erlang: Phase 9f — hot-BIF opcode table (+18 vm tests)

lib/erlang/scoreboard.json

@@ -1,7 +1,7 @@
 {
   "language": "erlang",
-  "total_pass": 691,
-  "total": 691,
+  "total_pass": 709,
+  "total": 709,
   "suites": [
     {"name":"tokenize","pass":62,"total":62,"status":"ok"},
     {"name":"parse","pass":52,"total":52,"status":"ok"},
@@ -13,6 +13,6 @@
     {"name":"echo","pass":7,"total":7,"status":"ok"},
     {"name":"fib","pass":8,"total":8,"status":"ok"},
     {"name":"ffi","pass":14,"total":14,"status":"ok"},
-    {"name":"vm","pass":54,"total":54,"status":"ok"}
+    {"name":"vm","pass":72,"total":72,"status":"ok"}
   ]
 }

lib/erlang/scoreboard.md

@@ -1,6 +1,6 @@
 # Erlang-on-SX Scoreboard
 
-**Total: 691 / 691 tests passing**
+**Total: 709 / 709 tests passing**
 
 |  | Suite | Pass | Total |
 |---|---|---|---|
@@ -14,7 +14,7 @@
 | ✅ | echo | 7 | 7 |
 | ✅ | fib | 8 | 8 |
 | ✅ | ffi | 14 | 14 |
-| ✅ | vm | 54 | 54 |
+| ✅ | vm | 72 | 72 |
 
 
 Generated by `lib/erlang/conformance.sh`.

lib/erlang/tests/vm.sx

@@ -304,4 +304,66 @@
 (er-vm-test "reset resets pid counter"
   (er-vm-dispatch 134 (list er-vm-fn (list))) 0)
 
+
+;; ── Phase 9f — hot-BIF dispatch table ───────────────────────────
+;; Each opcode skips the registry lookup and calls the underlying
+;; er-bif-* directly. Verify each returns the same result as going
+;; through er-apply-bif.
+
+(er-vm-test "BIF_LENGTH opcode by id"
+  (get (er-vm-lookup-opcode-by-id 136) :name) "OP_BIF_LENGTH")
+(er-vm-test "BIF_LENGTH on 3-cons"
+  (er-vm-dispatch 136
+    (list (er-mk-cons 1 (er-mk-cons 2 (er-mk-cons 3 (er-mk-nil))))))
+  3)
+
+(er-vm-test "BIF_HD on cons"
+  (er-vm-dispatch 137 (list (er-mk-cons 99 (er-mk-nil)))) 99)
+
+(er-vm-test "BIF_TL is cons"
+  (er-cons? (er-vm-dispatch 138
+    (list (er-mk-cons 1 (er-mk-cons 2 (er-mk-nil)))))) true)
+
+(er-vm-test "BIF_ELEMENT pulls index"
+  (er-vm-dispatch 139 (list 2 (er-mk-tuple (list "a" "b" "c")))) "b")
+
+(er-vm-test "BIF_TUPLE_SIZE on 4-tuple"
+  (er-vm-dispatch 140 (list (er-mk-tuple (list 1 2 3 4)))) 4)
+
+(er-vm-test "BIF_LISTS_REVERSE preserves elements"
+  (er-list-length (er-vm-dispatch 141
+    (list (er-mk-cons 1 (er-mk-cons 2 (er-mk-cons 3 (er-mk-nil))))))) 3)
+
+(er-vm-test "BIF_LISTS_REVERSE actually reverses"
+  (get (er-vm-dispatch 141
+    (list (er-mk-cons 1 (er-mk-cons 2 (er-mk-cons 3 (er-mk-nil)))))) :head) 3)
+
+(er-vm-test "BIF_IS_INTEGER true on int"
+  (get (er-vm-dispatch 142 (list 42)) :name) "true")
+(er-vm-test "BIF_IS_INTEGER false on float"
+  (get (er-vm-dispatch 142 (list 3.14)) :name) "false")
+
+(er-vm-test "BIF_IS_ATOM true"
+  (get (er-vm-dispatch 143 (list (er-mk-atom "ok"))) :name) "true")
+(er-vm-test "BIF_IS_ATOM false on int"
+  (get (er-vm-dispatch 143 (list 7)) :name) "false")
+
+(er-vm-test "BIF_IS_LIST true on cons"
+  (get (er-vm-dispatch 144
+    (list (er-mk-cons 1 (er-mk-nil)))) :name) "true")
+(er-vm-test "BIF_IS_LIST true on nil"
+  (get (er-vm-dispatch 144 (list (er-mk-nil))) :name) "true")
+(er-vm-test "BIF_IS_LIST false on tuple"
+  (get (er-vm-dispatch 144 (list (er-mk-tuple (list)))) :name) "false")
+
+(er-vm-test "BIF_IS_TUPLE true"
+  (get (er-vm-dispatch 145 (list (er-mk-tuple (list 1)))) :name) "true")
+(er-vm-test "BIF_IS_TUPLE false on int"
+  (get (er-vm-dispatch 145 (list 5)) :name) "false")
+
+;; Sanity: total opcode count grew (3 patterns + perform + handle +
+;; receive-scan + spawn + send + 10 hot-BIFs = 16+ registered).
+(er-vm-test "opcode list has 16+"
+  (>= (len (er-vm-list-opcodes)) 16) true)
+
 (define er-vm-test-summary (str "vm " er-vm-test-pass "/" er-vm-test-count))

