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x86primop.c
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x86primop.c
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/****************************************************************************
*
* Realmode X86 Emulator Library
*
* Copyright (c) 1996-1999 SciTech Software, Inc.
* Copyright (c) David Mosberger-Tang
* Copyright (c) 1999 Egbert Eich
* Copyright (c) 2007-2017 SUSE LINUX GmbH; Author: Steffen Winterfeldt
*
* ========================================================================
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and that
* both that copyright notice and this permission notice appear in
* supporting documentation, and that the name of the authors not be used
* in advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The authors makes no
* representations about the suitability of this software for any purpose.
* It is provided "as is" without express or implied warranty.
*
* THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*
* ========================================================================
*
* Description:
* Implement the primitive machine operations used by the emulation code
* in ops.c
*
* Carry Chain Calculation
*
* This represents a somewhat expensive calculation which is
* apparently required to emulate the setting of the OF and AF flag.
* The latter is not so important, but the former is. The overflow
* flag is the XOR of the top two bits of the carry chain for an
* addition (similar for subtraction). Since we do not want to
* simulate the addition in a bitwise manner, we try to calculate the
* carry chain given the two operands and the result.
*
* So, given the following table, which represents the addition of two
* bits, we can derive a formula for the carry chain.
*
* a b cin r cout
* 0 0 0 0 0
* 0 0 1 1 0
* 0 1 0 1 0
* 0 1 1 0 1
* 1 0 0 1 0
* 1 0 1 0 1
* 1 1 0 0 1
* 1 1 1 1 1
*
* Construction of table for cout:
*
* ab
* r \ 00 01 11 10
* |------------------
* 0 | 0 1 1 1
* 1 | 0 0 1 0
*
* By inspection, one gets: cc = ab + r'(a + b)
*
* That represents alot of operations, but NO CHOICE....
*
* Borrow Chain Calculation.
*
* The following table represents the subtraction of two bits, from
* which we can derive a formula for the borrow chain.
*
* a b bin r bout
* 0 0 0 0 0
* 0 0 1 1 1
* 0 1 0 1 1
* 0 1 1 0 1
* 1 0 0 1 0
* 1 0 1 0 0
* 1 1 0 0 0
* 1 1 1 1 1
*
* Construction of table for cout:
*
* ab
* r \ 00 01 11 10
* |------------------
* 0 | 0 1 0 0
* 1 | 1 1 1 0
*
* By inspection, one gets: bc = a'b + r(a' + b)
*
****************************************************************************/
// This has been heavily modified to fit box86 purpose...
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "x86emu_private.h"
#include "x86run_private.h"
/*------------------------- Global Variables ------------------------------*/
#define PARITY(x) (((emu->x86emu_parity_tab[(x) / 32] >> ((x) % 32)) & 1) == 0)
#define XOR2(x) (((x) ^ ((x)>>1)) & 0x1)
/*----------------------------- Implementation ----------------------------*/
/****************************************************************************
REMARKS:
Implements the AAA instruction and side effects.
****************************************************************************/
uint16_t aaa16(x86emu_t *emu, uint16_t d)
{
uint16_t res;
CHECK_FLAGS(emu);
if ((d & 0xf) > 0x9 || ACCESS_FLAG(F_AF)) {
d += 0x6;
d += 0x100;
SET_FLAG(F_AF);
SET_FLAG(F_CF);
} else {
CLEAR_FLAG(F_CF);
CLEAR_FLAG(F_AF);
}
res = (uint16_t)(d & 0xFF0F);
CLEAR_FLAG(F_SF);
CONDITIONAL_SET_FLAG(res == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
return res;
}
/****************************************************************************
REMARKS:
Implements the AAA instruction and side effects.
****************************************************************************/
uint16_t aas16(x86emu_t *emu, uint16_t d)
{
uint16_t res;
CHECK_FLAGS(emu);
if ((d & 0xf) > 0x9 || ACCESS_FLAG(F_AF)) {
d -= 0x6;
d -= 0x100;
SET_FLAG(F_AF);
SET_FLAG(F_CF);
} else {
CLEAR_FLAG(F_CF);
CLEAR_FLAG(F_AF);
}
res = (uint16_t)(d & 0xFF0F);
CLEAR_FLAG(F_SF);
CONDITIONAL_SET_FLAG(res == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
return res;
}
/****************************************************************************
REMARKS:
Implements the AAD instruction and side effects.
