Fix the bug when pruning conv2d with small filter number. (#1424)

paddleslim/dygraph/prune/fpgm_pruner.py

@@ -42,6 +42,7 @@ class FPGMFilterPruner(FilterPruner):
 
         sorted_idx = scores.argsort()
         pruned_num = int(round(len(sorted_idx) * pruned_ratio))
+        pruned_num = min(len(sorted_idx) - 1, pruned_num)
         pruned_idx = sorted_idx[:pruned_num]
         mask_shape = [value.shape[pruned_axis]]
         mask = np.ones(mask_shape, dtype="int32")

paddleslim/dygraph/prune/l1norm_pruner.py

@@ -38,6 +38,7 @@ class L1NormFilterPruner(FilterPruner):
 
         sorted_idx = l1norm.argsort()
         pruned_num = int(round(len(sorted_idx) * pruned_ratio))
+        pruned_num = min(len(sorted_idx) - 1, pruned_num)
         pruned_idx = sorted_idx[:pruned_num]
 
         mask_shape = [value.shape[pruned_axis]]

paddleslim/dygraph/prune/l2norm_pruner.py

@@ -38,6 +38,7 @@ class L2NormFilterPruner(FilterPruner):
 
         sorted_idx = scores.argsort()
         pruned_num = int(round(len(sorted_idx) * pruned_ratio))
+        pruned_num = min(len(sorted_idx) - 1, pruned_num)
         pruned_idx = sorted_idx[:pruned_num]
 
         mask_shape = [value.shape[pruned_axis]]

paddleslim/prune/idx_selector.py

@@ -63,6 +63,7 @@ def default_idx_selector(group, scores, ratios):
     sorted_idx = score.argsort()
     ratio = ratios[name]
     pruned_num = int(round(len(sorted_idx) * ratio))
+    pruned_num = min(len(sorted_idx) - 1, pruned_num)
     pruned_idx = sorted_idx[:pruned_num]
     # convert indices of channel groups to indices of channels.
     if max_groups > 1:

tests/dygraph/test_sensitivity.py

@@ -52,7 +52,7 @@ class TestSensitivity(unittest.TestCase):
             for _ratio, _loss in _value.items():
                 if not np.allclose(_losses[_ratio], _loss, atol=1e-2):
                     print(
-                        f'static loss: {static_sen[_name][_ratio]}; dygraph loss: {_loss}'
+                        f'ratio: {_ratio}; static loss: {_losses[_ratio]}; dygraph loss: {_loss}'
                     )
                     all_right = False
         self.assertTrue(all_right)