Lexicon Entry
Constant Folding
A compiler optimization that evaluates constant expressions at compile time instead of generating code to compute them at runtime. For example, 3 + 4 * 2 is replaced by 11 in the compiled output.
Related Knowledge & Cross-References
Guide
The Ultimate Guide to Compiler Optimization Passes: Boosting Performance with -O2
You’ve been there. You write a complex calculation in C, compile it, and it feels a bit sluggish. You open your `Makefile`, add `-O2` to your `CFLAGS`, recompile, and suddenly your program is executing three times faster. But what actually is the compiler doing under the hood? Is it magic? Is it just removing debug…