Merge pull request #1422 from o1-labs/feature/mips/lbu

Implement `lbu`
o1-labs · Dec 6, 2023 · 59e6903 · 59e6903
2 parents 0313aff + 84af145
commit 59e6903
Showing 1 changed file with 13 additions and 1 deletion.
diff --git a/optimism/src/mips/interpreter.rs b/optimism/src/mips/interpreter.rs
@@ -1076,7 +1076,19 @@ pub fn interpret_itype<Env: InterpreterEnv>(env: &mut Env, instr: ITypeInstructi
             // REMOVEME: when all itype instructions are implemented.
             return;
         }
-        ITypeInstruction::Load8Unsigned => (),
+        ITypeInstruction::Load8Unsigned => {
+            let base = env.read_register(&rs);
+            let dest = rt;
+            let offset = env.sign_extend(&immediate, 16);
+            let addr = base + offset;
+            let v0 = env.read_memory(&addr);
+            let value = v0;
+            env.write_register(&dest, value);
+            env.set_instruction_pointer(next_instruction_pointer.clone());
+            env.set_next_instruction_pointer(next_instruction_pointer + Env::constant(4u32));
+            // REMOVEME: when all itype instructions are implemented.
+            return;
+        }
         ITypeInstruction::Load16Unsigned => (),
         ITypeInstruction::LoadWordLeft => (),
         ITypeInstruction::LoadWordRight => (),