Summary
This episode introduces the concept of 'stack elision', a term Jason coined to describe compiler optimizations that eliminate stack-allocated variables when they can be proven unnecessary. Building on the previous episode about heap elision, he demonstrates how both GCC and Clang can eliminate large arrays allocated on the stack, particularly when those arrays are unused or their uses can be optimized away. Through assembly output analysis, Jason shows that Clang is generally more aggressive at this optimization, often replacing stack arrays with register usage, while GCC requires higher optimization levels to achieve similar results. The episode emphasizes that modern compilers can perform much more sophisticated optimizations than developers might expect.