from itertools import izip

import numpy
import scipy

import theano
from theano import gof, scalar, tensor
from theano.tensor import blas
from theano.sparse import (CSC, CSR, csm_properties,
                           register_specialize,
                           csm_grad, usmm)
from theano.sparse import basic as sparse

_is_sparse_variable = sparse._is_sparse_variable

# This is tested in tests/test_opt.py:test_local_csm_properties_csm
@gof.local_optimizer([csm_properties])
def local_csm_properties_csm(node):
    """if we find csm_properties(CSM(*args)), then we can replace that with the
    *args directly"""
    if node.op == csm_properties:
        csm, = node.inputs
        if csm.owner and (csm.owner.op == CSC or csm.owner.op == CSR):
            # csm.owner.inputs could be broadcastable. In that case, we have
            # to adjust the broadcasting flag here.
            ret_var = [theano.tensor.patternbroadcast(i, o.broadcastable)
                       for i, o in izip(csm.owner.inputs, node.outputs)]
            return ret_var

    return False
sparse.register_specialize(local_csm_properties_csm)


# This is tested in tests/test_basic.py:test_remove0
@gof.local_optimizer([sparse.Remove0])
def local_inplace_remove0(node):
    """
    Optimization to insert inplace versions of Remove0.
    """
    # If inplace is not enabled, enable it and replace that op with a
    # new op which has inplace enabled
    if isinstance(node.op, sparse.Remove0) and not node.op.inplace:
        new_op = node.op.__class__(inplace=True)
        new_node = new_op(*node.inputs)
        return [new_node]
    return False

theano.compile.optdb.register('local_inplace_remove0',
                              gof.TopoOptimizer(local_inplace_remove0,
    failure_callback=gof.TopoOptimizer.warn_inplace),
                              60, 'fast_run', 'inplace')
@gof.local_optimizer([sparse.AddSD])
def local_inplace_addsd(node):
    """
    Optimization to insert inplace versions of AddSD.
    """
    if isinstance(node.op, sparse.AddSD) and not node.op.inplace:
        inputs = node.inputs[:3] + [node.inputs[3].shape]
        fmt = node.op.format
        if fmt == 'csc':
            x = sparse.CSC(*inputs)
        elif fmt == 'csr':
            x = sparse.CSR(*inputs)
        else:
            raise NotImplementedError('Sparse format %s is not supported' % fmt)
        new_op = node.op.__class__(inplace=True)
        new_node = new_op(x, node.inputs[3])
        return [new_node]
    return False
theano.compile.optdb.register('local_inplace_addsd',
                              gof.TopoOptimizer(local_inplace_addsd,
    failure_callback=gof.TopoOptimizer.warn_inplace),
                              60, 'fast_run', 'inplace')


class StructuredDotCSC(gof.Op):
    """Structured Dot CSC is like dot, except that only the
    gradient wrt non-zero elements of the sparse matrix
    `a` are calculated and propagated.

    The output is presumed to be a dense matrix, and is represented by a
    TensorType instance.

    :param a: A sparse matrix in csc format.
    :param b: A sparse or dense matrix.

    :return: The dot product of `a` and `b`.

    :note: The grad implemented is structured.
    :note: This op is used as an optimization for StructuredDot.
    """

    def __eq__(self, other):
        return (type(self) == type(other))

    def __hash__(self):
        return hash(type(self))

    def __str__(self):
        return self.__class__.__name__

    def make_node(self, a_val, a_ind, a_ptr, a_nrows, b):
        dtype_out = scalar.upcast(a_val.type.dtype, b.type.dtype)
        r = gof.Apply(self, [a_val, a_ind, a_ptr, a_nrows, b],
                [tensor.tensor(dtype_out, (False, b.type.broadcastable[1]))])
        return r

    def perform(self, node, (a_val, a_ind, a_ptr, a_nrows, b), (out,)):
        a = scipy.sparse.csc_matrix((a_val, a_ind, a_ptr),
                (a_nrows, b.shape[0]),
                copy=False)
        #out[0] = a.dot(b)
        out[0] = theano._asarray(a * b, dtype=node.outputs[0].type.dtype)
        assert _is_dense(out[0])  # scipy 0.7 automatically converts to dense

    def c_code(self, node, name, (a_val, a_ind, a_ptr, a_nrows, b), (z,), sub):
        # C-implementation of the dot product of the sparse matrix A and matrix
        # B.
        # @param a_val: non-zero values of the sparse matrix
        # @param a_ind: column indices of the non-null values (.indices of a
        # scipy.csc_matrix)
        # @param a_ptr: a_ptr indicates col indices for col. i are in the range
        # a_ptr[i]:a_ptr[i+1]
        # @param n_rows: number of rows of sparse matrix
        # @param b: dense matrix to perform dot product with, as in dot(a, b)
        # @param z: return value
        # @param sub: TODO, not too sure, something to do with weave probably


        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for a_val')
        if node.inputs[4].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for b')

        typenum_z = node.outputs[0].type.dtype_specs()[2]  # retrieve dtype number
        typenum_a_val = node.inputs[0].type.dtype_specs()[2]  # retrieve dtype number
        typenum_b = node.inputs[4].type.dtype_specs()[2]  # retrieve dtype number

        rval = """

        if (PyArray_NDIM(%(a_val)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_val) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(a_ind)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_ind) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(a_ptr)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_ptr) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(a_nrows)s) != 0) {PyErr_SetString(PyExc_NotImplementedError, "rank(nrows) != 0"); %(fail)s;}
        if (PyArray_NDIM(%(b)s) != 2) {PyErr_SetString(PyExc_NotImplementedError, "rank(b) != 2"); %(fail)s;}

        if (PyArray_TYPE(%(a_val)s) != %(typenum_a_val)s) {
        PyErr_SetString(PyExc_NotImplementedError, "Invalid type for a_val"); %(fail)s;}

        if (PyArray_TYPE(%(b)s) != %(typenum_b)s) {
        PyErr_SetString(PyExc_NotImplementedError, "Invalid type for b"); %(fail)s;}

        if (PyArray_TYPE(%(a_ind)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "a_ind dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(a_ptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "a_ptr dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(a_nrows)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "a_nrows dtype not INT32"); %(fail)s;}

        if (PyArray_DIMS(%(a_val)s)[0] != PyArray_DIMS(%(a_ind)s)[0])
        {PyErr_SetString(PyExc_NotImplementedError, "a_val and a_ind have different lengths"); %(fail)s;}

        if (PyArray_DIMS(%(a_ptr)s)[0] != PyArray_DIMS(%(b)s)[0]+1)
        {PyErr_SetString(PyExc_NotImplementedError, "a's number of columns doesn't match b's rows"); %(fail)s;}

        if ((!%(z)s)
            || (PyArray_DIMS(%(z)s)[0] != ((npy_int32 *)PyArray_DATA(%(a_nrows)s))[0])
            || (PyArray_DIMS(%(z)s)[1] != PyArray_DIMS(%(b)s)[1])
            )
        {
            {Py_XDECREF(%(z)s);}
            npy_intp dims[] = {0, 0};
            dims[0] = ((npy_int32 *)PyArray_DATA(%(a_nrows)s))[0];
            dims[1] = PyArray_DIMS(%(b)s)[1];
            %(z)s = (PyArrayObject*) PyArray_SimpleNew(2, dims, %(typenum_z)s);
        }

        {
            // sparse array has size MxK, dense KxN, output MxN
            npy_intp M = PyArray_DIMS(%(z)s)[0];
            npy_intp N = PyArray_DIMS(%(z)s)[1];
            npy_intp K = PyArray_DIMS(%(b)s)[0];

            // strides tell you how many bytes to skip to go to next column/row entry
            npy_intp Szm = PyArray_STRIDES(%(z)s)[0] / PyArray_DESCR(%(z)s)->elsize;
            npy_intp Szn = PyArray_STRIDES(%(z)s)[1] / PyArray_DESCR(%(z)s)->elsize;
            //npy_intp Sbm = PyArray_STRIDES(%(b)s)[0] / PyArray_DESCR(%(b)s)->elsize;
            npy_intp Sbn = PyArray_STRIDES(%(b)s)[1] / PyArray_DESCR(%(b)s)->elsize;
            npy_intp Sval = PyArray_STRIDES(%(a_val)s)[0] / PyArray_DESCR(%(a_val)s)->elsize;
            npy_intp Sind = PyArray_STRIDES(%(a_ind)s)[0] / PyArray_DESCR(%(a_ind)s)->elsize;
            npy_intp Sptr = PyArray_STRIDES(%(a_ptr)s)[0] / PyArray_DESCR(%(a_ptr)s)->elsize;

            // pointers to access actual data in the arrays passed as params.
            dtype_%(z)s*     __restrict__ Dz   = (dtype_%(z)s*)PyArray_DATA(%(z)s);
            const dtype_%(a_val)s* __restrict__ Dval = (dtype_%(a_val)s*)PyArray_DATA(%(a_val)s);
            const npy_int32 * __restrict__ Dind = (npy_int32*)PyArray_DATA(%(a_ind)s;
            const npy_int32 * __restrict__ Dptr = (npy_int32*)PyArray_DATA(%(a_ptr)s;

