[wip] [mypyc] feat: quasi-constant folding for DictExpr and TupleExpr

mypyc/irbuild/builder.py

@@ -602,7 +602,7 @@ def load_type_var(self, name: str, line: int) -> Value:
             )
         )
 
-    def load_literal_value(self, val: int | str | bytes | float | complex | bool) -> Value:
+    def load_literal_value(self, val: int | str | bytes | float | complex | bool | tuple[Any, ...], dict[Any, Any]) -> Value:
         """Load value of a final name, class-level attribute, or constant folded expression."""
         if isinstance(val, bool):
             if val:
@@ -619,6 +619,10 @@ def load_literal_value(self, val: int | str | bytes | float | complex | bool) ->
             return self.builder.load_bytes(val)
         elif isinstance(val, complex):
             return self.builder.load_complex(val)
+        elif isinstance(val, tuple):
+            return self.builder.load_tuple(val)
+        elif isinstance(val, dict):
+            return self.builder.load_dict(val)
         else:
             assert False, "Unsupported literal value"
 

mypyc/irbuild/constant_fold.py

@@ -10,28 +10,30 @@
 
 from __future__ import annotations
 
-from typing import Final, Union
+from typing import Any, Final, Union
 
 from mypy.constant_fold import constant_fold_binary_op, constant_fold_unary_op
 from mypy.nodes import (
     BytesExpr,
     ComplexExpr,
+    DictExpr,
     Expression,
     FloatExpr,
     IntExpr,
     MemberExpr,
     NameExpr,
     OpExpr,
     StrExpr,
+    TupleExpr,
     UnaryExpr,
     Var,
 )
 from mypyc.irbuild.builder import IRBuilder
 from mypyc.irbuild.util import bytes_from_str
 
 # All possible result types of constant folding
-ConstantValue = Union[int, float, complex, str, bytes]
-CONST_TYPES: Final = (int, float, complex, str, bytes)
+ConstantValue = Union[int, float, complex, str, bytes, tuple[Any, ...], dict[Any, Any]]
+CONST_TYPES: Final = (int, float, complex, str, bytes, tuple, dict)
 
 
 def constant_fold_expr(builder: IRBuilder, expr: Expression) -> ConstantValue | None:
@@ -72,6 +74,25 @@ def constant_fold_expr(builder: IRBuilder, expr: Expression) -> ConstantValue |
         value = constant_fold_expr(builder, expr.expr)
         if value is not None and not isinstance(value, bytes):
             return constant_fold_unary_op(expr.op, value)
+    elif isinstance(expr, TupleExpr):
+        folded = tuple(constant_fold_expr(builder, item_expr) for item_expr in expr.items)
+        if None not in folded:
+            return folded
+    elif isinstance(expr, DictExpr):
+        # NOTE: the builder can't simply use a dict constant like it can with other constants, since dicts are mutable.
+        # TODO: make the builder load the dict 'constant' by calling copy on a prebuilt constant template instead of building from scratch each time
+        folded = {
+            constant_fold_expr(builder, key_expr): constant_fold_expr(builder, value_expr)
+            for key_expr, value_expr in expr.items
+        }
+        if (
+            len(folded) == len(expr.items)
+            and None not in folded.keys()
+            and None not in folded.values()
+        ):
+            return folded
+
+    # TODO use a placeholder instead of None so we can include None in folded tuples/dicts
     return None
 
 
@@ -82,7 +103,7 @@ def constant_fold_binary_op_extended(
 
     mypy cannot use constant folded bytes easily so it's simpler to only support them in mypyc.
     """
-    if not isinstance(left, bytes) and not isinstance(right, bytes):
+    if not isinstance(left, (bytes, tuple, dict)) and not isinstance(right, (bytes, tuple, dict)):
         return constant_fold_binary_op(op, left, right)
 
     if op == "+" and isinstance(left, bytes) and isinstance(right, bytes):

mypyc/irbuild/ll_builder.py

@@ -8,7 +8,7 @@
 
 import sys
 from collections.abc import Sequence
-from typing import Callable, Final, Optional
+from typing import Any, Callable, Final, Optional
 
 from mypy.argmap import map_actuals_to_formals
 from mypy.nodes import ARG_POS, ARG_STAR, ARG_STAR2, ArgKind
@@ -123,6 +123,7 @@
     pointer_rprimitive,
     short_int_rprimitive,
     str_rprimitive,
+    tuple_rprimitive,
 )
 from mypyc.irbuild.util import concrete_arg_kind
 from mypyc.options import CompilerOptions
@@ -1354,6 +1355,14 @@ def load_complex(self, value: complex) -> Value:
         """Load a complex literal value."""
         return self.add(LoadLiteral(value, object_rprimitive))
 
+    def load_tuple(
+        self, value: tuple[Any, ...]
+    ) -> Value:  # should this be RTuple? conditional RTuple when length is known?
+        return self.add(LoadLiteral(value, tuple_rprimitive))
+
+    def load_dict(self, value: dict[Any, Any]) -> Value:
+        return self.add(LoadLiteral(value, dict_rprimitive))
+
     def load_static_checked(
         self,
         typ: RType,