Merge branch 'v2.0-dev' into fhennig/nested-type-context

src/pystencils/backend/kernelcreation/freeze.py

@@ -58,7 +58,7 @@ from ..ast.expressions import (
 )
 
 from ..constants import PsConstant
-from ...types import PsStructType, PsType
+from ...types import PsNumericType, PsStructType, PsType
 from ..exceptions import PsInputError
 from ..functions import PsMathFunction, MathFunctions
 
@@ -469,7 +469,7 @@ class FreezeExpressions:
             ]
         return cast(PsCall, args[0])
 
-    def map_CastFunc(self, cast_expr: CastFunc) -> PsCast:
+    def map_CastFunc(self, cast_expr: CastFunc) -> PsCast | PsConstantExpr:
         dtype: PsType
         match cast_expr.dtype:
             case DynamicType.NUMERIC_TYPE:
@@ -479,7 +479,19 @@ class FreezeExpressions:
             case other if isinstance(other, PsType):
                 dtype = other
 
-        return PsCast(dtype, self.visit_expr(cast_expr.expr))
+        arg = self.visit_expr(cast_expr.expr)
+        if (
+            isinstance(arg, PsConstantExpr)
+            and arg.constant.dtype is None
+            and isinstance(dtype, PsNumericType)
+        ):
+            # As of now, the typifier can not infer the type of a bare constant.
+            # However, untyped constants may not appear in ASTs from which
+            # kernel functions are generated. Therefore, we annotate constants
+            # instead of casting them.
+            return PsConstantExpr(arg.constant.interpret_as(dtype))
+        else:
+            return PsCast(dtype, arg)
 
     def map_Relational(self, rel: sympy.core.relational.Relational) -> PsRel:
         arg1, arg2 = [self.visit_expr(arg) for arg in rel.args]

src/pystencils/backend/kernelcreation/typification.py

@@ -734,7 +734,14 @@ class Typifier:
                     tc.apply_dtype(arr_type, expr)
 
             case PsCast(dtype, arg):
-                self.visit_expr(arg, TypeContext())
+                arg_tc = TypeContext()
+                self.visit_expr(arg, arg_tc)
+
+                if arg_tc.target_type is None:
+                    raise TypificationError(
+                        f"Unable to determine type of argument to Cast: {arg}"
+                    )
+
                 tc.apply_dtype(dtype, expr)
 
             case _:

tests/nbackend/kernelcreation/test_freeze.py

@@ -29,6 +29,7 @@ from pystencils.backend.ast.expressions import (
     PsGe,
     PsCall,
     PsCast,
+    PsConstantExpr,
 )
 from pystencils.backend.constants import PsConstant
 from pystencils.backend.functions import PsMathFunction, MathFunctions
@@ -305,3 +306,6 @@ def test_cast_func():
 
     expr = freeze(CastFunc.as_index(z))
     assert expr.structurally_equal(PsCast(ctx.index_dtype, z2))
+
+    expr = freeze(CastFunc(42, create_type("int16")))
+    assert expr.structurally_equal(PsConstantExpr(PsConstant(42, create_type("int16"))))

tests/nbackend/kernelcreation/test_typification.py

@@ -14,6 +14,9 @@ from pystencils.backend.ast.structural import (
     PsBlock,
 )
 from pystencils.backend.ast.expressions import (
+    PsAddressOf,
+    PsArrayInitList,
+    PsCast,
     PsConstantExpr,
     PsSymbolExpr,
     PsSubscript,
@@ -568,3 +571,19 @@ def test_cfunction():
 
     with pytest.raises(TypificationError):
         _ = typify(PsCall(threeway, (x, p)))
+
+
+def test_inference_fails():
+    ctx = KernelCreationContext()
+    typify = Typifier(ctx)
+
+    x = PsExpression.make(PsConstant(42))
+
+    with pytest.raises(TypificationError):
+        typify(PsEq(x, x))
+
+    with pytest.raises(TypificationError):
+        typify(PsArrayInitList([x]))
+
+    with pytest.raises(TypificationError):
+        typify(PsCast(ctx.default_dtype, x))