            //npy_intp nnz = PyArray_DIMS(%(a_ind)s)[0];

            //clear the output array
            memset(Dz, 0, M*N*sizeof(dtype_%(z)s));

            //iterate over the sparse array, making the most of an entry wherever we find it.
            //
            // Normal matrix matrix multiply: A MxK, B KxN =>  Z = AB
            // for m
            //   for n
            //     for k
            //        z[m, n] += a[m, k] * b[k, n]
            // Here instead: Z =
            // for k
            //   for m (sparse)
            //     for n
            //        z[m, n] += a[m, k] * b[k, n]

            // loop over inner dimension
            for (npy_int32 k = 0; k < K; ++k)
            {
                // get pointer to k-th row of dense matrix
                const dtype_%(b)s* __restrict__ bk = (dtype_%(b)s*)(PyArray_BYTES(%(b)s) + PyArray_STRIDES(%(b)s)[0] * k);

                // loop over sparse column indices through index pointer array
                // (amounts to looping over rows M of sparse matrix)

                for (npy_int32 m_idx = Dptr[k * Sptr]; m_idx < Dptr[(k+1) * Sptr]; ++m_idx)
                {
                    npy_int32 m = Dind[m_idx * Sind]; // row index of non-null value for column K
                    const dtype_%(a_val)s Amk = Dval[m_idx * Sval]; // actual value at that location

                    // pointer to m-th row of the output matrix Z
                    dtype_%(z)s* __restrict__ zm = (dtype_%(z)s*)(PyArray_BYTES(%(z)s) + PyArray_STRIDES(%(z)s)[0] * m);

                    //RESOLVE: a.shape[0] equals z.shape[0], why is this not an equality constraint?
                    if (m >= PyArray_DIMS(%(z)s)[0])
                    {PyErr_SetString(PyExc_NotImplementedError, "illegal row index in a"); %(fail)s;}

                    // loop over final dimension (cols of dense matrix) and perform dot product
                    if ((Szn == 1) && (Sbn == 1)) {
                        for(npy_int32 n = 0; n < N; ++n)
                        {
                            zm[n] += Amk * bk[n];
                        }
                    }
                    else
                    {
                        for(npy_int32 n = 0; n < N; ++n)
                        {
                            zm[n*Szn] += Amk * bk[n*Sbn];
                        }
                    }
                }
            }
        }
        """ % dict(locals(), **sub)

        return rval

    def c_code_cache_version(self):
        return (2,)
sd_csc = StructuredDotCSC()


class StructuredDotCSR(gof.Op):
    """Structured Dot CSR is like dot, except that only the
    gradient wrt non-zero elements of the sparse matrix
    `a` are calculated and propagated.

    The output is presumed to be a dense matrix, and is represented by a
    TensorType instance.

    :param a: A sparse matrix in csr format.
    :param b: A sparse or dense matrix.

    :return: The dot product of `a` and `b`.

    :note: The grad implemented is structured.
    :note: This op is used as an optimization for StructuredDot.
    """

    def __eq__(self, other):
        return (type(self) == type(other))

    def __hash__(self):
        return hash(type(self))

    def __str__(self):
        return self.__class__.__name__

    def make_node(self, a_val, a_ind, a_ptr, b):
        self.dtype_out = scalar.upcast(a_val.type.dtype, b.type.dtype)
        r = gof.Apply(self, [a_val, a_ind, a_ptr, b],
                [tensor.tensor(self.dtype_out, (False,
                                                b.type.broadcastable[1]))])
        return r

    def perform(self, node, (a_val, a_ind, a_ptr, b), (out,)):
        a = scipy.sparse.csr_matrix((a_val, a_ind, a_ptr),
                (len(a_ptr) - 1, b.shape[0]),
                copy=True)  # use view_map before setting this to False
        #out[0] = a.dot(b)
        out[0] = a * b
        # scipy 0.7 automatically converts to dense, but not .6 sometimes
        assert _is_dense(out[0])

    def c_code(self, node, name, (a_val, a_ind, a_ptr, b), (z,), sub):
        """
        C-implementation of the dot product of the sparse matrix A and matrix
        B.
        @param a_val: non-zero values of the sparse matrix
        @param a_ind: column indices of the non-null values (.indices of a
        scipy.csc_matrix)
        @param a_ptr: a_ptr indicates col indices for col. i are in the range
        a_ptr[i]:a_ptr[i+1]
        @param n_cols: number of columns of sparse matrix
        @param b: dense matrix to perform dot product with, as in dot(a, b)
        @param z: return value
        @param sub: TODO, not too sure, something to do with weave probably
        """
        # retrieve dtype number
        typenum_z = tensor.TensorType(self.dtype_out, []).dtype_specs()[2]
        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for a_val')
        if node.inputs[3].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for b')

        return """
        if (PyArray_NDIM(%(a_val)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_val) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(a_ind)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_ind) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(a_ptr)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_ptr) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(b)s) != 2) {PyErr_SetString(PyExc_NotImplementedError, "rank(b) != 2"); %(fail)s;}

        if (PyArray_TYPE(%(a_ind)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "a_ind dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(a_ptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "a_ptr dtype not INT32"); %(fail)s;}

        if (PyArray_DIMS(%(a_val)s)[0] != PyArray_DIMS(%(a_ind)s)[0])
        {PyErr_SetString(PyExc_NotImplementedError, "a_val and a_ind have different lengths"); %(fail)s;}

        if ((!%(z)s)
            || (PyArray_DIMS(%(z)s)[0] != PyArray_DIMS(%(a_ptr)s)[0]-1) //a's rows
            || (PyArray_DIMS(%(z)s)[1] != PyArray_DIMS(%(b)s)[1])       //b's columns
            )
        {
            {Py_XDECREF(%(z)s);}
            npy_intp dims[] = {0, 0};
            dims[0] = PyArray_DIMS(%(a_ptr)s)[0]-1;
            dims[1] = PyArray_DIMS(%(b)s)[1];
            %(z)s = (PyArrayObject*) PyArray_SimpleNew(2, dims, %(typenum_z)s);
        }

        {
            // sparse array has size MxK, dense KxN, output MxN
            npy_intp M = PyArray_DIMS(%(z)s)[0];
            npy_intp N = PyArray_DIMS(%(z)s)[1];
            npy_intp K = PyArray_DIMS(%(b)s)[0];

            // strides tell you how many bytes to skip to go to next column/row entry
            npy_intp Szm = PyArray_STRIDES(%(z)s)[0] / PyArray_DESCR(%(z)s)->elsize;
            npy_intp Szn = PyArray_STRIDES(%(z)s)[1] / PyArray_DESCR(%(z)s)->elsize;
            npy_intp Sbm = PyArray_STRIDES(%(b)s)[0] / PyArray_DESCR(%(b)s)->elsize;
            npy_intp Sbn = PyArray_STRIDES(%(b)s)[1] / PyArray_DESCR(%(b)s)->elsize;
            npy_intp Sval = PyArray_STRIDES(%(a_val)s)[0] / PyArray_DESCR(%(a_val)s)->elsize;
            npy_intp Sind = PyArray_STRIDES(%(a_ind)s)[0] / PyArray_DESCR(%(a_ind)s)->elsize;
            npy_intp Sptr = PyArray_STRIDES(%(a_ptr)s)[0] / PyArray_DESCR(%(a_ptr)s)->elsize;

            // pointers to access actual data in the arrays passed as params.
            dtype_%(z)s* __restrict__ Dz = (dtype_%(z)s*)PyArray_DATA(%(z)s);
            const dtype_%(a_val)s* __restrict__ Dval = (dtype_%(a_val)s*)PyArray_DATA(%(a_val)s);
            const npy_int32 * __restrict__ Dind = (npy_int32*)PyArray_DATA(%(a_ind)s);
            const npy_int32 * __restrict__ Dptr = (npy_int32*)PyArray_DATA(%(a_ptr)s);

            //npy_intp nnz = PyArray_DIMS(%(a_ind)s)[0];

            //clear the output array
            memset(Dz, 0, M*N*sizeof(dtype_%(z)s));

            //iterate over the sparse array, making the most of an entry wherever we find it.
            // Normal matrix matrix multiply:
            // for m
            //   for n
            //     for k
            //        z[m, n] += a[m, k] * b[k, n]
            // Here instead:
            // for m
            //   for k (sparse)
            //     for n
            //        z[m, n] += a[m, k] * b[k, n]

            // loop over inner dimension
            for (npy_int64 m = 0; m < M; ++m)
            {
                // pointer to m-th row of the output matrix Z
                dtype_%(z)s* __restrict__ zm = (dtype_%(z)s*)(PyArray_BYTES(%(z)s) + PyArray_STRIDES(%(z)s)[0] * m);

                // loop over sparse rows indices through index pointer array
                // (amounts to looping over cols k of sparse matrix)
                for (npy_int32 k_idx = Dptr[m * Sptr]; k_idx < Dptr[(m+1) * Sptr]; ++k_idx)
                {
                    npy_int32 k = Dind[k_idx * Sind]; // col index of non-null value for row m
                    const dtype_%(a_val)s Amk = Dval[k_idx * Sval]; // actual value at that location

