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| author | Cliff Click <cliffc@acm.org> | 2026-10-01 15:47:15 -0700 |
|---|---|---|
| committer | Cliff Click <cliffc@acm.org> | 2026-10-01 15:47:15 -0700 |
| commit | bd0ef17d0f9563ed9579fe060b785211e8378006 (patch) | |
| tree | d8f45cdfd6e7ee295997d11ff948ca4950153721 /skills | |
| parent | 5dd5b7a2d03885cb767bbf2b609d56f8ef897301 (diff) | |
| download | Simple-bd0ef17d0f9563ed9579fe060b785211e8378006.tar.gz Simple-bd0ef17d0f9563ed9579fe060b785211e8378006.zip | |
Restore missing anti-dependence walk
Diffstat (limited to 'skills')
| -rw-r--r-- | skills/chapter25-codex-notes.md | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/skills/chapter25-codex-notes.md b/skills/chapter25-codex-notes.md index 208494e7..c409cd55 100644 --- a/skills/chapter25-codex-notes.md +++ b/skills/chapter25-codex-notes.md @@ -260,7 +260,10 @@ For shared viewer work, read [the graph viewer notes](graph-viewer-codex-notes.m - Keep anti-dependence marks in a pass-local array, not CFGNode. In 11-20 the evaluator independently reschedules nodes, so retain the full store placement range when constraining loads; using only GCM's final store block breaks - `SchedulerTest.testStoreInIf2`. From 21, the chosen store block suffices. + `SchedulerTest.testStoreInIf2`. Retain the dominator walk from 21 onward too: + a conditional Store can precede a Load's late block without dominating it. + Its exact block need not be marked, but an ancestor intersects the Load's + placement range. `Chapter21Test.testReadBeforeConditionalStore` checks this. Preserve each chapter's alias/tuple memory representation when finding stores. - Changes in node order can expose encoding bugs. Chapter 21's empty-block scan mistook entry to a nested loop for a backedge; require the same loop-tree node, |