import os
import numpy
import warnings

import theano
from theano import Apply, tensor, config, Variable
from theano.scalar import as_scalar, constant, Log
from theano.gradient import DisconnectedType, grad_not_implemented
from theano.gof import Optimizer, local_optimizer, COp
from theano.gof.type import CDataType, Generic
from theano.compile import optdb
from theano.compile.ops import shape_i
from theano.tensor.nnet import SoftmaxGrad
from theano.tensor.signal.downsample import (
    DownsampleFactorMax, MaxPoolGrad, AveragePoolGrad)
from theano.tensor.opt import register_specialize_device
from theano.sandbox.cuda.type import CudaNdarrayType

from theano.sandbox.cuda import GpuOp
from theano.sandbox.cuda.basic_ops import (as_cuda_ndarray_variable,
                                           host_from_gpu,
                                           gpu_contiguous, HostFromGpu,
                                           gpu_alloc_empty, GpuAllocEmpty,
                                           GpuElemwise)
from theano.sandbox.cuda.blas import (GpuConv, GpuDownsampleFactorMax,
                                      GpuDownsampleFactorMaxGrad)
from theano.sandbox.cuda.nnet import GpuSoftmax
from theano.sandbox.cuda.opt_util import alpha_merge, output_merge
from theano.sandbox.cuda import gpu_seqopt, register_opt

from theano.sandbox.cuda.nvcc_compiler import NVCC_compiler

from theano.tensor.nnet.abstract_conv2d import (AbstractConv2d,
                                                AbstractConv2d_gradWeights,
                                                AbstractConv2d_gradInputs)
from theano.tensor.opt import register_specialize_device



def dnn_available():
    if dnn_available.avail is None:
        if not theano.sandbox.cuda.cuda_available:
            dnn_available.msg = "CUDA not available"
            dnn_available.avail = False
            return False
        dev = theano.sandbox.cuda.active_device_number()
        if theano.sandbox.cuda.device_properties(dev)['major'] < 3:
            dnn_available.msg = "Device not supported by cuDNN"
            dnn_available.avail = False
        else:
            preambule = """
#include <stdio.h>
#include <cuda.h>
#include <cudnn.h>
#include <cudnn_helper.h>
            """

            body = """
cudnnHandle_t _handle = NULL;
cudnnStatus_t err;
if ((err = cudnnCreate(&_handle)) != CUDNN_STATUS_SUCCESS) {
  fprintf(stderr, "could not create cuDNN handle: %s",
          cudnnGetErrorString(err));
  return 1;
}
"""
            params = ["-l", "cudnn", "-I" + os.path.dirname(__file__)]
            if config.dnn.include_path:
                params.append("-I" + config.dnn.include_path)
            if config.dnn.library_path:
                params.append("-L" + config.dnn.library_path)
            # Do not run here the test program. It would run on the
            # default gpu, not the one selected by the user. If mixed
            # GPU are installed or if the GPUs are configured in
            # exclusive mode, this cause bad detection.
            comp, out, err = NVCC_compiler.try_flags(
                flag_list=params, preambule=preambule, body=body,
                try_run=False, output=True)

            dnn_available.avail = comp
            if not dnn_available.avail:
                dnn_available.msg = (
                    "Theano can not compile with cuDNN. We got this error:\n" +
                    str(err))
            else:
                # If we can compile, check that we can import and run.
                v = version()
                if isinstance(v, tuple) and v[0] != v[1]:
                    dnn_available.avail = False
                    dnn_available.msg = ("Mixed dnn version. The header is"
                                         " from one version, but we link with"
                                         " a different version %s" % str(v))
                    raise RuntimeError(dnn_available.msg)
                if v == -1:
                    dnn_available.avail = False
                    dnn_available.msg = (
                        "CuDNN v1 detected. This version is no longer "
                        "supported by Theano. Update your CuDNN installation "
                        "to a more recent version")
                    raise RuntimeError(dnn_available.msg)
                if v == (20, 20):
                    dnn_available.avail = False
                    dnn_available.msg = (
                        "You have installed a release candidate of CuDNN v2."
                        " This isn't supported anymore."
                        " Update to CuDNN v2 final version.")
                    raise RuntimeError(dnn_available.msg)
                if 3000 <= v[0] < 3007:
                    # 3007 is the final release of cudnn v3
                    dnn_available.avail = False
                    dnn_available.msg = (
                        "You have installed a release candidate of CuDNN v3."
                        " This isn't supported anymore."
                        " Update to CuDNN v3 final version.")
                    raise RuntimeError(dnn_available.msg)

    return dnn_available.avail


dnn_available.avail = None
dnn_available.msg = None


def c_set_tensor4d(var, desc, err, fail):
    return """
{
    int str0, str1, str2, str3;
    str3 = CudaNdarray_HOST_STRIDES(%(var)s)[3]?CudaNdarray_HOST_STRIDES(%(var)s)[3]:1;
    str2 = CudaNdarray_HOST_STRIDES(%(var)s)[2]?CudaNdarray_HOST_STRIDES(%(var)s)[2]:CudaNdarray_HOST_DIMS(%(var)s)[3];
    str1 = CudaNdarray_HOST_STRIDES(%(var)s)[1]?CudaNdarray_HOST_STRIDES(%(var)s)[1]:CudaNdarray_HOST_DIMS(%(var)s)[2]*CudaNdarray_HOST_DIMS(%(var)s)[3];
    str0 = CudaNdarray_HOST_STRIDES(%(var)s)[0]?CudaNdarray_HOST_STRIDES(%(var)s)[0]:CudaNdarray_HOST_DIMS(%(var)s)[2]*CudaNdarray_HOST_DIMS(%(var)s)[3]*CudaNdarray_HOST_DIMS(%(var)s)[1];
%(err)s = cudnnSetTensor4dDescriptorEx(
    %(desc)s, CUDNN_DATA_FLOAT,
    CudaNdarray_HOST_DIMS(%(var)s)[0],
    CudaNdarray_HOST_DIMS(%(var)s)[1],
    CudaNdarray_HOST_DIMS(%(var)s)[2],
    CudaNdarray_HOST_DIMS(%(var)s)[3],
    str0, str1, str2, str3
);
if (%(err)s != CUDNN_STATUS_SUCCESS) {
    PyErr_Format(PyExc_RuntimeError,
    "could not set tensor4d descriptor: %%s"
    "shapes=%%d %%d %%d %%d strides=%%d %%d %%d %%d",
    cudnnGetErrorString(%(err)s),
    CudaNdarray_HOST_DIMS(%(var)s)[0],
    CudaNdarray_HOST_DIMS(%(var)s)[1],
    CudaNdarray_HOST_DIMS(%(var)s)[2],
    CudaNdarray_HOST_DIMS(%(var)s)[3],
    str0, str1, str2, str3
    );
    %(fail)s
}
}
        """ % dict(var=var, err=err, desc=desc, fail=fail)


class DnnBase(GpuOp, COp):
    """
    Creates a handle for cudnn and pulls in the cudnn libraries and headers.

    """

    # dnn does not know about broadcasting, so we do not need to assert
    # the input broadcasting pattern.
    check_broadcast = False

    def __init__(self):
        COp.__init__(self, "dnn_base.c")

    def c_headers(self):
        return ['cudnn.h', 'cudnn_helper.h']

    def c_header_dirs(self):
        return [os.path.dirname(__file__)]

    def c_libraries(self):
        return ['cudnn']


class DnnVersion(GpuOp):
    def c_compiler(self):
        return NVCC_compiler

    def c_headers(self):
        return ['cudnn.h']

    def c_libraries(self):
        return ['cudnn']

    def c_support_code(self):
        return """
#if PY_MAJOR_VERSION >= 3
#define PyInt_FromLong PyLong_FromLong
#endif
"""

    def make_node(self):
        return Apply(self, [], [Generic()()])

    def c_code(self, node, name, inputs, outputs, sub):
        o = outputs[0]
        return """
        #if defined(CUDNN_VERSION)
        %(o)s = PyTuple_Pack(2, PyInt_FromLong(CUDNN_VERSION), PyInt_FromLong(cudnnGetVersion()));
        #else
        %(o)s = PyInt_FromLong(-1);
        #endif
        """ % locals()

    def do_constant_folding(self, node):
        # Needed as we do not want to cache this information.
        return False

    def c_code_cache_version(self):
        # Not needed, but make it clear that we do not want to cache this.
        return None


def version():
    """Return the current cuDNN version we compile with.

    This returns a tuple with the header version and the library
    version we link with. For older cudnn version without version
    information, we return -1.

