From 874808ef981b0d6b4e83e09329c3354e628365b8 Mon Sep 17 00:00:00 2001
From: Apoorva Ranade <apoorvaranade02@gmail.com>
Date: Mon, 3 May 2021 23:40:11 +0530
Subject: [PATCH] Added is operator

---
 src/main/java/chocopy/pa3/CodeGenImpl.java | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/main/java/chocopy/pa3/CodeGenImpl.java b/src/main/java/chocopy/pa3/CodeGenImpl.java
index 13d3270..6d522cf 100644
--- a/src/main/java/chocopy/pa3/CodeGenImpl.java
+++ b/src/main/java/chocopy/pa3/CodeGenImpl.java
@@ -728,7 +728,17 @@ public class CodeGenImpl extends CodeGenBase
                 sp_off -= 2;
                 backend.emitADDI(SP, FP, -sp_off*wordSize, "restore sp");
             }
-            // TODO: Implement "is" for objects
+            else if(operator.equals("is"))
+            {
+                node.right.dispatch(this);
+                backend.emitSW(Register.A0, Register.FP, -sp_off*wordSize, "Push on stack slot "+sp_off);
+                incSp(1);
+                node.left.dispatch(this);
+                sp_off--;
+                backend.emitLW(Register.T0, Register.FP, -sp_off*wordSize, "Pop stack slot "+sp_off);
+                backend.emitXOR(Register.A0,  Register.A0, Register.T0, "Operator: is");
+                backend.emitSEQZ(Register.A0,  Register.A0, "Result is True if XOR equals 0");
+            }
             else
             {
                 backend.emitJAL(errorNI, "Operator not implemented");