****************************************************************************/
uint16_t aad16(x86emu_t *emu, uint16_t d, uint8_t base)
{
uint16_t l;
uint8_t hb, lb;
RESET_FLAGS(emu);
hb = (uint8_t)((d >> 8) & 0xff);
lb = (uint8_t)((d & 0xff));
l = (uint16_t)((lb + base * hb) & 0xFF);
CLEAR_FLAG(F_CF);
CLEAR_FLAG(F_AF);
CLEAR_FLAG(F_OF);
CONDITIONAL_SET_FLAG(l & 0x80, F_SF);
CONDITIONAL_SET_FLAG(l == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(l & 0xff), F_PF);
return l;
}
/****************************************************************************
REMARKS:
Implements the AAM instruction and side effects.
****************************************************************************/
uint16_t aam16(x86emu_t *emu, uint8_t d, uint8_t base)
{
uint16_t h, l;
RESET_FLAGS(emu);
h = (uint16_t)(d / base);
l = (uint16_t)(d % base);
l |= (uint16_t)(h << 8);
CLEAR_FLAG(F_CF);
CLEAR_FLAG(F_AF);
CLEAR_FLAG(F_OF);
CONDITIONAL_SET_FLAG(l & 0x80, F_SF);
CONDITIONAL_SET_FLAG(l == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(l & 0xff), F_PF);
return l;
}
/****************************************************************************
REMARKS:
Implements the ADC instruction and side effects.
****************************************************************************/
uint8_t adc8(x86emu_t *emu, uint8_t d, uint8_t s)
{
uint32_t res; /* all operands in native machine order */
uint32_t cc;
CHECK_FLAGS(emu);
if (ACCESS_FLAG(F_CF))
res = 1 + d + s;
else
res = d + s;
CONDITIONAL_SET_FLAG(res & 0x100, F_CF);
CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
/* calculate the carry chain SEE NOTE AT TOP. */
cc = (s & d) | ((~res) & (s | d));
CONDITIONAL_SET_FLAG(XOR2(cc >> 6), F_OF);
CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
return (uint8_t)res;
}
/****************************************************************************
REMARKS:
Implements the ADC instruction and side effects.
****************************************************************************/
uint16_t adc16(x86emu_t *emu, uint16_t d, uint16_t s)
{
uint32_t res; /* all operands in native machine order */
uint32_t cc;
CHECK_FLAGS(emu);
if (ACCESS_FLAG(F_CF))
res = 1 + d + s;
else
res = d + s;
CONDITIONAL_SET_FLAG(res & 0x10000, F_CF);
CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
/* calculate the carry chain SEE NOTE AT TOP. */
cc = (s & d) | ((~res) & (s | d));
CONDITIONAL_SET_FLAG(XOR2(cc >> 14), F_OF);
CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
return (uint16_t)res;
}
/****************************************************************************
REMARKS:
Implements the ADC instruction and side effects.
****************************************************************************/
uint32_t adc32(x86emu_t *emu, uint32_t d, uint32_t s)
{
uint32_t lo; /* all operands in native machine order */
uint32_t hi;
uint32_t res;
uint32_t cc;
CHECK_FLAGS(emu);
if (ACCESS_FLAG(F_CF)) {
lo = 1 + (d & 0xFFFF) + (s & 0xFFFF);
res = 1 + d + s;
}
else {
lo = (d & 0xFFFF) + (s & 0xFFFF);
res = d + s;
}
hi = (lo >> 16) + (d >> 16) + (s >> 16);
CONDITIONAL_SET_FLAG(hi & 0x10000, F_CF);
CONDITIONAL_SET_FLAG(!res, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
/* calculate the carry chain SEE NOTE AT TOP. */
cc = (s & d) | ((~res) & (s | d));
CONDITIONAL_SET_FLAG(XOR2(cc >> 30), F_OF);
CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
return res;
}
/****************************************************************************
REMARKS:
Implements the CMP instruction and side effects.