    """
    if not dnn_available():
        raise Exception(
            "We can't determine the cudnn version as it is not available",
            dnn_available.msg)

    if version.v is None:
        f = theano.function([], DnnVersion()(),
                            theano.Mode(optimizer=None),
                            profile=False)
        version.v = f()
    return version.v
version.v = None


class GpuDnnConvDesc(GpuOp):
    """
    This Op builds a convolution descriptor for use in the other
    convolution operations.

    See the doc of :func:`dnn_conv` for a description of the parameters.

    """

    __props__ = ('border_mode', 'subsample', 'conv_mode')

    def c_headers(self):
        return ['cudnn.h', 'cudnn_helper.h']

    def c_header_dirs(self):
        return [os.path.dirname(__file__)]

    def c_libraries(self):
        return ['cudnn']

    def c_compiler(self):
        return NVCC_compiler

    def do_constant_folding(self, node):
        return False

    def __init__(self, border_mode, subsample=(1, 1), conv_mode='conv'):
        if isinstance(border_mode, int):
            border_mode = (border_mode,) * len(subsample)
        if isinstance(border_mode, tuple):
            assert len(border_mode) == len(subsample)
            border_mode = tuple(map(int, border_mode))
        if not ((isinstance(border_mode, tuple) and min(border_mode) >= 0) or
                border_mode in ('valid', 'full')):
            raise ValueError(
                'invalid border_mode {}, which must be either '
                '"valid", "full", an integer or a pair of'
                ' integers'.format(border_mode))
        self.border_mode = border_mode
        assert len(subsample) in [2, 3]
        self.subsample = subsample
        assert conv_mode in ('conv', 'cross')
        self.conv_mode = conv_mode

    def make_node(self, img_shape, kern_shape):
        if img_shape.type.ndim != 1 or img_shape.type.dtype != 'int64':
            raise TypeError('img must be 1D shape tensor')
        if kern_shape.type.ndim != 1 or kern_shape.type.dtype != 'int64':
            raise TypeError('kern must be 1D shape tensor')

        return Apply(self, [img_shape, kern_shape],
                     [CDataType("cudnnConvolutionDescriptor_t",
                                freefunc="cudnnDestroyConvolutionDescriptor")()])

    def c_code(self, node, name, inputs, outputs, sub):
        img_shape, kern_shape = inputs
        desc, = outputs

        nb_dim = len(self.subsample)

        if isinstance(self.border_mode, tuple):
            pad_desc = tuple(map(int, self.border_mode))
            assert min(pad_desc) >= 0
            bmode = 2
        else:
            pad_desc = [0] * nb_dim

            if self.border_mode == "valid":
                bmode = 1
            else:
                assert self.border_mode == "full"
                bmode = 0

        if self.conv_mode == 'conv':
            conv_flag = 'CUDNN_CONVOLUTION'
        else:
            conv_flag = 'CUDNN_CROSS_CORRELATION'

        pad_str = ", ".join([str(s) for s in pad_desc])
        subsample_str = ", ".join([str(s) for s in self.subsample])
        upscale_str = ", ".join(["1"] * nb_dim)

        return """
{
  cudnnStatus_t err;

  if ((err = cudnnCreateConvolutionDescriptor(&%(desc)s)) != CUDNN_STATUS_SUCCESS) {
    PyErr_Format(PyExc_MemoryError, "could not allocate convolution "
                 "descriptor: %%s", cudnnGetErrorString(err));
    %(fail)s
  }

#if defined(CUDNN_VERSION) && CUDNN_VERSION >= 30

  int pad[%(nb_dim)d] = {%(pad_str)s};
  int subsample[%(nb_dim)d] = {%(subsample_str)s};
  int upscale[%(nb_dim)d] = {%(upscale_str)s};

  // Adjust padding values if using full convolution
  if (%(bmode)d == 0) {
    pad[0] = *(npy_int64 *)PyArray_GETPTR1(%(kern_shape)s, 2) - 1;
    pad[1] = *(npy_int64 *)PyArray_GETPTR1(%(kern_shape)s, 3) - 1;
    if (%(nb_dim)d >= 3) {
        pad[2] = *(npy_int64 *)PyArray_GETPTR1(%(kern_shape)s, 4) - 1;
    }
  }

  err = cudnnSetConvolutionNdDescriptor(
  %(desc)s,
  %(nb_dim)d,
  pad, subsample, upscale,
  %(conv_flag)s
  );
#else
  PyErr_Format(PyExc_RuntimeError, "could not set op descriptor: CUDNN_VERSION must be >= 30");
#endif
  if (err != CUDNN_STATUS_SUCCESS) {
    PyErr_Format(PyExc_RuntimeError, "could not set op descriptor: %%s",
                 cudnnGetErrorString(err));
    %(fail)s
  }
}
""" % dict(name=name, img_shape=img_shape, kern_shape=kern_shape, desc=desc,
           bmode=bmode, conv_flag=conv_flag, fail=sub['fail'],
           pad_str=pad_str, subsample_str=subsample_str,
           upscale_str=upscale_str, nb_dim=nb_dim)

    def c_code_cache_version(self):
        return (2, version())

# scalar constants
_zero = constant(numpy.asarray(0.0, dtype='float32'))
_one = constant(numpy.asarray(1.0, dtype='float32'))


def ensure_float(val, default, name):
    if val is None:
        return default.clone()
    if not isinstance(val, Variable):
        val = constant(val)
    if hasattr(val, 'ndim') and val.ndim == 0:
        val = as_scalar(val)
    if not isinstance(val.type, theano.scalar.Scalar):
        raise TypeError("%s: expected a scalar value" % (name,))
    if not val.type.dtype == 'float32':
        raise TypeError("%s: type is not float32" % (name,))
    return val


class GpuDnnConv(DnnBase, COp):
    """
    The forward convolution.

    Parameters
    ----------
    image
    kernel
    descr
        The convolution descriptor.
    workmem
        *deprecated*, use parameter algo instead.
    algo
        ['none', 'small', 'large', 'fft', 'guess_once',
         'guess_on_shape_change', 'time_once',
         'time_on_shape_change']

        Default is the value of :attr:`config.dnn.conv.algo_fwd`.

    """

    __props__ = ('algo', 'inplace')
    __input_name__ = ('image', 'kernel', 'output',
                      'descriptor', 'alpha', 'beta')

    def __init__(self, workmem=None, inplace=False, algo=None):
        COp.__init__(self, ["dnn_base.c", "dnn_conv_base.c", "dnn_fwd.c"],
                     "APPLY_SPECIFIC(conv_fwd)")

        if workmem is not None:
            warnings.warn(("GpuDnnConv: parameter 'workmem' is deprecated. "
                           "Use 'algo' instead."), stacklevel=3)
            assert algo is None
            self.algo = workmem
        else:
            if algo is None:
                algo = config.dnn.conv.algo_fwd
            self.algo = algo

        self.inplace = inplace
        if self.inplace:
            self.destroy_map = {0: [2]}

        # In CuDNN version older than V3, the FFT implementation and the
        # option to time the different implementations to get the fastest
        # are both unavailable.
        if version() < (3000, 3000):
            if self.algo == 'fft':
                raise RuntimeError("CuDNN FFT convolution requires CuDNN v3")
            elif self.algo in ['guess_once', 'guess_on_shape_change']:
                raise RuntimeError("CuDNN selection of convolution "
                                   "implementation based on heuristics "
                                   "requires CuDNN v3")
            elif self.algo in ['time_once', 'time_on_shape_change']:
                raise RuntimeError("CuDNN convolution timing requires CuDNN "
                                   "v3")

        assert self.algo in ['none', 'small', 'large', 'fft', 'guess_once',
                             'guess_on_shape_change', 'time_once',
                             'time_on_shape_change']

    def __setstate__(self, d):
        self.__dict__.update(d)
        if not hasattr(self, 'algo'):
            if hasattr(self, 'workmem'):
                self.algo = self.workmem
            else:
                self.algo = config.dnn.conv.algo_fwd
        if not hasattr(self, 'inplace'):
            self.inplace = False

    def get_op_params(self):
        if self.inplace:
            inpl_def = [('CONV_INPLACE', '1')]
        else:
            inpl_def = []

        choose_alg = '0'
        choose_alg_once = '0'
        choose_alg_time = '0'
        if version() == -1:
            alg = "0"
        else:
            if self.algo == 'none':
                alg = 'CUDNN_CONVOLUTION_FWD_ALGO_IMPLICIT_GEMM'
            elif self.algo == 'small':
                alg = 'CUDNN_CONVOLUTION_FWD_ALGO_IMPLICIT_PRECOMP_GEMM'
            elif self.algo == 'large':
                alg = 'CUDNN_CONVOLUTION_FWD_ALGO_GEMM'
            elif self.algo == 'fft':
                alg = 'CUDNN_CONVOLUTION_FWD_ALGO_FFT'
            elif self.algo in ['guess_once', 'guess_on_shape_change']:
                # The convolution implementation should be choosen according
                # to a heuristic
                alg = 'CUDNN_CONVOLUTION_FWD_ALGO_IMPLICIT_PRECOMP_GEMM'
                choose_alg = '1'
                if self.algo == 'guess_once':
                    choose_alg_once = '1'
            elif self.algo in ['time_once', 'time_on_shape_change']:
                # The convolution implementation should be choosen by timing
                # every available implementation
                alg = 'CUDNN_CONVOLUTION_FWD_ALGO_IMPLICIT_PRECOMP_GEMM'
                choose_alg = '1'
                choose_alg_time = '1'
                if self.algo == 'time_once':
                    choose_alg_once = '1'

