Bochs/bochs/cpu/shift16.cc

693 lines
18 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001-2017 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::SHLD_EwGwM(bxInstruction_c *i)
{
Bit32u temp_32, result_32;
unsigned count;
unsigned of, cf;
/* op1:op2 << count. result stored in op1 */
if (i->getIaOpcode() == BX_IA_SHLD_EwGw)
count = CL;
else // BX_IA_SHLD_EwGwIb
count = i->Ib();
count &= 0x1f; // use only 5 LSB's
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
Bit32u op1_16 = (Bit32u) read_RMW_virtual_word(i->seg(), eaddr);
if (count) {
Bit32u op2_16 = (Bit32u) BX_READ_16BIT_REG(i->src());
/* count < 32, since only lower 5 bits used */
temp_32 = (op1_16 << 16) | (op2_16); // double formed by op1:op2
result_32 = temp_32 << count;
// hack to act like x86 SHLD when count > 16
if (count > 16) {
// for Pentium processor, when count > 16, actually shifting op1:op2:op2 << count,
// it is the same as shifting op2:op2 by count-16
// For P6 and later (CPU_LEVEL >= 6), when count > 16, actually shifting op1:op2:op1 << count,
// which is the same as shifting op2:op1 by count-16
// The behavior is undefined so both ways are correct, we prefer P6 way of implementation
result_32 |= (op1_16 << (count - 16));
}
Bit16u result_16 = (Bit16u)(result_32 >> 16);
write_RMW_linear_word(result_16);
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
cf = (temp_32 >> (32 - count)) & 0x1;
of = cf ^ (result_16 >> 15); // of = cf ^ result15
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHLD_EwGwR(bxInstruction_c *i)
{
Bit32u temp_32, result_32;
unsigned count;
unsigned of, cf;
/* op1:op2 << count. result stored in op1 */
if (i->getIaOpcode() == BX_IA_SHLD_EwGw)
count = CL;
else // BX_IA_SHLD_EwGwIb
count = i->Ib();
count &= 0x1f; // use only 5 LSB's
if (count) {
Bit32u op1_16 = (Bit32u) BX_READ_16BIT_REG(i->dst());
Bit32u op2_16 = (Bit32u) BX_READ_16BIT_REG(i->src());
/* count < 32, since only lower 5 bits used */
temp_32 = (op1_16 << 16) | (op2_16); // double formed by op1:op2
result_32 = temp_32 << count;
// hack to act like x86 SHLD when count > 16
if (count > 16) {
// for Pentium processor, when count > 16, actually shifting op1:op2:op2 << count,
// it is the same as shifting op2:op2 by count-16
// For P6 and later (CPU_LEVEL >= 6), when count > 16, actually shifting op1:op2:op1 << count,
// which is the same as shifting op2:op1 by count-16
// The behavior is undefined so both ways are correct, we prefer P6 way of implementation
result_32 |= (op1_16 << (count - 16));
}
Bit16u result_16 = (Bit16u)(result_32 >> 16);
BX_WRITE_16BIT_REG(i->dst(), result_16);
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
cf = (temp_32 >> (32 - count)) & 0x1;
of = cf ^ (result_16 >> 15); // of = cf ^ result15
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHRD_EwGwM(bxInstruction_c *i)
{
Bit32u temp_32, result_32;
unsigned count;
unsigned cf, of;
if (i->getIaOpcode() == BX_IA_SHRD_EwGw)
count = CL;
else // BX_IA_SHRD_EwGwIb
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
Bit32u op1_16 = (Bit32u) read_RMW_virtual_word(i->seg(), eaddr);
if (count) {
Bit32u op2_16 = (Bit32u) BX_READ_16BIT_REG(i->src());
/* count < 32, since only lower 5 bits used */
temp_32 = (op2_16 << 16) | op1_16; // double formed by op2:op1
result_32 = temp_32 >> count;
// hack to act like x86 SHRD when count > 16
if (count > 16) {
// for Pentium processor, when count > 16, actually shifting op2:op2:op1 >> count,
// it is the same as shifting op2:op2 by count-16
