Introduce a notion of 'scope' for temporary variables, in preparation for global temporaries

doc/ref_kernel.rst

@@ -345,6 +345,8 @@ Temporary Variables
 Temporary variables model OpenCL's ``private`` and ``local`` address spaces. Both
 have the lifetime of a kernel invocation.
 
+.. autoclass:: temp_var_scope
+
 .. autoclass:: TemporaryVariable
     :members:
     :undoc-members:

loopy/__init__.py

@@ -42,7 +42,7 @@ from loopy.kernel.data import (
         ValueArg, GlobalArg, ConstantArg, ImageArg,
         memory_ordering, memory_scope, VarAtomicity, AtomicInit, AtomicUpdate,
         InstructionBase, Assignment, ExpressionInstruction, CInstruction,
-        TemporaryVariable,
+        temp_var_scope, TemporaryVariable,
         SubstitutionRule)
 
 from loopy.kernel import LoopKernel, kernel_state
@@ -129,7 +129,7 @@ __all__ = [
         "memory_ordering", "memory_scope", "VarAtomicity",
         "AtomicInit", "AtomicUpdate",
         "ValueArg", "ScalarArg", "GlobalArg", "ArrayArg", "ConstantArg", "ImageArg",
-        "TemporaryVariable",
+        "temp_var_scope", "TemporaryVariable",
         "SubstitutionRule",
 
         "InstructionBase", "Assignment", "ExpressionInstruction", "CInstruction",

loopy/kernel/data.py

@@ -267,6 +267,19 @@ class ValueArg(KernelArgument):
 
 # {{{ temporary variable
 
+class temp_var_scope:
+    """Storage location of a temporary
+
+    .. attribute:: PRIVATE
+    .. attribute:: LOCAL
+    .. attribute:: GLOBAL
+    """
+
+    PRIVATE = 0
+    LOCAL = 1
+    GLOBAL = 2
+
+
 class TemporaryVariable(ArrayBase):
     __doc__ = ArrayBase.__doc__ + """
     .. attribute:: storage_shape
@@ -281,6 +294,8 @@ class TemporaryVariable(ArrayBase):
 
         The name of a storage array that is to be used to actually
         hold the data in this temporary.
+
+    .. autoattribute:: scope
     """
 
     min_target_axes = 0
@@ -318,6 +333,15 @@ class TemporaryVariable(ArrayBase):
                 storage_shape=storage_shape,
                 base_storage=base_storage)
 
+    @property
+    def scope(self):
+        """One of :class:`loopy.temp_var_scope`."""
+
+        if self.is_local:
+            return temp_var_scope.LOCAL
+        else:
+            return temp_var_scope.PRIVATE
+
     @property
     def nbytes(self):
         shape = self.shape