176 lines
5.9 KiB
C
176 lines
5.9 KiB
C
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/*
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* fpu_emu.h
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*
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*
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* Copyright (C) 1992, 1993 W. Metzenthen, 22 Parker St, Ormond,
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* Vic 3163, Australia.
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* E-mail apm233m@vaxc.cc.monash.edu.au
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* All rights reserved.
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*
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* This copyright notice covers the redistribution and use of the
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* FPU emulator developed by W. Metzenthen. It covers only its use
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* in the 386BSD operating system. Any other use is not permitted
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* under this copyright.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must include information specifying
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* that source code for the emulator is freely available and include
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* either:
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* a) an offer to provide the source code for a nominal distribution
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* fee, or
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* b) list at least two alternative methods whereby the source
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* can be obtained, e.g. a publically accessible bulletin board
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* and an anonymous ftp site from which the software can be
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* downloaded.
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* 3. All advertising materials specifically mentioning features or use of
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* this emulator must acknowledge that it was developed by W. Metzenthen.
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* 4. The name of W. Metzenthen may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* W. METZENTHEN BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#ifndef _FPU_EMU_H_
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#define _FPU_EMU_H_
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/*
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* Define DENORM_OPERAND to make the emulator detect denormals
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* and use the denormal flag of the status word. Note: this only
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* affects the flag and corresponding interrupt, the emulator
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* will always generate denormals and operate upon them as required.
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*/
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#define DENORM_OPERAND
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/*
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* Define PECULIAR_486 to get a closer approximation to 80486 behaviour,
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* rather than behaviour which appears to be cleaner.
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* This is a matter of opinion: for all I know, the 80486 may simply
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* be complying with the IEEE spec. Maybe one day I'll get to see the
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* spec...
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*/
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#define PECULIAR_486
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#ifdef LOCORE
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#include "fpu_asm.h"
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#define Const(x) $/**/x
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#else
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#define Const(x) x
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#endif
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#define EXP_BIAS Const(0)
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#define EXP_OVER Const(0x4000) /* smallest invalid large exponent */
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#define EXP_UNDER Const(-0x3fff) /* largest invalid small exponent */
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#define SIGN_POS Const(0)
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#define SIGN_NEG Const(1)
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/* Keep the order TW_Valid, TW_Zero, TW_Denormal */
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#define TW_Valid Const(0)/* valid */
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#define TW_Zero Const(1)/* zero */
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/* The following fold to 2 (Special) in the Tag Word */
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#define TW_Denormal Const(4)/* De-normal */
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#define TW_Infinity Const(5)/* + or - infinity */
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#define TW_NaN Const(6)/* Not a Number */
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#define TW_Empty Const(7)/* empty */
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/* #define TW_FPU_Interrupt Const(0x80) *//* Signals an interrupt */
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#ifndef LOCORE
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#include "types.h"
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#include "math_emu.h"
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#ifdef PARANOID
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extern char emulating;
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#define REENTRANT_CHECK(state) emulating = (state)
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#define ON 1
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#define OFF 0
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#else
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#define REENTRANT_CHECK(state)
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#endif /* PARANOID */
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typedef void (*FUNC) (void);
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typedef struct fpu_reg FPU_REG;
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#define st(x) ( regs[((top+x) &7 )] )
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#define STACK_OVERFLOW (st_new_ptr = &st(-1), st_new_ptr->tag != TW_Empty)
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#define NOT_EMPTY(i) (st(i).tag != TW_Empty)
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#define NOT_EMPTY_0 (FPU_st0_tag ^ TW_Empty)
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extern unsigned char FPU_rm;
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extern char FPU_st0_tag;
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extern FPU_REG *FPU_st0_ptr;
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extern void *FPU_data_address;
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extern FPU_REG FPU_loaded_data;
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#define pop() { FPU_st0_ptr->tag = TW_Empty; top++; }
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/* push() does not affect the tags */
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#define push() { top--; FPU_st0_ptr = st_new_ptr; }
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#define reg_move(x, y) { \
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*(short *)&((y)->sign) = *(short *)&((x)->sign); \
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*(long *)&((y)->exp) = *(long *)&((x)->exp); \
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*(long long *)&((y)->sigl) = *(long long *)&((x)->sigl); }
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/*----- Prototypes for functions written in assembler -----*/
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/* extern void reg_move(FPU_REG *a, FPU_REG *b); */
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extern void mul64(long long *a, long long *b, long long *result);
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extern void poly_div2(long long *x);
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extern void poly_div4(long long *x);
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extern void poly_div16(long long *x);
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extern void
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polynomial(unsigned accum[], unsigned x[],
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unsigned short terms[][4], int n);
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extern void normalize(FPU_REG * x);
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extern void normalize_nuo(FPU_REG * x);
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extern void reg_div(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
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unsigned int control_w);
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extern void reg_u_sub(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
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unsigned int control_w);
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extern void reg_u_mul(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
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unsigned int control_w);
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extern void reg_u_div(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
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unsigned int control_w);
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extern void reg_u_add(FPU_REG * arg1, FPU_REG * arg2, FPU_REG * answ,
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unsigned int control_w);
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extern void wm_sqrt(FPU_REG * n, unsigned int control_w);
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extern unsigned shrx(void *l, unsigned x);
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extern unsigned shrxs(void *v, unsigned x);
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extern unsigned long div_small(unsigned long long *x, unsigned long y);
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extern void round_reg(FPU_REG * arg, unsigned int extent,
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unsigned int control_w);
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#ifndef MAKING_PROTO
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#include "fpu_proto.h"
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#endif
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#endif /* LOCORE */
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#endif /* _FPU_EMU_H_ */
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