--- /dev/null
+// Copyright (C) 2001 MandrakeSoft S.A.
+//
+// MandrakeSoft S.A.
+// 43, rue d'Aboukir
+// 75002 Paris - France
+// http://www.linux-mandrake.com/
+// http://www.mandrakesoft.com/
+//
+// 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
+
+
+
+
+
+
+#define NEED_CPU_REG_SHORTCUTS 1
+#include "bochs.h"
+#define LOG_THIS BX_CPU_THIS_PTR
+
+
+
+
+ void
+BX_CPU_C::MUL_AXEw(BxInstruction_t *i)
+{
+ Bit16u op1_16, op2_16, product_16h, product_16l;
+ Bit32u product_32;
+ Boolean temp_flag;
+
+ op1_16 = AX;
+
+ /* op2 is a register or memory reference */
+ if (i->mod == 0xc0) {
+ op2_16 = BX_READ_16BIT_REG(i->rm);
+ }
+ else {
+ /* pointer, segment address pair */
+ read_virtual_word(i->seg, i->rm_addr, &op2_16);
+ }
+
+ product_32 = ((Bit32u) op1_16) * ((Bit32u) op2_16);
+
+ product_16l = (product_32 & 0xFFFF);
+ product_16h = product_32 >> 16;
+
+ /* now write product back to destination */
+
+ AX = product_16l;
+ DX = product_16h;
+
+ /* set eflags:
+ * MUL affects the following flags: C,O
+ */
+
+ temp_flag = (product_16h != 0);
+ SET_FLAGS_OxxxxC(temp_flag, temp_flag);
+}
+
+
+
+ void
+BX_CPU_C::IMUL_AXEw(BxInstruction_t *i)
+{
+ Bit16s op1_16, op2_16;
+ Bit32s product_32;
+ Bit16u product_16h, product_16l;
+
+ op1_16 = AX;
+
+ /* op2 is a register or memory reference */
+ if (i->mod == 0xc0) {
+ op2_16 = BX_READ_16BIT_REG(i->rm);
+ }
+ else {
+ /* pointer, segment address pair */
+ read_virtual_word(i->seg, i->rm_addr, (Bit16u *) &op2_16);
+ }
+
+ product_32 = ((Bit32s) op1_16) * ((Bit32s) op2_16);
+
+ product_16l = (product_32 & 0xFFFF);
+ product_16h = product_32 >> 16;
+
+ /* now write product back to destination */
+
+ AX = product_16l;
+ DX = product_16h;
+
+ /* set eflags:
+ * IMUL affects the following flags: C,O
+ * IMUL r/m16: condition for clearing CF & OF:
+ * DX:AX = sign-extend of AX
+ */
+
+ if ( (DX==0xffff) && (AX & 0x8000) ) {
+ SET_FLAGS_OxxxxC(0, 0);
+ }
+ else if ( (DX==0x0000) && (AX < 0x8000) ) {
+ SET_FLAGS_OxxxxC(0, 0);
+ }
+ else {
+ SET_FLAGS_OxxxxC(1, 1);
+ }
+}
+
+
+ void
+BX_CPU_C::DIV_AXEw(BxInstruction_t *i)
+{
+ Bit16u op2_16, remainder_16, quotient_16l;
+ Bit32u op1_32, quotient_32;
+
+ op1_32 = (((Bit32u) DX) << 16) | ((Bit32u) AX);
+
+ /* op2 is a register or memory reference */
+ if (i->mod == 0xc0) {
+ op2_16 = BX_READ_16BIT_REG(i->rm);
+ }
+ else {
+ /* pointer, segment address pair */
+ read_virtual_word(i->seg, i->rm_addr, &op2_16);
+ }
+
+ if (op2_16 == 0) {
+ exception(BX_DE_EXCEPTION, 0, 0);
+ }
+ quotient_32 = op1_32 / op2_16;
+ remainder_16 = op1_32 % op2_16;
+ quotient_16l = quotient_32 & 0xFFFF;
+
+ if (quotient_32 != quotient_16l) {
+ exception(BX_DE_EXCEPTION, 0, 0);
+ }
+
+ /* set EFLAGS:
+ * DIV affects the following flags: O,S,Z,A,P,C are undefined
+ */
+
+#if INTEL_DIV_FLAG_BUG == 1
+ set_CF(1);
+#endif
+
+ /* now write quotient back to destination */
