revert: reject marginal numeric VM slot reuse

2026-09-06 05:37:20 +08:00
parent 5122c73aa8
commit 52c7831bf6
2 changed files with 100 additions and 65 deletions
@@ -0,0 +1,74 @@
+{
+  "schemaVersion": "fidc-numeric-vm-binding-generation-rejection/v1",
+  "measuredAt": "2026-09-06T05:36:00+08:00",
+  "host": "192.168.31.177",
+  "baseline": {
+    "engineCommit": "5f08978",
+    "primaryFiveYearHotMedianEngineSeconds": 2.629,
+    "primaryFiveYearTotalReturn": 0.9219861819172002,
+    "primaryFiveYearTradeCount": 26088,
+    "primaryCanonicalSha256": "b42fea66237d06eadb24f6b8c9e2760e7319fe3699f315b99e01f433ef2aa234",
+    "primaryResultStoreSha256": "9ccf0c0fc6f5d72e974381ad4cd09a80241d7de99f2649f2b01736f7c80dc2c7",
+    "profileInstructions": 16600366059,
+    "profileBranches": 2592214949
+  },
+  "compileTimeIdentifierBinding": {
+    "engineCommit": "2135a5b",
+    "implementation": "map every numeric VM identifier to a typed runtime enum during expression plan compilation",
+    "primaryFiveYearHotEngineSeconds": [2.608, 2.624, 2.651, 2.619, 2.781],
+    "primaryFiveYearHotMedianEngineSeconds": 2.624,
+    "observedMedianImprovementPercent": 0.190186,
+    "profileInstructions": 16360894880,
+    "instructionReductionPercent": 1.442566,
+    "secondaryFiveYearResultConsistent": true,
+    "secondaryFiveYearPerformanceExcluded": true,
+    "secondaryFiveYearExclusionReason": "the symbolic campaign entered a high-memory-bandwidth phase between the primary and secondary batches",
+    "netCodeLinesAdded": 562,
+    "retained": false
+  },
+  "generationStampedScratchSlots": {
+    "engineCommit": "5122c73",
+    "implementation": "invalidate numeric VM variable and local slots with a generation counter instead of clearing Option arrays for each evaluation",
+    "localReleaseBenchmark": {
+      "baselineVmNanosecondsPerEvaluation": 86.992,
+      "candidateSamples": [83.284, 94.166, 86.275, 84.138, 85.453],
+      "candidateMedianNanosecondsPerEvaluation": 85.453,
+      "componentImprovementPercent": 1.769136,
+      "comparisonStrength": "weak because the baseline contains one sample"
+    },
+    "primaryFiveYearHotEngineSeconds": [2.634, 2.636, 2.608, 2.642, 2.710],
+    "primaryFiveYearHotMedianEngineSeconds": 2.636,
+    "observedMedianRegressionPercent": 0.266261,
+    "profileInstructions": 16521146700,
+    "instructionReductionPercent": 0.477215,
+    "netCodeLinesAdded": 39,
+    "retained": false
+  },
+  "hostLoad": {
+    "symbolicWorkersObserved": 3,
+    "symbolicWorkerCpuPercentApproximate": [720, 718, 698],
+    "symbolicWorkerRssBytesApproximate": [54479982592, 53353455616, 53941170176],
+    "wallTimeComparisonsAcrossPhasesExcluded": true
+  },
+  "testGate": {
+    "workspacePassedBeforeFirstCandidateRejection": 539,
+    "workspacePassedForGenerationCandidate": 540,
+    "failed": 0,
+    "ignoredManualBenchmarks": 8
+  },
+  "remoteArtifacts": [
+    "/srv/fidc/canonical/run/fidc-private/evidence/goal-primary-five-year-20260906.json",
+    "/srv/fidc/canonical/run/fidc-private/evidence/identifier-binding-primary-five-year-20260906.json",
+    "/srv/fidc/canonical/run/fidc-private/evidence/identifier-binding-secondary-five-year-20260906.json",
+    "/srv/fidc/canonical/run/fidc-private/evidence/identifier-binding-candidate-perf-stat-20260906.csv",
+    "/srv/fidc/canonical/run/fidc-private/evidence/identifier-binding-rollback-primary-five-year-20260906.json",
+    "/srv/fidc/canonical/run/fidc-private/evidence/identifier-binding-rollback-perf-stat-20260906.csv",
+    "/srv/fidc/canonical/run/fidc-private/evidence/vm-generation-primary-five-year-20260906.json",
+    "/srv/fidc/canonical/run/fidc-private/evidence/vm-generation-candidate-perf-stat-20260906.csv"
+  ],
+  "decision": {
+    "status": "rejected_and_removed",
+    "reason": "both candidates preserved exact business results but failed to produce a material, stable end-to-end improvement; the typed binding added disproportionate code and the generation slots slightly regressed the five-year median",
+    "nextTarget": "profile and specialize the numeric VM instruction dispatch or runtime helper execution without changing expression, PIT, or lazy short-circuit semantics"
+  }
+}