// For P6 and later (CPU_LEVEL >= 6), when count > 16, actually shifting op1:op2:op1 >> count,
// which is the same as shifting op1:op2 by count-16
// The behavior is undefined so both ways are correct, we prefer P6 way of implementation
result_32 |= (op1_16 << (32 - count));
}
Bit16u result_16 = (Bit16u) result_32;
write_RMW_linear_word(result_16);
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
cf = (op1_16 >> (count - 1)) & 0x1;
of = ((Bit16u)((result_16 << 1) ^ result_16) >> 15) & 0x1; // of = result14 ^ result15
if (count > 16) cf = (op2_16 >> (count - 17)) & 0x1; // undefined flags behavior matching real HW
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHRD_EwGwR(bxInstruction_c *i)
{
Bit32u temp_32, result_32;
unsigned count;
unsigned cf, of;
if (i->getIaOpcode() == BX_IA_SHRD_EwGw)
count = CL;
else // BX_IA_SHRD_EwGwIb
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
if (count) {
Bit32u op1_16 = (Bit32u) BX_READ_16BIT_REG(i->dst());
Bit32u op2_16 = (Bit32u) BX_READ_16BIT_REG(i->src());
/* count < 32, since only lower 5 bits used */
temp_32 = (op2_16 << 16) | op1_16; // double formed by op2:op1
result_32 = temp_32 >> count;
// hack to act like x86 SHRD when count > 16
if (count > 16) {
// for Pentium processor, when count > 16, actually shifting op2:op2:op1 >> count,
// it is the same as shifting op2:op2 by count-16
// For P6 and later (CPU_LEVEL >= 6), when count > 16, actually shifting op1:op2:op1 >> count,
// which is the same as shifting op1:op2 by count-16
// The behavior is undefined so both ways are correct, we prefer P6 way of implementation
result_32 |= (op1_16 << (32 - count));
}
Bit16u result_16 = (Bit16u) result_32;
BX_WRITE_16BIT_REG(i->dst(), result_16);
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
cf = (op1_16 >> (count - 1)) & 0x1;
of = ((Bit16u)((result_16 << 1) ^ result_16) >> 15) & 0x1; // of = result14 ^ result15
if (count > 16) cf = (op2_16 >> (count - 17)) & 0x1; // undefined flags behavior matching real HW
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROL_EwM(bxInstruction_c *i)
{
unsigned count;
unsigned bit0, bit15;
if (i->getIaOpcode() == BX_IA_ROL_Ew)
count = CL;
else
count = i->Ib();
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit16u op1_16 = read_RMW_virtual_word(i->seg(), eaddr);
if ((count & 0x0f) == 0) {
if (count & 0x10) {
bit0 = (op1_16 & 0x1);
bit15 = (op1_16 >> 15);
// of = cf ^ result15
SET_FLAGS_OxxxxC(bit0 ^ bit15, bit0);
}
}
else {
count &= 0x0f; // only use bottom 4 bits
Bit16u result_16 = (op1_16 << count) | (op1_16 >> (16 - count));
write_RMW_linear_word(result_16);
bit0 = (result_16 & 0x1);
bit15 = (result_16 >> 15);
// of = cf ^ result15
SET_FLAGS_OxxxxC(bit0 ^ bit15, bit0);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROL_EwR(bxInstruction_c *i)
{
unsigned count;
unsigned bit0, bit15;
if (i->getIaOpcode() == BX_IA_ROL_Ew)
count = CL;
else
count = i->Ib();
Bit16u op1_16 = BX_READ_16BIT_REG(i->dst());
if ((count & 0x0f) == 0) {
if (count & 0x10) {
bit0 = (op1_16 & 0x1);
bit15 = (op1_16 >> 15);
// of = cf ^ result15
SET_FLAGS_OxxxxC(bit0 ^ bit15, bit0);
}
}
else {
count &= 0x0f; // only use bottom 4 bits
Bit16u result_16 = (op1_16 << count) | (op1_16 >> (16 - count));
BX_WRITE_16BIT_REG(i->dst(), result_16);
bit0 = (result_16 & 0x1);
bit15 = (result_16 >> 15);
// of = cf ^ result15
SET_FLAGS_OxxxxC(bit0 ^ bit15, bit0);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROR_EwM(bxInstruction_c *i)
{
unsigned count;
unsigned bit14, bit15;
if (i->getIaOpcode() == BX_IA_ROR_Ew)
count = CL;
else
count = i->Ib();
