opcode_greater_than

src/compiler.cairo

@@ -39,6 +39,7 @@ pub impl CompilerTraitImpl of CompilerTrait {
         opcodes.insert('OP_DEPTH', Opcode::OP_DEPTH);
         opcodes.insert('OP_1ADD', Opcode::OP_1ADD);
         opcodes.insert('OP_ADD', Opcode::OP_ADD);
+        opcodes.insert('OP_GREATERTHAN', Opcode::OP_GREATERTHAN);
         opcodes.insert('OP_MAX', Opcode::OP_MAX);
         Compiler { opcodes }
     }

src/opcodes/opcodes.cairo

@@ -20,6 +20,7 @@ pub mod Opcode {
     pub const OP_DEPTH: u8 = 116;
     pub const OP_1ADD: u8 = 139;
     pub const OP_ADD: u8 = 147;
+    pub const OP_GREATERTHAN: u8 = 160;
     pub const OP_MAX: u8 = 164;
 
     use shinigami::engine::Engine;
@@ -186,7 +187,7 @@ pub mod Opcode {
             157 => not_implemented(ref engine),
             158 => not_implemented(ref engine),
             159 => not_implemented(ref engine),
-            160 => not_implemented(ref engine),
+            160 => opcode_greater_than(ref engine),
             161 => not_implemented(ref engine),
             162 => not_implemented(ref engine),
             163 => not_implemented(ref engine),
@@ -225,6 +226,16 @@ pub mod Opcode {
         panic!("Opcode not implemented");
     }
 
+    fn opcode_greater_than(ref engine: Engine) {
+        let a = engine.dstack.pop_int();
+        let b = engine.dstack.pop_int();
+        engine.dstack.push_int(if b > a {
+            1
+        } else {
+            0
+        });
+    }
+
     fn opcode_max(ref engine: Engine) {
         let a = engine.dstack.pop_int();
         let b = engine.dstack.pop_int();

src/opcodes/tests/test_opcodes.cairo

@@ -52,6 +52,24 @@ fn test_op_add() {
     assert_eq!(dstack, expected_stack.span(), "Stack is not equal to expected");
 }
 
+#[test]
+fn test_op_greater_than() {
+    let program = "OP_1 OP_0 OP_GREATERTHAN";
+    let mut compiler = CompilerTraitImpl::new();
+    let bytecode = compiler.compile(program);
+    let mut engine = EngineTraitImpl::new(bytecode);
+    let _ = engine.step();
+    let _ = engine.step();
+    let res = engine.step();
+    assert!(res, "Execution of run failed");
+
+    let dstack = engine.get_dstack();
+    assert_eq!(dstack.len(), 1, "Stack length is not 1");
+
+    let expected_stack = array!["\0\0\0\0\0\0\0\x01"];
+    assert_eq!(dstack, expected_stack.span(), "Stack is not equal to expected");
+}
+
 #[test]
 fn test_op_max() {
     let program = "OP_1 OP_0 OP_MAX";