	89	#endif /* RE_ENTRANT_CHECKING */
	90
	91	#define FWAIT_OPCODE 0x9b
	92	#define OP_SIZE_PREFIX 0x66
	93	#define ADDR_SIZE_PREFIX 0x67
	94	#define PREFIX_CS 0x2e
	95	#define PREFIX_DS 0x3e
	96	#define PREFIX_ES 0x26
	97	#define PREFIX_SS 0x36
	98	#define PREFIX_FS 0x64
	99	#define PREFIX_GS 0x65
	100	#define PREFIX_REPE 0xf3
	101	#define PREFIX_REPNE 0xf2
	102	#define PREFIX_LOCK 0xf0
	103	#define PREFIX_CS_ 1
	104	#define PREFIX_DS_ 2
	105	#define PREFIX_ES_ 3
	106	#define PREFIX_FS_ 4
	107	#define PREFIX_GS_ 5
	108	#define PREFIX_SS_ 6
	109	#define PREFIX_DEFAULT 7
	110
	111	struct address {
3d0d14f9 IM	112	unsigned int offset;
	113	unsigned int selector:16;
	114	unsigned int opcode:11;
	115	unsigned int empty:5;
1da177e4 LT	116	};
1da177e4 LT	117	struct fpu__reg {
3d0d14f9 IM	118	unsigned sigl;
	119	unsigned sigh;
	120	short exp;
1da177e4 LT	121	};
1da177e4 LT	122
3d0d14f9	123	typedef void (*FUNC) (void);
1da177e4	124	typedef struct fpu__reg FPU_REG;
e8d591dc	125	typedef void (FUNC_ST0) (FPU_REG st0_ptr, u_char st0_tag);
3d0d14f9 IM	126	typedef struct {
	127	u_char address_size, operand_size, segment;
	128	} overrides;
1da177e4	129	/* This structure is 32 bits: */
3d0d14f9 IM	130	typedef struct {
	131	overrides override;
	132	u_char default_mode;
	133	} fpu_addr_modes;
1da177e4 LT	134	/* PROTECTED has a restricted meaning in the emulator; it is used
	135	to signal that the emulator needs to do special things to ensure
	136	that protection is respected in a segmented model. */
	137	#define PROTECTED 4
3d0d14f9	138	#define SIXTEEN 1 /* We rely upon this being 1 (true) */
1da177e4 LT	139	#define VM86 SIXTEEN
	140	#define PM16 (SIXTEEN \| PROTECTED)
	141	#define SEG32 PROTECTED
	142	extern u_char const data_sizes_16[32];
	143
	144	#define register_base ((u_char *) registers )
	145	#define fpu_register(x) ( * ((FPU_REG )( register_base + 10 (x & 7) )) )
	146	#define st(x) ( * ((FPU_REG )( register_base + 10 ((top+x) & 7) )) )
	147
	148	#define STACK_OVERFLOW (FPU_stackoverflow(&st_new_ptr))
	149	#define NOT_EMPTY(i) (!FPU_empty_i(i))
	150
	151	#define NOT_EMPTY_ST0 (st0_tag ^ TAG_Empty)
	152
	153	#define poppop() { FPU_pop(); FPU_pop(); }
	154
	155	/* push() does not affect the tags */
	156	#define push() { top--; }
	157
	158	#define signbyte(a) (((u_char *)(a))[9])
	159	#define getsign(a) (signbyte(a) & 0x80)
5623452a	160	#define setsign(a,b) { if ((b) != 0) signbyte(a) \|= 0x80; else signbyte(a) &= 0x7f; }
1da177e4 LT	161	#define copysign(a,b) { if (getsign(a)) signbyte(b) \|= 0x80; \
	162	else signbyte(b) &= 0x7f; }
	163	#define changesign(a) { signbyte(a) ^= 0x80; }
	164	#define setpositive(a) { signbyte(a) &= 0x7f; }
	165	#define setnegative(a) { signbyte(a) \|= 0x80; }
	166	#define signpositive(a) ( (signbyte(a) & 0x80) == 0 )
	167	#define signnegative(a) (signbyte(a) & 0x80)
	168
e8d591dc	169	static inline void reg_copy(FPU_REG const x, FPU_REG y)
1da177e4	170	{
3d0d14f9 IM	171	(short )&(y->exp) = (const short )&(x->exp);
3d0d14f9 IM	172	(long long )&(y->sigl) = (const long long )&(x->sigl);
1da177e4 LT	173	}
	174
	175	#define exponent(x) ((((short )&((x)->exp)) & 0x7fff) - EXTENDED_Ebias)
	176	#define setexponentpos(x,y) { ((short )&((x)->exp)) = \
	177	((y) + EXTENDED_Ebias) & 0x7fff; }
	178	#define exponent16(x) ((short )&((x)->exp))
	179	#define setexponent16(x,y) { ((short )&((x)->exp)) = (y); }
	180	#define addexponent(x,y) { ((short )&((x)->exp)) += (y); }
	181	#define stdexp(x) { ((short )&((x)->exp)) += EXTENDED_Ebias; }
	182
	183	#define isdenormal(ptr) (exponent(ptr) == EXP_BIAS+EXP_UNDER)
	184
	185	#define significand(x) ( ((unsigned long long *)&((x)->sigl))[0] )
	186
1da177e4 LT	187	/----- Prototypes for functions written in assembler -----/
	188	/* extern void reg_move(FPU_REG a, FPU_REG b); */
	189
e8d591dc IM	190	asmlinkage int FPU_normalize(FPU_REG *x);
e8d591dc IM	191	asmlinkage int FPU_normalize_nuo(FPU_REG *x);
1da177e4	192	asmlinkage int FPU_u_sub(FPU_REG const arg1, FPU_REG const arg2,
3d0d14f9	193	FPU_REG * answ, unsigned int control_w, u_char sign,
1da177e4 LT	194	int expa, int expb);
1da177e4 LT	195	asmlinkage int FPU_u_mul(FPU_REG const arg1, FPU_REG const arg2,
3d0d14f9	196	FPU_REG * answ, unsigned int control_w, u_char sign,
1da177e4 LT	197	int expon);
1da177e4 LT	198	asmlinkage int FPU_u_div(FPU_REG const arg1, FPU_REG const arg2,
3d0d14f9	199	FPU_REG * answ, unsigned int control_w, u_char sign);
1da177e4	200	asmlinkage int FPU_u_add(FPU_REG const arg1, FPU_REG const arg2,
3d0d14f9	201	FPU_REG * answ, unsigned int control_w, u_char sign,
1da177e4	202	int expa, int expb);
e8d591dc	203	asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2,
1da177e4	204	unsigned int control_w, u_char sign);
3d0d14f9 IM	205	asmlinkage unsigned FPU_shrx(void *l, unsigned x);
3d0d14f9 IM	206	asmlinkage unsigned FPU_shrxs(void *v, unsigned x);
1da177e4	207	asmlinkage unsigned long FPU_div_small(unsigned long long *x, unsigned long y);
e8d591dc	208	asmlinkage int FPU_round(FPU_REG *arg, unsigned int extent, int dummy,
1da177e4 LT	209	unsigned int control_w, u_char sign);
	210
	211	#ifndef MAKING_PROTO
	212	#include "fpu_proto.h"
	213	#endif
	214
	215	#endif /* __ASSEMBLY__ */
	216
	217	#endif /* _FPU_EMU_H_ */