        alg_def = ('CONV_ALGO', alg)
        alg_choose_def = ('CHOOSE_ALGO', choose_alg)
        alg_choose_once_def = ('CHOOSE_ALGO_ONCE', choose_alg_once)
        alg_choose_time_def = ('CHOOSE_ALGO_TIME', choose_alg_time)

        return [alg_def, alg_choose_def, alg_choose_once_def,
                alg_choose_time_def] + inpl_def

    def make_node(self, img, kern, output, desc, alpha=None, beta=None):
        img = as_cuda_ndarray_variable(img)
        kern = as_cuda_ndarray_variable(kern)
        output = as_cuda_ndarray_variable(output)
        if img.type.ndim != 4:
            raise TypeError('img must be 4D tensor')
        if kern.type.ndim != 4:
            raise TypeError('kern must be 4D tensor')
        if output.type.ndim != 4:
            raise TypeError('output must be a 4D tensor')

        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnConvolutionDescriptor_t':
            raise TypeError('desc must be cudnnConvolutionDescriptor_t')

        alpha = ensure_float(alpha, _one, 'alpha')
        beta = ensure_float(beta, _zero, 'beta')

        return Apply(self, [img, kern, output, desc, alpha, beta],
                     [output.type()])

    def grad(self, inp, grads):
        img, kerns, output, desc, alpha, beta = inp
        top, = grads

        top = gpu_contiguous(top)

        d_img = GpuDnnConvGradI()(kerns, top, gpu_alloc_empty(*img.shape),
                                  desc)
        d_kerns = GpuDnnConvGradW()(img, top, gpu_alloc_empty(*kerns.shape),
                                    desc)
        d_alpha = grad_not_implemented(self, 4, alpha)
        d_beta = grad_not_implemented(self, 5, beta)

        return [d_img * alpha, d_kerns * alpha, top * beta,
                DisconnectedType()(), d_alpha, d_beta]

    def connection_pattern(self, node):
        # not connected to desc
        return [[1], [1], [1], [0], [1], [1]]

    @staticmethod
    def get_out_shape(ishape, kshape, border_mode, subsample):
        """
        This function computes the output shape for a convolution with
        the specified parameters. `ishape` and `kshape` can be symbolic
        or scalar.

        """
        b = ishape[0]  # Number of inputs
        h = ishape[2]  # Height of input feature maps
        w = ishape[3]  # Width of input feature maps
        nb = kshape[0]  # Number of output feature maps
        kh = kshape[2]  # Height of each filter
        kw = kshape[3]  # Width of each filter

        sh, sw = subsample
        if border_mode == 'full':
            padh = kh - 1
            padw = kw - 1
        elif isinstance(border_mode, tuple):
            padh, padw = border_mode
        else:
            assert border_mode == 'valid'
            padh = 0
            padw = 0

        return (
            b, nb,
            (h + 2*padh - kh)//sh + 1,
            (w + 2*padw - kw)//sw + 1
        )

    def infer_shape(self, node, shape):
        return [shape[2]]


class GpuDnnConv3d(GpuDnnConv):
    """
    The forward convolution.

    :param image:
    :param kernel:
    :param descr: the convolution descriptor
    :param workmem:
        *deprecated*, use parameter algo instead.
    :param algo: ['none', 'guess_once', 'guess_on_shape_change', 'time_once', 'time_on_shape_change']
        Default is the value of :attr:`config.dnn.conv.algo_fwd`.

    """
    __props__ = ('algo', 'inplace')
    __input_name__ = ('image', 'kernel', 'output',
                      'descriptor', 'alpha', 'beta')

    def __init__(self, workmem=None, inplace=False, algo=None):
        if workmem is not None:
            warnings.warn(("GpuDnnConv3d: parameter 'workmem' is deprecated. "
                           "Use 'algo' instead."), stacklevel=3)
            assert algo is None
            algo = workmem

        super(GpuDnnConv3d, self).__init__(inplace=inplace, algo='none')
        assert self.algo in ['none', 'guess_once', 'guess_on_shape_change',
                             'time_once', 'time_on_shape_change']

    def make_node(self, img, kern, output, desc, alpha=None, beta=None):

        img = as_cuda_ndarray_variable(img)
        kern = as_cuda_ndarray_variable(kern)
        output = as_cuda_ndarray_variable(output)
        if img.type.ndim != 5:
            raise TypeError('img must be 5D tensor')
        if kern.type.ndim != 5:
            raise TypeError('kern must be 5D tensor')
        if output.type.ndim != 5:
            raise TypeError('output must be a 5D tensor')
        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnConvolutionDescriptor_t':
            raise TypeError('desc must be cudnnConvolutionDescriptor_t')
        alpha = ensure_float(alpha, _one, 'alpha')
        beta = ensure_float(beta, _zero, 'beta')

        return Apply(self, [img, kern, output, desc, alpha, beta],
                     [output.type()])

    def grad(self, inp, grads):
        img, kerns, output, desc, alpha, beta = inp
        top, = grads

        top = gpu_contiguous(top)

        d_img = GpuDnnConv3dGradI()(kerns, top, gpu_alloc_empty(*img.shape),
                                    desc)
        d_kerns = GpuDnnConv3dGradW()(img, top, gpu_alloc_empty(*kerns.shape),
                                      desc)
        d_alpha = grad_not_implemented(self, 4, alpha)
        d_beta = grad_not_implemented(self, 5, beta)

        return [d_img * alpha, d_kerns * alpha, top * beta,
                DisconnectedType()(), d_alpha, d_beta]

    @staticmethod
    def get_out_shape(ishape, kshape, border_mode, subsample):
        """
        This function computes the output shape for a convolution with
        the specified parameters.  `ishape` and `kshape` can be symbolic
        or scalar.
        """
        b = ishape[0]  # Number of inputs
        d = ishape[2]  # Depth of input feature maps
        h = ishape[3]  # Height of input feature maps
        w = ishape[4]  # Width of input feature maps
        nb = kshape[0]  # Number of output feature maps
        kd = kshape[2]  # Depth of each filter
        kh = kshape[3]  # Height of each filter
        kw = kshape[4]  # Width of each filter

        sd, sh, sw = subsample
        if border_mode == 'full':
            padd = kd - 1
            padh = kh - 1
            padw = kw - 1
        elif isinstance(border_mode, tuple):
            padd, padh, padw = border_mode
        else:
            assert border_mode == 'valid'
            padd = 0
            padh = 0
            padw = 0

        return (
            b, nb,
            (d + 2*padd - kd)//sd + 1,
            (h + 2*padh - kh)//sh + 1,
            (w + 2*padw - kw)//sw + 1
        )


class GpuDnnConvGradW(DnnBase, COp):
    """
    The convolution gradient with respect to the weights.

    Parameters
    ----------
    image
    kernel
    descr
        The convolution descriptor.
    workmem
        *deprecated*, use parameter algo instead.
    algo : {'none', 'deterministic', 'fft', 'guess_once', 'guess_on_shape_change', 'time_once', 'time_on_shape_change'}
        Default is the value of :attr:`config.dnn.conv.algo_bwd`.

