From ff161a69e6ae5bc63e3152eda1508db05e8a33ba Mon Sep 17 00:00:00 2001
From: taitep <taitep@taitep.se>
Date: Mon, 22 Dec 2025 19:19:19 +0100
Subject: [PATCH] Implement ADD

---
 src/instructions.rs     |  5 +++++
 src/instructions/rvi.rs | 10 ++++++++++
 2 files changed, 15 insertions(+)

diff --git a/src/instructions.rs b/src/instructions.rs
index a2edc53..c9c1c52 100644
--- a/src/instructions.rs
+++ b/src/instructions.rs
@@ -13,6 +13,11 @@ use crate::{
 
 pub(crate) fn find_and_exec(instr: Instruction, core: &mut Core) -> Option<InstructionResult> {
     match instr.opcode_noncompressed() {
+        0b01100 => match (instr.funct7(), instr.funct3()) {
+            // OP
+            (0b0000000, 0b000) => Some(rvi::add(core, instr)),
+            _ => None,
+        },
         0b00100 => match instr.funct3() {
             // OP_IMM
             0b000 => Some(rvi::addi(core, instr)),
diff --git a/src/instructions/rvi.rs b/src/instructions/rvi.rs
index 0920e80..608b1ae 100644
--- a/src/instructions/rvi.rs
+++ b/src/instructions/rvi.rs
@@ -11,6 +11,16 @@ use crate::{
     mem::PageNum,
 };
 
+pub fn add(core: &mut Core, instr: Instruction) -> InstructionResult {
+    core.reg_write(
+        instr.rd(),
+        core.reg_read(instr.rs1())
+            .wrapping_add(core.reg_read(instr.rs2())),
+    );
+    core.advance_pc();
+    InstructionResult::Normal
+}
+
 pub fn addi(core: &mut Core, instr: Instruction) -> InstructionResult {
     core.reg_write(
         instr.rd(),