added loop unroling

main.py

@@ -1866,16 +1866,24 @@ class _CTHandleTable:
 
 
 class Assembler:
-    def __init__(self, dictionary: Dictionary, *, enable_constant_folding: bool = True) -> None:
+    def __init__(
+        self,
+        dictionary: Dictionary,
+        *,
+        enable_constant_folding: bool = True,
+        loop_unroll_threshold: int = 8,
+    ) -> None:
         self.dictionary = dictionary
         self._string_literals: Dict[str, Tuple[str, int]] = {}
         self._float_literals: Dict[float, str] = {}
         self._data_section: Optional[List[str]] = None
         self._inline_stack: List[str] = []
         self._inline_counter: int = 0
+        self._unroll_counter: int = 0
         self._emit_stack: List[str] = []
         self._export_all_defs: bool = False
         self.enable_constant_folding = enable_constant_folding
+        self.loop_unroll_threshold = loop_unroll_threshold
 
     def _fold_constants_in_definition(self, definition: Definition) -> None:
         optimized: List[Op] = []
@@ -1906,6 +1914,128 @@ class Assembler:
             new_loc = operands[0].loc or last.loc
             nodes[-(arity + 1):] = [Op(op="literal", data=result, loc=new_loc)]
 
+    def _for_pairs(self, nodes: Sequence[Op]) -> Dict[int, int]:
+        stack: List[int] = []
+        pairs: Dict[int, int] = {}
+        for idx, node in enumerate(nodes):
+            if node.op == "for_begin":
+                stack.append(idx)
+            elif node.op == "for_end":
+                if not stack:
+                    raise CompileError("'end' without matching 'for'")
+                begin_idx = stack.pop()
+                pairs[begin_idx] = idx
+                pairs[idx] = begin_idx
+        if stack:
+            raise CompileError("'for' without matching 'end'")
+        return pairs
+
+    def _collect_internal_labels(self, nodes: Sequence[Op]) -> Set[str]:
+        labels: Set[str] = set()
+        for node in nodes:
+            kind = node.op
+            data = node.data
+            if kind == "label":
+                labels.add(str(data))
+            elif kind in ("for_begin", "for_end"):
+                labels.add(str(data["loop"]))
+                labels.add(str(data["end"]))
+            elif kind in ("list_begin", "list_end"):
+                labels.add(str(data))
+        return labels
+
+    def _clone_nodes_with_label_remap(
+        self,
+        nodes: Sequence[Op],
+        internal_labels: Set[str],
+        suffix: str,
+    ) -> List[Op]:
+        label_map: Dict[str, str] = {}
+
+        def remap(label: str) -> str:
+            if label not in internal_labels:
+                return label
+            if label not in label_map:
+                label_map[label] = f"{label}__unr{suffix}"
+            return label_map[label]
+
+        cloned: List[Op] = []
+        for node in nodes:
+            kind = node.op
+            data = node.data
+            if kind == "label":
+                cloned.append(Op(op="label", data=remap(str(data)), loc=node.loc))
+                continue
+            if kind in ("jump", "branch_zero"):
+                target = str(data)
+                mapped = remap(target) if target in internal_labels else target
+                cloned.append(Op(op=kind, data=mapped, loc=node.loc))
+                continue
+            if kind in ("for_begin", "for_end"):
+                cloned.append(
+                    Op(
+                        op=kind,
+                        data={
+                            "loop": remap(str(data["loop"])),
+                            "end": remap(str(data["end"])),
+                        },
+                        loc=node.loc,
+                    )
+                )
+                continue
+            if kind in ("list_begin", "list_end"):
+                cloned.append(Op(op=kind, data=remap(str(data)), loc=node.loc))
+                continue
+            cloned.append(Op(op=kind, data=data, loc=node.loc))
+        return cloned
+
+    def _unroll_constant_for_loops(self, definition: Definition) -> None:
+        threshold = self.loop_unroll_threshold
+        if threshold <= 0:
+            return
+        nodes = definition.body
+        pairs = self._for_pairs(nodes)
+        if not pairs:
+            return
+
+        rebuilt: List[Op] = []
+        idx = 0
+        while idx < len(nodes):
+            node = nodes[idx]
+            if node.op == "for_begin" and idx > 0:
+                prev = nodes[idx - 1]
+                if prev.op == "literal" and isinstance(prev.data, int):
+                    count = int(prev.data)
+                    end_idx = pairs.get(idx)
+                    if end_idx is None:
+                        raise CompileError("internal loop bookkeeping error")
+                    if count <= 0:
+                        if rebuilt and rebuilt[-1] is prev:
+                            rebuilt.pop()
+                        idx = end_idx + 1
+                        continue
+                    if count <= threshold:
+                        if rebuilt and rebuilt[-1] is prev:
+                            rebuilt.pop()
+                        body = nodes[idx + 1:end_idx]
+                        internal_labels = self._collect_internal_labels(body)
+                        for copy_idx in range(count):
+                            suffix = f"{self._unroll_counter}_{copy_idx}"
+                            rebuilt.extend(
+                                self._clone_nodes_with_label_remap(
+                                    body,
+                                    internal_labels,
+                                    suffix,
+                                )
+                            )
+                        self._unroll_counter += 1
+                        idx = end_idx + 1
+                        continue
+            rebuilt.append(node)
+            idx += 1
+
+        definition.body = rebuilt
+
     def _reachable_runtime_defs(self, runtime_defs: Sequence[Union[Definition, AsmDefinition]]) -> Set[str]:
         edges: Dict[str, Set[str]] = {}
         for definition in runtime_defs:
@@ -1950,6 +2080,9 @@ class Assembler:
             valid_defs = (Definition, AsmDefinition)
             raw_defs = [form for form in module.forms if isinstance(form, valid_defs)]
             definitions = self._dedup_definitions(raw_defs)
+            for defn in definitions:
+                if isinstance(defn, Definition):
+                    self._unroll_constant_for_loops(defn)
             if self.enable_constant_folding:
                 for defn in definitions:
                     if isinstance(defn, Definition):