****************************************************************************/
uint8_t cmp8(x86emu_t *emu, uint8_t d, uint8_t s)
{
uint32_t res; /* all operands in native machine order */
uint32_t bc;
RESET_FLAGS(emu);
res = d - s;
CLEAR_FLAG(F_CF);
CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
/* calculate the borrow chain. See note at top */
bc = (res & (~d | s)) | (~d & s);
CONDITIONAL_SET_FLAG(bc & 0x80, F_CF);
CONDITIONAL_SET_FLAG(XOR2(bc >> 6), F_OF);
CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
return d;
}
/****************************************************************************
REMARKS:
Implements the CMP instruction and side effects.
****************************************************************************/
uint16_t cmp16(x86emu_t *emu, uint16_t d, uint16_t s)
{
uint32_t res; /* all operands in native machine order */
uint32_t bc;
RESET_FLAGS(emu);
res = d - s;
CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
/* calculate the borrow chain. See note at top */
bc = (res & (~d | s)) | (~d & s);
CONDITIONAL_SET_FLAG(bc & 0x8000, F_CF);
CONDITIONAL_SET_FLAG(XOR2(bc >> 14), F_OF);
CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
return d;
}
/****************************************************************************
REMARKS:
Implements the CMP instruction and side effects.
****************************************************************************/
uint32_t cmp32(x86emu_t *emu, uint32_t d, uint32_t s)
{
uint32_t res; /* all operands in native machine order */
uint32_t bc;
RESET_FLAGS(emu);
res = d - s;
CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
CONDITIONAL_SET_FLAG(!res, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
/* calculate the borrow chain. See note at top */
bc = (res & (~d | s)) | (~d & s);
CONDITIONAL_SET_FLAG(bc & 0x80000000, F_CF);
CONDITIONAL_SET_FLAG(XOR2(bc >> 30), F_OF);
CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
return d;
}
/****************************************************************************
REMARKS:
Implements the DAA instruction and side effects.
****************************************************************************/
uint8_t daa8(x86emu_t *emu, uint8_t d)
{
uint32_t res = d;
CHECK_FLAGS(emu);
if ((d & 0xf) > 9 || ACCESS_FLAG(F_AF)) {
res += 6;
SET_FLAG(F_AF);
}
if (d > 0x99 || ACCESS_FLAG(F_CF)) {
res += 0x60;
SET_FLAG(F_CF);
} else
CLEAR_FLAG(F_CF);
CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
CONDITIONAL_SET_FLAG((res & 0xFF) == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
return (uint8_t)res;
}
/****************************************************************************
REMARKS:
Implements the DAS instruction and side effects.
****************************************************************************/
uint8_t das8(x86emu_t *emu, uint8_t d)
{
uint32_t res = d;
CHECK_FLAGS(emu);
uint32_t newcf = 0;
if ((d & 0xf) > 9 || ACCESS_FLAG(F_AF)) {
res -= 6;
newcf = (d < 6);
SET_FLAG(F_AF);
} else
CLEAR_FLAG(F_AF);
if (d > 0x99 || ACCESS_FLAG(F_CF)) {
res -= 0x60;
newcf = 1;
}
CONDITIONAL_SET_FLAG(newcf, F_CF);
CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
CONDITIONAL_SET_FLAG((res & 0xFF) == 0, F_ZF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
return res;
}
/****************************************************************************
REMARKS:
Implements the RCL instruction and side effects.
****************************************************************************/
uint8_t rcl8(x86emu_t *emu, uint8_t d, uint8_t s)
{
unsigned int res, cnt, mask, cf;
CHECK_FLAGS(emu);
s = s&0x1f;
/* s is the rotate distance. It varies from 0 - 8. */
/* have
CF B_7 B_6 B_5 B_4 B_3 B_2 B_1 B_0
want to rotate through the carry by "s" bits. We could
loop, but that's inefficient. So the width is 9,
and we split into three parts:
The new carry flag (was B_n)
the stuff in B_n-1 .. B_0
the stuff in B_7 .. B_n+1
The new rotate is done mod 9, and given this,
for a rotation of n bits (mod 9) the new carry flag is
then located n bits from the MSB. The low part is
then shifted up cnt bits, and the high part is or'd
in. Using CAPS for new values, and lowercase for the
original values, this can be expressed as:
IF n > 0
1) CF <- b_(8-n)
2) B_(7) .. B_(n) <- b_(8-(n+1)) .. b_0
3) B_(n-1) <- cf
4) B_(n-2) .. B_0 <- b_7 .. b_(8-(n-1))
*/
res = d;
if ((cnt = s % 9) != 0) {
/* extract the new CARRY FLAG. */
/* CF <- b_(8-n) */
cf = (d >> (8 - cnt)) & 0x1;
/* get the low stuff which rotated
into the range B_7 .. B_cnt */
/* B_(7) .. B_(n) <- b_(8-(n+1)) .. b_0 */
/* note that the right hand side done by the mask */
res = (d << cnt) & 0xff;
/* now the high stuff which rotated around
into the positions B_cnt-2 .. B_0 */
/* B_(n-2) .. B_0 <- b_7 .. b_(8-(n-1)) */
/* shift it downward, 7-(n-2) = 9-n positions.
