3 Commits

Author	SHA1	Message	Date
Tarik Moussa	d7a61975b4	perf: architecture-touch quick-wins #6 + #10; skip #5 + #7 with honest notes ... Evaluated all four mid-tier architecture-touch levers from doc/architecture/compile-time.md. Outcome: ship two opt-in improvements, defer two with explicit rationale. #6 — Eager-include reduction (Dense → Core) ✅ shipped ───────────────────────────────────────────────────── Three headers downgraded from `<Eigen/Dense>` to `<Eigen/Core>`: * projective_math.hpp * hyper_ideal_visualization_utility.hpp * mesh_utils.hpp All three only use Matrix/Vector primitives, no Eigen decompositions. The other five Dense-including headers were inspected and KEPT on `<Eigen/Dense>` because they use `.inverse()`, `.determinant()`, `ColPivHouseholderQR`, or `SelfAdjointEigenSolver`. Measured Apple M1 cold rebuild after this change: 58 / 60 / 63 s across three runs. The prior analysis predicted ~10 % gain; reality landed within the ±5 s natural variance band of repeated builds, so the net build-time effect on the test target is "noise-level". The change is still kept because downstream consumers who include ONLY one of the three downgraded headers see a real per-TU drop (Core preprocesses to ~250 k lines vs Dense's ~350 k). #10 — Fast test-build mode (-O0 -g) ✅ shipped ─────────────────────────────────────────────── New option CONFORMALLAB_FAST_TEST_BUILD (default OFF). When ON, both test targets (`conformallab_tests` and `conformallab_cgal_tests`) compile with `-O0 -g -UNDEBUG`, overriding the inherited Release `-O3 -DNDEBUG`. Measured Apple clang: 51.6 s vs 46.8 s without -O0 → slightly slower. The Backend phase that prior analysis predicted would drop from 9.3 s to ~2 s doesn't dominate on Apple clang the way it does with GCC; the bigger `-g` debug info also lengthens the link step. Kept shipped because: * On Linux + g++ (CI runner) the picture flips — Backend dominates more, `-O0` typically delivers the predicted ~40 % build-time cut. * Cross-platform parity: users on Linux see the same CMake option they see locally. Honest documentation in doc/architecture/compile-time.md notes that the Apple-clang-local benefit is currently 0 %. Tests RUN ~15× slower under `-O0` (1.5 s → 23 s for 236 tests); acceptable for CI "did anything break" loops, NOT acceptable for benchmark workloads. #5 — Move detail:: impls to .inl files ⏸ deferred ─────────────────────────────────────────────────── Pure enabler for #7. Without #7 landing, the .inl extraction would just add an extra hop to header reading. Reconsider once a concrete maintenance reason emerges (e.g. a downstream user wants to override a detail helper). #7 — Pimpl on newton_solver + priority_BFS ⏸ deferred ─────────────────────────────────────────────────────── Honest assessment: Newton_solver is template-on-Functional, so a faithful Pimpl would require either type erasure or a virtual-method interface across the five solver instantiations. Estimated 1-2 weeks of refactor with measurable API-surface risk. PCH already absorbs the SimplicialLDLT + SparseQR template parse cost, so the remaining delta is small. Deferred until a concrete user reports compile-time pain from these specific templates. Documentation ───────────── README.md gains a "Compile-time workflow modes" section with all six opt-in switches (BUILD_TESTING, HEADERS_CHECK, DEV_BUILD, FAST_TEST_BUILD, USE_PCH, USE_CCACHE) as ready-to-paste command lines. doc/architecture/compile-time.md gains: * an "Architecture-touch quick-wins" section with the four-row status table (5 deferred / 6 shipped / 7 deferred / 10 shipped) * the FAST_TEST_BUILD row added to the workflow-modes table * the mode-matrix table updated with Linux-vs-macOS expected values * an honest "variance" note explaining the ±5 s spread between repeated cold builds and why #6's net effect lands in that noise Verified: default build 55 s (within usual variance), 236/236 tests pass under default; FAST_TEST_BUILD=ON build 52 s, 236/236 PASS. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>	2026-05-26 08:56:36 +02:00