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit16u op1_16 = read_RMW_virtual_word(i->seg(), eaddr);
if ((count & 0x0f) == 0) {
if (count & 0x10) {
bit14 = (op1_16 >> 14) & 1;
bit15 = (op1_16 >> 15) & 1;
// of = result14 ^ result15
SET_FLAGS_OxxxxC(bit14 ^ bit15, bit15);
}
}
else {
count &= 0x0f; // use only 4 LSB's
Bit16u result_16 = (op1_16 >> count) | (op1_16 << (16 - count));
write_RMW_linear_word(result_16);
bit14 = (result_16 >> 14) & 1;
bit15 = (result_16 >> 15) & 1;
// of = result14 ^ result15
SET_FLAGS_OxxxxC(bit14 ^ bit15, bit15);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROR_EwR(bxInstruction_c *i)
{
unsigned count;
unsigned bit14, bit15;
if (i->getIaOpcode() == BX_IA_ROR_Ew)
count = CL;
else
count = i->Ib();
Bit16u op1_16 = BX_READ_16BIT_REG(i->dst());
if ((count & 0x0f) == 0) {
if (count & 0x10) {
bit14 = (op1_16 >> 14) & 1;
bit15 = (op1_16 >> 15) & 1;
// of = result14 ^ result15
SET_FLAGS_OxxxxC(bit14 ^ bit15, bit15);
}
}
else {
count &= 0x0f; // use only 4 LSB's
Bit16u result_16 = (op1_16 >> count) | (op1_16 << (16 - count));
BX_WRITE_16BIT_REG(i->dst(), result_16);
bit14 = (result_16 >> 14) & 1;
bit15 = (result_16 >> 15) & 1;
// of = result14 ^ result15
SET_FLAGS_OxxxxC(bit14 ^ bit15, bit15);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCL_EwM(bxInstruction_c *i)
{
Bit16u result_16;
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_RCL_Ew)
count = CL;
else
count = i->Ib();
count = (count & 0x1f) % 17;
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit16u op1_16 = read_RMW_virtual_word(i->seg(), eaddr);
unsigned temp_CF = getB_CF();
if (count) {
if (count==1) {
result_16 = (op1_16 << 1) | temp_CF;
}
else if (count==16) {
result_16 = (temp_CF << 15) | (op1_16 >> 1);
}
else { // 2..15
result_16 = (op1_16 << count) | (temp_CF << (count - 1)) |
(op1_16 >> (17 - count));
}
write_RMW_linear_word(result_16);
cf = (op1_16 >> (16 - count)) & 0x1;
of = cf ^ (result_16 >> 15); // of = cf ^ result15
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCL_EwR(bxInstruction_c *i)
{
Bit16u result_16;
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_RCL_Ew)
count = CL;
else
count = i->Ib();
count = (count & 0x1f) % 17;
unsigned temp_CF = getB_CF();
if (count) {
Bit16u op1_16 = BX_READ_16BIT_REG(i->dst());
if (count==1) {
result_16 = (op1_16 << 1) | temp_CF;
}
else if (count==16) {
result_16 = (temp_CF << 15) | (op1_16 >> 1);
}
else { // 2..15
result_16 = (op1_16 << count) | (temp_CF << (count - 1)) |
(op1_16 >> (17 - count));
}
BX_WRITE_16BIT_REG(i->dst(), result_16);
cf = (op1_16 >> (16 - count)) & 0x1;
of = cf ^ (result_16 >> 15); // of = cf ^ result15
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCR_EwM(bxInstruction_c *i)
{
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_RCR_Ew)
count = CL;
else
count = i->Ib();
count = (count & 0x1f) % 17;
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit16u op1_16 = read_RMW_virtual_word(i->seg(), eaddr);
if (count) {
unsigned temp_CF = getB_CF();
Bit16u result_16 = (op1_16 >> count) | (temp_CF << (16 - count)) |
(op1_16 << (17 - count));
write_RMW_linear_word(result_16);
cf = (op1_16 >> (count - 1)) & 0x1;
of = ((Bit16u)((result_16 << 1) ^ result_16) >> 15) & 0x1; // of = result15 ^ result14
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCR_EwR(bxInstruction_c *i)
{
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_RCR_Ew)
count = CL;
else
count = i->Ib();
count = (count & 0x1f) % 17;
if (count) {
Bit16u op1_16 = BX_READ_16BIT_REG(i->dst());
unsigned temp_CF = getB_CF();
