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+# Session save — 2026-09-27: short-circuit AND/OR
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+
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+`master` — suite **111/111**, tree clean except the user's uncommitted
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+`compiler/toto.mod` edit.
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+
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+## Done today
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+
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+**Short-circuit `AND`/`OR`** (task 1). Tag `v3-short-circuit`; details in
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+`docs/summary_short-circuit.md`.
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+
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+- V3 used to evaluate both sides; gm2 and the compiler's own sources
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+ rely on short-circuit (~25 guard sites like
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+ `… AND (tform[t] = FAlias)`).
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+- Implemented by **deferring the RHS operand's code**: `QbeGen.DelayBegin`
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+ buffers it, `DelayEnd` restores output, `DelayFlush` replays it inside
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+ the branch; a **4-byte memory slot** (`Slot4`/`StoreW`/`LoadW`) merges
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+ the branch results (robust when the RHS spans blocks; a `phi` was not).
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+- `SimExpr` (OR) / `Term` (AND): `if a { r=1/0 } else { <RHS>; r=b }`.
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+- The `wip/short-circuit` branch (14 failing tests) was debugged — two
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+ bugs: `DelayFlush` popped the wrong index, and the `CopyOp`-only merge
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+ collapsed the branches to one operand — then merged and the branch
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+ deleted.
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+
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+## In progress (task 2: full self-image)
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+
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+The self-compiled V3 (`/tmp/M2self`) compiles a single file to a
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+**byte-identical `.ssa`**, but the **whole compiler source set** still
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+aborts (rc 134), now in the scanner's **`GetName`**
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+(`LexName ← GetIdent ← ProcTypeSection`) — a bounds trap in the
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+token-text copy loop (`0 ≤ i ≤ count` on the destination buffer).
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+Likely the caller's buffer descriptor header is wrong; needs more
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+diagnosis. (Earlier self-image aborts fixed: `Resolve`'s eager-`AND`
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+`tform[t]` guard → resolved by short-circuit.)
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+
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+## Next
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+
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+1. Diagnose the `GetName` bounds trap; iterate until `/tmp/M2self`
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+ compiles the whole set to a byte-identical `M2.ssa` (full fixpoint).
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+2. Cross-stage `FileIO` selection and `bootstrap/fixpoint.sh`
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+ (Stage1 gm2 → Stage2 V3 → Stage3 V3), with the stage-aware CR flag
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+ (`-m` for gm2, no `-m` for V3).
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+
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+## Tags added
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+
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+`v3-short-circuit` (merge + summary).
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