Address Brandt's feedback.

Tools/jit/_stencils.py

@@ -252,9 +252,14 @@ class StencilGroup:
         default_factory=dict, init=False
     )
     _got: dict[str, int] = dataclasses.field(default_factory=dict, init=False)
-    trampolines: set[int] = dataclasses.field(default_factory=set, init=False)
-
-    def process_relocations(self, *, alignment: int = 1) -> None:
+    _trampolines: set[int] = dataclasses.field(default_factory=set, init=False)
+
+    def process_relocations(
+        self,
+        known_symbols: dict[str | None, int],
+        *,
+        alignment: int = 1,
+    ) -> None:
         """Fix up all GOT and internal relocations for this stencil group."""
         for hole in self.code.holes.copy():
             if (
@@ -268,7 +273,7 @@ def process_relocations(self, *, alignment: int = 1) -> None:
                 else:
                     ordinal = len(known_symbols)
                     known_symbols[hole.symbol] = ordinal
-                self.trampolines.add(ordinal)
+                self._trampolines.add(ordinal)
                 hole.addend = ordinal
                 hole.symbol = None
         self.code.remove_jump(alignment=alignment)
@@ -328,18 +333,17 @@ def _emit_global_offset_table(self) -> None:
     def _get_trampoline_mask(self) -> str:
         bitmask: int = 0
         trampoline_mask: list[str] = []
-        for ordinal in self.trampolines:
+        for ordinal in self._trampolines:
             bitmask |= 1 << ordinal
-        if bitmask:
-            trampoline_mask = [
-                f"0x{(bitmask >> i*32) & ((1 << 32) - 1):x}"
-                for i in range(0, SYMBOL_MASK_SIZE)
-            ]
-        return ", ".join(trampoline_mask)
+        while bitmask:
+            word = bitmask & ((1 << 32) - 1)
+            trampoline_mask.append(f"{word:#04x}")
+            bitmask >>= 32
+        return "{" + ", ".join(trampoline_mask) + "}"
 
     def as_c(self, opname: str) -> str:
         """Dump this hole as a StencilGroup initializer."""
-        return f"{{emit_{opname}, {len(self.code.body)}, {len(self.data.body)}, {{{self._get_trampoline_mask()}}}}}"
+        return f"{{emit_{opname}, {len(self.code.body)}, {len(self.data.body)}, {self._get_trampoline_mask()}}}"
 
 
 def symbol_to_value(symbol: str) -> tuple[HoleValue, str | None]:

Tools/jit/_targets.py

@@ -44,6 +44,7 @@ class _Target(typing.Generic[_S, _R]):
     stable: bool = False
     debug: bool = False
     verbose: bool = False
+    known_symbols: dict[str | None, int] = dataclasses.field(default_factory=dict)
 
     def _compute_digest(self, out: pathlib.Path) -> str:
         hasher = hashlib.sha256()
@@ -95,7 +96,9 @@ async def _parse(self, path: pathlib.Path) -> _stencils.StencilGroup:
         if group.data.body:
             line = f"0: {str(bytes(group.data.body)).removeprefix('b')}"
             group.data.disassembly.append(line)
-        group.process_relocations(alignment=self.alignment)
+        group.process_relocations(
+            known_symbols=self.known_symbols, alignment=self.alignment
+        )
         return group
 
     def _handle_section(self, section: _S, group: _stencils.StencilGroup) -> None:
@@ -231,7 +234,7 @@ def build(
                 if comment:
                     file.write(f"// {comment}\n")
                 file.write("\n")
-                for line in _writer.dump(stencil_groups):
+                for line in _writer.dump(stencil_groups, self.known_symbols):
                     file.write(f"{line}\n")
             try:
                 jit_stencils_new.replace(jit_stencils)

Tools/jit/_writer.py

@@ -2,12 +2,16 @@
 
 import itertools
 import typing
+import math
 
 import _stencils
 
 
-def _dump_footer(groups: dict[str, _stencils.StencilGroup]) -> typing.Iterator[str]:
-    yield f"typedef uint32_t SymbolMask[{_stencils.SYMBOL_MASK_SIZE}];"
+def _dump_footer(
+    groups: dict[str, _stencils.StencilGroup], symbols: dict[str | None, int]
+) -> typing.Iterator[str]:
+    symbol_mask_size = math.ceil(len(symbols) / 32)
+    yield f"typedef uint32_t SymbolMask[{symbol_mask_size}];"
     yield ""
     yield "typedef struct {"
     yield "    void (*emit)("
@@ -27,8 +31,8 @@ def _dump_footer(groups: dict[str, _stencils.StencilGroup]) -> typing.Iterator[s
         yield f"    [{opname}] = {group.as_c(opname)},"
     yield "};"
     yield ""
-    yield f"static const void * const symbols_map[{max(len(_stencils.known_symbols), 1)}] = {{"
-    for symbol, ordinal in _stencils.known_symbols.items():
+    yield f"static const void * const symbols_map[{max(len(symbols), 1)}] = {{"
+    for symbol, ordinal in symbols.items():
         yield f"    [{ordinal}] = &{symbol},"
     yield "};"
 
@@ -66,8 +70,10 @@ def _dump_stencil(opname: str, group: _stencils.StencilGroup) -> typing.Iterator
     yield ""
 
 
-def dump(groups: dict[str, _stencils.StencilGroup]) -> typing.Iterator[str]:
+def dump(
+    groups: dict[str, _stencils.StencilGroup], symbols: dict[str | None, int]
+) -> typing.Iterator[str]:
     """Yield a JIT compiler line-by-line as a C header file."""
     for opname, group in sorted(groups.items()):
         yield from _dump_stencil(opname, group)
-    yield from _dump_footer(groups)
+    yield from _dump_footer(groups, symbols)