                    // get pointer to k-th row of dense matrix
                    const dtype_%(b)s* __restrict__ bk = (dtype_%(b)s*)(PyArray_BYTES(%(b)s) + PyArray_STRIDES(%(b)s)[0] * k);

                    // loop over final dimension (cols of dense matrix) and perform dot product
                    for(npy_int32 n = 0; n < N; ++n)
                    {
                        zm[n*Szn] += Amk * bk[n*Sbn];
                    }
                }
            }
        }

        """ % dict(locals(), **sub)

    def c_code_cache_version(self):
        return (1,)
sd_csr = StructuredDotCSR()


# register a specialization to replace StructuredDot -> StructuredDotCSx
# This is tested in tests/test_basic.py:792
@gof.local_optimizer([sparse._structured_dot])
def local_structured_dot(node):
    if node.op == sparse._structured_dot:
        a, b = node.inputs
        if a.type.format == 'csc':
            a_val, a_ind, a_ptr, a_shape = csm_properties(a)
            a_nsparse = a_shape[0]
            return [sd_csc(a_val, a_ind, a_ptr, a_nsparse, b)]
        if a.type.format == 'csr':
            a_val, a_ind, a_ptr, a_shape = csm_properties(a)
            return [sd_csr(a_val, a_ind, a_ptr, b)]
    return False


# Commented out because
# a) it is only slightly faster than scipy these days, and sometimes a little
# slower, and
# b) the resulting graphs make it very difficult for an op to do size checking
# on the matrices involved.  dimension mismatches are hard to detect sensibly.
#register_specialize(local_structured_dot)


class UsmmCscDense(gof.Op):
    """Performs the expression is `alpha` * `x` `y` + `z`.

    :param x: Matrix variable.
    :param y: Matrix variable.
    :param z: Dense matrix.
    :param alpha: A tensor scalar.

    :return: The dense matrix resulting from `alpha` * `x` `y` + `z`.

    :note: The grad is not implemented for this op.
    :note: Optimized version os Usmm when `x` is in csc format and
           `y` is dense.
    """

    def __init__(self, inplace):
        self.inplace = inplace
        if inplace:
            self.destroy_map = {0: [6]}

    def __str__(self):
        if self.inplace:
            return 'UsmmCscDense{inplace}'
        else:
            return 'UsmmCscDense{no_inplace}'

    def __eq__(self, other):
        return (type(self) == type(other)) and self.inplace == other.inplace

    def __hash__(self):
        return hash(type(self)) ^ self.inplace

    def make_node(self, alpha, x_val, x_ind, x_ptr, x_nrows, y, z):
        alpha = tensor.as_tensor_variable(alpha)
        x_val = tensor.as_tensor_variable(x_val)
        x_ind = tensor.as_tensor_variable(x_ind)
        x_ptr = tensor.as_tensor_variable(x_ptr)
        x_nrows = tensor.as_tensor_variable(x_nrows)
        y = tensor.as_tensor_variable(y)
        z = tensor.as_tensor_variable(z)
        assert x_ind.dtype == 'int32'
        assert x_ptr.dtype == 'int32'
        assert x_nrows.dtype == 'int32'
        assert alpha.ndim == 2 and alpha.type.broadcastable == (True, True)
        assert x_val.ndim == 1
        assert y.ndim == 2
        assert z.ndim == 2

        dtype_out = scalar.upcast(alpha.type.dtype, x_val.type.dtype,
            y.type.dtype, z.type.dtype)

        if dtype_out not in ('float32', 'float64'):
            raise NotImplementedError('only float types are supported in '
                                      'operands')

        if self.inplace:
            assert z.type.dtype == dtype_out

        # axpy work only with the same dtype, so we should upcast the input
        if dtype_out != alpha.type.dtype:
            alpha = tensor.cast(alpha, dtype_out)
        if dtype_out != x_val.type.dtype:
            x_val = tensor.cast(x_val, dtype_out)
        if dtype_out != y.type.dtype:
            y = tensor.cast(y, dtype_out)
        if dtype_out != z.type.dtype:
            z = tensor.cast(z, dtype_out)

        r = gof.Apply(self, [alpha, x_val, x_ind, x_ptr, x_nrows, y, z],
                [tensor.tensor(dtype_out, (False, y.type.broadcastable[1]))])
        return r

    def c_support_code(self):
        return blas.blas_header_text()

    def c_libraries(self):
        return blas.ldflags()

    def c_compile_args(self):
        return blas.ldflags(libs=False, flags=True)

    def c_lib_dirs(self):
        return blas.ldflags(libs=False, libs_dir=True)

    def c_header_dirs(self):
        return blas.ldflags(libs=False, include_dir=True)

    def c_code(self, node, name, inputs, outputs, sub):
        alpha, x_val, x_ind, x_ptr, x_nrows, y, z = inputs
        zn = outputs[0]
        if node.inputs[1].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for '
                                      'x_val')
        if node.inputs[5].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for y')
        if node.inputs[6].type.dtype != node.outputs[0].type.dtype:
            raise NotImplementedError('z and output must have same type')

        if node.inputs[1].type.dtype == "float32":
            conv_type = "float"
            axpy = "saxpy_"
        else:
            conv_type = "double"
            axpy = "daxpy_"
        # retrieve dtype numbers
        typenum_alpha = node.inputs[0].type.dtype_specs()[2]
        typenum_x_val = node.inputs[1].type.dtype_specs()[2]
        typenum_y = node.inputs[5].type.dtype_specs()[2]
        typenum_z = node.inputs[6].type.dtype_specs()[2]
        typenum_zn = node.outputs[0].type.dtype_specs()[2]

        inplace = int(self.inplace)

        rval = """

        if (PyArray_NDIM(%(x_val)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(x_val) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(x_ind)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(x_ind) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(x_ptr)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(x_ptr) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(x_nrows)s) != 0) {PyErr_SetString(PyExc_NotImplementedError, "rank(nrows) != 0"); %(fail)s;}
        if (PyArray_NDIM(%(y)s) != 2) {PyErr_SetString(PyExc_NotImplementedError, "rank(y) != 2"); %(fail)s;}

        if (PyArray_TYPE(%(x_val)s) != %(typenum_x_val)s) {
        PyErr_SetString(PyExc_NotImplementedError, "Invalid type for x_val"); %(fail)s;}

        if (PyArray_TYPE(%(y)s) != %(typenum_y)s) {
        PyErr_SetString(PyExc_NotImplementedError, "Invalid type for y"); %(fail)s;}

        if (PyArray_TYPE(%(z)s) != %(typenum_z)s) {
        PyErr_SetString(PyExc_NotImplementedError, "Invalid type for z"); %(fail)s;}

        if (PyArray_TYPE(%(alpha)s) != %(typenum_alpha)s) {
        PyErr_SetString(PyExc_NotImplementedError, "Invalid type for alpha"); %(fail)s;}

        if (PyArray_TYPE(%(x_ind)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "x_ind dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(x_ptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "x_ptr dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(x_nrows)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "x_nrows dtype not INT32"); %(fail)s;}

        if (PyArray_DIMS(%(x_val)s)[0] != PyArray_DIMS(%(x_ind)s)[0])
        {PyErr_SetString(PyExc_NotImplementedError, "x_val and x_ind have different lengths"); %(fail)s;}

        if (PyArray_DIMS(%(x_ptr)s)[0] != PyArray_DIMS(%(y)s)[0]+1)
        {PyErr_SetString(PyExc_NotImplementedError, "x's number of columns doesn't match y's rows"); %(fail)s;}

        if (PyArray_DIMS(%(z)s)[0] != ((npy_int32 *)PyArray_DATA(%(x_nrows)s))[0] || PyArray_DIMS(%(z)s)[1] != PyArray_DIMS(%(y)s)[1])
        {PyErr_SetString(PyExc_NotImplementedError, "The dimension of the allocated output doesn't match the correct output size."); %(fail)s;}

        if (PyArray_SIZE(%(alpha)s) != 1)
        {PyErr_SetString(PyExc_NotImplementedError, "The number of element in alpha must be 1"); %(fail)s;}

        if (PyArray_NDIM(%(alpha)s) != 2)
        {PyErr_SetString(PyExc_NotImplementedError, "The number dimension of alpha must be 2"); %(fail)s;}

        if (PyArray_NDIM(%(x_val)s) != 1)
        {PyErr_SetString(PyExc_NotImplementedError, "The number dimension of x_val must be 1"); %(fail)s;}

        if (PyArray_NDIM(%(y)s) != 2)
        {PyErr_SetString(PyExc_NotImplementedError, "The number dimension of y must be 2"); %(fail)s;}

        if (PyArray_NDIM(%(z)s) != 2)
        {PyErr_SetString(PyExc_NotImplementedError, "The number dimension of z must be 2"); %(fail)s;}

        if (%(inplace)s)
        {
            if (%(typenum_zn)s != %(typenum_z)s) {
            PyErr_SetString(PyExc_NotImplementedError, "When inplace the output dtype must be the same as the input"); %(fail)s;}

