fib(n) if (n < 2) return n; else int a = fib(n-1); int b = fib(n-2); return a + b;
A simple but powerful optimization: If x = 5 in block A and x is not redefined in block B, then any use of x in block B can be replaced with 5 . This is trivial in SSA form, but C-- is not inherently SSA; thus, optimization passes often convert C-- to SSA and back. Optimized C-- Pdf
An optimizer collapses redundant jumps and straightens the flow. fib(n) if (n < 2) return n; else
Give hints to the register allocator to avoid spills in hot loops: fib(n) if (n <
The keyword is not merely a document search—it is a gateway to mastering low-level performance engineering. To recap: