From 1ce883a1a0ac49d0b0c16849303a1b0a02fa53a4 Mon Sep 17 00:00:00 2001
From: tuz358 <orca00358@gmail.com>
Date: Mon, 5 Mar 2018 10:12:34 +0900
Subject: [PATCH] Add dec_ecx(0x49) instruction

---
 include/instructions.h | 1 +
 instructions.cpp       | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/include/instructions.h b/include/instructions.h
index 2373cc4..b77fe79 100644
--- a/include/instructions.h
+++ b/include/instructions.h
@@ -25,6 +25,7 @@ public:
 
   void add_rm32_r32();  // 0x01
   void xor_rm32_r32();  // 0x31
+  void dec_ecx();       // 0x49
   void mov_rm32_r32();  // 0x89
   void nop();           // 0x90
   void mov_ecx_imm32(); // 0xb9
diff --git a/instructions.cpp b/instructions.cpp
index 511be6d..094e5ea 100644
--- a/instructions.cpp
+++ b/instructions.cpp
@@ -22,6 +22,7 @@ void Instructions::init_instructions(){
 
   this->instructions[0x01] = &Instructions::add_rm32_r32;
   this->instructions[0x31] = &Instructions::xor_rm32_r32;
+  this->instructions[0x49] = &Instructions::dec_ecx;
   this->instructions[0x89] = &Instructions::mov_rm32_r32;
   this->instructions[0x90] = &Instructions::nop;
   this->instructions[0xb9] = &Instructions::mov_ecx_imm32;
@@ -146,6 +147,11 @@ void Instructions::xor_rm32_r32(){
   }
 }
 
+void Instructions::dec_ecx(){
+  printf("dec_ecx called.\n");
+  this->registers[1]--;
+}
+
 void Instructions::mov_rm32_r32(){
   printf("mov_rm32_r32 called.\n");
   uint32_t addr, imm32;