diff options
Diffstat (limited to 'graph')
| -rw-r--r-- | graph/README.md | 12 | ||||
| -rw-r--r-- | graph/web/layout.js | 7 |
2 files changed, 16 insertions, 3 deletions
diff --git a/graph/README.md b/graph/README.md index f7037548..8d3850e7 100644 --- a/graph/README.md +++ b/graph/README.md @@ -156,6 +156,18 @@ This keeps both graphs side by side in the chapter README. Chapter 10a's [load-after-store example](../chapter10a/README.md#local-memory-optimizations) uses this format to isolate a single rewrite. +Choose how much control to show according to the lesson. Keep it when teaching +control construction, branch elimination, loop nesting, or `break`/`continue`. +For a value rewrite inside an otherwise obvious branch or loop, omit the +routine CFG and its predicate-only computations, while preserving Phi data +inputs and their order. Chapter 5's arithmetic/Phi examples and Chapter 9's +optimization examples use this convention. Detached True/False projections +can identify important gates, including the two Returns in Chapter 9's first +GVN example. Describe omitted context in the caption or surrounding text. +If a snapshot omits a Loop, retain `"backedge": true` on its Phis' backedge +inputs so layout still puts the loop header values above their updates. This +is a documentation layout hint; live snapshots derive it from the Loop node. + The memory diagrams in 10a, 10b, and 11 also use viewer snapshots, with definitions above uses (apart from loop backedges) and arrows from use to definition. They omit control-flow context, including Regions and their Phi bindings, diff --git a/graph/web/layout.js b/graph/web/layout.js index 04d6f338..bd164854 100644 --- a/graph/web/layout.js +++ b/graph/web/layout.js @@ -155,9 +155,10 @@ class GraphLayout { const bundle = e.refs.length > 1; const id = bundle ? `b${use.id}d${e.def}` : "e" + e.orig.use + "i" + e.orig.idx; const reg = byId.get(use.edges[0]?.def)?.n; - const back = !use.fold && e.idx === 2 && (use.kind === "LOOP" || - (use.kind === "PHI" && reg?.kind === "LOOP")); - const loop = back ? (use.kind === "LOOP" ? use.id : reg.id) : 0; + // Focused documentation can omit the Loop but retain its backedge cue. + const back = !use.fold && (e.backedge === true || (e.idx === 2 && + (use.kind === "LOOP" || (use.kind === "PHI" && reg?.kind === "LOOP")))); + const loop = back ? (use.kind === "LOOP" ? use.id : (reg?.kind === "LOOP" ? reg.id : 0)) : 0; const wrap = loop && view.groups.has(loop) && !raw.get(loop).fold ? loop : 0; if (wrap) backs.set(wrap, (backs.get(wrap) || 0) + 1); edges.push({id, use: use.id, def: e.def, idx: e.orig.idx, orig: e.orig, refs: e.refs, bundle, role: e.role, label: e.label, |