From 836f9d2106912e101e933d3ca873eecb3401682a Mon Sep 17 00:00:00 2001
From: Ronit Dsilva <124994670+Cherrytree56567@users.noreply.github.com>
Date: Wed, 13 Sep 2023 04:19:08 +0000
Subject: [PATCH] Addu Comment and Addi Fix

---
 PSEMU/CPU.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/PSEMU/CPU.cpp b/PSEMU/CPU.cpp
index a2db352..3cffab2 100644
--- a/PSEMU/CPU.cpp
+++ b/PSEMU/CPU.cpp
@@ -29,6 +29,7 @@ void CPU::op_add(uint32_t instruction) {
     std::cout << "ADDING: RESULT = " << registers.reg[rs] + registers.reg[rt] << ", RS = " << std::to_string(rs) << ", RT = " << std::to_string(rt) << ", RD = " << std::to_string(rd) << std::endl;
 
     registers.reg[rd] = registers.reg[rs] + registers.reg[rt];
+    // raise exception if overflow
 }
 
 // First take the data from RT (Register) and stores it in IMM + RS (memory)
@@ -62,18 +63,20 @@ void CPU::op_lui(uint32_t instruction) {
     std::cout << "Loading Value: RS = " << std::to_string(rs) << ", IMM = " << std::to_string(imm) << std::endl;
 } 
 
-// The op_addi function adds imm to rs, and stores the result in rt.
+// The op_addi function adds imm and rs, and stores the result in rt.
 
 void CPU::op_addi(uint32_t instruction) {
     uint8_t rs = (instruction >> 21) & 0x1F; // Extract bits 25 to 21
     uint8_t rt = (instruction >> 16) & 0x1F; // Extract bits 20 to 16
     uint16_t imm = instruction & 0xFFFF;      // Extract the immediate value
 
-    registers.reg[rt] = imm + rs;
+    registers.reg[rt] = imm + registers.reg[rs];
 
     std::cout << "Adding Immediate Value: RS = " << std::to_string(rs) << ", IMM = " << std::to_string(imm) << ", RT = " << std::to_string(rt) << std::endl;
 }
 
+// op_addu adds values in two registers and stores in another. No overflow exception raised.
+
 void CPU::loadBIOS(const char* filename) {
     FILE* file = fopen(filename, "rb");
     if (!file) {