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 <uapi/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 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 { 112 unsigned int offset; 113 unsigned int selector:16; 114 unsigned int opcode:11; 115 unsigned int empty:5; 116 }; 117 struct fpu__reg { 118 unsigned sigl; 119 unsigned sigh; 120 short exp; 121 }; 122 123 typedef void (*FUNC) (void); 124 typedef struct fpu__reg FPU_REG; 125 typedef void (*FUNC_ST0) (FPU_REG *st0_ptr, u_char st0_tag); 126 typedef struct { 127 u_char address_size, operand_size, segment; 128 } overrides; 129 /* This structure is 32 bits: */ 130 typedef 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 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) 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) 168 169 static 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); */ 189 190 asmlinkage int FPU_normalize(FPU_REG *x); 191 asmlinkage int FPU_normalize_nuo(FPU_REG *x); 192 asmlinkage 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); 195 asmlinkage 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); 198 asmlinkage int FPU_u_div(FPU_REG const *arg1, FPU_REG const *arg2, 199 FPU_REG * answ, unsigned int control_w, u_char sign); 200 asmlinkage 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); 203 asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2, 204 unsigned int control_w, u_char sign); 205 asmlinkage unsigned FPU_shrx(void *l, unsigned x); 206 asmlinkage unsigned FPU_shrxs(void *v, unsigned x); 207 asmlinkage unsigned long FPU_div_small(unsigned long long *x, unsigned long y); 208 asmlinkage 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