Explore the security aspects of JavaScript JIT compilers in this Black Hat conference talk. Delve into the challenges faced by these compilers and the solutions implemented by prominent engines. Examine JavaScript values, type information, speculation guards, and the JIT compiler pipeline. Investigate bug categories, optimization techniques, and potential vulnerabilities. Learn about shape guards, arrays, objects, and abstract interpretation. Analyze practical examples and demonstrations, including a calculator exploit. Gain insights into new trends in browser exploitation and understand the implications for client-side security.