            Py_XDECREF(%(zn)s);
            %(zn)s = %(z)s;
            Py_INCREF(%(zn)s);
        }
        else if (!%(zn)s
            || (PyArray_DIMS(%(zn)s)[0] != ((npy_int32 *)PyArray_DATA(%(x_nrows)s))[0])
            || (PyArray_DIMS(%(zn)s)[1] != PyArray_DIMS(%(y)s)[1])
            )
        {
            {Py_XDECREF(%(zn)s);}
            npy_intp dims[] = {0, 0};
            dims[0] = ((npy_int32 *)PyArray_DATA(%(x_nrows)s))[0];
            dims[1] = PyArray_DIMS(%(y)s)[1];
            %(zn)s = (PyArrayObject*) PyArray_SimpleNew(2, dims, %(typenum_zn)s);
        }

        {
            // sparse array has size MxK, dense KxN, output MxN
            npy_intp M = PyArray_DIMS(%(zn)s)[0];
            npy_intp N = PyArray_DIMS(%(zn)s)[1];
            npy_intp K = PyArray_DIMS(%(y)s)[0];

            // pointers to access actual data in the arrays passed as params.
            const dtype_%(x_val)s* __restrict__ Dval = (dtype_%(x_val)s*)PyArray_DATA(%(x_val)s);
            const npy_int32 * __restrict__ Dind = (npy_int32*)PyArray_DATA(%(x_ind)s);
            const npy_int32 * __restrict__ Dptr = (npy_int32*)PyArray_DATA(%(x_ptr)s);
            const dtype_%(alpha)s alpha = ((dtype_%(alpha)s*)PyArray_DATA(%(alpha)s))[0];

            npy_intp Sz = PyArray_STRIDES(%(z)s)[1] / PyArray_DESCR(%(z)s)->elsize;
            npy_intp Szn = PyArray_STRIDES(%(zn)s)[1] / PyArray_DESCR(%(zn)s)->elsize;
            npy_intp Sval = PyArray_STRIDES(%(x_val)s)[0] / PyArray_DESCR(%(x_val)s)->elsize;
            npy_intp Sind = PyArray_STRIDES(%(x_ind)s)[0] / PyArray_DESCR(%(x_ind)s)->elsize;
            npy_intp Sptr = PyArray_STRIDES(%(x_ptr)s)[0] / PyArray_DESCR(%(x_ptr)s)->elsize;
            npy_intp Sy = PyArray_STRIDES(%(y)s)[1] / PyArray_DESCR(%(y)s)->elsize;


            if (!(%(inplace)s))
            {
                if (PyArray_CopyInto(%(zn)s, %(z)s))
                {
                    Py_XDECREF(%(zn)s);
                    %(fail)s;
                }
            }

            for (npy_int32 k = 0; k < K; ++k)
            {
                for (npy_int32 m_idx = Dptr[k * Sptr]; m_idx < Dptr[(k+1)*Sptr]; ++m_idx)
                {
                    const npy_int32 m = Dind[m_idx * Sind]; // row index of non-null value for column K

                    const dtype_%(x_val)s Amk = alpha * Dval[m_idx * Sval]; // actual value at that location

                    dtype_%(y)s* y_row = (dtype_%(y)s*)(PyArray_BYTES(%(y)s) + PyArray_STRIDES(%(y)s)[0] * k);
                    // axpy expects pointer to the beginning of memory arrays,
                    // so when the stride is negative, we need to get the
                    // last element
                    if (Sy < 0)
                        y_row += (K - 1) * Sy;

                    dtype_%(zn)s* z_row = (dtype_%(zn)s*)(PyArray_BYTES(%(zn)s) + PyArray_STRIDES(%(zn)s)[0] * m);
                    if (Szn < 0)
                        z_row += (N - 1) * Szn;

                    %(axpy)s((int*)&N, (%(conv_type)s*)&Amk, (%(conv_type)s*)y_row, (int*)&Sy, (%(conv_type)s*)z_row, (int*)&Szn);
                }
            }
        }
        """ % dict(locals(), **sub)

        return rval

    def c_code_cache_version(self):
        return (1, blas.blas_header_version())
usmm_csc_dense = UsmmCscDense(inplace=False)
usmm_csc_dense_inplace = UsmmCscDense(inplace=True)


# This is tested in tests/test_basic.py:UsmmTests
local_usmm = gof.opt.PatternSub(
    (theano.tensor.sub, 'z',
     (theano.tensor.mul,
      {'pattern': 'alpha',
       'constraint': lambda expr: (numpy.all(expr.type.broadcastable) and
                                   theano.config.blas.ldflags)},
    (sparse._dot, 'x', 'y'))),
    (usmm, (theano.tensor.neg, 'alpha'), 'x', 'y', 'z'))
register_specialize(local_usmm, name="local_usmm")


# register a specialization to replace usmm_csc_dense -> usmm_csc_dense_inplace
# This is tested in tests/test_basic.py:UsmmTests
@gof.local_optimizer([usmm_csc_dense])
def local_usmm_csc_dense_inplace(node):
    if node.op == usmm_csc_dense:
        return [usmm_csc_dense_inplace(*node.inputs)]
register_specialize(local_usmm_csc_dense_inplace, 'cxx_only', 'inplace')


# This is tested in tests/test_basic.py:UsmmTests
@gof.local_optimizer([usmm])
def local_usmm_csx(node):
    """ usmm -> usmm_csc_dense """
    if node.op == usmm:
        alpha, x, y, z = node.inputs

        x_is_sparse_variable = _is_sparse_variable(x)
        y_is_sparse_variable = _is_sparse_variable(y)

        if x_is_sparse_variable and not y_is_sparse_variable:
            if x.type.format == 'csc':
                x_val, x_ind, x_ptr, x_shape = csm_properties(x)
                x_nsparse = x_shape[0]
                dtype_out = scalar.upcast(alpha.type.dtype, x.type.dtype,
                                          y.type.dtype, z.type.dtype)
                if dtype_out not in ('float32', 'float64'):
                    return False
                # Sparse cast is not implemented.
                if y.type.dtype != dtype_out:
                    return False

                return [usmm_csc_dense(alpha, x_val, x_ind, x_ptr,
                                       x_nsparse, y, z)]
    return False
sparse.register_specialize(local_usmm_csx, 'cxx_only')


class CSMGradC(gof.Op):
    def __eq__(self, other):
        return (type(self) == type(other))

    def __hash__(self):
        return hash(type(self))

    def __str__(self):
        return self.__class__.__name__

    def make_node(self, a_val, a_ind, a_ptr, a_dim,
                  b_val, b_ind, b_ptr, b_dim):
        return gof.Apply(self, [a_val, a_ind, a_ptr, a_dim,
             b_val, b_ind, b_ptr, b_dim], [b_val.type()])

    def c_code(self, node, name, (a_val, a_ind, a_ptr, a_dim,
                        b_val, b_ind, b_ptr, b_dim), (z,), sub):
        # retrieve dtype number
        typenum_z = node.outputs[0].type.dtype_specs()[2]
        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for a_val')
        if node.inputs[3].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for b_val')

        return """
        if (PyArray_NDIM(%(a_val)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_val) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(a_ind)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_ind) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(a_ptr)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(a_ptr) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(b_val)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(b_val) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(b_ind)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(b_ind) != 1"); %(fail)s;}
        if (PyArray_NDIM(%(b_ptr)s) != 1) {PyErr_SetString(PyExc_NotImplementedError, "rank(b_ptr) != 1"); %(fail)s;}

        if (PyArray_TYPE(%(a_ind)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "a_ind dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(a_ptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "a_ptr dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(b_ind)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "b_ind dtype not INT32"); %(fail)s;}

        if (PyArray_TYPE(%(b_ptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "b_ptr dtype not INT32"); %(fail)s;}

        if (PyArray_DIMS(%(a_val)s)[0] != PyArray_DIMS(%(a_ind)s)[0])
        {PyErr_SetString(PyExc_NotImplementedError, "a_val and a_ind have different lengths"); %(fail)s;}

        if (PyArray_DIMS(%(b_val)s)[0] != PyArray_DIMS(%(b_ind)s)[0])
        {PyErr_SetString(PyExc_NotImplementedError, "b_val and b_ind have different lengths"); %(fail)s;}

        if (PyArray_DIMS(%(a_ptr)s)[0] != PyArray_DIMS(%(b_ptr)s)[0])
        {PyErr_SetString(PyExc_NotImplementedError, "a_ptr and b_ptr have different lengths"); %(fail)s;}

        if ((!%(z)s) || (PyArray_DIMS(%(z)s)[0] != PyArray_DIMS(%(a_val)s)[0]))
        {
            {Py_XDECREF(%(z)s);}
            npy_intp dims[] = {0};
            dims[0] = PyArray_DIMS(%(a_val)s)[0];
            %(z)s = (PyArrayObject*) PyArray_SimpleNew(1, dims, %(typenum_z)s);
        }

        {
            // sparse array has size MxK, dense KxN, output MxN
            npy_intp M = PyArray_DIMS(%(a_ptr)s)[0] - 1;
            npy_intp a_dim_0 = ((npy_int32 *)PyArray_DATA(%(a_dim)s))[0];
            npy_intp a_dim_1 = ((npy_int32 *)PyArray_DATA(%(a_dim)s))[1];

            npy_intp sp_dim = (M == a_dim_0)?a_dim_1:a_dim_0;