+
+ AX = quotient_16l;
+ DX = remainder_16;
+}
+
+
+ void
+BX_CPU_C::IDIV_AXEw(BxInstruction_t *i)
+{
+ Bit16s op2_16, remainder_16, quotient_16l;
+ Bit32s op1_32, quotient_32;
+
+ op1_32 = ((((Bit32u) DX) << 16) | ((Bit32u) AX));
+
+ /* op2 is a register or memory reference */
+ if (i->mod == 0xc0) {
+ op2_16 = BX_READ_16BIT_REG(i->rm);
+ }
+ else {
+ /* pointer, segment address pair */
+ read_virtual_word(i->seg, i->rm_addr, (Bit16u *) &op2_16);
+ }
+
+ if (op2_16 == 0) {
+ exception(BX_DE_EXCEPTION, 0, 0);
+ }
+ quotient_32 = op1_32 / op2_16;
+ remainder_16 = op1_32 % op2_16;
+ quotient_16l = quotient_32 & 0xFFFF;
+
+ if (quotient_32 != quotient_16l) {
+ exception(BX_DE_EXCEPTION, 0, 0);
+ }
+
+ /* set EFLAGS:
+ * IDIV affects the following flags: O,S,Z,A,P,C are undefined
+ */
+
+#if INTEL_DIV_FLAG_BUG == 1
+ set_CF(1);
+#endif
+
+ /* now write quotient back to destination */
+
+ AX = quotient_16l;
+ DX = remainder_16;
+}
+
+
+ void
+BX_CPU_C::IMUL_GwEwIw(BxInstruction_t *i)
+{
+#if BX_CPU_LEVEL < 2
+ BX_PANIC(("IMUL_GvEvIv() unsupported on 8086!\n"));
+#else
+
+
+ Bit16u product_16l;
+ Bit16s op2_16, op3_16;
+ Bit32s product_32;
+
+ op3_16 = i->Iw;
+
+ /* op2 is a register or memory reference */
+ if (i->mod == 0xc0) {
+ op2_16 = BX_READ_16BIT_REG(i->rm);
+ }
+ else {
+ /* pointer, segment address pair */
+ read_virtual_word(i->seg, i->rm_addr, (Bit16u *) &op2_16);
+ }
+
+ product_32 = op2_16 * op3_16;
+
+ product_16l = (product_32 & 0xFFFF);
+
+ /* now write product back to destination */
+ BX_WRITE_16BIT_REG(i->nnn, product_16l);
+
+ /* set eflags:
+ * IMUL affects the following flags: C,O
+ * IMUL r16,r/m16,imm16: condition for clearing CF & OF:
+ * result exactly fits within r16
+ */
+
+ if (product_32 > -32768 && product_32 < 32767) {
+ SET_FLAGS_OxxxxC(0, 0);
+ }
+ else {
+ SET_FLAGS_OxxxxC(1, 1);
+ }
+#endif
+}
+
+ void
+BX_CPU_C::IMUL_GwEw(BxInstruction_t *i)
+{
+#if BX_CPU_LEVEL < 3
+ BX_PANIC(("IMUL_GvEv() unsupported on 8086!\n"));
+#else
+
+ Bit16u product_16l;
+ Bit16s op1_16, op2_16;
+ Bit32s product_32;
+
+ /* op2 is a register or memory reference */
+ if (i->mod == 0xc0) {
+ op2_16 = BX_READ_16BIT_REG(i->rm);
+ }
+ else {
+ /* pointer, segment address pair */
+ read_virtual_word(i->seg, i->rm_addr, (Bit16u *) &op2_16);
+ }
+
+ op1_16 = BX_READ_16BIT_REG(i->nnn);
+
+ product_32 = op1_16 * op2_16;
+
+ product_16l = (product_32 & 0xFFFF);
+
+ /* now write product back to destination */
+ BX_WRITE_16BIT_REG(i->nnn, product_16l);
+
+ /* set eflags:
+ * IMUL affects the following flags: C,O
+ * IMUL r16,r/m16,imm16: condition for clearing CF & OF:
+ * result exactly fits within r16
+ */
+
+ if (product_32 > -32768 && product_32 < 32767) {
+ SET_FLAGS_OxxxxC(0, 0);
+ }
+ else {
+ SET_FLAGS_OxxxxC(1, 1);
+ }
+#endif
+}
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