forth: LSHIFT/RSHIFT + 32-bit arith truncation + early binding (Hayes 174→268)

plans/forth-on-sx.md

@@ -82,7 +82,7 @@ Representation:
 - [x] `CHAR`, `[CHAR]`, `KEY`, `ACCEPT`
 - [x] `BASE` manipulation: `DECIMAL`, `HEX`
 - [x] `DEPTH`, `SP@`, `SP!`
-- [ ] Drive Hayes Core pass-rate up
+- [x] Drive Hayes Core pass-rate up
 
 ### Phase 5 — Core Extension + optional word sets
 - [ ] Full Core + Core Extension
@@ -99,6 +99,23 @@ Representation:
 
 _Newest first._
 
+- **Phase 4 close — LSHIFT/RSHIFT, 32-bit arith truncation, early
+  binding; Hayes 174→268 (42%).** Added `LSHIFT` / `RSHIFT` as logical
+  shifts on 32-bit unsigned values, converted through
+  `forth-to-unsigned`/`forth-from-unsigned`. All arithmetic
+  primitives (`+` `-` `*` `/` `MOD` `NEGATE` `ABS` `1+` `1-` `2+`
+  `2-` `2*` `2/`) now clip results to 32-bit signed via a new
+  `forth-clip` helper, so loop idioms that rely on `2*` shifting the
+  MSB out (e.g. Hayes' `BITS` counter) actually terminate.
+  Changed colon-def call compilation from late-binding to early
+  binding: `forth-compile-call` now resolves the target word at
+  compile time, which makes `: GDX 123 ; : GDX GDX 234 ;` behave
+  per ANS (inner `GDX` → old def, not infinite recursion). `RECURSE`
+  keeps its late-binding thunk via the new `forth-compile-recurse`
+  helper. Raised `MAX_CHUNKS` default to 638 (full `core.fr`) now
+  that the BITS and COUNT-BITS loops terminate. Hayes: 268 pass /
+  368 error / 2 fail.
+
 - **Phase 4 — `SP@`/`SP!` (+4; Hayes unchanged; `DEPTH` was already present).**
   `SP@` pushes the current data-stack depth (our closest analogue to a
   stack pointer — SX lists have no addressable backing). `SP!` pops a