Summary
In this episode, Jason investigates performance differences between GCC and Clang compilers using his Game of Life simulation code. He shares data from extensive testing across different optimization levels, discovering that GCC consistently outperformed Clang in most cases - until one specific code change. When he switched from compact, minimum-sized integer types to larger integers (int64_t/size_t) for array indices, Clang suddenly produced code 5x faster than before and outperformed GCC. The assembly code generated by Clang differed dramatically between these versions, showing that optimization behaviors can be counterintuitive and compiler-specific, even for seemingly simple code changes.