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Diffstat (limited to 'arch/x86/math-emu/fpu_emu.h')
| -rw-r--r-- | arch/x86/math-emu/fpu_emu.h | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/arch/x86/math-emu/fpu_emu.h b/arch/x86/math-emu/fpu_emu.h new file mode 100644 index 000000000..0c122226c --- /dev/null +++ b/arch/x86/math-emu/fpu_emu.h @@ -0,0 +1,218 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*---------------------------------------------------------------------------+ + | 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)) = (u16)(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_ */ |