    """

    __props__ = ('algo', 'inplace',)
    __input_name__ = ('image', 'grad', 'output', 'descriptor', 'alpha', 'beta')

    def __init__(self, inplace=False, workmem=None, algo=None):
        COp.__init__(self, ["dnn_base.c", "dnn_conv_base.c", "dnn_gw.c"],
                     "APPLY_SPECIFIC(conv_gw)")

        if workmem is not None:
            warnings.warn(("GpuDnnConvGradW: parameter 'workmem' is "
                           "deprecated. Use 'algo' instead."), stacklevel=3)
            assert algo is None
            self.algo = workmem
        else:
            if algo is None:
                algo = config.dnn.conv.algo_bwd
            self.algo = algo

        self.inplace = inplace
        if self.inplace:
            self.destroy_map = {0: [2]}
        assert self.algo in ['none', 'deterministic', 'fft', 'guess_once',
                             'guess_on_shape_change', 'time_once',
                             'time_on_shape_change']

    def __setstate__(self, d):
        self.__dict__.update(d)
        if not hasattr(self, 'algo'):
            if hasattr(self, 'workmem'):
                self.algo = self.workmem
            else:
                self.algo = config.dnn.conv.algo_bwd
        if not hasattr(self, 'inplace'):
            self.inplace = False

    def grad(self, inp, grads):
        img, top, output, desc, alpha, beta = inp
        kerns, = grads

        kerns = gpu_contiguous(kerns)

        d_img = GpuDnnConvGradI()(kerns, top, gpu_alloc_empty(*img.shape),
                                  desc)
        d_top = GpuDnnConv()(img, kerns, gpu_alloc_empty(*top.shape), desc)
        d_alpha = grad_not_implemented(self, 4, alpha)
        d_beta = grad_not_implemented(self, 5, beta)

        return (d_img * alpha, d_top * alpha, kerns * beta,
                DisconnectedType()(), d_alpha, d_beta)

    def connection_pattern(self, node):
        # not connected to desc
        return [[1], [1], [1], [0], [1], [1]]

    def get_op_params(self):
        if self.inplace:
            inplace_def = [('CONV_INPLACE', '1')]
        else:
            inplace_def = []

        choose_alg = '0'
        choose_alg_once = '0'
        choose_alg_time = '0'

        if version() == -1 or version() < (3000, 3000):
            alg = "0"
        else:
            if self.algo == 'none':
                alg = 'CUDNN_CONVOLUTION_BWD_FILTER_ALGO_0'
            elif self.algo == 'deterministic':
                alg = 'CUDNN_CONVOLUTION_BWD_FILTER_ALGO_1'
            elif self.algo == 'fft':
                alg = 'CUDNN_CONVOLUTION_BWD_FILTER_ALGO_FFT'
            elif self.algo in ['guess_once', 'guess_on_shape_change']:
                # The convolution implementation should be chosen according
                # to a heuristic
                alg = 'CUDNN_CONVOLUTION_BWD_FILTER_ALGO_0'
                choose_alg = '1'
                if self.algo == 'guess_once':
                    choose_alg_once = '1'
            elif self.algo in ['time_once', 'time_on_shape_change']:
                # The convolution implementation should be chosen according
                # to timing
                alg = 'CUDNN_CONVOLUTION_BWD_FILTER_ALGO_0'
                choose_alg = '1'
                choose_alg_time = '1'
                if self.algo == 'time_once':
                    choose_alg_once = '1'

        alg_def = ('CONV_ALGO', alg)
        alg_choose_def = ('CHOOSE_ALGO', choose_alg)
        alg_choose_once_def = ('CHOOSE_ALGO_ONCE', choose_alg_once)
        alg_choose_time_def = ('CHOOSE_ALGO_TIME', choose_alg_time)

        return inplace_def + [alg_def, alg_choose_def, alg_choose_once_def,
                              alg_choose_time_def]

    def make_node(self, img, topgrad, output, desc, alpha=None, beta=None):
        img = as_cuda_ndarray_variable(img)
        topgrad = as_cuda_ndarray_variable(topgrad)
        output = as_cuda_ndarray_variable(output)
        if img.type.ndim != 4:
            raise TypeError('img must be 4D tensor')
        if topgrad.type.ndim != 4:
            raise TypeError('topgrad must be 4D tensor')
        if output.type.ndim != 4:
            raise TypeError('output must be 4D tensor')

        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnConvolutionDescriptor_t':
            raise TypeError('desc must be cudnnConvolutionDescriptor_t')

        alpha = ensure_float(alpha, _one, 'alpha')
        beta = ensure_float(beta, _zero, 'beta')

        return Apply(self, [img, topgrad, output, desc, alpha, beta],
                     [output.type()])

    def infer_shape(self, node, shape):
        return [shape[2]]


class GpuDnnConv3dGradW(GpuDnnConvGradW):
    """
    The convolution gradient with respect to the weights.

    :param image:
    :param kernel:
    :param descr: the convolution descriptor
    :param workmem:
        *deprecated*, use parameter algo instead.
    :param algo: ['none', 'guess_once', 'guess_on_shape_change', 'time_once', 'time_on_shape_change']
        Default is the value of :attr:`config.dnn.conv.algo_bwd`.

    """
    __props__ = ('algo', 'inplace',)
    __input_name__ = ('image', 'grad', 'output', 'descriptor', 'alpha', 'beta')

    def __init__(self, inplace=False, workmem=None, algo=None):
        if workmem is not None:
            warnings.warn(("GpuDnnConv3dGradW: parameter 'workmem' is "
                           "deprecated. Use 'algo' instead."), stacklevel=3)
            assert algo is None
            algo = workmem

        super(GpuDnnConv3dGradW, self).__init__(inplace=inplace,
                                                algo='none')
        assert self.algo in ['none', 'guess_once', 'guess_on_shape_change',
                             'time_once', 'time_on_shape_change']

    def grad(self, inp, grads):
        img, top, output, desc, alpha, beta = inp
        kerns, = grads

        kerns = gpu_contiguous(kerns)

        d_img = GpuDnnConv3dGradI()(kerns, top, gpu_alloc_empty(*img.shape),
                                    desc)
        d_top = GpuDnnConv3d()(img, kerns, gpu_alloc_empty(*top.shape), desc)
        d_alpha = grad_not_implemented(self, 4, alpha)
        d_beta = grad_not_implemented(self, 5, beta)

        return (d_img * alpha, d_top * alpha, kerns * beta,
                DisconnectedType()(), d_alpha, d_beta)

    def make_node(self, img, topgrad, output, desc, alpha=None, beta=None):
        img = as_cuda_ndarray_variable(img)
        topgrad = as_cuda_ndarray_variable(topgrad)
        output = as_cuda_ndarray_variable(output)
        if img.type.ndim != 5:
            raise TypeError('img must be 5D tensor')
        if topgrad.type.ndim != 5:
            raise TypeError('topgrad must be 5D tensor')
        if output.type.ndim != 5:
            raise TypeError('output must be 5D tensor')

        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnConvolutionDescriptor_t':
            raise TypeError('desc must be cudnnConvolutionDescriptor_t')

        alpha = ensure_float(alpha, _one, 'alpha')
        beta = ensure_float(beta, _zero, 'beta')

        return Apply(self, [img, topgrad, output, desc, alpha, beta],
                     [output.type()])


class GpuDnnConvGradI(DnnBase, COp):
    """
    The convolution gradient with respect to the inputs.

    Parameters
    ----------
    image
    kernel
    descr
        The convolution descriptor.
    workmem
        *deprecated*, use parameter algo instead.
    algo
        ['none', 'deterministic', 'fft', 'guess_once',
         'guess_on_shape_change', 'time_once',
         'time_on_shape_change']

        Default is the value of :attr:`config.dnn.conv.algo_bwd`.

    """

    __props__ = ('algo', 'inplace',)
    __input_name__ = ('kernel', 'grad', 'output', 'descriptor', 'alpha',
                      'beta')

    def __init__(self, inplace=False, workmem=None, algo=None):
        COp.__init__(self, ["dnn_base.c", "dnn_conv_base.c", "dnn_gi.c"],
                     "APPLY_SPECIFIC(conv_gi)")

        if workmem is not None:
            warnings.warn(("GpuDnnConvGradI: parameter 'workmem' is "
                           "deprecated. Use 'algo' instead."), stacklevel=3)
            assert algo is None
            self.algo = workmem
        else:
            if algo is None:
                algo = config.dnn.conv.algo_bwd
            self.algo = algo

        self.inplace = inplace
        if self.inplace:
            self.destroy_map = {0: [2]}
        assert self.algo in ['none', 'deterministic', 'fft', 'guess_once',
                             'guess_on_shape_change', 'time_once',
                             'time_on_shape_change']

    def __setstate__(self, d):
        self.__dict__.update(d)
        if not hasattr(self, 'algo'):
            if hasattr(self, 'workmem'):
                self.algo = self.workmem
            else:
                self.algo = config.dnn.conv.algo_bwd
        if not hasattr(self, 'inplace'):
            self.inplace = False

    def grad(self, inp, grads):
        kerns, top, output, desc, alpha, beta = inp
        img, = grads

        img = gpu_contiguous(img)

        d_kerns = GpuDnnConvGradW()(img, top, gpu_alloc_empty(*kerns.shape),
                                    desc)
        d_top = GpuDnnConv()(img, kerns, gpu_alloc_empty(*top.shape), desc)
        d_alpha = grad_not_implemented(self, 4, alpha)
        d_beta = grad_not_implemented(self, 5, beta)

        return (d_kerns * alpha, d_top * alpha, img * beta,
                DisconnectedType()(), d_alpha, d_beta)

    def connection_pattern(self, node):
        # not connected to desc
        return [[1], [1], [1], [0], [1], [1]]

