ripwire-opt-remarks

# Triaging clang optimization remarks in this repo > Nearest neighbours: > • A measured slow operation, any codebase → **ripwire-perf-target**. Do that FIRST; remarks are the > second question, not the first. > • Maintenance risk / complexity in a subsystem → **ripwire-fresh-eyes**. Different axis entirely. Full record of the pass this skill came from, with every number: **`docs/OPTREMARKS.md`**. ## The one rule **A remark is an observation, not a defect.** Clang is reporting a decision, usually the right one. The pass that produced this skill read ~1.1 M remarks over `src/`. **Zero of them justified a source edit.** Two justified a BUILD change (LTO, then PGO), and the best-looking source-level candidate was implemented, verified to do exactly what the remark asked, measured, and reverted. Budget your attention accordingly: on this codebase, the answer to a remark is far more often a compiler flag than a diff. ## Step 0 — profile first, or you will optimize a millisecond ```bash cmake -S . -B build_prof -DRIPWIRE_PROFILE=ON && cmake --build build_prof -j 6 ./build_prof/ripwire . --no-cache 2>&1 >/dev/null | sed -n '/hottest scopes/,/PROF_TSV/p' ``` On this codebase the answer is stable and counterintuitive: **PageRank is ~1 ms** of a ~2.7 s cold CPU profile, the build-model sorts are ~1.7 ms, and ~29% sits in two phases now living in `src/ingest_sidecap.h` (`captureTagsFacts`, `captureSideFacts`) that spend it calling tree-sitter. So a remark in `src/pagerank.cpp`, ...