and mask off the result before or'ing in.
*/
mask = (1 << (cnt - 1)) - 1;
res |= (d >> (9 - cnt)) & mask;
/* if the carry flag was set, or it in. */
if (ACCESS_FLAG(F_CF)) { /* carry flag is set */
/* B_(n-1) <- cf */
res |= 1 << (cnt - 1);
}
/* set the new carry flag, based on the variable "cf" */
CONDITIONAL_SET_FLAG(cf, F_CF);
/* OVERFLOW is set *IFF* cnt==1, then it is the
xor of CF and the most significant bit. Blecck. */
/* parenthesized this expression since it appears to
be causing OF to be misset */
CONDITIONAL_SET_FLAG(cnt == 1 && XOR2(cf + ((res >> 6) & 0x2)),
F_OF);
}
return (uint8_t)res;
}
/****************************************************************************
REMARKS:
Implements the RCL instruction and side effects.
****************************************************************************/
uint16_t rcl16(x86emu_t *emu, uint16_t d, uint8_t s)
{
unsigned int res, cnt, mask, cf;
CHECK_FLAGS(emu);
s = s&0x1f;
res = d;
if ((cnt = s % 17) != 0) {
cf = (d >> (16 - cnt)) & 0x1;
res = (d << cnt) & 0xffff;
mask = (1 << (cnt - 1)) - 1;
res |= (d >> (17 - cnt)) & mask;
if (ACCESS_FLAG(F_CF)) {
res |= 1 << (cnt - 1);
}
CONDITIONAL_SET_FLAG(cf, F_CF);
CONDITIONAL_SET_FLAG(cnt == 1 && XOR2(cf + ((res >> 14) & 0x2)),
F_OF);
}
return (uint16_t)res;
}
/****************************************************************************
REMARKS:
Implements the RCL instruction and side effects.
****************************************************************************/
uint32_t rcl32(x86emu_t *emu, uint32_t d, uint8_t s)
{
uint32_t res, cnt, mask, cf;
CHECK_FLAGS(emu);
s = s&0x1f;
res = d;
if ((cnt = s % 33) != 0) {
cf = (d >> (32 - cnt)) & 0x1;
res = (d << cnt);
mask = (1 << (cnt - 1)) - 1;
res |= (d >> (33 - cnt)) & mask;
if (ACCESS_FLAG(F_CF)) { /* carry flag is set */
res |= 1 << (cnt - 1);
}
CONDITIONAL_SET_FLAG(cf, F_CF);
CONDITIONAL_SET_FLAG(cnt == 1 && XOR2(cf + ((res >> 30) & 0x2)),
F_OF);
}
return res;
}
/****************************************************************************
REMARKS:
Implements the RCR instruction and side effects.
****************************************************************************/
uint8_t rcr8(x86emu_t *emu, uint8_t d, uint8_t s)
{
uint32_t res, cnt;
uint32_t mask, cf, ocf = 0;
CHECK_FLAGS(emu);
s = s&0x1f;
/* rotate right through carry */
/*
s is the rotate distance. It varies from 0 - 8.
d is the byte object rotated.
have
CF B_7 B_6 B_5 B_4 B_3 B_2 B_1 B_0
The new rotate is done mod 9, and given this,
for a rotation of n bits (mod 9) the new carry flag is
then located n bits from the LSB. The low part is
then shifted up cnt bits, and the high part is or'd
in. Using CAPS for new values, and lowercase for the
original values, this can be expressed as:
IF n > 0
1) CF <- b_(n-1)
2) B_(8-(n+1)) .. B_(0) <- b_(7) .. b_(n)
3) B_(8-n) <- cf
4) B_(7) .. B_(8-(n-1)) <- b_(n-2) .. b_(0)
*/
res = d;
if ((cnt = s % 9) != 0) {
/* extract the new CARRY FLAG. */
/* CF <- b_(n-1) */
if (cnt == 1) {
cf = d & 0x1;
/* note hackery here. Access_flag(..) evaluates to either
0 if flag not set
non-zero if flag is set.
doing access_flag(..) != 0 casts that into either
0..1 in any representation of the flags register
(i.e. packed bit array or unpacked.)