    def get_op_params(self):
        if self.inplace:
            inplace_def = [('CONV_INPLACE', '1')]
        else:
            inplace_def = []

        choose_alg = '0'
        choose_alg_once = '0'
        choose_alg_time = '0'

        if version() == -1 or version() < (3000, 3000):
            alg = "0"
        else:
            if self.algo == 'none':
                alg = 'CUDNN_CONVOLUTION_BWD_DATA_ALGO_0'
            elif self.algo == 'deterministic':
                alg = 'CUDNN_CONVOLUTION_BWD_DATA_ALGO_1'
            elif self.algo == 'fft':
                alg = 'CUDNN_CONVOLUTION_BWD_DATA_ALGO_FFT'
            elif self.algo in ['guess_once', 'guess_on_shape_change']:
                # The convolution implementation should be chosen according
                # to a heuristic
                alg = 'CUDNN_CONVOLUTION_BWD_DATA_ALGO_0'
                choose_alg = '1'
                if self.algo == 'guess_once':
                    choose_alg_once = '1'
            elif self.algo in ['time_once', 'time_on_shape_change']:
                # The convolution implementation should be chosen according
                # to timing
                alg = 'CUDNN_CONVOLUTION_BWD_DATA_ALGO_0'
                choose_alg = '1'
                choose_alg_time = '1'
                if self.algo == 'time_once':
                    choose_alg_once = '1'

        alg_def = ('CONV_ALGO', alg)
        alg_choose_def = ('CHOOSE_ALGO', choose_alg)
        alg_choose_once_def = ('CHOOSE_ALGO_ONCE', choose_alg_once)
        alg_choose_time_def = ('CHOOSE_ALGO_TIME', choose_alg_time)

        return inplace_def + [alg_def, alg_choose_def, alg_choose_once_def,
                              alg_choose_time_def]

    def make_node(self, kern, topgrad, output, desc, alpha=None, beta=None):
        kern = as_cuda_ndarray_variable(kern)
        topgrad = as_cuda_ndarray_variable(topgrad)
        output = as_cuda_ndarray_variable(output)
        if kern.type.ndim != 4:
            raise TypeError('kern must be 4D tensor')
        if topgrad.type.ndim != 4:
            raise TypeError('topgrad must be 4D tensor')
        if output.type.ndim != 4:
            raise TypeError('output must be 4D tensor')

        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnConvolutionDescriptor_t':
            raise TypeError('desc must be cudnnConvolutionDescriptor_t')

        alpha = ensure_float(alpha, _one, 'alpha')
        beta = ensure_float(beta, _zero, 'beta')

        return Apply(self, [kern, topgrad, output, desc, alpha, beta],
                     [output.type()])

    def infer_shape(self, node, shape):
        return [shape[2]]


class GpuDnnConv3dGradI(GpuDnnConvGradI):
    """
    The convolution gradient with respect to the inputs.

    :param image:
    :param kernel:
    :param descr: the convolution descriptor
    :param workmem:
        *deprecated*, use parameter algo instead.
    :param algo: ['none', 'guess_once', 'guess_on_shape_change',
                  'time_once', 'time_on_shape_change']

        Default is the value of :attr:`config.dnn.conv.algo_bwd`.

    """
    __props__ = ('algo', 'inplace',)
    __input_name__ = ('kernel', 'grad', 'output', 'descriptor', 'alpha',
                      'beta')

    def __init__(self, inplace=False, workmem=None, algo=None):
        if workmem is not None:
            warnings.warn(("GpuDnnConv3dGradI: parameter 'workmem' is "
                           "deprecated. Use 'algo' instead."), stacklevel=3)
            assert algo is None
            algo = workmem

        super(GpuDnnConv3dGradI, self).__init__(inplace=inplace,
                                                algo="none")
        assert self.algo in ['none', 'guess_once', 'guess_on_shape_change',
                             'time_once', 'time_on_shape_change']

    def grad(self, inp, grads):
        kerns, top, output, desc, alpha, beta = inp
        img, = grads

        img = gpu_contiguous(img)

        d_kerns = GpuDnnConv3dGradW()(img, top, gpu_alloc_empty(*kerns.shape),
                                      desc)
        d_top = GpuDnnConv3d()(img, kerns, gpu_alloc_empty(*top.shape), desc)
        d_alpha = grad_not_implemented(self, 4, alpha)
        d_beta = grad_not_implemented(self, 5, beta)

        return (d_kerns * alpha, d_top * alpha, img * beta,
                DisconnectedType()(), d_alpha, d_beta)

    def make_node(self, kern, topgrad, output, desc, alpha=None, beta=None):
        kern = as_cuda_ndarray_variable(kern)
        topgrad = as_cuda_ndarray_variable(topgrad)
        output = as_cuda_ndarray_variable(output)
        if kern.type.ndim != 5:
            raise TypeError('kern must be 5D tensor')
        if topgrad.type.ndim != 5:
            raise TypeError('topgrad must be 5D tensor')
        if output.type.ndim != 5:
            raise TypeError('output must be 5D tensor')

        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnConvolutionDescriptor_t':
            raise TypeError('desc must be cudnnConvolutionDescriptor_t')

        alpha = ensure_float(alpha, _one, 'alpha')
        beta = ensure_float(beta, _zero, 'beta')

        return Apply(self, [kern, topgrad, output, desc, alpha, beta],
                     [output.type()])


def dnn_conv(img, kerns, border_mode='valid', subsample=(1, 1),
             conv_mode='conv', direction_hint=None, workmem=None, algo=None):
    """
    GPU convolution using cuDNN from NVIDIA.

    The memory layout to use is 'bc01', that is 'batch', 'channel',
    'first dim', 'second dim' in that order.

    Parameters
    ----------
    img
        Images to do the convolution over.
    kerns
        Convolution filters.
    border_mode
        One of 'valid', 'full'; additionally, the padding size can be
        directly specified by an integer or a pair of integers (as a tuple),
        specifying the amount of zero padding added to _both_ the top and
        bottom (first entry) and left and right (second entry) sides of
        the image.
    subsample
        Perform subsampling of the output (default: (1, 1)).
    conv_mode
        Perform convolution (kernels flipped) or cross-correlation.
        One of 'conv', 'cross' (default: 'conv').
    direction_hint
        Used by graph optimizers to change algorithm choice.
        By default, GpuDnnConv will be used to carry out the convolution.
        If border_mode is 'valid', subsample is (1,1) and direction_hint is
        'bprop weights', it will use GpuDnnConvGradW.
        If border_mode is 'full', subsample is (1,1) and direction_hint is
        'bprop inputs', it will use GpuDnnConvGradI.
        This parameter is used internally by graph optimizers and may be
        removed at any time without a deprecation period. You have been warned.
    workmem
	*deprecated*, use parameter algo instead.
    algo : {'none', 'small', 'large', 'fft', 'guess_once', 'guess_on_shape_change', 'time_once', 'time_on_shape_change'}
	Convolution implementation to use. Some of its  values may require certain
        versions of CuDNN to be installed. Default is the value of
        :attr:`config.dnn.conv.algo_fwd`.

    """

    # Check if deprecated param 'workmem' is used
    if workmem is not None:
        warnings.warn(("dnn_conv: parameter 'workmem' is deprecated. Use "
                       "'algo' instead."), stacklevel=3)
        assert algo is None
        algo = workmem

    # Ensure the value of direction_hint is supported
    assert direction_hint in [None, 'bprop weights', 'bprop inputs', 'forward']

    fgraph = getattr(img, 'fgraph', None) or getattr(kerns, 'fgraph', None)
    if (border_mode == 'valid' and subsample == (1, 1) and
            direction_hint == 'bprop weights'):
        # Special case: We are asked to use GpuDnnConvGradW. We need to set
        # up a suitable 'fake' convolution to compute the gradient for.
        img = gpu_contiguous(img.dimshuffle(1, 0, 2, 3))
        if conv_mode == 'conv':
            # We need to flip manually. These 'kerns' are not the kernels
            # that would be flipped by conv_mode='conv' in GpuDnnConvGradW.
            kerns = kerns[:, :, ::-1, ::-1]
        kerns = gpu_contiguous(kerns.dimshuffle(1, 0, 2, 3))
        shape2 = shape_i(img, 2, fgraph) - shape_i(kerns, 2, fgraph) + 1
        shape3 = shape_i(img, 3, fgraph) - shape_i(kerns, 3, fgraph) + 1
        out = gpu_alloc_empty(shape_i(kerns, 1, fgraph),
                              shape_i(img, 1, fgraph), shape2, shape3)
        desc = GpuDnnConvDesc(border_mode='valid', subsample=(1, 1),
                              conv_mode='cross')(img.shape, out.shape)
        conv = GpuDnnConvGradW()(img, kerns, out, desc)
        return as_cuda_ndarray_variable(conv.dimshuffle(1, 0, 2, 3))

    elif (border_mode == 'full' and subsample == (1, 1) and
            direction_hint == 'bprop inputs'):
        # Special case: We are asked to use GpuDnnConvGradI. We need to set
        # up a suitable 'fake' convolution to compute the gradient for.
        img = gpu_contiguous(img)
        kerns = gpu_contiguous(kerns.dimshuffle(1, 0, 2, 3))
        conv_mode = 'cross' if conv_mode == 'conv' else 'conv'
        shape2 = shape_i(img, 2, fgraph) + shape_i(kerns, 2, fgraph) - 1
        shape3 = shape_i(img, 3, fgraph) + shape_i(kerns, 3, fgraph) - 1
        out = gpu_alloc_empty(shape_i(img, 0, fgraph),
                              shape_i(kerns, 1, fgraph), shape2, shape3)
        desc = GpuDnnConvDesc(border_mode='valid', subsample=(1, 1),
                              conv_mode=conv_mode)(out.shape, kerns.shape)
        return GpuDnnConvGradI()(kerns, img, out, desc)

