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Diffstat (limited to 'skills/chapter25-codex-notes.md')
| -rw-r--r-- | skills/chapter25-codex-notes.md | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/skills/chapter25-codex-notes.md b/skills/chapter25-codex-notes.md index d2b97bdd..f267c030 100644 --- a/skills/chapter25-codex-notes.md +++ b/skills/chapter25-codex-notes.md @@ -44,9 +44,9 @@ For shared viewer work, read [the graph viewer notes](graph-viewer-codex-notes.m - Chapter 10 is split into `chapter10a` (one bulk memory chain) and `chapter10b` (lazy graph partitioning). Both are standalone snapshots. Cliff reviewed and - committed the forward port through Chapter 15. Chapter 16 now carries lazy - memory through constructors and removes ScopeMinNode. Stop for implementation - review here; leave 17-24 unchanged. See the concrete boundary notes + committed the forward port through Chapter 16. Chapters 17-18 now carry lazy + memory through mutability and functions. Stop for implementation review at + Chapter 18; leave 19-24 unchanged. See the concrete boundary notes in `docs/chapter-backports.md`. GCM readiness and anti-dependency checks must both filter by alias and ignore MemMerge as a clobber; keep the evaluator's same alias filtering too. MemMerge still needs ordinary data-dependency placement. @@ -77,11 +77,20 @@ For shared viewer work, read [the graph viewer notes](graph-viewer-codex-notes.m sole-use Store-to-New guard is intentionally conservative with a shared memory result; do not add alias traversal just to recover a small constant fold. -- Generalized Phi factoring now starts in 10a and is forwarded through 16. +- Chapter 18 keeps memory Parm 1 and CallEnd memory opaque: heap arguments make + the earlier empty-entry-heap assumption invalid. Local/return merges use + BulkMemPhi; calls carry the complete memory state and clobber all aliases. + MemMerge no longer tracks parser state. GCM can raise a Load before a Call's + terminating block position, but must not append anti-dependence inputs to + Call: the last input is its function pointer. The one-step Phi Load guard + stops at Calls. Eval2's New initializer indexing and tuple printer use ptr 0, + memory 1, size input 2, field inputs 3 onward. + +- Generalized Phi factoring now starts in 10a and is forwarded through 18. Memory-specific eligibility lives in `MemOpNode.canDrop`, with virtual Load and Store checks. Load owns `clobbered`: all these chapters check only immediate memory users, without recursion or a visited set. Stop at Stores, - Phis, MemMerges (10b+), and New (15); do not chase aliases or aggregates just + Phis, MemMerges (10b+), New (15+), and Calls (18+); do not chase aliases or aggregates just to save one Load. Keep this teaching optimization simple and conservative. Preserve exact operation attributes with clone-based `copyEmpty`, type each operand Phi separately, reuse identical inputs, and reject type widening. @@ -92,7 +101,7 @@ For shared viewer work, read [the graph viewer notes](graph-viewer-codex-notes.m lookup assumes Region/alias identifies the completed memory point. Existing control-bound Stores in 11-14 remain ineligible. `delUse` wakes recorded dependents for user-count queries; Region's empty-diamond fold depends on - projection rewiring as well as projection types. Carry these with the 17+ + projection rewiring as well as projection types. Carry these with the 19+ memory port; do not duplicate the later chapters' existing `copyEmpty`. `subsume` must wake each rewired user's recorded dependents, just as `setDef` does: operand identity changes can enable a Phi fold without changing the |