*/
ocf = ACCESS_FLAG(F_CF) != 0;
} else
cf = (d >> (cnt - 1)) & 0x1;
/* B_(8-(n+1)) .. B_(0) <- b_(7) .. b_n */
/* note that the right hand side done by the mask
This is effectively done by shifting the
object to the right. The result must be masked,
in case the object came in and was treated
as a negative number. Needed??? */
mask = (1 << (8 - cnt)) - 1;
res = (d >> cnt) & mask;
/* now the high stuff which rotated around
into the positions B_cnt-2 .. B_0 */
/* B_(7) .. B_(8-(n-1)) <- b_(n-2) .. b_(0) */
/* shift it downward, 7-(n-2) = 9-n positions.
and mask off the result before or'ing in.
*/
res |= (d << (9 - cnt));
/* if the carry flag was set, or it in. */
if (ACCESS_FLAG(F_CF)) { /* carry flag is set */
/* B_(8-n) <- cf */
res |= 1 << (8 - cnt);
}
/* set the new carry flag, based on the variable "cf" */
CONDITIONAL_SET_FLAG(cf, F_CF);
/* OVERFLOW is set *IFF* cnt==1, then it is the
xor of CF and the most significant bit. Blecck. */
/* parenthesized... */
if (cnt == 1) {
CONDITIONAL_SET_FLAG(XOR2(ocf + ((d >> 6) & 0x2)),
F_OF);
}
}
return (uint8_t)res;
}
/****************************************************************************
REMARKS:
Implements the RCR instruction and side effects.
****************************************************************************/
uint16_t rcr16(x86emu_t *emu, uint16_t d, uint8_t s)
{
uint32_t res, cnt;
uint32_t mask, cf, ocf = 0;
CHECK_FLAGS(emu);
s = s&0x1f;
/* rotate right through carry */
res = d;
if ((cnt = s % 17) != 0) {
if (cnt == 1) {
cf = d & 0x1;
ocf = ACCESS_FLAG(F_CF) != 0;
} else
cf = (d >> (cnt - 1)) & 0x1;
mask = (1 << (16 - cnt)) - 1;
res = (d >> cnt) & mask;
res |= (d << (17 - cnt));
if (ACCESS_FLAG(F_CF)) {
res |= 1 << (16 - cnt);
}
CONDITIONAL_SET_FLAG(cf, F_CF);
if (cnt == 1) {
CONDITIONAL_SET_FLAG(XOR2(ocf + ((d >> 14) & 0x2)),
F_OF);
}
}
return (uint16_t)res;
}
/****************************************************************************
REMARKS:
Implements the RCR instruction and side effects.
****************************************************************************/
uint32_t rcr32(x86emu_t *emu, uint32_t d, uint8_t s)
{
uint32_t res, cnt;
uint32_t mask, cf, ocf = 0;
CHECK_FLAGS(emu);
s = s&0x1f;
/* rotate right through carry */
res = d;
if ((cnt = s % 33) != 0) {
if (cnt == 1) {
cf = d & 0x1;
ocf = ACCESS_FLAG(F_CF) != 0;
} else
cf = (d >> (cnt - 1)) & 0x1;
mask = (1 << (32 - cnt)) - 1;
res = (d >> cnt) & mask;
if (cnt != 1)
res |= (d << (33 - cnt));
if (ACCESS_FLAG(F_CF)) { /* carry flag is set */
res |= 1 << (32 - cnt);
}
CONDITIONAL_SET_FLAG(cf, F_CF);
if (cnt == 1) {
CONDITIONAL_SET_FLAG(XOR2(ocf + ((d >> 30) & 0x2)),
F_OF);
}
}
return res;
}
/****************************************************************************
REMARKS:
Implements the ROL instruction and side effects.
