Rodrigo Mesquita pushed to branch wip/spj-reinstallable-base2 at Glasgow Haskell Compiler / GHC Commits: 4460f533 by Rodrigo Mesquita at 2026-06-18T14:52:18+01:00 WIP - - - - - 6bdd11fc by Rodrigo Mesquita at 2026-06-18T14:52:20+01:00 Revert "WIP" This reverts commit 4460f533a57f0e18f9d501919179fce2f2b9b707. - - - - - ead3bd4c by Rodrigo Mesquita at 2026-06-23T17:03:20+01:00 Empty commit, accept metrics: Metrics: compile_time/bytes allocated ------------------------------------- Baseline Test Metric value New value Change ------------------------------------------------------------------------------------------ InstanceMatching(normal) ghc/alloc 1,145,959,113 1,186,619,544 +3.5% BAD MultiComponentModulesRecomp(normal) ghc/alloc 597,207,232 618,028,168 +3.5% BAD MultiLayerModules(normal) ghc/alloc 3,758,938,427 3,599,359,024 -4.2% GOOD T10547(normal) ghc/alloc 24,791,700 26,882,568 +8.4% BAD T12234(optasm) ghc/alloc 50,179,044 51,470,552 +2.6% BAD T12425(optasm) ghc/alloc 76,129,240 77,611,840 +1.9% BAD T13035(normal) ghc/alloc 81,107,420 82,879,768 +2.2% BAD T13701(normal) ghc/alloc 3,455,572,124 3,170,909,168 -8.2% GOOD T13820(normal) ghc/alloc 27,310,260 28,962,824 +6.1% BAD T14697(normal) ghc/alloc 454,460,496 427,282,904 -6.0% GOOD T18140(normal) ghc/alloc 46,025,476 48,039,600 +4.4% BAD T18282(normal) ghc/alloc 118,979,708 121,371,368 +2.0% BAD T18698a(normal) ghc/alloc 195,729,417 198,210,960 +1.3% BAD T18698b(normal) ghc/alloc 176,091,489 178,839,680 +1.6% BAD T18730(optasm) ghc/alloc 129,923,785 131,490,416 +1.2% BAD T18923(normal) ghc/alloc 54,812,876 55,997,576 +2.2% BAD T20049(normal) ghc/alloc 65,225,572 67,339,024 +3.2% BAD T21839c(normal) ghc/alloc 339,233,494 345,159,824 +1.7% BAD T5030(normal) ghc/alloc 140,657,548 143,617,992 +2.1% BAD T9198(normal) ghc/alloc 40,466,900 41,381,736 +2.3% BAD hard_hole_fits(normal) ghc/alloc 208,002,867 202,293,816 -2.7% GOOD mhu-perf(normal) ghc/alloc 47,144,955 45,556,872 -3.4% GOOD geo. mean +1.1% minimum -8.2% maximum +8.4% Investigated in depth T10547(8.4%; 24MB): One-off cost of reading GHC.Essentials, one interface more than before (https://gitlab.haskell.org/ghc/ghc/-/merge_requests/15899#note_680477) InstanceMatching(3.5%;1.14GB): Inconclusive investigation starting from https://gitlab.haskell.org/ghc/ghc/-/merge_requests/15899#note_680504, where it is very hard to justify why getDictionary allocates 25MB more than before. That said, the investigation yielded a separately-merged change which reduces allocates by 10%. I've run out of time and ideas to investigate this small regression, but considering the big win yielded I'm tempted to just accept this one, as I don't know how else to investigate. The tests which allocate very little and regress for about 1MB more are most likely caused by the GHC.Essentials additional cost: T9198, T18923, T13820, T13035, T12234, T12425, T18730, T20049. Even if they aren't directly by GHC.Essentials, these are small one-shot cost regressions when we don't allocate a lot, which is acceptable for the payload of this patch Missing investigation: MultiComponentModulesRecomp, T18140, T18282, T18698a, T18698b, T21839c, T5030 ------------------------- Metric Decrease: MultiLayerModules T13701 T14697 hard_hole_fits mhu-perf size_hello_obj Metric Increase: InstanceMatching T10547 T9198 T18923 T13820 T13035 T12234 T12425 T18730 T20049 ------------------------- - - - - - 0 changed files: Changes: View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/7a4d1cf1f43cb1885bfcd8a8710e427... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/7a4d1cf1f43cb1885bfcd8a8710e427... You're receiving this email because of your account on gitlab.haskell.org.