            // strides tell you how many bytes to skip to go to next column/row entry
            npy_intp Sz = PyArray_STRIDES(%(z)s)[0] / PyArray_DESCR(%(z)s)->elsize;
            npy_intp Sa_val = PyArray_STRIDES(%(a_val)s)[0] / PyArray_DESCR(%(a_val)s)->elsize;
            npy_intp Sa_ind = PyArray_STRIDES(%(a_ind)s)[0] / PyArray_DESCR(%(a_ind)s)->elsize;
            npy_intp Sa_ptr = PyArray_STRIDES(%(a_ptr)s)[0] / PyArray_DESCR(%(a_ptr)s)->elsize;
            npy_intp Sb_val = PyArray_STRIDES(%(b_val)s)[0] / PyArray_DESCR(%(b_val)s)->elsize;
            npy_intp Sb_ind = PyArray_STRIDES(%(b_ind)s)[0] / PyArray_DESCR(%(b_ind)s)->elsize;
            npy_intp Sb_ptr = PyArray_STRIDES(%(b_ptr)s)[0] / PyArray_DESCR(%(b_ptr)s)->elsize;

            // pointers to access actual data in the arrays passed as params.
            dtype_%(z)s* __restrict__ Dz = (dtype_%(z)s*)PyArray_DATA(%(z)s);
            const dtype_%(a_val)s* __restrict__ Da_val = (dtype_%(a_val)s*)PyArray_DATA(%(a_val)s);
            const npy_int32 * __restrict__ Da_ind = (npy_int32*)PyArray_DATA(%(a_ind)s);
            const npy_int32 * __restrict__ Da_ptr = (npy_int32*)PyArray_DATA(%(a_ptr)s);
            const dtype_%(b_val)s* __restrict__ Db_val = (dtype_%(b_val)s*)PyArray_DATA(%(b_val)s);
            const npy_int32 * __restrict__ Db_ind = (npy_int32*)PyArray_DATA(%(b_ind)s);
            const npy_int32 * __restrict__ Db_ptr = (npy_int32*)PyArray_DATA(%(b_ptr)s);

            npy_intp nnz = PyArray_DIMS(%(a_ind)s)[0];

            dtype_%(b_val)s b_row[sp_dim];

            //clear the output array
            for (npy_int64 i = 0; i < nnz; ++i)
            {
                Dz[i*Sz] = 0;
            }
            memset(b_row, 0, sp_dim*sizeof(dtype_%(b_val)s));

            // loop over inner dimension
            for (npy_int64 m = 0; m < M; ++m)
            {
                for (npy_int32 j_ptr = Db_ptr[m * Sb_ptr];
                    j_ptr < Db_ptr[(m + 1) * Sb_ptr]; j_ptr++) {
                    b_row[Db_ind[j_ptr * Sb_ind]] += Db_val[j_ptr*Sb_val];
                }

                for (npy_int32 j_ptr = Da_ptr[m * Sa_ptr];
                    j_ptr < Da_ptr[(m + 1) * Sa_ptr]; j_ptr++) {
                    Dz[j_ptr*Sz] = b_row[Da_ind[j_ptr * Sa_ind]];
                }

                for (npy_int32 j_ptr = Db_ptr[m * Sb_ptr];
                    j_ptr < Db_ptr[(m + 1) * Sb_ptr]; j_ptr++) {
                    b_row[Db_ind[j_ptr * Sb_ind]] = 0;
                }
            }
        }

        """ % dict(locals(), **sub)

    def c_code_cache_version(self):
        return (3,)
csm_grad_c = CSMGradC()


# register a specialization to replace csm_grad -> csm_grad_c
# This is tested in tests/test_opt.py:test_local_csm_grad_c
@gof.local_optimizer([csm_grad(None)])
def local_csm_grad_c(node):
    """ csm_grad(None) -> csm_grad_c """
    if node.op == csm_grad(None):
        return [csm_grad_c(*node.inputs)]
    return False
#DISABLED AS IT IS BROKEN FOR UNSORTED INDICES!
#register_specialize(local_csm_grad_c, 'cxx_only')


class MulSDCSC(gof.Op):
    """Multiplication of sparse matrix by a broadcasted dense vector
    element wise.

    :param a_data: Sparse matrix data.
    :param a_indices: Sparse matrix indices.
    :param a_indptr: Sparse matrix indptr.
    :param b: Tensor type matrix.

    :return: The multiplication of the two matrix element wise.

    :note: `a_data`, `a_indices` and `a_indptr` must be the properties
            of a sparse matrix in csc format.
    :note: The dtype of `a_data`, i.e. the dtype of the sparse matrix,
           cannot be a complex type.
    :note: This op is used as an optimization of mul_s_d.
    """

    def __eq__(self, other):
        return (type(self) == type(other))

    def __hash__(self):
        return hash(type(self))

    def make_node(self, a_data, a_indices, a_indptr, b):
        assert b.type.ndim == 2
        return gof.Apply(self, [a_data, a_indices, a_indptr, b],
                               [tensor.tensor(b.dtype, (False,))])

    def c_code_cache_version(self):
        return (2,)

    #def perform(self, node, (a_data, a_indices, a_indptr, b), (out,)):
    #    return NotImplementedError()

    def c_code(self, node, name, (_data, _indices, _indptr, _b,),
               (_zout, ), sub):

        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for a')
        if node.inputs[3].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for b')

        return """
        if (PyArray_NDIM(%(_b)s) != 2) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(b) != 2");
            %(fail)s;}
        if (PyArray_NDIM(%(_data)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(data) != 1");
            %(fail)s;}
        if (PyArray_NDIM(%(_indices)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indices) != 1");
            %(fail)s;}
        if (PyArray_NDIM(%(_indptr)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indptr) != 1");
            %(fail)s;}

        if( PyArray_TYPE(%(_indices)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "C"); %(fail)s;}

        if( PyArray_TYPE(%(_indptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "D"); %(fail)s;}

        if (!%(_zout)s ||
            (PyArray_DIMS(%(_zout)s)[0] != PyArray_DIMS(%(_indices)s)[0]) ||
            !(PyArray_ISCONTIGUOUS(%(_zout)s)))
        {
            Py_XDECREF(%(_zout)s);
            %(_zout)s = (PyArrayObject*) PyArray_SimpleNew(1,
                  PyArray_DIMS(%(_indices)s), PyArray_TYPE(%(_b)s));
            if (!%(_zout)s)
            {
                PyErr_SetString(PyExc_MemoryError,
                    "Could not allocate output memory.");
                %(fail)s;
            }
        }

        { //makes it compile even though labels jump over variable definitions.
            const npy_intp nnz = PyArray_DIMS(%(_indices)s)[0];
            //TODO: error checking with this
            const npy_intp N =  PyArray_DIMS(%(_indptr)s)[0]-1;

            const dtype_%(_data)s * const __restrict__ data = (dtype_%(_data)s*)PyArray_DATA(%(_data)s);
            const npy_int32 * const __restrict__ indptr = (npy_int32 *)PyArray_DATA(%(_indptr)s);
            const npy_int32 * const __restrict__ indices = (npy_int32 *)PyArray_DATA(%(_indices)s);

            dtype_%(_zout)s * const __restrict__ zout = (dtype_%(_zout)s*)PyArray_DATA(%(_zout)s);

            const npy_intp Sb = PyArray_STRIDES(%(_b)s)[0];

            // loop over columns
            for (npy_int32 j = 0; j < N; ++j)
            {
                // for each non-null value in the sparse column
                for (npy_int32 i_idx = indptr[j]; i_idx < indptr[j+1]; ++i_idx)
                {
                    // extract row index of non-null value
                    npy_int32 i = indices[i_idx];

                    // extract i-th row of dense matrix
                    const dtype_%(_b)s* __restrict__ b_row = (dtype_%(_b)s*)(PyArray_BYTES(%(_b)s) + Sb * i);

                    // write resulting gradient to sparse output
                    zout[i_idx] = data[i_idx] * b_row[j];
                }
            }
        }

        """ % dict(locals(), **sub)

    def __str__(self):
        return self.__class__.__name__
mul_s_d_csc = MulSDCSC()


class MulSDCSR(gof.Op):
    """Multiplication of sparse matrix by a broadcasted dense vector
    element wise.

    :param a_data: Sparse matrix data.
    :param a_indices: Sparse matrix indices.
    :param a_indptr: Sparse matrix indptr.
    :param b: Tensor type matrix.

    :return: The multiplication of the two matrix element wise.

