Adds SpatialSoftMaxCUDNN from VisualComputingInstitute/Beacon8#13.

Credit also goes to Ilya Kostrikov.

DeepFried2/layers/SpatialSoftMaxCUDNN.py

@@ -0,0 +1,21 @@
+from .Module import Module
+
+import theano.sandbox.cuda.dnn as _dnn
+import theano.sandbox.cuda.basic_ops as _cuops
+
+
+def spatial_softmax(img, algo, mode):
+    img = _cuops.gpu_contiguous(img)
+    return _dnn.GpuDnnSoftmax(tensor_format='bc01', algo=algo, mode=mode)(img)
+
+
+class SpatialSoftMaxCUDNN(Module):
+    def __init__(self, algo='accurate', mode='channel'):
+        # algo: 'fast' is straightforward softmax, 'accurate' is shifting inputs to avoid overflow.
+        # mode: 'instance' is a softmax per image (across C,W,H), 'channel' is a softmax per pixel per image (across C).
+        Module.__init__(self)
+        self.algo = algo
+        self.mode = mode
+
+    def symb_forward(self, symb_input):
+        return spatial_softmax(symb_input, self.algo, self.mode)

DeepFried2/layers/__init__.py

@@ -12,3 +12,4 @@
 from .SpatialMaxPooling import *
 from .SpatialConvolutionCUDNN import *
 from .SpatialMaxPoolingCUDNN import *
+from .SpatialSoftMaxCUDNN import *