/**
 * Optimize assembly code with peephole strategy.
 * @param O Optimization level:
 * - 0: No optimization
 * - 1: Very basic optimization, just remove silly/unused code
 * - 2: Safely changes and delete code for smarter outcome
 * - 3: Use final optimizations tracing variable contents (beta)
 * - 4: Dangerous deep optimizations. Must be checked by developer
 * @param assemblyCode Input assembly
 * @param labels Array with labels (they will not be removed)
 * @returns Assembly code processed
 */
export default function optimizer(O: number, assemblyCode: string, labels: string[]): string;