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/* $OpenBSD: fpu_etc.c,v 1.1 1996/08/27 10:32:48 downsj Exp $ */
/*
* fpu_etc.c
*
* Implement a few FPU instructions.
*
*
* Copyright (C) 1992,1993,1994
* W. Metzenthen, 22 Parker St, Ormond, Vic 3163,
* Australia. E-mail billm@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, FreeBSD and NetBSD operating systems. 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.
*
*
* The purpose of this copyright, based upon the Berkeley copyright, is to
* ensure that the covered software remains freely available to everyone.
*
* The software (with necessary differences) is also available, but under
* the terms of the GNU copyleft, for the Linux operating system and for
* the djgpp ms-dos extender.
*
* W. Metzenthen June 1994.
*
*
* $FreeBSD: fpu_etc.c,v 1.3 1994/06/10 07:44:24 rich Exp $
*
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <machine/cpu.h>
#include <machine/pcb.h>
#include <gnu/arch/i386/fpemul/fpu_emu.h>
#include <gnu/arch/i386/fpemul/fpu_system.h>
#include <gnu/arch/i386/fpemul/exception.h>
#include <gnu/arch/i386/fpemul/status_w.h>
#include <gnu/arch/i386/fpemul/reg_constant.h>
static void
fchs(void)
{
if (NOT_EMPTY_0) {
FPU_st0_ptr->sign ^= SIGN_POS ^ SIGN_NEG;
status_word &= ~SW_C1;
} else
stack_underflow();
}
static void
fabs(void)
{
if (FPU_st0_tag ^ TW_Empty) {
FPU_st0_ptr->sign = SIGN_POS;
status_word &= ~SW_C1;
} else
stack_underflow();
}
static void
ftst_(void)
{
switch (FPU_st0_tag) {
case TW_Zero:
setcc(SW_C3);
break;
case TW_Valid:
#ifdef DENORM_OPERAND
if ((FPU_st0_ptr->exp <= EXP_UNDER) && (denormal_operand()))
return;
#endif /* DENORM_OPERAND */
if (FPU_st0_ptr->sign == SIGN_POS)
setcc(0);
else
setcc(SW_C0);
break;
case TW_NaN:
setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
EXCEPTION(EX_Invalid);
break;
case TW_Infinity:
if (FPU_st0_ptr->sign == SIGN_POS)
setcc(0);
else
setcc(SW_C0);
EXCEPTION(EX_Invalid);
break;
case TW_Empty:
setcc(SW_C0 | SW_C2 | SW_C3);
EXCEPTION(EX_StackUnder);
break;
default:
setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
EXCEPTION(EX_INTERNAL | 0x14);
break;
}
}
static void
fxam(void)
{
int c = 0;
switch (FPU_st0_tag) {
case TW_Empty:
c = SW_C3 | SW_C0;
break;
case TW_Zero:
c = SW_C3;
break;
case TW_Valid:
/* This will need to be changed if TW_Denormal is ever used. */
if (FPU_st0_ptr->exp <= EXP_UNDER)
c = SW_C2 | SW_C3; /* Denormal */
else
c = SW_C3;
break;
case TW_NaN:
c = SW_C0;
break;
case TW_Infinity:
c = SW_C2 | SW_C0;
break;
}
if (FPU_st0_ptr->sign == SIGN_NEG)
c |= SW_C1;
setcc(c);
}
static FUNC fp_etc_table[] = {
fchs, fabs, Un_impl, Un_impl, ftst_, fxam, Un_impl, Un_impl
};
void
fp_etc()
{
(fp_etc_table[FPU_rm]) ();
}
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