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Implement immediate versions of PUSH operations (#12)

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Implement immediate versions of bit-shifting operations

Make word read/write operations not overflow when offset is 0xFFFF on 8018x
This commit is contained in:
Cacodemon345
2022-09-07 02:59:39 +06:00
committed by GitHub
parent 3dbfcf1fd3
commit 2b0dff2ec6
1 changed files with 109 additions and 2 deletions
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111
src/cpu/808x.c
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@@ -333,7 +333,7 @@ readmemw(uint32_t s, uint16_t a)
else {
wait(4, 1);
ret = read_mem_b(s + a);
ret |= read_mem_b(s + ((a + 1) & 0xffff)) << 8;
ret |= read_mem_b(s + (is186 ? (a + 1) : (a + 1) & 0xffff)) << 8;
}
return ret;
@@ -411,7 +411,7 @@ writememw(uint32_t s, uint32_t a, uint16_t v)
else {
write_mem_b(addr, v & 0xff);
wait(4, 1);
addr = s + ((a + 1) & 0xffff);
addr = s + (is186 ? (a + 1) : ((a + 1) & 0xffff));
write_mem_b(addr, v >> 8);
}
@@ -1703,6 +1703,96 @@ execx86(int cycs)
completed = 1;
// pclog("[%04X:%04X] Opcode: %02X\n", CS, cpu_state.pc, opcode);
if (is186) {
switch (opcode) {
case 0xC0: case 0xC1: /*rot imm8 */
bits = 8 << (opcode & 1);
do_mod_rm();
if (cpu_mod == 3)
wait(1, 0);
access(53, bits);
cpu_data = get_ea();
cpu_src = pfq_fetchb();
wait((cpu_mod != 3) ? 9 : 6, 0);
while (cpu_src != 0) {
cpu_dest = cpu_data;
oldc = cpu_state.flags & C_FLAG;
switch (rmdat & 0x38) {
case 0x00: /* ROL */
set_cf(top_bit(cpu_data, bits));
cpu_data <<= 1;
cpu_data |= ((cpu_state.flags & C_FLAG) ? 1 : 0);
set_of_rotate(bits);
set_af(0);
break;
case 0x08: /* ROR */
set_cf((cpu_data & 1) != 0);
cpu_data >>= 1;
if (cpu_state.flags & C_FLAG)
cpu_data |= (!(opcode & 1) ? 0x80 : 0x8000);
set_of_rotate(bits);
set_af(0);
break;
case 0x10: /* RCL */
set_cf(top_bit(cpu_data, bits));
cpu_data = (cpu_data << 1) | (oldc ? 1 : 0);
set_of_rotate(bits);
set_af(0);
break;
case 0x18: /* RCR */
set_cf((cpu_data & 1) != 0);
cpu_data >>= 1;
if (oldc)
cpu_data |= (!(opcode & 0x01) ? 0x80 : 0x8000);
set_cf((cpu_dest & 1) != 0);
set_of_rotate(bits);
set_af(0);
break;
case 0x20: /* SHL */
set_cf(top_bit(cpu_data, bits));
cpu_data <<= 1;
set_of_rotate(bits);
set_af((cpu_data & 0x10) != 0);
set_pzs(bits);
break;
case 0x28: /* SHR */
set_cf((cpu_data & 1) != 0);
cpu_data >>= 1;
set_of_rotate(bits);
set_af(0);
set_pzs(bits);
break;
case 0x30: /* SETMO - undocumented? */
bitwise(bits, 0xffff);
set_cf(0);
set_of_rotate(bits);
set_af(0);
set_pzs(bits);
break;
case 0x38: /* SAR */
set_cf((cpu_data & 1) != 0);
cpu_data >>= 1;
if (!(opcode & 1))
cpu_data |= (cpu_dest & 0x80);
else
cpu_data |= (cpu_dest & 0x8000);
set_of_rotate(bits);
set_af(0);
set_pzs(bits);
break;
}
if ((opcode & 2) != 0)
wait(4, 0);
--cpu_src;
}
access(17, bits);
set_ea(cpu_data);
handled = 1;
break;
}
}
if (!handled) {
switch (opcode) {
case 0x06: case 0x0E: case 0x16: case 0x1E: /* PUSH seg */
access(29, 16);
@@ -2236,12 +2326,27 @@ execx86(int cycs)
jcc(opcode, cpu_state.flags & (C_FLAG | Z_FLAG));
break;
case 0x68: /*JS alias*/
if (is186) { /* PUSH imm16 */
uint16_t wordtopush = pfq_fetchw();
wait(1, 0);
push(&wordtopush);
break;
}
case 0x78: /*JS*/
case 0x69: /*JNS alias*/
case 0x79: /*JNS*/
jcc(opcode, cpu_state.flags & N_FLAG);
break;
case 0x6A: /*JP alias*/
if (is186) { /* PUSH imm8 */
uint8_t bytetopush = pfq_fetchb();
{
SP -= 1;
cpu_state.eaaddr = (SP & 0xffff);
writememb(ss, cpu_state.eaaddr, bytetopush);
}
break;
}
case 0x7A: /*JP*/
case 0x6B: /*JNP alias*/
case 0x7B: /*JNP*/
@@ -2944,6 +3049,7 @@ execx86(int cycs)
wait(1, 0);
in_rep = (opcode == 0xf2 ? 1 : 2);
completed = 0;
rep_c_flag = 0;
break;
case 0xF4: /*HLT*/
@@ -3134,6 +3240,7 @@ execx86(int cycs)
wait(8, 0);
break;
}
}
if (completed) {
repeating = 0;