Bochs/bochs/cpu/shift8.cc

514 lines
11 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001-2015 The Bochs Project
//
// 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., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
/////////////////////////////////////////////////////////////////////////
#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#include "cpu.h"
#define LOG_THIS BX_CPU_THIS_PTR
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROL_EbR(bxInstruction_c *i)
{
unsigned count;
unsigned bit0, bit7;
if (i->getIaOpcode() == BX_IA_ROL_Eb)
count = CL;
else
count = i->Ib();
Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
if ((count & 0x07) == 0) {
if (count & 0x18) {
bit0 = (op1_8 & 1);
bit7 = (op1_8 >> 7);
SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
}
}
else {
count &= 0x7; // use only lowest 3 bits
Bit8u result_8 = (op1_8 << count) | (op1_8 >> (8 - count));
BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
/* set eflags:
* ROL count affects the following flags: C, O
*/
bit0 = (result_8 & 1);
bit7 = (result_8 >> 7);
SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROL_EbM(bxInstruction_c *i)
{
unsigned count;
unsigned bit0, bit7;
if (i->getIaOpcode() == BX_IA_ROL_Eb)
count = CL;
else
count = i->Ib();
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
if ((count & 0x07) == 0) {
if (count & 0x18) {
bit0 = (op1_8 & 1);
bit7 = (op1_8 >> 7);
SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
}
}
else {
count &= 0x7; // use only lowest 3 bits
Bit8u result_8 = (op1_8 << count) | (op1_8 >> (8 - count));
write_RMW_linear_byte(result_8);
/* set eflags:
* ROL count affects the following flags: C, O
*/
bit0 = (result_8 & 1);
bit7 = (result_8 >> 7);
SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROR_EbR(bxInstruction_c *i)
{
unsigned count;
unsigned bit6, bit7;
if (i->getIaOpcode() == BX_IA_ROR_Eb)
count = CL;
else
count = i->Ib();
Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
if ((count & 0x07) == 0) {
if (count & 0x18) {
bit6 = (op1_8 >> 6) & 1;
bit7 = (op1_8 >> 7) & 1;
SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
}
}
else {
count &= 0x7; /* use only bottom 3 bits */
Bit8u result_8 = (op1_8 >> count) | (op1_8 << (8 - count));
BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
/* set eflags:
* ROR count affects the following flags: C, O
*/
bit6 = (result_8 >> 6) & 1;
bit7 = (result_8 >> 7) & 1;
SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROR_EbM(bxInstruction_c *i)
{
unsigned count;
unsigned bit6, bit7;
if (i->getIaOpcode() == BX_IA_ROR_Eb)
count = CL;
else
count = i->Ib();
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
if ((count & 0x07) == 0) {
if (count & 0x18) {
bit6 = (op1_8 >> 6) & 1;
bit7 = (op1_8 >> 7) & 1;
SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
}
}
else {
count &= 0x7; /* use only bottom 3 bits */
Bit8u result_8 = (op1_8 >> count) | (op1_8 << (8 - count));
write_RMW_linear_byte(result_8);
/* set eflags:
* ROR count affects the following flags: C, O
*/
bit6 = (result_8 >> 6) & 1;
bit7 = (result_8 >> 7) & 1;
SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCL_EbR(bxInstruction_c *i)
{
Bit8u result_8;
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_RCL_Eb)
count = CL;
else
count = i->Ib();
count = (count & 0x1f) % 9;
if (! count) {
BX_NEXT_INSTR(i);
}
Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
unsigned temp_CF = getB_CF();
if (count==1) {
result_8 = (op1_8 << 1) | temp_CF;
}
else {
result_8 = (op1_8 << count) | (temp_CF << (count - 1)) |
(op1_8 >> (9 - count));
}
BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
cf = (op1_8 >> (8 - count)) & 0x01;
of = cf ^ (result_8 >> 7); // of = cf ^ result7
SET_FLAGS_OxxxxC(of, cf);
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCL_EbM(bxInstruction_c *i)
{
Bit8u result_8;
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_RCL_Eb)
count = CL;
else
count = i->Ib();
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
count = (count & 0x1f) % 9;
if (! count) {
BX_NEXT_INSTR(i);
}
unsigned temp_CF = getB_CF();
if (count==1) {
result_8 = (op1_8 << 1) | temp_CF;
}
else {
result_8 = (op1_8 << count) | (temp_CF << (count - 1)) |
(op1_8 >> (9 - count));
}
write_RMW_linear_byte(result_8);
cf = (op1_8 >> (8 - count)) & 0x01;
of = cf ^ (result_8 >> 7); // of = cf ^ result7
SET_FLAGS_OxxxxC(of, cf);
