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 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) 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. */ 34#define EXP_Infinity EXP_OVER 35#define EXP_NaN EXP_OVER 36 37#define EXTENDED_Ebias Const(0x3fff) 38#define EXTENDED_Emin (-0x3ffe) /* smallest valid exponent */ 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 46/* Keep the order TAG_Valid, TAG_Zero, TW_Denormal */ 47/* The following fold to 2 (Special) in the Tag Word */ 48#define TW_Denormal Const(4) /* De-normal */ 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 */ 58#define TAG_Error Const(0x80) /* probably need to abort */ 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 68#define FPU_Exception Const(0x80000000) /* Added to tag returns. */ 69 70#ifndef __ASSEMBLY__ 71 72#include "fpu_system.h" 73 74#include <asm/sigcontext.h> /* for struct _fpstate */ 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 83extern 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 111struct address { 112 unsigned int offset; 113 unsigned int selector:16; 114 unsigned int opcode:11; 115 unsigned int empty:5; 116}; 117struct fpu__reg { 118 unsigned sigl; 119 unsigned sigh; 120 short exp; 121}; 122 123typedef void (*FUNC) (void); 124typedef struct fpu__reg FPU_REG; 125typedef void (*FUNC_ST0) (FPU_REG *st0_ptr, u_char st0_tag); 126typedef struct { 127 u_char address_size, operand_size, segment; 128} overrides; 129/* This structure is 32 bits: */ 130typedef struct { 131 overrides override; 132 u_char default_mode; 133} fpu_addr_modes; 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 4 138#define SIXTEEN 1 /* We rely upon this being 1 (true) */ 139#define VM86 SIXTEEN 140#define PM16 (SIXTEEN | PROTECTED) 141#define SEG32 PROTECTED 142extern 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) 160#define setsign(a,b) { if (b) signbyte(a) |= 0x80; else signbyte(a) &= 0x7f; } 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 169static inline void reg_copy(FPU_REG const *x, FPU_REG *y) 170{ 171 *(short *)&(y->exp) = *(const short *)&(x->exp); 172 *(long long *)&(y->sigl) = *(const long long *)&(x->sigl); 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] ) 186 187/*----- Prototypes for functions written in assembler -----*/ 188/* extern void reg_move(FPU_REG *a, FPU_REG *b); */ 189 190asmlinkage int FPU_normalize(FPU_REG *x); 191asmlinkage int FPU_normalize_nuo(FPU_REG *x); 192asmlinkage int FPU_u_sub(FPU_REG const *arg1, FPU_REG const *arg2, 193 FPU_REG * answ, unsigned int control_w, u_char sign, 194 int expa, int expb); 195asmlinkage int FPU_u_mul(FPU_REG const *arg1, FPU_REG const *arg2, 196 FPU_REG * answ, unsigned int control_w, u_char sign, 197 int expon); 198asmlinkage int FPU_u_div(FPU_REG const *arg1, FPU_REG const *arg2, 199 FPU_REG * answ, unsigned int control_w, u_char sign); 200asmlinkage int FPU_u_add(FPU_REG const *arg1, FPU_REG const *arg2, 201 FPU_REG * answ, unsigned int control_w, u_char sign, 202 int expa, int expb); 203asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2, 204 unsigned int control_w, u_char sign); 205asmlinkage unsigned FPU_shrx(void *l, unsigned x); 206asmlinkage unsigned FPU_shrxs(void *v, unsigned x); 207asmlinkage unsigned long FPU_div_small(unsigned long long *x, unsigned long y); 208asmlinkage int FPU_round(FPU_REG *arg, unsigned int extent, int dummy, 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_ */ 218