diff options
Diffstat (limited to 'skills/chapter25-codex-notes.md')
| -rw-r--r-- | skills/chapter25-codex-notes.md | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/skills/chapter25-codex-notes.md b/skills/chapter25-codex-notes.md index d2c19988..e85bd303 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 18. Chapter 19 now carries lazy - memory through instruction selection. Stop for implementation review at - Chapter 19; leave 20-24 unchanged. See the concrete boundary notes + committed the forward port through Chapter 19. Chapter 20 now carries lazy + memory through register allocation on all three targets. Stop for implementation + review at Chapter 20; leave 21-24 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. @@ -95,7 +95,16 @@ For shared viewer work, read [the graph viewer notes](graph-viewer-codex-notes.m requirement. Direct machine Calls embed the target, but still must not gain scheduling-only inputs. The one-step Phi Load guard remains unchanged. -- Generalized Phi factoring now starts in 10a and is forwarded through 19. +- Chapter 20 includes ARM and moves CodeGen to the codegen package. Memory + Phis and projections have no live range; the existing allocator already + excludes TypeMem. Preserve its inlining-safe Return compute and rejected-Phi + operand dependencies. Folded x86 Add requires a register value in slot 4 even + for a constant addend, because that value is also its two-address result. + Spill counts use the same fixed 39-entry cohort and seed 123: the lazy-memory + port changes 238 / 357 moves / weighted moves to 234 / 360 without changing + allocator heuristics. Selected-read ordering explains the extra hot array move. + +- Generalized Phi factoring now starts in 10a and is forwarded through 20. 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, @@ -110,7 +119,7 @@ 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 20+ + projection rewiring as well as projection types. Carry these with the 21+ 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 |