    # Standard case: We use GpuDnnConv with suitable padding.
    # contig_version will return a gpu_contiguous copy
    # if the img contains negative strides
    img = gpu_contiguous(img)
    kerns = gpu_contiguous(kerns)
    desc = GpuDnnConvDesc(border_mode=border_mode, subsample=subsample,
                          conv_mode=conv_mode)(img.shape, kerns.shape)
    desc_op = desc.owner.op
    out_shp = GpuDnnConv.get_out_shape(img.shape, kerns.shape,
                                       desc_op.border_mode,
                                       desc_op.subsample)
    out = gpu_alloc_empty(*out_shp)
    return GpuDnnConv(algo=algo)(img, kerns, out, desc)


def dnn_conv3d(img, kerns, border_mode='valid', subsample=(1, 1, 1),
               conv_mode='conv', direction_hint=None, workmem=None,
               algo='none'):
    """
    GPU convolution using cuDNN from NVIDIA.

    The memory layout to use is 'bct01', that is 'batch', 'channel',
    'first dim', 'second dim', 'third dim' in that order.

    :param img: images to do the convolution over
    :param kerns: convolution filters
    :param border_mode: One of 'valid', 'full'; additionally, the padding
    	size can be directly specified by an integer or a pair of integers
    	(as a tuple), specifying the amount of zero padding added to _both_
    	the top and bottom (first entry) and left and right (second entry)
    	sides of the image.
    :param subsample: perform subsampling of the output (default: (1, 1, 1))
    :param conv_mode: perform convolution (kernels flipped) or
        cross-correlation. One of 'conv', 'cross'. (default: 'conv')
    :param direction_hint: Used by graph optimizers to change algorithm choice.
        By default, GpuDnnConv will be used to carry out the convolution.
        If border_mode is 'valid', subsample is (1,1,1) and direction_hint is
        'bprop weights', it will use GpuDnnConvGradW.
        This parameter is used internally by graph optimizers and may be
        removed at any time without a deprecation period. You have been warned.
    :param workmem: *deprecated*, use param algo instead
    :param algo: convolution implementation to use. Only 'none' is implemented
        for the conv3d. Default is the value of
        :attr:`config.dnn.conv.algo_fwd`.

    :warning: The cuDNN library only works with GPU that have a compute
      capability of 3.0 or higer.  This means that older GPU will not
      work with this Op.
    :warning: dnn_conv3d only works with cuDNN library 3.0

    """

    # Check if deprecated param 'workmem' is used
    if workmem is not None:
        warnings.warn(("dnn_conv3d: parameter 'workmem' is deprecated. Use "
                       "'algo' instead."), stacklevel=3)
        assert algo is None
        algo = workmem

    # Ensure the value of direction_hint is supported
    assert direction_hint in [None, 'bprop weights', 'forward']

    fgraph = getattr(img, 'fgraph', None) or getattr(kerns, 'fgraph', None)
    if (border_mode == 'valid' and subsample == (1, 1, 1) and
            direction_hint == 'bprop weights'):
        # Special case: We are asked to use GpuDnnConvGradW. We need to set
        # up a suitable 'fake' convolution to compute the gradient for.
        img = gpu_contiguous(img.dimshuffle(1, 0, 2, 3, 4))
        if conv_mode == 'conv':
            # We need to flip manually. These 'kerns' are not the kernels
            # that would be flipped by conv_mode='conv' in GpuDnnConvGradW.
            kerns = kerns[:, :, ::-1, ::-1, ::-1]
        kerns = gpu_contiguous(kerns.dimshuffle(1, 0, 2, 3, 4))
        shape2 = shape_i(img, 2, fgraph) - shape_i(kerns, 2, fgraph) + 1
        shape3 = shape_i(img, 3, fgraph) - shape_i(kerns, 3, fgraph) + 1
        shape4 = shape_i(img, 4, fgraph) - shape_i(kerns, 4, fgraph) + 1
        out = gpu_alloc_empty(shape_i(kerns, 1, fgraph),
                              shape_i(img, 1, fgraph), shape2, shape3, shape4)
        desc = GpuDnnConvDesc(border_mode='valid', subsample=(1, 1, 1),
                              conv_mode='cross')(img.shape, out.shape)
        conv = GpuDnnConv3dGradW()(img, kerns, out, desc)
        return as_cuda_ndarray_variable(conv.dimshuffle(1, 0, 2, 3, 4))

    # Standard case: We use GpuDnnConv with suitable padding.
    # contig_version will return a gpu_contiguous copy
    # if the img contains negative strides
    img = gpu_contiguous(img)
    kerns = gpu_contiguous(kerns)
    desc = GpuDnnConvDesc(border_mode=border_mode, subsample=subsample,
                          conv_mode=conv_mode)(img.shape, kerns.shape)
    desc_op = desc.owner.op
    out_shp = GpuDnnConv3d.get_out_shape(img.shape, kerns.shape,
                                         desc_op.border_mode,
                                         desc_op.subsample)
    out = gpu_alloc_empty(*out_shp)
    return GpuDnnConv3d(algo=algo)(img, kerns, out, desc)


def dnn_gradweight(img, topgrad,
                   kerns_shp,
                   border_mode='valid', subsample=(1, 1),
                   conv_mode='conv'):
    """
    GPU convolution gradient with respect to weight using cuDNN from NVIDIA.

    The memory layout to use is 'bc01', that is 'batch', 'channel',
    'first dim', 'second dim' in that order.

    FIXME parameters doc

    :warning: The cuDNN library only works with GPU that have a compute
      capability of 3.0 or higer.  This means that older GPU will not
      work with this Op.
    """

    img = gpu_contiguous(img)
    topgrad = gpu_contiguous(topgrad)
    kerns_shp = theano.tensor.as_tensor_variable(kerns_shp) 
    desc = GpuDnnConvDesc(border_mode=border_mode, subsample=subsample,
                          conv_mode=conv_mode)(img.shape, kerns_shp)
    out = gpu_alloc_empty(*kerns_shp)
    return GpuDnnConvGradW()(img, topgrad, out, desc)

def dnn_gradinput(kerns, topgrad,
                  img_shp,
                  border_mode='valid', subsample=(1, 1),
                  conv_mode='conv'):
    """
    GPU convolution gradient with respect to input using cuDNN from NVIDIA.

    The memory layout to use is 'bc01', that is 'batch', 'channel',
    'first dim', 'second dim' in that order.

    FIXME parameters doc

    :warning: The cuDNN library only works with GPU that have a compute
      capability of 3.0 or higer.  This means that older GPU will not
      work with this Op.
    """

    kerns = gpu_contiguous(kerns)
    topgrad = gpu_contiguous(topgrad)
    img_shp = theano.tensor.as_tensor_variable(img_shp)
    desc = GpuDnnConvDesc(border_mode=border_mode, subsample=subsample,
                          conv_mode=conv_mode)(img_shp, kerns.shape)

    out = gpu_alloc_empty(*img_shp)
    return GpuDnnConvGradI()(kerns, topgrad, out, desc)


class GpuDnnPoolDesc(GpuOp):
    """
    This Op builds a pooling descriptor for use in the other pooling operations.

    Parameters
    ----------
    ws
        Windows size.
    stride
        (dx, dy).
    mode : {'max', 'average_inc_pad', 'average_exc_pad'}
        The old deprecated name 'average' correspond to 'average_inc_pad'.
    pad
        (pad_h, pad_w) padding information.
        pad_h is the number of zero-valued pixels added to each of the top and
        bottom borders.
        pad_w is the number of zero-valued pixels added to each of the left and
        right borders.

