mirror of
https://git.hardenedbsd.org/hardenedbsd/HardenedBSD.git
synced 2024-11-19 09:44:30 +01:00
163 lines
4.1 KiB
C
163 lines
4.1 KiB
C
/*
|
|
* fpu_etc.c
|
|
*
|
|
* Implement a few FPU instructions.
|
|
*
|
|
*
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#include "param.h"
|
|
#include "proc.h"
|
|
#include "machine/cpu.h"
|
|
#include "machine/pcb.h"
|
|
|
|
#include "fpu_emu.h"
|
|
#include "fpu_system.h"
|
|
#include "exception.h"
|
|
#include "status_w.h"
|
|
#include "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]) ();
|
|
}
|