From f631d16de080a67116f653426ed3366f0b5df73b Mon Sep 17 00:00:00 2001
From: mrmr1993 <mr_1993@hotmail.co.uk>
Date: Tue, 5 Dec 2023 23:38:01 +0000
Subject: [PATCH] Implement `xor`

---
 optimism/src/mips/interpreter.rs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/optimism/src/mips/interpreter.rs b/optimism/src/mips/interpreter.rs
index 459f0196b3..797d08b320 100644
--- a/optimism/src/mips/interpreter.rs
+++ b/optimism/src/mips/interpreter.rs
@@ -798,7 +798,19 @@ pub fn interpret_rtype<Env: InterpreterEnv>(env: &mut Env, instr: RTypeInstructi
             env.set_next_instruction_pointer(next_instruction_pointer + Env::constant(4u32));
             return;
         }
-        RTypeInstruction::Xor => (),
+        RTypeInstruction::Xor => {
+            let rs = env.read_register(&rs);
+            let rt = env.read_register(&rt);
+            let res = {
+                // FIXME: Constrain
+                let pos = env.alloc_scratch();
+                unsafe { env.xor_witness(&rs, &rt, pos) }
+            };
+            env.write_register(&rd, res);
+            env.set_instruction_pointer(next_instruction_pointer.clone());
+            env.set_next_instruction_pointer(next_instruction_pointer + Env::constant(4u32));
+            return;
+        }
         RTypeInstruction::Nor => (),
         RTypeInstruction::SetLessThan => {
             let rs = env.read_register(&rs);