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/*
* plex86: run multiple x86 operating systems concurrently
* Copyright (C) 1999-2001 Kevin P. Lawton
*
* mult8.c: emulation of 8-bit multiplication instructions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "plex86.h"
#include "monitor.h"
void
MUL_ALEb(vm_t *vm)
{
Bit8s op2, op1;
Bit16s product_16;
Bit32u eflags, arithmetic_eflags;
op1 = G_AL(vm);
if (vm->i.mod == 0xc0) {
op2 = ReadReg8(vm, vm->i.rm);
}
else {
read_virtual_byte(vm, vm->i.seg, vm->i.rm_addr, &op2);
}
arithmetic_eflags = read_eflags(vm) & 0x000008d5;
eflags = 0; /* keep compiler quiet */
asm volatile (
/* First copy guest arithmetic flags to monitor flags */
"pushfl \n\t" /* Get mon flags */
"popl %0 \n\t"
"andl $0xfffff700, %0 \n\t" /* Erase mon arithmetic flags */
"orl %5, %0 \n\t" /* Or in guest arithmetic flags */
"pushl %0 \n\t" /* Set flags in mon */
"popfl \n\t"
"mulb %4 \n\t"
"pushfl \n\t"
"popl %0"
: "=r" (eflags), "=a" (product_16)
: "0" (eflags), "1" (op1), "mq" (op2), "g" (arithmetic_eflags)
: "memory", "cc"
);
G_AX(vm) = product_16;
SetOSZAPC(vm, eflags);
}
void
IMUL_ALEb(vm_t *vm)
{
Bit8s op2, op1;
Bit16s product_16;
Bit32u eflags, arithmetic_eflags;
op1 = G_AL(vm);
if (vm->i.mod == 0xc0) {
op2 = ReadReg8(vm, vm->i.rm);
}
else {
read_virtual_byte(vm, vm->i.seg, vm->i.rm_addr, &op2);
}
arithmetic_eflags = read_eflags(vm) & 0x000008d5;
eflags = 0; /* keep compiler quiet */
asm volatile (
/* First copy guest arithmetic flags to monitor flags */
"pushfl \n\t" /* Get mon flags */
"popl %0 \n\t"
"andl $0xfffff700, %0 \n\t" /* Erase mon arithmetic flags */
"orl %5, %0 \n\t" /* Or in guest arithmetic flags */
"pushl %0 \n\t" /* Set flags in mon */
"popfl \n\t"
"imulb %4 \n\t"
"pushfl \n\t"
"popl %0"
: "=r" (eflags), "=a" (product_16)
: "0" (eflags), "1" (op1), "mq" (op2), "g" (arithmetic_eflags)
: "memory", "cc"
);
G_AX(vm) = product_16;
SetOSZAPC(vm, eflags);
}
void
DIV_ALEb(vm_t *vm)
{
Bit8u op2;
Bit16u ax;
Bit32u eflags, arithmetic_eflags;
ax = G_AX(vm);
if (vm->i.mod == 0xc0) {
op2 = ReadReg8(vm, vm->i.rm);
}
else {
read_virtual_byte(vm, vm->i.seg, vm->i.rm_addr, &op2);
}
if (op2 == 0) {
exception(vm, ExceptionDE, 0);
}
arithmetic_eflags = read_eflags(vm) & 0x000008d5;
eflags = 0; /* keep compiler quiet */
asm volatile (
/* First copy guest arithmetic flags to monitor flags */
"pushfl \n\t" /* Get mon flags */
"popl %0 \n\t"
"andl $0xfffff700, %0 \n\t" /* Erase mon arithmetic flags */
"orl %5, %0 \n\t" /* Or in guest arithmetic flags */
"pushl %0 \n\t" /* Set flags in mon */
"popfl \n\t"
"divb %4 \n\t"
"pushfl \n\t"
"popl %0"
: "=r" (eflags), "=a" (ax)
: "0" (eflags), "1" (ax), "mq" (op2), "g" (arithmetic_eflags)
: "memory", "cc"
);
G_AX(vm) = ax;
SetOSZAPC(vm, eflags);
}
void
IDIV_ALEb(vm_t *vm)
{
Bit8u op2;
Bit16u ax;
Bit32u eflags, arithmetic_eflags;
ax = G_AX(vm);
if (vm->i.mod == 0xc0) {
op2 = ReadReg8(vm, vm->i.rm);
}
else {
read_virtual_byte(vm, vm->i.seg, vm->i.rm_addr, &op2);
}
if (op2 == 0) {
exception(vm, ExceptionDE, 0);
}
arithmetic_eflags = read_eflags(vm) & 0x000008d5;
eflags = 0; /* keep compiler quiet */
asm volatile (
/* First copy guest arithmetic flags to monitor flags */
"pushfl \n\t" /* Get mon flags */
"popl %0 \n\t"
"andl $0xfffff700, %0 \n\t" /* Erase mon arithmetic flags */
"orl %5, %0 \n\t" /* Or in guest arithmetic flags */
"pushl %0 \n\t" /* Set flags in mon */
"popfl \n\t"
"idivb %4 \n\t"
"pushfl \n\t"
"popl %0"
: "=r" (eflags), "=a" (ax)
: "0" (eflags), "1" (ax), "mq" (op2), "g" (arithmetic_eflags)
: "memory", "cc"
);
G_AX(vm) = ax;
SetOSZAPC(vm, eflags);
}
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