/*
* fpu_aux.c
*
* Code to implement some of the FPU auxiliary 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.
*
*
* $Id: fpu_aux.c,v 1.4 1995/12/14 09:50:21 phk Exp $
*
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <machine/cpu.h>
#include <machine/pcb.h>
#include <gnu/i386/fpemul/fpu_emu.h>
#include <gnu/i386/fpemul/fpu_system.h>
#include <gnu/i386/fpemul/exception.h>
#include <gnu/i386/fpemul/status_w.h>
static void
fclex(void)
{
status_word &= ~(SW_Backward | SW_Summary | SW_Stack_Fault | SW_Precision |
SW_Underflow | SW_Overflow | SW_Zero_Div | SW_Denorm_Op |
SW_Invalid);
FPU_entry_eip = ip_offset; /* We want no net effect */
}
/* Needs to be externally visible */
void
finit()
{
int r;
control_word = 0x037f;
status_word = 0;
top = 0; /* We don't keep top in the status word
* internally. */
for (r = 0; r < 8; r++) {
regs[r].tag = TW_Empty;
}
FPU_entry_eip = ip_offset = 0;
}
static FUNC finit_table[] = {
Un_impl, Un_impl, fclex, finit, Un_impl, Un_impl, Un_impl, Un_impl
};
void
finit_()
{
(finit_table[FPU_rm]) ();
}
static void
fstsw_ax(void)
{
status_word &= ~SW_Top;
status_word |= (top & 7) << SW_Top_Shift;
*(short *) &FPU_EAX = status_word;
}
static FUNC fstsw_table[] = {
fstsw_ax, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl
};
void
fstsw_()
{
(fstsw_table[FPU_rm]) ();
}
static void
fnop(void)
{
}
static FUNC fp_nop_table[] = {
fnop, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl
};
void
fp_nop()
{
(fp_nop_table[FPU_rm]) ();
}
void
fld_i_()
{
FPU_REG *st_new_ptr;
if (STACK_OVERFLOW) {
stack_overflow();
return;
}
/* fld st(i) */
if (NOT_EMPTY(FPU_rm)) {
reg_move(&st(FPU_rm), st_new_ptr);
push();
} else {
if (control_word & EX_Invalid) {
/* The masked response */
push();
stack_underflow();
} else
EXCEPTION(EX_StackUnder);
}
}
void
fxch_i()
{
/* fxch st(i) */
FPU_REG t;
register FPU_REG *sti_ptr = &st(FPU_rm);
if (FPU_st0_tag == TW_Empty) {
if (sti_ptr->tag == TW_Empty) {
stack_underflow();
stack_underflow_i(FPU_rm);
return;
}
reg_move(sti_ptr, FPU_st0_ptr);
stack_underflow_i(FPU_rm);
return;
}
if (sti_ptr->tag == TW_Empty) {
reg_move(FPU_st0_ptr, sti_ptr);
stack_underflow();
return;
}
reg_move(FPU_st0_ptr, &t);
reg_move(sti_ptr, FPU_st0_ptr);
reg_move(&t, sti_ptr);
}
void
ffree_()
{
/* ffree st(i) */
st(FPU_rm).tag = TW_Empty;
}
void
ffreep()
{
/* ffree st(i) + pop - unofficial code */
st(FPU_rm).tag = TW_Empty;
pop();
}
void
fst_i_()
{
/* fst st(i) */
reg_move(FPU_st0_ptr, &st(FPU_rm));
}
void
fstp_i()
{
/* fstp st(i) */
reg_move(FPU_st0_ptr, &st(FPU_rm));
pop();
}