****************************************************************************/
uint8_t rol8(x86emu_t *emu, uint8_t d, uint8_t s)
{
unsigned cnt;
s = s&0x1f;
if(!s) return d;
if((cnt = s % 8) != 0) {
d = (d << cnt) + ((d >> (8 - cnt)) & ((1 << cnt) - 1));
}
CHECK_FLAGS(emu);
/* OF flag is set if s == 1; OF = CF _XOR_ MSB of result */
if(s == 1) {
CONDITIONAL_SET_FLAG((d + (d >> 7)) & 1, F_OF);
}
/* set new CF; note that it is the LSB of the result */
CONDITIONAL_SET_FLAG(d & 0x1, F_CF);
return d;
}
/****************************************************************************
REMARKS:
Implements the ROL instruction and side effects.
****************************************************************************/
uint16_t rol16(x86emu_t *emu, uint16_t d, uint8_t s)
{
unsigned cnt;
s = s&0x1f;
if(!s) return d;
if((cnt = s % 16) != 0) {
d = (d << cnt) + ((d >> (16 - cnt)) & ((1 << cnt) - 1));
}
CHECK_FLAGS(emu);
/* OF flag is set if s == 1; OF = CF _XOR_ MSB of result */
if(s == 1) {
CONDITIONAL_SET_FLAG((d + (d >> 15)) & 1, F_OF);
}
/* set new CF; note that it is the LSB of the result */
CONDITIONAL_SET_FLAG(d & 0x1, F_CF);
return d;
}
/****************************************************************************
REMARKS:
Implements the ROL instruction and side effects.
****************************************************************************/
uint32_t rol32(x86emu_t *emu, uint32_t d, uint8_t s)
{
unsigned cnt;
s = s&0x1f;
if(!s) return d;
if((cnt = s % 32) != 0) {
d = (d << cnt) + ((d >> (32 - cnt)) & ((1 << cnt) - 1));
}
CHECK_FLAGS(emu);
/* OF flag is set if s == 1; OF = CF _XOR_ MSB of result */
if(s == 1) {
CONDITIONAL_SET_FLAG((d + (d >> 31)) & 1, F_OF);
}
/* set new CF; note that it is the LSB of the result */
CONDITIONAL_SET_FLAG(d & 0x1, F_CF);
return d;
}
/****************************************************************************
REMARKS:
Implements the ROR instruction and side effects.
****************************************************************************/
uint8_t ror8(x86emu_t *emu, uint8_t d, uint8_t s)
{
unsigned cnt;
s = s&0x1f;
if(!s) return d;
if((cnt = s % 8) != 0) {
d = (d << (8 - cnt)) + ((d >> (cnt)) & ((1 << (8 - cnt)) - 1));
}
CHECK_FLAGS(emu);
/* OF flag is set if s == 1; OF = MSB _XOR_ (M-1)SB of result */
if(s == 1) {
CONDITIONAL_SET_FLAG(XOR2(d >> 6), F_OF);
}
/* set new CF; note that it is the MSB of the result */
CONDITIONAL_SET_FLAG(d & (1 << 7), F_CF);
return d;
}
/****************************************************************************
REMARKS:
Implements the ROR instruction and side effects.
****************************************************************************/
uint16_t ror16(x86emu_t *emu, uint16_t d, uint8_t s)
{
unsigned cnt;
s = s&0x1f;
if(!s) return d;
if((cnt = s % 16) != 0) {
d = (d << (16 - cnt)) + ((d >> (cnt)) & ((1 << (16 - cnt)) - 1));
}
CHECK_FLAGS(emu);
/* OF flag is set if s == 1; OF = MSB _XOR_ (M-1)SB of result */
if(s == 1) {
CONDITIONAL_SET_FLAG(XOR2(d >> 14), F_OF);
}
/* set new CF; note that it is the MSB of the result */
CONDITIONAL_SET_FLAG(d & (1 << 15), F_CF);
return d;
}
/****************************************************************************
REMARKS:
Implements the ROR instruction and side effects.