    """

    __props__ = ('ws', 'stride', 'mode', 'pad')

    def c_headers(self):
        return ['cudnn.h', 'cudnn_helper.h']

    def c_header_dirs(self):
        return [os.path.dirname(__file__)]

    def c_libraries(self):
        return ['cudnn']

    def c_compiler(self):
        return NVCC_compiler

    def do_constant_folding(self, node):
        return False

    def __init__(self, ws=(1, 1), stride=(1, 1), mode='max', pad=(0, 0)):
        if mode == 'average':
            mode = 'average_inc_pad'
        assert mode in ('max', 'average_inc_pad', 'average_exc_pad')
        self.mode = mode

        assert len(ws) == len(stride) and len(stride) == len(pad)
        assert len(ws) in (2, 3)
        self.ws = ws
        self.stride = stride
        self.pad = pad

        if (pad[0] != 0 or pad[1] != 0) and version() == -1:
            raise RuntimeError("CuDNN pooling with padding requires CuDNN v2")
        if self.get_ndim() == 3 and version() < (3000, 3000):
            raise RuntimeError("CuDNN 3d pooling requires CuDNN v3")

    def get_ndim(self):
        return len(self.ws)

    def __setstate__(self, d):
        self.__dict__.update(d)
        if not hasattr(self, 'pad'):
            self.pad = (0, 0)

    def make_node(self):
        if self.pad != (0, 0) and version() == -1:
            raise RuntimeError("CuDNN pooling with padding requires CuDNN v2")

        return Apply(self, [],
                     [CDataType("cudnnPoolingDescriptor_t",
                                freefunc="cudnnDestroyPoolingDescriptor")()])

    def c_code(self, node, name, inputs, outputs, sub):
        desc, = outputs

        if self.mode == 'max':
            mode_flag = 'CUDNN_POOLING_MAX'
        elif self.mode == "average_inc_pad":
            mode_flag = 'CUDNN_POOLING_AVERAGE_COUNT_INCLUDE_PADDING'
        elif self.mode == "average_exc_pad":
            mode_flag = 'CUDNN_POOLING_AVERAGE_COUNT_EXCLUDE_PADDING'
            if version() == -1:
                raise Exception("cudnn v1 do not support average_exc_pad")
        else:
            raise NotImplementedError("Unsupported pooling model.")

        return """
{
  cudnnStatus_t err;

  if ((err = cudnnCreatePoolingDescriptor(&%(desc)s)) != CUDNN_STATUS_SUCCESS) {
    PyErr_Format(PyExc_MemoryError, "could not allocate pooling "
                 "descriptor: %%s", cudnnGetErrorString(err));
    %(fail)s
  }
  {
    int win[%(nd)d] = {%(win)s};
    int pad[%(nd)d] = {%(pad)s};
    int str[%(nd)d] = {%(str)s};
    err = cudnnSetPoolingNdDescriptor(
      %(desc)s, %(mode_flag)s, %(nd)d,
      win, pad, str);
  }
  if (err != CUDNN_STATUS_SUCCESS) {
    PyErr_Format(PyExc_RuntimeError, "could not set op descriptor: %%s",
                 cudnnGetErrorString(err));
    %(fail)s
  }
}
""" % dict(name=name, desc=desc, mode_flag=mode_flag, fail=sub['fail'],
           nd=self.get_ndim(), win=', '.join(str(w) for w in self.ws),
           pad=', '.join(str(p) for p in self.pad),
           str=', '.join(str(s) for s in self.stride))

    def c_code_cache_version(self):
        return (3, version())


class GpuDnnPool(DnnBase):
    """
    Pooling.

    Parameters
    ----------
    img
        The image 4d or 5d tensor.
    desc
        The pooling descriptor.

    """

    __props__ = ()

    def make_node(self, img, desc):
        img = as_cuda_ndarray_variable(img)
        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnPoolingDescriptor_t':
            raise TypeError('desc must be cudnnPoolingDescriptor_t')

        if desc.owner is not None:
            dop = desc.owner.op
            e_ndim = dop.get_ndim() + 2  # 4 or 5

            if img.type.ndim != e_ndim:
                raise TypeError('img must be %dD tensor' % e_ndim)

        return Apply(self, [img, desc], [img.type()])

    def infer_shape(self, node, shape):
        if not node.inputs[1].owner:
            raise theano.tensor.ShapeError()
        desc = node.inputs[1].owner.op
        nd = desc.get_ndim()
        w = desc.ws
        s = desc.stride
        p = desc.pad
        ret = [shape[0][0], shape[0][1],
               (shape[0][2] + 2 * p[0] - w[0]) // s[0] + 1,
               (shape[0][3] + 2 * p[1] - w[1]) // s[1] + 1]
        if nd == 3:
            ret.append((shape[0][4] + 2 * p[2] - w[2]) // s[2] + 1)
        return [ret]

    def c_support_code_struct(self, node, name):
        return """
cudnnTensorDescriptor_t input%(name)s;
cudnnTensorDescriptor_t output%(name)s;
""" % dict(name=name)

    def c_init_code_struct(self, node, name, sub):
        return """
cudnnStatus_t err%(name)s;
input%(name)s = NULL;
output%(name)s = NULL;
if ((err%(name)s = cudnnCreateTensorDescriptor(&input%(name)s)) != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_MemoryError, "could not allocate tensor descriptor "
               "(inp): %%s", cudnnGetErrorString(err%(name)s));
  %(fail)s
}
if ((err%(name)s = cudnnCreateTensorDescriptor(&output%(name)s)) != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_MemoryError, "could not allocate tensor descriptor "
               "(out): %%s", cudnnGetErrorString(err%(name)s));
  %(fail)s
}
""" % dict(name=name, fail=sub['fail'])

    def c_cleanup_code_struct(self, node, name):
        return """
if (input%(name)s != NULL) { cudnnDestroyTensorDescriptor(input%(name)s); }
if (output%(name)s != NULL) { cudnnDestroyTensorDescriptor(output%(name)s); }
""" % dict(name=name)

    def c_code(self, node, name, inputs, outputs, sub):
        desc = inputs[1]
        out, = outputs

        return """
cudnnStatus_t err%(name)s;

int %(out)s_dims[5];

if (!CudaNdarray_is_c_contiguous(%(input)s)) {
  PyErr_SetString(PyExc_ValueError, "Only contiguous inputs are supported.");
  %(fail)s
}

if (c_set_tensorNd(%(input)s, %(input_desc)s) != 0)
  %(fail)s

cudnnPoolingMode_t mode;
int win[3];
int pad[3];
int str[3];
int ndims;
err%(name)s = cudnnGetPoolingNdDescriptor(
        %(desc)s, 3,
        &mode, &ndims,
        win, pad, str);

if (err%(name)s != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_RuntimeError,
               "GpuDnnPool: error doing cudnnGetPoolingNdDescriptor operation: %%s",
               cudnnGetErrorString(err%(name)s));
  %(fail)s
}

%(out)s_dims[0] = CudaNdarray_HOST_DIMS(%(input)s)[0];
%(out)s_dims[1] = CudaNdarray_HOST_DIMS(%(input)s)[1];
%(out)s_dims[2] = (CudaNdarray_HOST_DIMS(%(input)s)[2] + (pad[0]*2) - win[0]) / str[0] + 1;
%(out)s_dims[3] = (CudaNdarray_HOST_DIMS(%(input)s)[3] + (pad[1]*2) - win[1]) / str[1] + 1;
if (ndims == 3)
  %(out)s_dims[4] = (CudaNdarray_HOST_DIMS(%(input)s)[4] + (pad[2]*2) - win[2]) / str[2] + 1;

if (CudaNdarray_prep_output(&%(out)s, ndims+2, %(out)s_dims) != 0)
{
  %(fail)s
}

if (c_set_tensorNd(%(out)s, %(output_desc)s) != 0)
  %(fail)s

{
const float alpha = 1;
const float beta = 0;
err%(name)s = cudnnPoolingForward(
_handle,
%(desc)s,
&alpha,
%(input_desc)s, CudaNdarray_DEV_DATA(%(input)s),
&beta,
%(output_desc)s, CudaNdarray_DEV_DATA(%(out)s)
);
}
if (err%(name)s != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_RuntimeError,
               "GpuDnnPool: error doing cudnnPoolingForward operation: %%s",
               cudnnGetErrorString(err%(name)s));
  %(fail)s
}
""" % dict(out=out, desc=desc, fail=sub['fail'],
           name=name, input=inputs[0],
           input_desc="input"+name,
           output_desc="output"+name)

    def grad(self, inp, grads):
        img, desc = inp
        grad, = grads

        grad = gpu_contiguous(grad)

        out = self(img, desc)

        g_out = GpuDnnPoolGrad()(img, out, grad, desc)

        return g_out, theano.gradient.DisconnectedType()()

    def connection_pattern(self, node):
        # not connected to desc
        return [[1], [0]]

    def c_code_cache_version(self):
        return (7, version())


class GpuDnnPoolGrad(DnnBase):
    """
    The pooling gradient.

