dialects: (builtin) add CompileTimeFixedBitwidthType

tests/dialects/test_builtin.py

@@ -19,6 +19,7 @@
     Float80Type,
     Float128Type,
     FloatAttr,
+    IndexType,
     IntAttr,
     IntegerAttr,
     IntegerType,
@@ -78,6 +79,10 @@ def test_IntegerType_formats():
     assert IntegerType(64).format == "<q"
 
 
+def test_IndexType_formats():
+    assert IndexType().format == "<q"
+
+
 def test_FloatType_packing():
     nums = (-128, -1, 0, 1, 127)
     buffer = f32.pack(nums)

xdsl/dialects/builtin.py

@@ -349,7 +349,23 @@ def print_parameter(self, printer: Printer) -> None:
                 raise ValueError(f"Invalid signedness {data}")
 
 
-class FixedBitwidthType(TypeAttribute, ABC):
+class CompileTimeFixedBitwidthType(TypeAttribute, ABC):
+    """
+    A type attribute whose runtime bitwidth is fixed, but may be target-dependent.
+    """
+
+    name = "abstract.compile_time_fixed_bitwidth_type"
+
+    @property
+    @abstractmethod
+    def compile_time_size(self) -> int:
+        """
+        Contiguous memory footprint of the value during compilation.
+        """
+        raise NotImplementedError()
+
+
+class FixedBitwidthType(CompileTimeFixedBitwidthType, ABC):
     """
     A type attribute whose runtime bitwidth is target-independent.
     """
@@ -375,7 +391,7 @@ def size(self) -> int:
 _PyT = TypeVar("_PyT")
 
 
-class PackableType(Generic[_PyT], FixedBitwidthType, ABC):
+class PackableType(Generic[_PyT], CompileTimeFixedBitwidthType, ABC):
     """
     Abstract base class for xDSL types whose values can be encoded and decoded as bytes.
     """
@@ -439,9 +455,13 @@ def pack(self, values: Sequence[_PyT]) -> bytes:
         fmt = self.format[0] + str(len(values)) + self.format[1:]
         return struct.pack(fmt, *values)
 
+    @property
+    def compile_time_size(self) -> int:
+        return struct.calcsize(self.format)
+
 
 @irdl_attr_definition
-class IntegerType(ParametrizedAttribute, StructPackableType[int]):
+class IntegerType(ParametrizedAttribute, StructPackableType[int], FixedBitwidthType):
     name = "integer_type"
     width: ParameterDef[IntAttr]
     signedness: ParameterDef[SignednessAttr]
@@ -556,7 +576,7 @@ class LocationAttr(ParametrizedAttribute):
 
 
 @irdl_attr_definition
-class IndexType(ParametrizedAttribute):
+class IndexType(ParametrizedAttribute, StructPackableType[int]):
     name = "index"
 
     def print_value_without_type(self, value: int, printer: Printer):
@@ -565,6 +585,11 @@ def print_value_without_type(self, value: int, printer: Printer):
         """
         printer.print_string(f"{value}")
 
+    @property
+    def format(self) -> str:
+        # index types are always packable as int64
+        return "<q"
+
 
 IndexTypeConstr = BaseAttr(IndexType)
 
@@ -669,7 +694,7 @@ def constr(
 BoolAttr: TypeAlias = IntegerAttr[Annotated[IntegerType, IntegerType(1)]]
 
 
-class _FloatType(StructPackableType[float], ABC):
+class _FloatType(StructPackableType[float], FixedBitwidthType, ABC):
     @property
     @abstractmethod
     def bitwidth(self) -> int:

xdsl/interpreters/utils/ptr.py

@@ -95,7 +95,7 @@ class TypedPtr(Generic[_T]):
 
     @property
     def size(self) -> int:
-        return self.xtype.size
+        return self.xtype.compile_time_size
 
     def copy(self) -> Self:
         return type(self)(self.raw.copy(), xtype=self.xtype)
@@ -122,15 +122,15 @@ def __setitem__(self, index: int, value: _T):
 
     @staticmethod
     def zeros(count: int, *, xtype: PackableType[_T]) -> TypedPtr[_T]:
-        size = xtype.size
+        size = xtype.compile_time_size
         return TypedPtr(RawPtr.zeros(size * count), xtype=xtype)
 
     @staticmethod
     def new(els: Sequence[_T], *, xtype: PackableType[_T]) -> TypedPtr[_T]:
         """
         Returns a new TypedPtr with the specified els packed into memory.
         """
-        el_size = xtype.size
+        el_size = xtype.compile_time_size
         res = RawPtr.zeros(len(els) * el_size)
         for i, el in enumerate(els):
             xtype.pack_into(res.memory, i * el_size, el)