Hash table optimization

table.c

@@ -20,7 +20,7 @@ void freeTable(Table* table) {
 }
 
 static Entry* findEntry(Entry* entries, int capacity, ObjString* key) {
-  uint32_t index = key->hash % capacity;
+  uint32_t index = key->hash & (capacity-1);
   Entry* tombstone = NULL;
 
   for (;;) {
@@ -35,7 +35,7 @@ static Entry* findEntry(Entry* entries, int capacity, ObjString* key) {
       return entry;
     }
 
-    index = (index+1) % capacity;
+    index = (index+1) & (capacity-1);
   }
 }
 
@@ -90,7 +90,7 @@ ObjString* tableFindString(Table* table, const char* chars,
     int length, uint32_t hash) {
     if (table->count == 0) return NULL;
 
-  uint32_t index = hash % table->capacity;
+  uint32_t index = hash & (table->capacity-1);
   for (;;) {
     Entry* entry = &table->entries[index];
     if (entry->key == NULL) {
@@ -102,7 +102,7 @@ ObjString* tableFindString(Table* table, const char* chars,
       // We found it.
       return entry->key;
     }
-    index = (index + 1) % table->capacity;
+    index = (index + 1) & (table->capacity-1);
   }
 }