From b460334d2526dd3005d9adfe6208beac8bd408b4 Mon Sep 17 00:00:00 2001
From: tuz358 <orca00358@gmail.com>
Date: Tue, 6 Mar 2018 11:44:20 +0900
Subject: [PATCH] Add cmp_eax_imm32(0x3d) instruction

---
 include/instructions.h |  1 +
 instructions.cpp       | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/instructions.h b/include/instructions.h
index c7616b4..a2e39fb 100644
--- a/include/instructions.h
+++ b/include/instructions.h
@@ -43,6 +43,7 @@ public:
   void xor_r32_rm32();  // 0x33
   void xor_eax_imm32(); // 0x35
   void cmp_rm32_r32();  // 0x39
+  void cmp_eax_imm32(); // 0x3d
   void inc_eax();       // 0x40
   void inc_ecx();       // 0x41
   void inc_edx();       // 0x42
diff --git a/instructions.cpp b/instructions.cpp
index 5018d21..d771fc7 100644
--- a/instructions.cpp
+++ b/instructions.cpp
@@ -36,6 +36,8 @@ void Instructions::init_instructions(){
   this->instructions[0x33] = &Instructions::xor_r32_rm32;
   this->instructions[0x35] = &Instructions::xor_eax_imm32;
   this->instructions[0x39] = &Instructions::cmp_rm32_r32;
+  this->instructions[0x3b] = &Instructions::cmp_rm32_r32;
+  this->instructions[0x3d] = &Instructions::cmp_eax_imm32;
   this->instructions[0x40] = &Instructions::inc_eax;
   this->instructions[0x41] = &Instructions::inc_ecx;
   this->instructions[0x42] = &Instructions::inc_edx;
@@ -694,6 +696,14 @@ void Instructions::cmp_rm32_r32(){
   }
 }
 
+void Instructions::cmp_eax_imm32(){
+  this->eip++;
+  uint32_t imm32 = memory.read_uint32(this->eip);
+  imm32 = swap_endian32(imm32);
+  uint32_t result = this->registers[0] - imm32;
+  set_flag(!result, ZF);
+}
+
 void Instructions::inc_eax(){
   //printf("inc_eax called.\n");
   this->registers[0]++;