added more informative shape error message to gemm

theano/tensor/blas.py

@@ -149,16 +149,32 @@ class GemmRelated(Op):
         """
 
     check_dims_strides = """
-        if ((Nx[0] != Nz[0]) || (Nx[1] != Ny[0]) || (Ny[1] != Nz[1]))
+        if (Nx[0] != Nz[0])
         {
-            PyErr_SetString(PyExc_ValueError, "Input dimensions do not agree");
+            PyErr_Format(PyExc_ValueError, 
+                "Shape mismatch: x has %%ld rows but z has %%ld rows",
+                (long int)Nx[0], (long int)Nz[0]);
+            %(fail)s;
+        }
+        if (Nx[1] != Ny[0])
+        {
+            PyErr_Format(PyExc_ValueError, 
+                "Shape mismatch: x has %%ld cols but y has %%ld rows",
+                (long int)Nx[1], (long int)Ny[0]);
+            %(fail)s;
+        }
+        if (Ny[1] != Nz[1])
+        {
+            PyErr_Format(PyExc_ValueError, 
+                "Shape mismatch: y has %%ld cols but z has %%ld cols",
+                (long int)Ny[1], (long int)Nz[1]);
             %(fail)s;
         }
         if ((Sx[0] < 1) || (Sx[1] < 1) || (Sx[0] MOD type_size) || (Sx[1] MOD type_size)
            || (Sy[0] < 1) || (Sy[1] < 1) || (Sy[0] MOD type_size) || (Sy[1] MOD type_size)
            || (Sz[0] < 1) || (Sz[1] < 1) || (Sz[0] MOD type_size) || (Sz[1] MOD type_size))
         {
-            PyErr_SetString(PyExc_ValueError, "stride is not multiple of element size"); %(fail)s;
+            PyErr_SetString(PyExc_NotImplementedError, "stride is not multiple of element size"); %(fail)s;
         }
         """
 
@@ -275,7 +291,7 @@ class GemmRelated(Op):
             self.end_switch_typenum), '')
 
     def build_gemm_version(self):
-        return (1,)
+        return (2,)
 
 class Gemm(GemmRelated):
     """In-place version of matrix-matrix multiplication (with accumulation):