misc: Fix oversight regarding SparseTimeFunction index errors

Author: EdCaunt

devito/types/dense.py

@@ -950,7 +950,9 @@ def _arg_check(self, args, intervals, **kwargs):
         for i, s in zip(self.dimensions, data.shape, strict=True):
             i._arg_check(args, s, intervals[i])
 
-        if args.options['index-mode'] == 'int32' and \
+        # SparseTimeFunctions use int64 indexing regardless of index mode
+        if not self.is_SparseTimeFunction and \
+           args.options['index-mode'] == 'int32' and \
            args.options['linearize'] and \
            self.is_regular and \
            data.size - 1 >= np.iinfo(np.int32).max:

tests/test_linearize.py

@@ -149,6 +149,18 @@ def test_interpolation_enforcing_int64_indexing():
     assert 'long p_src_stride0' in str(op)  # for `src`
 
 
+def test_interpolation_enforcing_int64_indexing_v2():
+    grid = Grid(shape=(4, 4))
+
+    # Too many elements for int32 (1e10), but should not trigger any errors, as
+    # will be indexed with int64
+    rec = SparseTimeFunction(name='rec', grid=grid, npoint=int(1e6), nt=int(1e4))
+    u = TimeFunction(name="u", grid=grid, time_order=2)
+
+    Operator(rec.interpolate(expr=u.forward),
+             opt=('advanced', {'linearize': True, 'index-mode': 'int32'}))
+
+
 def test_interpolation_msf():
     grid = Grid(shape=(4, 4))