use lookup method for preimage length checks

o1-labs · Aug 26, 2024 · e99aac1 · e99aac1
1 parent 6b03d7d
commit e99aac1
Showing 1 changed file with 5 additions and 20 deletions.
diff --git a/o1vm/src/mips/constraints.rs b/o1vm/src/mips/constraints.rs
@@ -532,26 +532,11 @@ impl<Fp: Field> InterpreterEnv for Env<Fp> {
 
         // FIXED LOOKUPS
         // Check that 0 <= preimage read <= actual read <= len <= 4
-        self.add_lookup(Lookup::write_one(
-            LookupTableIDs::AtMost4Lookup,
-            vec![len.clone()],
-        ));
-        self.add_lookup(Lookup::write_one(
-            LookupTableIDs::AtMost4Lookup,
-            vec![actual_read_bytes.clone()],
-        ));
-        self.add_lookup(Lookup::write_one(
-            LookupTableIDs::AtMost4Lookup,
-            vec![num_preimage_bytes_read.clone()],
-        ));
-        self.add_lookup(Lookup::write_one(
-            LookupTableIDs::AtMost4Lookup,
-            vec![len.clone() - actual_read_bytes.clone()],
-        ));
-        self.add_lookup(Lookup::write_one(
-            LookupTableIDs::AtMost4Lookup,
-            vec![actual_read_bytes.clone() - num_preimage_bytes_read.clone()],
-        ));
+        self.lookup_2bits(len);
+        self.lookup_2bits(&actual_read_bytes);
+        self.lookup_2bits(&num_preimage_bytes_read);
+        self.lookup_2bits(&(len.clone() - actual_read_bytes.clone()));
+        self.lookup_2bits(&(actual_read_bytes.clone() - num_preimage_bytes_read.clone()));
 
         // COMMUNICATION CHANNEL: Write preimage chunk (1, 2, 3, or 4 bytes)
         for i in 0..MIPS_CHUNK_BYTES_LEN {