    :note: `a_data`, `a_indices` and `a_indptr` must be the properties
            of a sparse matrix in csr format.
    :note: The dtype of `a_data`, i.e. the dtype of the sparse matrix,
           cannot be a complex type.
    :note: This op is used as an optimization of mul_s_d.
    """

    def __eq__(self, other):
        return (type(self) == type(other))

    def __hash__(self):
        return hash(type(self))

    def make_node(self, a_data, a_indices, a_indptr, b):
        assert b.type.ndim == 2
        return gof.Apply(self, [a_data, a_indices, a_indptr, b],
                               [tensor.tensor(b.dtype, (False,))])

    def c_code_cache_version(self):
        return (2,)

    #def perform(self, node, (a_data, a_indices, a_indptr, b), (out,)):
    #    return NotImplemented()

    def c_code(self, node, name, (_data, _indices, _indptr, _b,),
               (_zout, ), sub):

        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for a')
        if node.inputs[3].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for b')

        return """
        if (PyArray_NDIM(%(_b)s) != 2) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(b) != 2");
            %(fail)s;}
        if (PyArray_NDIM(%(_data)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(data) != 1");
            %(fail)s;}
        if (PyArray_NDIM(%(_indices)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indices) != 1");
            %(fail)s;}
        if (PyArray_NDIM(%(_indptr)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indptr) != 1");
            %(fail)s;}

        if( PyArray_TYPE(%(_indices)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "C"); %(fail)s;}

        if( PyArray_TYPE(%(_indptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "D"); %(fail)s;}

        if (!%(_zout)s ||
            (PyArray_DIMS(%(_zout)s)[0] != PyArray_DIMS(%(_indices)s)[0]) ||
            !(PyArray_ISCONTIGUOUS(%(_zout)s)))
        {
            Py_XDECREF(%(_zout)s);
            %(_zout)s = (PyArrayObject*) PyArray_SimpleNew(1,
                    PyArray_DIMS(%(_indices)s), PyArray_TYPE(%(_b)s));
            if (!%(_zout)s)
            {
                PyErr_SetString(PyExc_MemoryError,
                    "Could not allocate output memory.");
                %(fail)s;
            }
        }

        { //makes it compile even though labels jump over variable definitions.
            const npy_intp nnz = PyArray_DIMS(%(_indices)s)[0];
            //TODO: error checking with this
            const npy_intp N =  PyArray_DIMS(%(_indptr)s)[0]-1;

            const dtype_%(_data)s * const __restrict__ data = (dtype_%(_data)s*)PyArray_DATA(%(_data)s);
            const npy_int32 * const __restrict__ indptr = (npy_int32 *)PyArray_DATA(%(_indptr)s);
            const npy_int32 * const __restrict__ indices = (npy_int32 *)PyArray_DATA(%(_indices)s);

            dtype_%(_zout)s * const __restrict__ zout = (dtype_%(_zout)s*)PyArray_DATA(%(_zout)s);

            const npy_intp Sb = PyArray_STRIDES(%(_b)s)[0];

            // loop over columns
            for (npy_int32 j = 0; j < N; ++j)
            {
                // extract i-th row of dense matrix
                const dtype_%(_b)s* __restrict__ b_row = (dtype_%(_b)s*)(PyArray_BYTES(%(_b)s) + Sb * j);

                // for each non-null value in the sparse column
                for (npy_int32 i_idx = indptr[j]; i_idx < indptr[j+1]; ++i_idx)
                {
                    // extract row index of non-null value
                    npy_int32 i = indices[i_idx];

                    // write resulting gradient to sparse output
                    zout[i_idx] = data[i_idx] * b_row[i];
                }
            }
        }

        """ % dict(locals(), **sub)

    def __str__(self):
        return self.__class__.__name__
mul_s_d_csr = MulSDCSR()


# register a specialization to replace MulSD -> MulSDCSX
@gof.local_optimizer([sparse.mul_s_d])
def local_mul_s_d(node):
    if node.op == sparse.mul_s_d:
        x, y = node.inputs

        x_is_sparse_variable = _is_sparse_variable(x)

        if x_is_sparse_variable:
            svar = x
            dvar = y
        else:
            svar = y
            dvar = x

        if dvar.type.ndim != 2:
            return False
        if svar.type.format == 'csc':
            CSx = sparse.CSC
            mul_s_d_csx = mul_s_d_csc
        elif svar.type.format == 'csr':
            CSx = sparse.CSR
            mul_s_d_csx = mul_s_d_csr
        else:
            raise NotImplemented()

        c_data = mul_s_d_csx(sparse.csm_data(svar),
                             sparse.csm_indices(svar),
                             sparse.csm_indptr(svar), dvar)

        return [CSx(c_data,
                    sparse.csm_indices(svar),
                    sparse.csm_indptr(svar),
                    sparse.csm_shape(svar))]

    return False
sparse.register_specialize(local_mul_s_d, 'cxx_only')


class MulSVCSR(gof.Op):
    """Multiplication of sparse matrix by a broadcasted dense vector
    element wise.

    :param a_data: Sparse matrix data.
    :param a_indices: Sparse matrix indices.
    :param a_indptr: Sparse matrix indptr.
    :param b: Tensor type matrix.

    :return: The multiplication of the two matrix element wise.

    :note: `a_data`, `a_indices` and `a_indptr` must be the properties
            of a sparse matrix in csr format.
    :note: The dtype of `a_data`, i.e. the dtype of the sparse matrix,
           cannot be a complex type.
    :note: This op is used as an optimization of MulSV.
    """

    def __eq__(self, other):
        return (type(self) == type(other))

    def __hash__(self):
        return hash(type(self))

    def make_node(self, a_data, a_indices, a_indptr, b):
        assert b.type.ndim == 1
        return gof.Apply(self, [a_data, a_indices, a_indptr, b],
                               [tensor.tensor(b.dtype, (False,))])

    def c_code_cache_version(self):
        return (1,)

    def c_code(self, node, name, inputs, outputs, sub):
        _data, _indices, _indptr, _b, = inputs
        _zout, = outputs
        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for a')
        if node.inputs[3].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for b')

        return """
        if (PyArray_NDIM(%(_b)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(b) != 1");
            %(fail)s;
        }
        if (PyArray_NDIM(%(_data)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(data) != 1");
            %(fail)s;
        }
        if (PyArray_NDIM(%(_indices)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indices) != 1");
            %(fail)s;
        }
        if (PyArray_NDIM(%(_indptr)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indptr) != 1");
            %(fail)s;
        }

        if( PyArray_TYPE(%(_indices)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "C"); %(fail)s;}

        if( PyArray_TYPE(%(_indptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "D"); %(fail)s;}

        if (!%(_zout)s
            || PyArray_DIMS(%(_zout)s)[0] != PyArray_DIMS(%(_indices)s)[0]
            || !PyArray_ISCONTIGUOUS(%(_zout)s))
        {
            Py_XDECREF(%(_zout)s);
            %(_zout)s = (PyArrayObject*) PyArray_SimpleNew(1,
                    PyArray_DIMS(%(_indices)s), PyArray_TYPE(%(_b)s));
        }

        { //makes it compile even though labels jump over variable definitions.
            const npy_intp nnz = PyArray_DIMS(%(_indices)s)[0];
            //TODO: error checking with this
            const npy_intp N =  PyArray_DIMS(%(_indptr)s)[0]-1;

            const dtype_%(_data)s * const __restrict__ data = (dtype_%(_data)s*)PyArray_DATA(%(_data)s);
            const npy_int32 * const __restrict__ indptr = (npy_int32 *)PyArray_DATA(%(_indptr)s);
            const npy_int32 * const __restrict__ indices = (npy_int32 *)PyArray_DATA(%(_indices)s);

            const dtype_%(_b)s* __restrict__ Db = (dtype_%(_b)s*)PyArray_DATA(%(_b)s);

            dtype_%(_zout)s * const __restrict__ zout = (dtype_%(_zout)s*)PyArray_DATA(%(_zout)s);

            const npy_intp Sb = PyArray_STRIDES(%(_b)s)[0] / PyArray_DESCR(%(_b)s)->elsize;

            // loop over rows
            for (npy_int32 j = 0; j < N; ++j)
            {
                // for each non-null value in the sparse column
                for (npy_int32 i_idx = indptr[j]; i_idx < indptr[j+1]; ++i_idx)
                {
                    // extract row index of non-null value
                    npy_int32 i = indices[i_idx];

                    zout[i_idx] = data[i_idx] * Db[i * Sb];
                }
            }
        }

        """ % dict(locals(), **sub)

    def __str__(self):
        return self.__class__.__name__
mul_s_v_csr = MulSVCSR()


# register a specialization to replace MulSV -> MulSVCSR
@gof.local_optimizer([sparse.mul_s_v])
def local_mul_s_v(node):
    if node.op == sparse.mul_s_v:
        x, y = node.inputs

        x_is_sparse_variable = _is_sparse_variable(x)

        if x_is_sparse_variable:
            svar = x
            dvar = y
        else:
            svar = y
            dvar = x

        if dvar.type.ndim != 1:
            return False
        elif svar.type.format == 'csr':
            CSx = sparse.CSR
            mul_s_v_csx = mul_s_v_csr
        else:
            return False

        s_val, s_ind, s_ptr, s_shape = sparse.csm_properties(svar)

        c_data = mul_s_v_csx(s_val, s_ind, s_ptr, dvar)

        return [CSx(c_data, s_ind, s_ptr, s_shape)]

    return False
sparse.register_specialize(local_mul_s_v, 'cxx_only')


class StructuredAddSVCSR(gof.Op):
    """Structured addition of a sparse matrix and a dense vector.
    The elements of the vector are are only added to the corresponding
    non-zero elements. Therefore, this operation outputs another sparse
    matrix.

