From 199bbed5ee02547f41167805bd86401884dc2050 Mon Sep 17 00:00:00 2001
From: Cacodemon345 <wahil1976@outlook.com>
Date: Mon, 5 Sep 2022 02:00:29 +0600
Subject: [PATCH] NEC CLR1 instructions (#8)

Wraps up the fixed bitfield manipulation instructions
---
 src/cpu/808x.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/cpu/808x.c b/src/cpu/808x.c
index 6602e244a..f192bf085 100644
--- a/src/cpu/808x.c
+++ b/src/cpu/808x.c
@@ -1805,6 +1805,25 @@ execx86(int cycs)
 						handled = 1;
 						break;
 					}
+					case 0x12: /* CLR1 r8/m8, CL*/
+					case 0x13: /* CLR1 r16/m16, CL*/
+					case 0x1a: /* CLR1 r8/m8, imm3 */
+					case 0x1b: /* CLR1 r16/m16, imm4 */
+					{
+						bits = 8 << (opcode & 0x1);
+						do_mod_rm();
+						wait(3, 0);
+						{
+							uint8_t bit = (opcode & 0x8) ? (pfq_fetchb()) : (CL);
+							bit &= ((1 << (3 + (opcode & 0x1))) - 1);
+							read_ea(0, bits);
+
+							if (bits == 8) seteab((cpu_data & 0xFF) & ~(1 << bit));
+							else seteaw((cpu_data & 0xFFFF) & ~(1 << bit));
+						}
+						handled = 1;
+						break;
+					}
 					default: {
 						opcode = orig_opcode;
 						break;