compiler: autotuning

devito/core/autotuning.py

@@ -89,9 +89,16 @@ def autotune(operator, args, level, mode):
 
     # Perform autotuning
     timings = {}
+    processed = []
     for n, tree in enumerate(trees):
+
         blockable = [i.dim for i in tree if not is_integer(i.step)]
+        # Drop dimensions that have been already tested
+        # Encountered in cases where blockable appear more than once under a tree
+        if all(i in processed for i in blockable):
+            continue
 
+        processed.extend(blockable)
         # Tunable arguments
         try:
             tunable = []
@@ -250,8 +257,9 @@ def finalize_time_bounds(stepper, at_args, args, mode):
 
 
 def calculate_nblocks(tree, blockable):
-    pos = [n for n, i in enumerate(tree) if i.dim in blockable]
-    collapsed = tree[:(tree[pos[0]].ncollapsed or 1)]
+    block_indices = [n for n, i in enumerate(tree) if i.dim in blockable]
+    index = block_indices[0]
+    collapsed = tree[index:(tree[index].ncollapsed or index+1)]
     blocked = [i.dim for i in collapsed if i.dim in blockable]
     remainders = [(d.root.symbolic_max-d.root.symbolic_min+1) % d.step for d in blocked]
     niters = [d.root.symbolic_max - i for d, i in zip(blocked, remainders)]

tests/test_autotuner.py

@@ -142,7 +142,7 @@ def test_mixed_blocking_w_skewing(openmp, expected):
         assert 'nthreads' not in op._state['autotuning'][0]['tuned']
 
 
-@pytest.mark.parametrize('opt, expected', [('advanced', 60),
+@pytest.mark.parametrize('opt, expected', [('advanced', 30),
                                            (('blocking', {'skewing': True}), 30)])
 def test_tti_aggressive(opt, expected):
     from test_dse import TestTTI