    :param a_data: Sparse matrix data.
    :param a_indices: Sparse matrix indices.
    :param a_indptr: Sparse matrix indptr.
    :param b: Tensor type vector.

    :return: A sparse matrix containing the addition of the vector to
             the data of the sparse matrix.

    :note: The a_* are the properties of a sparse matrix in csr
           format.
    :note: This op is used as an optimization for StructuredAddSV.
    """

    def __eq__(self, other):
        return (type(self) == type(other))

    def __hash__(self):
        return hash(type(self))

    def make_node(self, a_data, a_indices, a_indptr, b):
        b = tensor.as_tensor_variable(b)
        a_data = tensor.as_tensor_variable(a_data)
        a_indices = tensor.as_tensor_variable(a_indices)
        a_indptr = tensor.as_tensor_variable(a_indptr)
        assert a_data.type.ndim == 1
        assert a_indices.type.ndim == 1
        assert a_indptr.type.ndim == 1
        assert b.type.ndim == 1
        return gof.Apply(self, [a_data, a_indices, a_indptr, b],
                               [tensor.tensor(b.dtype, (False,))])

    def c_code_cache_version(self):
        return (2,)

    def c_code(self, node, name, inputs, outputs, sub):
        _data, _indices, _indptr, _b, = inputs
        _zout, = outputs
        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for a')
        if node.inputs[3].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for b')

        return """
        if (PyArray_NDIM(%(_b)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(b) != 1");
            %(fail)s;
        }
        if (PyArray_NDIM(%(_data)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(data) != 1");
            %(fail)s;
        }
        if (PyArray_NDIM(%(_indices)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indices) != 1");
            %(fail)s;
        }
        if (PyArray_NDIM(%(_indptr)s) != 1) {
            PyErr_SetString(PyExc_NotImplementedError, "rank(indptr) != 1");
            %(fail)s;
        }

        if( PyArray_TYPE(%(_indices)s) != NPY_INT32) {
        PyErr_SetString(PyExc_NotImplementedError, "C"); %(fail)s;}

        if( PyArray_TYPE(%(_indptr)s) != NPY_INT32)
        {PyErr_SetString(PyExc_NotImplementedError, "D"); %(fail)s;}

        if (!%(_zout)s
            || (PyArray_DIMS(%(_zout)s)[0] != PyArray_DIMS(%(_indices)s)[0])
            || !(PyArray_ISCONTIGUOUS(%(_zout)s)))
        {
            Py_XDECREF(%(_zout)s);
            %(_zout)s = (PyArrayObject*) PyArray_SimpleNew(1,
                    PyArray_DIMS(%(_indices)s), PyArray_TYPE(%(_b)s));
            if (!%(_zout)s)
            {
                PyErr_SetString(PyExc_MemoryError,
                    "Could not allocate output memory.");
                %(fail)s;
            }
        }

        { //makes it compile even though labels jump over variable definitions.
            const npy_intp nnz = PyArray_DIMS(%(_indices)s)[0];
            //TODO: error checking with this
            const npy_intp N =  PyArray_DIMS(%(_indptr)s)[0]-1;

            const dtype_%(_data)s * const __restrict__ data = (dtype_%(_data)s*)PyArray_DATA(%(_data)s);
            const npy_int32 * const __restrict__ indptr = (npy_int32 *)PyArray_DATA(%(_indptr)s);
            const npy_int32 * const __restrict__ indices = (npy_int32 *)PyArray_DATA(%(_indices)s);

            const dtype_%(_b)s* __restrict__ Db = (dtype_%(_b)s*)PyArray_DATA(%(_b)s);

            dtype_%(_zout)s * const __restrict__ zout = (dtype_%(_zout)s*)PyArray_DATA(%(_zout)s);

            const npy_intp Sb = PyArray_STRIDES(%(_b)s)[0] / PyArray_DESCR(%(_b)s)->elsize;

            // loop over columns
            for (npy_int32 j = 0; j < N; ++j)
            {
                // for each non-null value in the sparse column
                for (npy_int32 i_idx = indptr[j]; i_idx < indptr[j+1]; ++i_idx)
                {
                    // extract row index of non-null value
                    npy_int32 i = indices[i_idx];

                    // write resulting gradient to sparse output
                    zout[i_idx] = data[i_idx] + Db[i * Sb];
                }
            }
        }

        """ % dict(locals(), **sub)

    def __str__(self):
        return self.__class__.__name__
structured_add_s_v_csr = StructuredAddSVCSR()


# register a specialization to replace
# structured_add_s_v -> structured_add_s_v_csr
@gof.local_optimizer([sparse.structured_add_s_v])
def local_structured_add_s_v(node):
    if node.op == sparse.structured_add_s_v:
        x, y = node.inputs

        x_is_sparse_variable = _is_sparse_variable(x)
        #y_is_sparse_variable = _is_sparse_variable(y)

        if x_is_sparse_variable:
            svar = x
            dvar = y
        else:
            svar = y
            dvar = x

        if dvar.type.ndim != 1:
            return False
        elif svar.type.format == 'csr':
            CSx = sparse.CSR
            structured_add_s_v_csx = structured_add_s_v_csr
        else:
            return False

        s_val, s_ind, s_ptr, s_shape = sparse.csm_properties(svar)

        c_data = structured_add_s_v_csx(s_val, s_ind, s_ptr, dvar)

        return [CSx(c_data, s_ind, s_ptr, s_shape)]

    return False
sparse.register_specialize(local_structured_add_s_v, 'cxx_only')


class SamplingDotCSR(gof.Op):
    """Operand optimized for calculating the dot product dot(`x`, `y`.T) = `z`
    when you only want to calculate a subset of `z`.

    It is equivalent to `p` o (`x` . `y`.T) where o is the element-wise
    product, `x` and `y` operands of the dot product and `p` is a matrix
    that contains 1 when the corresponding element of `z` should be
    calculated and 0 when it shouldn't. Note that SamplingDot has a different
    interface than `dot` because SamplingDot requires `x` to be a `m`x`k`
    matrix while `y` is a `n`x`k` matrix instead of the usual `k`x`n` matrix.

    .. note::

        It will work if the pattern is not binary value, but if the
        pattern doesn't have a high sparsity proportion it will be slower
        then a more optimized dot followed by a normal elemwise
        multiplication.

    :param x: Tensor matrix.
    :param y: Tensor matrix.
    :param p_data: Sparse matrix data.
    :param p_ind: Sparse matrix indices.
    :param p_ptr: Sparse matric indptr.
    :param p_ncols: Sparse matrix number of columns.

    :return: A dense matrix containing the dot product of `x` by `y`.T only
             where `p` is 1.

    :note: If we have the input of mixed dtype, we insert cast elemwise
           in the graph to be able to call blas function as they don't
           allow mixed dtype.
    :note: This op is used as an optimization for SamplingDot.
    """

    def __eq__(self, other):
        return type(self) == type(other)

    def __hash__(self):
        return hash(type(self))

    def __str__(self):
        return 'SamplingDot{Csr}'

    def make_node(self, x, y, p_data, p_ind, p_ptr, p_ncols):
        x = tensor.as_tensor_variable(x)
        y = tensor.as_tensor_variable(y)
        p_data = tensor.as_tensor_variable(p_data)
        p_ind = tensor.as_tensor_variable(p_ind)
        p_ptr = tensor.as_tensor_variable(p_ptr)
        p_ncols = tensor.as_tensor_variable(p_ncols)

        assert p_ncols.dtype == 'int32'

        dtype_out = scalar.upcast(x.type.dtype, y.type.dtype,
                                  p_data.type.dtype)
        dot_out = scalar.upcast(x.type.dtype, y.type.dtype)

        # We call blas ?dot function that take only param of the same type
        x = tensor.cast(x, dot_out)
        y = tensor.cast(y, dot_out)

        return gof.Apply(self, [x, y, p_data, p_ind, p_ptr, p_ncols], [
            tensor.tensor(dtype=dtype_out, broadcastable=(False,)),
            tensor.tensor(dtype=p_ind.type.dtype, broadcastable=(False,)),
            tensor.tensor(dtype=p_ptr.type.dtype, broadcastable=(False,))
        ])

    def c_code_cache_version(self):
        return (2, blas.blas_header_version())

    def c_support_code(self):
        return blas.blas_header_text()

    def c_libraries(self):
        return blas.ldflags()

    def c_compile_args(self):
        return blas.ldflags(libs=False, flags=True)

    def c_lib_dirs(self):
        return blas.ldflags(libs=False, libs_dir=True)

    def c_header_dirs(self):
        return blas.ldflags(libs=False, include_dir=True)

    def c_code(self, node, name, inputs, outputs, sub):
        x, y, p_data, p_ind, p_ptr, p_ncols = inputs
        z_data, z_ind, z_ptr = outputs
        if node.inputs[0].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for x')
        if node.inputs[1].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError('Complex types are not supported for y')
        if node.inputs[2].type.dtype in ('complex64', 'complex128'):
            raise NotImplementedError(
                'Complex types are not supported for pattern')

        dot_out = scalar.upcast(node.inputs[0].type.dtype,
                                node.inputs[1].type.dtype)

        if dot_out == "float32":
            conv_type = "float"
            cdot = "sdot_"
        else:
            conv_type = "double"
            cdot = "ddot_"

