GoKawiilTechnical series explains second phase of profile-guided optimization in compiler builds
A blog post details how profile-guided optimization (PGO) works in its second installment, describing a two-pass compilation process where an instrumented first build records per-edge counters across branches, loops, and call sites. The author explains how these fine-grained counts feed into the compiler's second-pass decisions, starting with inlining choices that can override static size and cost heuristics based on actual execution frequency.