Bit16u result_16 = (op1_16 >> count) | (temp_CF << (16 - count)) |
(op1_16 << (17 - count));
BX_WRITE_16BIT_REG(i->dst(), result_16);
cf = (op1_16 >> (count - 1)) & 0x1;
of = ((Bit16u)((result_16 << 1) ^ result_16) >> 15) & 0x1; // of = result15 ^ result14
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHL_EwM(bxInstruction_c *i)
{
Bit16u result_16;
unsigned count;
unsigned of = 0, cf = 0;
if (i->getIaOpcode() == BX_IA_SHL_Ew)
count = CL;
else
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit16u op1_16 = read_RMW_virtual_word(i->seg(), eaddr);
if (count) {
if (count <= 16) {
result_16 = (op1_16 << count);
cf = (op1_16 >> (16 - count)) & 0x1;
of = cf ^ (result_16 >> 15); // of = cf ^ result15
}
else {
result_16 = 0;
}
write_RMW_linear_word(result_16);
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHL_EwR(bxInstruction_c *i)
{
Bit16u result_16;
unsigned count;
unsigned of = 0, cf = 0;
if (i->getIaOpcode() == BX_IA_SHL_Ew)
count = CL;
else
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
if (count) {
Bit16u op1_16 = BX_READ_16BIT_REG(i->dst());
if (count <= 16) {
result_16 = (op1_16 << count);
cf = (op1_16 >> (16 - count)) & 0x1;
of = cf ^ (result_16 >> 15); // of = cf ^ result15
}
else {
result_16 = 0;
}
BX_WRITE_16BIT_REG(i->dst(), result_16);
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHR_EwM(bxInstruction_c *i)
{
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_SHR_Ew)
count = CL;
else
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
/* pointer, segment address pair */
Bit16u op1_16 = read_RMW_virtual_word(i->seg(), eaddr);
if (count) {
Bit16u result_16 = (op1_16 >> count);
write_RMW_linear_word(result_16);
cf = (op1_16 >> (count - 1)) & 0x1;
// note, that of == result15 if count == 1 and
// of == 0 if count >= 2
of = ((Bit16u)((result_16 << 1) ^ result_16) >> 15) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHR_EwR(bxInstruction_c *i)
{
unsigned count;
unsigned of, cf;
if (i->getIaOpcode() == BX_IA_SHR_Ew)
count = CL;
else
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
if (count) {
Bit16u op1_16 = BX_READ_16BIT_REG(i->dst());
Bit16u result_16 = (op1_16 >> count);
BX_WRITE_16BIT_REG(i->dst(), result_16);
cf = (op1_16 >> (count - 1)) & 0x1;
// note, that of == result15 if count == 1 and
// of == 0 if count >= 2
of = ((Bit16u)((result_16 << 1) ^ result_16) >> 15) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
SET_FLAGS_OxxxxC(of, cf);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SAR_EwM(bxInstruction_c *i)
{
unsigned count, cf;
if (i->getIaOpcode() == BX_IA_SAR_Ew)
count = CL;
else
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
Bit16u op1_16 = read_RMW_virtual_word(i->seg(), eaddr);
if (count) {
Bit16u result_16 = ((Bit16s) op1_16) >> count;
cf = (((Bit16s) op1_16) >> (count - 1)) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
/* signed overflow cannot happen in SAR instruction */
SET_FLAGS_OxxxxC(0, cf);
write_RMW_linear_word(result_16);
}
BX_NEXT_INSTR(i);
}
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SAR_EwR(bxInstruction_c *i)
{
unsigned count, cf;
if (i->getIaOpcode() == BX_IA_SAR_Ew)
count = CL;
else
count = i->Ib();
count &= 0x1f; /* use only 5 LSB's */
if (count) {
Bit16u op1_16 = BX_READ_16BIT_REG(i->dst());
Bit16u result_16 = ((Bit16s) op1_16) >> count;
BX_WRITE_16BIT_REG(i->dst(), result_16);
cf = (((Bit16s) op1_16) >> (count - 1)) & 0x1;
SET_FLAGS_OSZAPC_LOGIC_16(result_16);
/* signed overflow cannot happen in SAR instruction */
SET_FLAGS_OxxxxC(0, cf);
}
BX_NEXT_INSTR(i);
}