added test for gemm insertion when the scalars alpha and beta are equal and factorized.

theano/tensor/tests/test_blas.py

@@ -98,6 +98,34 @@ class t_gemm(TestCase):
     def test12(self): self.cmp(self.rand(3,4), -1.0,
             self.rand(3,5), self.rand(5,4), -1.0)
 
+    def test_factorised_scalar(self):
+        a=T.matrix()
+        b=T.matrix()
+        c=T.matrix()
+        s=theano.shared(numpy.zeros((5,5)))
+
+        lr1=T.constant(0.01)
+        lr2=T.constant(2)
+        l2_reg=T.constant(0.0001)
+
+        #test constant merge with gemm
+        f = theano.function([a,b],updates={s:lr1*T.dot(a,b)+l2_reg*lr2*s}).maker.env.toposort()
+        #[Gemm{inplace}(<TensorType(float64, matrix)>, 0.01, <TensorType(float64, matrix)>, <TensorType(float64, matrix)>, 2e-06)]
+        assert len(f)==1
+        assert f[0].op==gemm_inplace
+
+        #test factored scalar with merge
+        f = theano.function([a,b],updates={s:lr1*(T.dot(a,b)-l2_reg*s)}).maker.env.toposort()
+        #[Gemm{inplace}(<TensorType(float64, matrix)>, 0.01, <TensorType(float64, matrix)>, <TensorType(float64, matrix)>, -2e-06)]
+        assert len(f)==1
+        assert f[0].op==gemm_inplace
+
+        #test factored scalar with merge and neg
+        f = theano.function([a,b],updates={s:s-lr1*(s*.0002+T.dot(a,b))}).maker.env.toposort()
+        #[Gemm{inplace}(<TensorType(float64, matrix)>, -0.01, <TensorType(float64, matrix)>, <TensorType(float64, matrix)>, 0.999998)]
+        assert len(f)==1
+        assert f[0].op==gemm_inplace
+
     def test_destroy_map0(self):
         """test that only first input can be overwritten"""
         Z = as_tensor_variable(self.rand(2,2))