****************************************************************************/
uint32_t ror32(x86emu_t *emu, uint32_t d, uint8_t s)
{
unsigned cnt;
s = s&0x1f;
if(!s) return d;
if((cnt = s % 32) != 0) {
d = (d << (32 - cnt)) + ((d >> (cnt)) & ((1 << (32 - cnt)) - 1));
}
CHECK_FLAGS(emu);
/* OF flag is set if s == 1; OF = MSB _XOR_ (M-1)SB of result */
if(s == 1) {
CONDITIONAL_SET_FLAG(XOR2(d >> 30), F_OF);
}
/* set new CF; note that it is the MSB of the result */
CONDITIONAL_SET_FLAG(d & (1 << 31), F_CF);
return d;
}
/****************************************************************************
REMARKS:
Implements the SHLD instruction and side effects.
****************************************************************************/
uint16_t shld16 (x86emu_t *emu, uint16_t d, uint16_t fill, uint8_t s)
{
unsigned int cnt, res, cf;
RESET_FLAGS(emu);
s = s&0x1f;
cnt = s % 16;
if (s < 16) {
if (cnt > 0) {
res = (d << cnt) | (fill >> (16-cnt));
cf = d & (1 << (16 - cnt));
CONDITIONAL_SET_FLAG(cf, F_CF);
CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
} else {
res = d;
}
if (cnt == 1) {
CONDITIONAL_SET_FLAG((((res & 0x8000) == 0x8000) ^
(ACCESS_FLAG(F_CF) != 0)), F_OF);
} else {
CLEAR_FLAG(F_OF);
}
} else {
res = (fill << (cnt)) | (d >> (16 - cnt));
if(s==16)
cf = d & 1;
else
cf = fill & (1 << (16 - cnt));
CONDITIONAL_SET_FLAG(cf, F_CF);
CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
CLEAR_FLAG(F_OF);
}
return (uint16_t)res;
}
/****************************************************************************
REMARKS:
Implements the SHLD instruction and side effects.
****************************************************************************/
uint32_t shld32 (x86emu_t *emu, uint32_t d, uint32_t fill, uint8_t s)
{
unsigned int cnt, res, cf;
RESET_FLAGS(emu);
s = s&0x1f;
cnt = s % 32;
if (cnt > 0) {
res = (d << cnt) | (fill >> (32-cnt));
cf = d & (1 << (32 - cnt));
CONDITIONAL_SET_FLAG(cf, F_CF);
CONDITIONAL_SET_FLAG(!res, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
} else {
res = d;
}
if (cnt == 1) {
CONDITIONAL_SET_FLAG((((res & 0x80000000) == 0x80000000) ^
(ACCESS_FLAG(F_CF) != 0)), F_OF);
} else {
CLEAR_FLAG(F_OF);
}
return res;
}
/****************************************************************************
REMARKS:
Implements the SHRD instruction and side effects.
****************************************************************************/
uint16_t shrd16 (x86emu_t *emu, uint16_t d, uint16_t fill, uint8_t s)
{
unsigned int cnt, res, cf;
RESET_FLAGS(emu);
s = s&0x1f;
cnt = s % 16;
if (s < 16) {
if (cnt > 0) {
cf = d & (1 << (cnt - 1));
res = (d >> cnt) | (fill << (16 - cnt));
CONDITIONAL_SET_FLAG(cf, F_CF);
CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
} else {
res = d;
}
if (cnt == 1) {
CONDITIONAL_SET_FLAG(XOR2(res >> 14), F_OF);
} else {
CLEAR_FLAG(F_OF);
}
} else {
cf = fill & (1 << (cnt - 1));
res = (fill >> cnt) | (d << (16 - cnt));
CONDITIONAL_SET_FLAG(cf, F_CF);
CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
CLEAR_FLAG(F_OF);
#if 0
res = 0;
CLEAR_FLAG(F_CF);
CLEAR_FLAG(F_OF);
SET_FLAG(F_ZF);
CLEAR_FLAG(F_SF);
CLEAR_FLAG(F_PF);
#endif
}
return (uint16_t)res;
}
/****************************************************************************
REMARKS:
Implements the SHRD instruction and side effects.
****************************************************************************/
uint32_t shrd32 (x86emu_t *emu, uint32_t d, uint32_t fill, uint8_t s)
{
unsigned int cnt, res, cf;
RESET_FLAGS(emu);
s = s&0x1f;
cnt = s % 32;
if (cnt > 0) {
cf = d & (1 << (cnt - 1));
res = (d >> cnt) | (fill << (32 - cnt));
CONDITIONAL_SET_FLAG(cf, F_CF);