/*---------------------------------------------------------------------------+ | 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 // change a pointer to an int, with type conversions that make it legal. // On machines with 64-bit pointers, compilers complain when you typecast // a 64-bit pointer into a 32-bit integer. #define PTR2INT(x) ((bx_ptr_equiv_t)(void *)(x)) #ifdef __ASSEMBLY__ #include "fpu_asm.h" #define Const(x) $##x #else #include #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 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 /* for struct _fpstate */ #include #include /* #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 /* ifdef 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 { u32 offset; #ifdef EMU_BIG_ENDIAN u32 empty:5; u32 opcode:11; u32 selector:16; #else u32 selector:16; u32 opcode:11; u32 empty:5; #endif } GCC_ATTRIBUTE((packed)); struct fpu__reg { #ifdef EMU_BIG_ENDIAN u32 sigh; u32 sigl; s16 exp; /* Signed quantity used in internal arithmetic. */ #else u32 sigl; u32 sigh; s16 exp; /* Signed quantity used in internal arithmetic. */ #endif } GCC_ATTRIBUTE((aligned(16), packed)); #ifdef EMU_BIG_ENDIAN #define MAKE_REG(s,e,l,h) { h, l, \ ((EXTENDED_Ebias+(e)) | ((SIGN_##s != 0)*0x8000)) } #else #define MAKE_REG(s,e,l,h) { l, h, \ ((EXTENDED_Ebias+(e)) | ((SIGN_##s != 0)*0x8000)) } #endif 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; } GCC_ATTRIBUTE((packed)) overrides; /* This structure is 32 bits: */ typedef struct { overrides override; u_char default_mode; } GCC_ATTRIBUTE((packed)) 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 + sizeof(FPU_REG) * (x & 7) )) ) #define st(x) ( * ((FPU_REG *)( register_base + sizeof(FPU_REG) * ((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--; } #ifdef EMU_BIG_ENDIAN #define signbyte(a) (((u_char *)(a))[8]) #else #define signbyte(a) (((u_char *)(a))[9]) #endif #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) #ifdef EMU_BIG_ENDIAN #define significand(x) ( ((u64 *)&((x)->sigh))[0] ) #else #define significand(x) ( ((u64 *)&((x)->sigl))[0] ) #endif BX_C_INLINE void reg_copy(FPU_REG const *x, FPU_REG *y) { y->exp = x->exp; significand(y) = significand(x); } #define exponent(x) (((x)->exp & 0x7fff) - EXTENDED_Ebias) #define setexponentpos(x,y) { (x)->exp = ((y) + EXTENDED_Ebias) & 0x7fff; } #define exponent16(x) (x)->exp #define setexponent16(x,y) { (x)->exp = (y); } #define addexponent(x,y) { (x)->exp += (y); } #define stdexp(x) { (x)->exp += EXTENDED_Ebias; } #define isdenormal(ptr) (exponent(ptr) == EXP_BIAS+EXP_UNDER) /*----- Prototypes for functions written in assembler -----*/ /* extern void reg_move(FPU_REG *a, FPU_REG *b); */ asmlinkage int FPU_normalize_nuo(FPU_REG *x, int bias); asmlinkage int FPU_u_sub(FPU_REG const *arg1, FPU_REG const *arg2, FPU_REG *answ, u16 control_w, u_char sign, s32 expa, s32 expb); asmlinkage int FPU_u_mul(FPU_REG const *arg1, FPU_REG const *arg2, FPU_REG *answ, u16 control_w, u_char sign, s32 expon); asmlinkage int FPU_u_div(FPU_REG const *arg1, FPU_REG const *arg2, FPU_REG *answ, u16 control_w, u_char sign); asmlinkage int FPU_u_add(FPU_REG const *arg1, FPU_REG const *arg2, FPU_REG *answ, u16 control_w, u_char sign, s32 expa, s32 expb); asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2, u16 control_w, u_char sign); asmlinkage u32 FPU_shrx(void *l, u32 x); asmlinkage u32 FPU_shrxs(void *v, u32 x); asmlinkage u32 FPU_div_small(u64 *x, u32 y); asmlinkage int FPU_round(FPU_REG *arg, u32 extent, int dummy, u16 control_w, u_char sign); #ifndef MAKING_PROTO #include "fpu_proto.h" #endif #endif /* defined __ASSEMBLY__ */ #endif /* !defined _FPU_EMU_H_ */