Tarik Moussa	3fea36823f	perf: add 4 workflow modes (BUILD_TESTING / DEV_BUILD / HEADERS_CHECK / ccache) ... Four orthogonal opt-in build modes on top of the existing PCH + Unity defaults. Each addresses a specific iteration scenario; defaults are unchanged (PCH + Unity stays the canonical fast full-rebuild path). (A) HEADERS_CHECK target — opt-in via -DCONFORMALLAB_HEADERS_CHECK=ON Per-public-header smoke-compile sentinels. For each of the six public CGAL umbrella headers, a stub TU `#include <…>\nint main(){}` is generated at configure time and compiled in isolation. * Full headers_check build: ≈ 12 s * Incremental after touching one header: ≈ 0.1 s Use case: "did my refactor still parse the public API?" without waiting 55 s for the full CGAL test build. (C) DEV_BUILD mode — opt-in via -DCONFORMALLAB_DEV_BUILD=ON PCH stays on; Unity Build is forced off (both globally AND on the cgal-tests target which previously overrode the global setting). Trade-off: full clean rebuild ~75 s (+36 % vs the 55 s default) but incremental rebuild after editing a single test file drops from ~46 s (unity batch) to ~16 s (single TU + relink). Flip on for trial-and-error sessions, flip off before measuring CI build time or shipping a PR. (D) ccache integration — default ON, disable with -DCONFORMALLAB_USE_CCACHE=OFF Detects `ccache` on PATH and prepends it to compile + link launchers. On Apple clang + PCH + Unity the macOS-local hit rate is currently 0 % (3 separate friction points documented in doc/architecture/compile-time.md § "ccache — honesty notes"); stays neutral when it doesn't help. Real payoff on Linux CI (g++ + traditional PCH) where 80 %+ hit rates are typical. (BUILD_TESTING=OFF) Standard CMake gate, now respected end-to-end. Wrapped both `add_subdirectory(tests)` AND the FetchContent of GoogleTest in `if(BUILD_TESTING)`. Pass `-DBUILD_TESTING=OFF`: * Configure ≈ 1 s * Build ≈ 0 s * 0 object files * No GTest fetch Use case: IDE-syntax-check workflow that needs `compile_commands.json` but does NOT need to download GTest or build any test binary. doc/architecture/compile-time.md gains: * a "Workflow modes — what to choose when" section with a 4-row switch matrix and a "mode matrix at a glance" comparison table * a ccache honesty-notes block listing the three macOS friction points (PCH artefact caching, Unity Build path randomisation, CMake launcher integration) — Linux CI is where the lever pays off Verified: default build 53 s wall, 236/236 tests pass; all opt-in modes tested end-to-end with their expected workflow numbers documented in the doc. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>	2026-05-26 08:35:44 +02:00
Tarik Moussa	687a43e853	ci+perf: PCH + Unity Build cut CGAL test build wall-time 30% (78s -> 55s) ... Two structural compile-time optimisations on the conformallab_cgal_tests target, both opt-out-able and verified safe (236/236 tests pass under every configuration). (1) Precompiled headers — option CONFORMALLAB_USE_PCH (default ON) target_precompile_headers(conformallab_cgal_tests PRIVATE <CGAL/Surface_mesh.h> <CGAL/Simple_cartesian.h> <CGAL/Kernel_traits.h> <CGAL/boost/graph/iterator.h> <CGAL/Polygon_mesh_processing/triangulate_faces.h> <Eigen/Dense> <Eigen/Sparse> <Eigen/SparseCholesky> <Eigen/SparseQR> <gtest/gtest.h> <vector> <string> <cmath> <complex> ) Absorbs the per-TU CGAL+Eigen template-parse cost (measured at 5.9 s per minimal "include <CGAL/Discrete_conformal_map.h>" hello-world TU on Apple M1). (2) Unity Build — UNITY_BUILD ON with UNITY_BUILD_BATCH_SIZE 4 Concatenates the 22 test TUs into 5 batches of <=4 files each; CGAL+Eigen headers parsed once per batch instead of once per TU. Batch size 4 keeps gtest's TEST(...) macros and per-file `using namespace ...` from colliding across batched files. Numbers (Apple M1, Ninja, -j8, clean rebuild) ───────────────────────────────────────────── wall CPU tests baseline 78 s 676 s 236/236 + PCH 66 s 474 s 236/236 (-15% wall, -30% CPU) + PCH + Unity 55 s 167 s 236/236 (-30% wall, -75% CPU) Honest deferred items (documented in doc/architecture/compile-time.md): * `extern template` (lever #2 in the analysis) — subsumed by PCH; estimated residual gain <5%, would add Eigen-version fragility. * Header split <CGAL/Discrete_conformal_map_{euclidean,spherical, hyper_ideal}.h> (lever #3) — downstream-only benefit (our test build needs all three); kept as a future cleanup once a downstream user actually requests it. Opt-outs: `-DCONFORMALLAB_USE_PCH=OFF` and `-DCMAKE_UNITY_BUILD=OFF`. Detailed measurement methodology, per-TU breakdowns, clang -ftime-trace template hot-spots, and a "what comes next" lever list live in doc/architecture/compile-time.md. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>	2026-05-26 07:58:41 +02:00