lib/erlang/vm/dispatcher.sx

@@ -218,6 +218,16 @@
   (fn (operands)
     (er-vm-proc-send! (nth operands 0) (nth operands 1))))
 
+;; ── Phase 9f — hot-BIF dispatch table ──────────────────────────
+;; Specialized opcodes for the BIFs that the bytecode compiler emits
+;; on hot call sites. The handler is the underlying `er-bif-*` impl
+;; directly — same `(vs)` signature as the dispatcher uses for
+;; operands, so the cost is the opcode-id → handler hop with no
+;; registry-key string lookup. Cold BIFs continue going through the
+;; general path (`er-apply-bif` / `er-lookup-bif`).
+;;
+;; Opcodes 136-159 reserved for hot BIFs.
+
 ;; ── Phase 9b — pattern-match opcodes ────────────────────────────
 ;; Each handler takes a list (pattern-ast value env) and returns
 ;; true/false, mutating env on success (same contract as the
@@ -261,6 +271,17 @@
     (er-vm-register-opcode! 133 "OP_RECEIVE_SCAN" er-vm-op-receive-scan)
     (er-vm-register-opcode! 134 "OP_SPAWN" er-vm-op-spawn)
     (er-vm-register-opcode! 135 "OP_SEND" er-vm-op-send)
+    ;; Phase 9f — hot BIFs
+    (er-vm-register-opcode! 136 "OP_BIF_LENGTH"        er-bif-length)
+    (er-vm-register-opcode! 137 "OP_BIF_HD"            er-bif-hd)
+    (er-vm-register-opcode! 138 "OP_BIF_TL"            er-bif-tl)
+    (er-vm-register-opcode! 139 "OP_BIF_ELEMENT"       er-bif-element)
+    (er-vm-register-opcode! 140 "OP_BIF_TUPLE_SIZE"    er-bif-tuple-size)
+    (er-vm-register-opcode! 141 "OP_BIF_LISTS_REVERSE" er-bif-lists-reverse)
+    (er-vm-register-opcode! 142 "OP_BIF_IS_INTEGER"    er-bif-is-integer)
+    (er-vm-register-opcode! 143 "OP_BIF_IS_ATOM"       er-bif-is-atom)
+    (er-vm-register-opcode! 144 "OP_BIF_IS_LIST"       er-bif-is-list)
+    (er-vm-register-opcode! 145 "OP_BIF_IS_TUPLE"      er-bif-is-tuple)
     (er-mk-atom "ok")))
 
 (er-vm-register-erlang-opcodes!)