        # retrieve dtype number
        typenum_x = node.inputs[0].type.dtype_specs()[2]
        typenum_y = node.inputs[1].type.dtype_specs()[2]
        typenum_p = node.inputs[2].type.dtype_specs()[2]
        typenum_zd = tensor.TensorType(node.outputs[0].dtype,
                                       []).dtype_specs()[2]
        typenum_zi = tensor.TensorType(node.outputs[1].dtype,
                                       []).dtype_specs()[2]
        typenum_zp = tensor.TensorType(node.outputs[2].dtype,
                                       []).dtype_specs()[2]

        rval = """
        if (PyArray_NDIM(%(x)s) != 2) {
PyErr_SetString(PyExc_NotImplementedError, "rank(x) != 2"); %(fail)s;}
        if (PyArray_NDIM(%(y)s) != 2) {
PyErr_SetString(PyExc_NotImplementedError, "rank(y) != 2"); %(fail)s;}

        if (PyArray_TYPE(%(x)s) != %(typenum_x)s) {
            PyErr_SetString(PyExc_NotImplementedError,
                            "Invalid type for x");
            %(fail)s;}

        if (PyArray_TYPE(%(y)s) != %(typenum_y)s) {
            PyErr_SetString(PyExc_NotImplementedError,
                            "Invalid type for y");
            %(fail)s;}

        if (PyArray_TYPE(%(p_data)s) != %(typenum_p)s) {
            PyErr_SetString(PyExc_NotImplementedError,
                            "Invalid type for pattern");
            %(fail)s;}

        if (PyArray_DIMS(%(x)s)[1] != PyArray_DIMS(%(y)s)[1]) {
            PyErr_SetString(PyExc_NotImplementedError,
              "x's number of columns doesn't match y's rows! Note: sampling_dot is different from dot because y is assumed to be transposed.");
            %(fail)s;}

        if (PyArray_DIMS(%(y)s)[0] != ((npy_int32 *)PyArray_DATA(%(p_ncols)s))[0] ||
            PyArray_DIMS(%(x)s)[0] != (PyArray_DIMS(%(p_ptr)s)[0] - 1))
        {PyErr_SetString(PyExc_NotImplementedError,
        "The dimension of the pattern and the output must match"); %(fail)s;}

        // Allocate output
        if (!%(z_data)s
            || (PyArray_DIMS(%(z_data)s)[0] != PyArray_DIMS(%(p_data)s)[0])
            || (PyArray_TYPE(%(z_data)s) != %(typenum_zd)s)
            || !(PyArray_ISCONTIGUOUS(%(z_data)s)))
         {
            {Py_XDECREF(%(z_data)s);}
            npy_intp dims[] = {0};
            dims[0] = PyArray_DIMS(%(p_data)s)[0];
            %(z_data)s = (PyArrayObject*) PyArray_SimpleNew(1, dims,
                                                            %(typenum_zd)s);
        }
        if (!%(z_ind)s
            || (PyArray_DIMS(%(z_ind)s)[0] != PyArray_DIMS(%(p_ind)s)[0])
            || (PyArray_TYPE(%(z_ind)s) != %(typenum_zi)s)
            || !(PyArray_ISCONTIGUOUS(%(z_ind)s)))
        {
            {Py_XDECREF(%(z_ind)s);}
            npy_intp dims[] = {0};
            dims[0] = PyArray_DIMS(%(p_ind)s)[0];
            %(z_ind)s = (PyArrayObject*) PyArray_SimpleNew(1, dims,
                                                           %(typenum_zi)s);
        }
        if (!%(z_ptr)s
            || (PyArray_DIMS(%(z_ptr)s)[0] != PyArray_DIMS(%(p_ptr)s)[0])
            || (PyArray_TYPE(%(z_ptr)s) != %(typenum_zp)s)
            || !(PyArray_ISCONTIGUOUS(%(z_ptr)s)))
        {
            {Py_XDECREF(%(z_ptr)s);}
            npy_intp dims[] = {0};
            dims[0] = PyArray_DIMS(%(p_ptr)s)[0];
            %(z_ptr)s = (PyArrayObject*) PyArray_SimpleNew(1, dims,
                                                           %(typenum_zp)s);
        }

        {
            // Product of MxK and NxK, output MxN
            npy_intp M = PyArray_DIMS(%(x)s)[0];
            npy_intp N = PyArray_DIMS(%(y)s)[0];
            npy_intp K = PyArray_DIMS(%(y)s)[1];

            // pointers to access actual data in the arrays passed as params.
            const dtype_%(x)s* __restrict__ Dx = (dtype_%(x)s*)PyArray_DATA(%(x)s);
            const dtype_%(y)s* __restrict__ Dy = (dtype_%(y)s*)PyArray_DATA(%(y)s);
            const dtype_%(p_data)s* __restrict__ Dpd = (dtype_%(p_data)s*)PyArray_DATA(%(p_data)s);
            const dtype_%(p_ind)s* __restrict__ Dpi = (dtype_%(p_ind)s*)PyArray_DATA(%(p_ind)s);
            const dtype_%(p_ptr)s* __restrict__ Dpp = (dtype_%(p_ptr)s*)PyArray_DATA(%(p_ptr)s);
            dtype_%(z_data)s* __restrict__ Dzd = (dtype_%(z_data)s*)PyArray_DATA(%(z_data)s);
            dtype_%(z_ind)s* __restrict__ Dzi = (dtype_%(z_ind)s*)PyArray_DATA(%(z_ind)s);
            dtype_%(z_ptr)s* __restrict__ Dzp = (dtype_%(z_ptr)s*)PyArray_DATA(%(z_ptr)s);

            const npy_intp Sdx = PyArray_STRIDES(%(x)s)[1]/PyArray_DESCR(%(x)s)->elsize;
            const npy_intp Sdy = PyArray_STRIDES(%(y)s)[1]/PyArray_DESCR(%(y)s)->elsize;
            const npy_intp Sdpd = PyArray_STRIDES(%(p_data)s)[0] / PyArray_DESCR(%(p_data)s)->elsize;
            const npy_intp Sdpi = PyArray_STRIDES(%(p_ind)s)[0] / PyArray_DESCR(%(p_ind)s)->elsize;
            const npy_intp Sdpp = PyArray_STRIDES(%(p_ptr)s)[0] / PyArray_DESCR(%(p_ptr)s)->elsize;
            const npy_intp Sdzd = PyArray_STRIDES(%(z_data)s)[0] / PyArray_DESCR(%(z_data)s)->elsize;
            const npy_intp Sdzi = PyArray_STRIDES(%(z_ind)s)[0] / PyArray_DESCR(%(z_ind)s)->elsize;
            const npy_intp Sdzp = PyArray_STRIDES(%(z_ptr)s)[0] / PyArray_DESCR(%(z_ptr)s)->elsize;

            memcpy(Dzi, Dpi, PyArray_DIMS(%(p_ind)s)[0]*sizeof(dtype_%(p_ind)s));
            memcpy(Dzp, Dpp, PyArray_DIMS(%(p_ptr)s)[0]*sizeof(dtype_%(p_ptr)s));

            for (npy_int32 m = 0; m < M; ++m) {
                for (npy_int32 n_idx = Dpp[m * Sdpp]; n_idx < Dpp[(m+1)*Sdpp]; ++n_idx) {
                    const npy_int32 n = Dpi[n_idx * Sdpi]; // row index of non-null value for column K

                    const dtype_%(x)s* x_row = (dtype_%(x)s*)(PyArray_BYTES(%(x)s) + PyArray_STRIDES(%(x)s)[0] * m);

                    const dtype_%(y)s* y_col = (dtype_%(y)s*)(PyArray_BYTES(%(y)s) + PyArray_STRIDES(%(y)s)[0] * n);

                    Dzd[n_idx * Sdzd] = Dpd[n_idx * Sdpd] * %(cdot)s((int*)&K, (const %(conv_type)s*)x_row, (int*)&Sdx, (const %(conv_type)s*)y_col, (int*)&Sdy);
                }
            }
        }
        """ % dict(locals(), **sub)

        return rval
sampling_dot_csr = SamplingDotCSR()


# register a specialization to replace SamplingDot -> SamplingDotCsr
@gof.local_optimizer([sparse.sampling_dot])
def local_sampling_dot_csr(node):
    if not theano.config.blas.ldflags:
        # The C implementation of SamplingDotCsr relies on BLAS routines
        return
    if node.op == sparse.sampling_dot:
        x, y, p = node.inputs
        if p.type.format == 'csr':
            p_data, p_ind, p_ptr, p_shape = sparse.csm_properties(p)

            z_data, z_ind, z_ptr = sampling_dot_csr(x, y, p_data,
                p_ind, p_ptr, p_shape[1])

            return [sparse.CSR(z_data, z_ind, z_ptr, p_shape)]
    return False

sparse.register_specialize(local_sampling_dot_csr,
                           'cxx_only',
                           name='local_sampling_dot_csr')