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCR_EbR(bxInstruction_c *i)
{
unsigned count;
unsigned cf, of;
if (i->getIaOpcode() == BX_IA_RCR_Eb)
count = CL;
else
count = i->Ib();
count = (count & 0x1f) % 9;
if (count) {
Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
unsigned temp_CF = getB_CF();
Bit8u result_8 = (op1_8 >> count) | (temp_CF << (8 - count)) |
(op1_8 << (9 - count));
BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
cf = (op1_8 >> (count - 1)) & 0x1;
of = (((result_8 << 1) ^ result_8) >> 7) & 0x1; // of = result6 ^ result7
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCR_EbM(bxInstruction_c *i)
{
unsigned count;
unsigned cf, of;
if (i->getIaOpcode() == BX_IA_RCR_Eb)
count = CL;
else
count = i->Ib();
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
count = (count & 0x1f) % 9;
if (count) {
unsigned temp_CF = getB_CF();
Bit8u result_8 = (op1_8 >> count) | (temp_CF << (8 - count)) |
(op1_8 << (9 - count));
write_RMW_linear_byte(result_8);
cf = (op1_8 >> (count - 1)) & 0x1;
of = (((result_8 << 1) ^ result_8) >> 7) & 0x1; // of = result6 ^ result7
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHL_EbR(bxInstruction_c *i)
{
Bit8u result_8;
unsigned count;
unsigned of = 0, cf = 0;
if (i->getIaOpcode() == BX_IA_SHL_Eb)
count = CL;
else
count = i->Ib();
count &= 0x1f;
if (!count) {
BX_NEXT_INSTR(i);
}
Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
if (count <= 8) {
result_8 = (op1_8 << count);
cf = (op1_8 >> (8 - count)) & 0x1;
of = cf ^ (result_8 >> 7);
}
else {
result_8 = 0;
}
BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
SET_FLAGS_OSZAPC_LOGIC_8(result_8);
SET_FLAGS_OxxxxC(of, cf);
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHL_EbM(bxInstruction_c *i)
{
Bit8u result_8;
unsigned count;
unsigned of = 0, cf = 0;
if (i->getIaOpcode() == BX_IA_SHL_Eb)
count = CL;
else
count = i->Ib();
count &= 0x1f;
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
if (!count) {
BX_NEXT_INSTR(i);
}
if (count <= 8) {
result_8 = (op1_8 << count);
cf = (op1_8 >> (8 - count)) & 0x1;
of = cf ^ (result_8 >> 7);
}
else {
result_8 = 0;
}
write_RMW_linear_byte(result_8);
SET_FLAGS_OSZAPC_LOGIC_8(result_8);
SET_FLAGS_OxxxxC(of, cf);
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHR_EbR(bxInstruction_c *i)
{
unsigned count;
if (i->getIaOpcode() == BX_IA_SHR_Eb)
count = CL;
else
count = i->Ib();
count &= 0x1f;
if (count) {
Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
Bit8u result_8 = (op1_8 >> count);
BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
unsigned cf = (op1_8 >> (count - 1)) & 0x1;
// note, that of == result7 if count == 1 and
// of == 0 if count >= 2
unsigned of = (((result_8 << 1) ^ result_8) >> 7) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_8(result_8);
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHR_EbM(bxInstruction_c *i)
{
unsigned count;
if (i->getIaOpcode() == BX_IA_SHR_Eb)
count = CL;
else
count = i->Ib();
count &= 0x1f;
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
if (count) {
Bit8u result_8 = (op1_8 >> count);
write_RMW_linear_byte(result_8);
unsigned cf = (op1_8 >> (count - 1)) & 0x1;
// note, that of == result7 if count == 1 and
// of == 0 if count >= 2
unsigned of = (((result_8 << 1) ^ result_8) >> 7) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_8(result_8);
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SAR_EbR(bxInstruction_c *i)
{
unsigned count;
if (i->getIaOpcode() == BX_IA_SAR_Eb)
count = CL;
else
count = i->Ib();
count &= 0x1f;
if (count) {
Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
Bit8u result_8 = ((Bit8s) op1_8) >> count;
BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
unsigned cf = (((Bit8s) op1_8) >> (count - 1)) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_8(result_8);
/* signed overflow cannot happen in SAR instruction */
SET_FLAGS_OxxxxC(0, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SAR_EbM(bxInstruction_c *i)
{
unsigned count;
if (i->getIaOpcode() == BX_IA_SAR_Eb)
count = CL;
else
count = i->Ib();
count &= 0x1f;
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
if (count) {
Bit8u result_8 = ((Bit8s) op1_8) >> count;
write_RMW_linear_byte(result_8);
unsigned cf = (((Bit8s) op1_8) >> (count - 1)) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_8(result_8);
/* signed overflow cannot happen in SAR instruction */
SET_FLAGS_OxxxxC(0, cf);
}
BX_NEXT_INSTR(i);
}