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/*
* fpu_emu.h
*
*
* Copyright (C) 1992, 1993 W. Metzenthen, 22 Parker St, Ormond,
* Vic 3163, Australia.
* E-mail apm233m@vaxc.cc.monash.edu.au
* All rights reserved.
*
* This copyright notice covers the redistribution and use of the
* FPU emulator developed by W. Metzenthen. It covers only its use
* in the 386BSD operating system. Any other use is not permitted
* under this copyright.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must include information specifying
* that source code for the emulator is freely available and include
* either:
* a) an offer to provide the source code for a nominal distribution
* fee, or
* b) list at least two alternative methods whereby the source
* can be obtained, e.g. a publically accessible bulletin board
* and an anonymous ftp site from which the software can be
* downloaded.
* 3. All advertising materials specifically mentioning features or use of
* this emulator must acknowledge that it was developed by W. Metzenthen.
* 4. The name of W. Metzenthen may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* W. METZENTHEN BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef _FPU_EMU_H_
#define _FPU_EMU_H_
/*
* Define DENORM_OPERAND to make the emulator detect denormals
* and use the denormal flag of the status word. Note: this only
* affects the flag and corresponding interrupt, the emulator
* will always generate denormals and operate upon them as required.
*/
#define DENORM_OPERAND
/*
* 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 LOCORE
#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 SIGN_POS Const(0)
#define SIGN_NEG Const(1)
/* Keep the order TW_Valid, TW_Zero, TW_Denormal */
#define TW_Valid Const(0)/* valid */
#define TW_Zero Const(1)/* zero */
/* 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_Empty Const(7)/* empty */
/* #define TW_FPU_Interrupt Const(0x80) *//* Signals an interrupt */
#ifndef LOCORE
#include "types.h"
#include "math_emu.h"
#ifdef PARANOID
extern char emulating;
#define REENTRANT_CHECK(state) emulating = (state)
#define ON 1
#define OFF 0
#else
#define REENTRANT_CHECK(state)
#endif /* PARANOID */
typedef void (*FUNC) (void);
typedef struct fpu_reg FPU_REG;
#define st(x) ( regs[((top+x) &7 )] )
#define STACK_OVERFLOW (st_new_ptr = &st(-1), st_new_ptr->tag != TW_Empty)
#define NOT_EMPTY(i) (st(i).tag != TW_Empty)
#define NOT_EMPTY_0 (FPU_st0_tag ^ TW_Empty)
extern unsigned char FPU_rm;
extern char FPU_st0_tag;
extern FPU_REG *FPU_st0_ptr;
extern void *FPU_data_address;
extern FPU_REG FPU_loaded_data;
#define pop() { FPU_st0_ptr->tag = TW_Empty; top++; }
/* push() does not affect the tags */
#define push() { top--; FPU_st0_ptr = st_new_ptr; }
#define reg_move(x, y) { \
*(short *)&((y)->sign) = *(short *)&((x)->sign); \
*(long *)&((y)->exp) = *(long *)&((x)->exp); \
*(long long *)&((y)->sigl) = *(long long *)&((x)->sigl); }
/*----- Prototypes for functions written in assembler -----*/
/* extern void reg_move(FPU_REG *a, FPU_REG *b); */
extern void mul64(long long *a, long long *b, long long *result);
extern void poly_div2(long long *x);
extern void poly_div4(long long *x);
extern void poly_div16(long long *x);
extern void
polynomial(unsigned accum[], unsigned x[],
unsigned short terms[][4], int n);
extern void normalize(FPU_REG * x);
extern void normalize_nuo(FPU_REG * x);
extern void reg_div(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
unsigned int control_w);
extern void reg_u_sub(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
unsigned int control_w);
extern void reg_u_mul(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
unsigned int control_w);
extern void reg_u_div(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
unsigned int control_w);
extern void reg_u_add(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
unsigned int control_w);
extern void wm_sqrt(FPU_REG * n, unsigned int control_w);
extern unsigned shrx(void *l, unsigned x);
extern unsigned shrxs(void *v, unsigned x);
extern unsigned long div_small(unsigned long long *x, unsigned long y);
extern void round_reg(FPU_REG * arg, unsigned int extent,
unsigned int control_w);
#ifndef MAKING_PROTO
#include "fpu_proto.h"
#endif
#endif /* LOCORE */
#endif /* _FPU_EMU_H_ */
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