Merge pull request #1424 from o1-labs/feature/mips/slti

Implement `slti`
o1-labs · Dec 6, 2023 · 135e0da · 135e0da
2 parents 55d4cc4 + 3e91b7a
commit 135e0da
Showing 1 changed file with 13 additions and 1 deletion.
diff --git a/optimism/src/mips/interpreter.rs b/optimism/src/mips/interpreter.rs
@@ -1009,7 +1009,19 @@ pub fn interpret_itype<Env: InterpreterEnv>(env: &mut Env, instr: ITypeInstructi
             // REMOVEME: when all itype instructions are implemented.
             return;
         }
-        ITypeInstruction::SetLessThanImmediate => (),
+        ITypeInstruction::SetLessThanImmediate => {
+            let rs = env.read_register(&rs);
+            let immediate = env.sign_extend(&immediate, 16);
+            let res = {
+                // FIXME: Constrain
+                let pos = env.alloc_scratch();
+                unsafe { env.test_less_than_signed(&rs, &immediate, pos) }
+            };
+            env.write_register(&rt, res);
+            env.set_instruction_pointer(next_instruction_pointer.clone());
+            env.set_next_instruction_pointer(next_instruction_pointer + Env::constant(4u32));
+            return;
+        }
         ITypeInstruction::SetLessThanImmediateUnsigned => {
             let rs = env.read_register(&rs);
             let immediate = env.sign_extend(&immediate, 16);