compiler: Cast operands to long before multiplying dimensions to get allocation size

Author: EdCaunt

devito/passes/iet/definitions.py

@@ -20,7 +20,9 @@
     VOID, Byref, DefFunction, FieldFromPointer, IndexedPointer, ListInitializer, SizeOf,
     as_long, pow_to_mul, unevaluate
 )
-from devito.tools import as_list, as_mapper, as_tuple, filter_sorted, flatten, is_integer
+from devito.tools import (
+    as_list, as_mapper, as_tuple, filter_sorted, flatten, is_integer, prod
+)
 from devito.types import (
     Array, ComponentAccess, CustomDimension, DeviceMap, DeviceRM, Dimension, Eq, Symbol,
     size_t
@@ -192,7 +194,8 @@ def _alloc_host_array_on_high_bw_mem(self, site, obj, storage, *args):
 
         memptr = VOID(Byref(obj._C_symbol), '**')
         alignment = obj._data_alignment
-        nbytes = SizeOf(obj._C_typedata)*as_long(obj.size)
+        size = prod(as_long(i) for i in obj.symbolic_shape)
+        nbytes = SizeOf(obj._C_typedata)*size
         zeroing, efuncs = self._zero_init(obj, storage)
         allocs = [decl, self.langbb['host-alloc'](memptr, alignment, nbytes),
                   *zeroing]
@@ -601,7 +604,8 @@ def _alloc_local_array_on_high_bw_mem(self, site, obj, storage):
         doalloc = self.langbb['device-alloc']
         dofree = self.langbb['device-free']
 
-        nbytes = SizeOf(obj._C_typedata)*obj.size
+        size = prod(as_long(i) for i in obj.symbolic_shape)
+        nbytes = SizeOf(obj._C_typedata)*size
 
         zeroing, efuncs = self._zero_init(obj, storage)
         allocs = [doalloc(nbytes, deviceid, retobj=obj), *zeroing]

devito/types/basic.py

@@ -1141,6 +1141,13 @@ def ndim(self):
         """The rank of the object."""
         return len(self.indices)
 
+    # @property
+    # def safe_size(self):
+    #     """
+    #     The symbolic size of the object, casting to LONG to prevent overflow.
+    #     """
+    #     return prod(as_long(i) for i in self.symbolic_shape)
+
     @property
     def symbolic_shape(self):
         """