    Parameters
    ----------
    inp
        The input of the pooling.
    out
        The output of the pooling in the forward.
    inp_grad
        Same size as out, but is the corresponding gradient information.
    desc
        The pooling descriptor.

    """

    __props__ = ()

    def make_node(self, inp, out, inp_grad, desc):
        if not isinstance(desc.type, CDataType) \
                or desc.type.ctype != 'cudnnPoolingDescriptor_t':
            raise TypeError('desc must be cudnnPoolingDescriptor_t')

        inp = as_cuda_ndarray_variable(inp)
        inp_grad = as_cuda_ndarray_variable(inp_grad)
        out = as_cuda_ndarray_variable(out)

        if desc.owner is not None:
            nd = desc.owner.op.get_ndim() + 2  # 4 or 5

            if inp.type.ndim != nd:
                raise TypeError('inp must be %dD tensor' % (nd,))

            if inp_grad.type.ndim != nd:
                raise TypeError('inp_grad must be %dD tensor' % (nd,))

            if out.type.ndim != nd:
                raise TypeError('out must be %dD tensor' % (nd,))

        return Apply(self, [inp, out, inp_grad, desc],
                     [inp.type()])

    def c_support_code_struct(self, node, name):
        return """
cudnnTensorDescriptor_t input%(name)s;
cudnnTensorDescriptor_t input_grad%(name)s;
cudnnTensorDescriptor_t output%(name)s;
cudnnTensorDescriptor_t output_grad%(name)s;
""" % dict(name=name)

    def c_init_code_struct(self, node, name, sub):
        return """
cudnnStatus_t err%(name)s;
input%(name)s = NULL;
input_grad%(name)s = NULL;
output%(name)s = NULL;
output_grad%(name)s = NULL;
if ((err%(name)s = cudnnCreateTensorDescriptor(&input%(name)s)) != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_MemoryError,
               "GpuDnnPoolGrad: could not allocate tensor4d descriptor "
               "(input): %%s", cudnnGetErrorString(err%(name)s));
  %(fail)s
}
if ((err%(name)s = cudnnCreateTensorDescriptor(&input_grad%(name)s)) != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_MemoryError,
               "GpuDnnPoolGrad: could not allocate tensor4d descriptor "
               "(input_grad): %%s", cudnnGetErrorString(err%(name)s));
  %(fail)s
}
if ((err%(name)s = cudnnCreateTensorDescriptor(&output%(name)s)) != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_MemoryError,
               "GpuDnnPoolGrad: could not allocate tensor4d descriptor "
               "(output): %%s", cudnnGetErrorString(err%(name)s));
  %(fail)s
}
if ((err%(name)s = cudnnCreateTensorDescriptor(&output_grad%(name)s)) != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_MemoryError,
               "GpuDnnPoolGrad: could not allocate tensor4d descriptor "
               "(output_grad): %%s", cudnnGetErrorString(err%(name)s));
  %(fail)s
}
""" % dict(name=name, fail=sub['fail'])

    def c_cleanup_code_struct(self, node, name):
        return """
if (input%(name)s != NULL) { cudnnDestroyTensorDescriptor(input%(name)s); }
if (input_grad%(name)s != NULL) { cudnnDestroyTensorDescriptor(input_grad%(name)s); }
if (output%(name)s != NULL) { cudnnDestroyTensorDescriptor(output%(name)s); }
if (output_grad%(name)s != NULL) { cudnnDestroyTensorDescriptor(output_grad%(name)s); }
""" % dict(name=name)

    def c_code(self, node, name, inputs, outputs, sub):
        # Here the name out and inp are based on the cudnn definition.
        # Not the definition of this class.
        # This make it complicated.
        out, inp, inp_grad, desc = inputs
        out_grad, = outputs

        return """
cudnnStatus_t err%(name)s;

if (!CudaNdarray_is_c_contiguous(%(input)s)) {
  PyErr_SetString(PyExc_ValueError,
                  "GpuDnnPoolGrad: Only contiguous inputs are supported.");
  %(fail)s
}

if (!CudaNdarray_is_c_contiguous(%(input_grad)s)) {
  PyErr_SetString(PyExc_ValueError,
                  "GpuDnnPoolGrad: Only contiguous input gradients are supported.");
  %(fail)s
}

if (!CudaNdarray_is_c_contiguous(%(output)s)) {
  PyErr_SetString(PyExc_ValueError,
                  "GpuDnnPoolGrad: Only contiguous outputs are supported.");
  %(fail)s
}

if (c_set_tensorNd(%(input)s, %(input_desc)s) != 0)
  %(fail)s
if (c_set_tensorNd(%(input_grad)s, %(input_grad_desc)s) != 0)
  %(fail)s
if (c_set_tensorNd(%(output)s, %(output_desc)s) != 0)
  %(fail)s

if (CudaNdarray_prep_output(&%(output_grad)s,
                            %(output)s->nd,
                            CudaNdarray_HOST_DIMS(%(output)s)) != 0)
{
  %(fail)s
}

// Get the pooling_mode to be used. Variable 'tmp' is used because we don't
// care about the other outputs of the function
cudnnPoolingMode_t pooling_mode;
int tmp;
err%(name)s = cudnnGetPoolingNdDescriptor(%(desc)s, 0, &pooling_mode, &tmp,
                                          &tmp, &tmp, &tmp);
if (err%(name)s != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_RuntimeError,
               "GpuDnnPoolGrad: could not obtain pooling mode");
 %(fail)s
}

if (c_set_tensorNd(%(output_grad)s, %(output_grad_desc)s) != 0)
  %(fail)s

{
const float alpha = 1;
const float beta = 0;
err%(name)s = cudnnPoolingBackward(
_handle,
%(desc)s,
&alpha,
%(input_desc)s, CudaNdarray_DEV_DATA(%(input)s),
%(input_grad_desc)s, CudaNdarray_DEV_DATA(%(input_grad)s),
%(output_desc)s, CudaNdarray_DEV_DATA(%(output)s),
&beta,
%(output_grad_desc)s, CudaNdarray_DEV_DATA(%(output_grad)s)
);
}
if (err%(name)s != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_RuntimeError,
               "GpuDnnPoolGrad: error doing operation: %%s.",
               cudnnGetErrorString(err%(name)s));
 %(fail)s
}
""" % dict(output_grad=out_grad, desc=desc,
           fail=sub['fail'], name=name,
           input=inp, input_grad=inp_grad, output=out,
           input_desc="input"+name,
           input_grad_desc="input_grad"+name,
           output_desc="output"+name,
           output_grad_desc="output_grad"+name)

    def c_code_cache_version(self):
        return (7, version())

    def infer_shape(self, node, shape):
        return [shape[0]]


def dnn_pool(img, ws, stride=(1, 1), mode='max', pad=(0, 0)):
    """
    GPU pooling using cuDNN from NVIDIA.

    The memory layout to use is 'bc01', that is 'batch', 'channel',
    'first dim', 'second dim' in that order.

    Parameters
    ----------
    img
        Images to do the pooling over.
    ws
        Subsampling window size.
    stride
        Subsampling stride (default: (1, 1)).
    mode : {'max', 'average_inc_pad', 'average_exc_pad}
    pad
        (pad_h, pad_w) padding information.
        pad_h is the number of zero-valued pixels added to each of the top and
        bottom borders.
        pad_w is the number of zero-valued pixels added to each of the left
        and right borders.

    .. warning:: The cuDNN library only works with GPU that have a compute
      capability of 3.0 or higer.  This means that older GPU will not
      work with this Op.

    Notes
    -----
    This Op implements the ignore_border=True of max_pool_2d.

    """
    img = gpu_contiguous(img)
    desc = GpuDnnPoolDesc(ws=ws, stride=stride, mode=mode, pad=pad)()
    return GpuDnnPool()(img, desc)


class GpuDnnSoftmaxBase(DnnBase):
    """
    Op for the cuDNN Softmax.

    Parameters
    ----------
    tensor_format
        Always set this to 'bc01'.
    algo
        'fast', 'accurate' or 'log' indicating whether, respectively, computations
	should be optimized for speed, for accuracy, or if CuDNN should rather
	compute the log-softmax instead.
    mode
        'instance' or 'channel' indicating whether the softmax should
        be computed per image across 'c01' or per spatial location '01' per
        image across 'c'.

    """

    __props__ = ('tensor_format', 'mode', 'algo')

    def __init__(self, tensor_format, algo, mode):
        if tensor_format != 'bc01':
            raise ValueError(
                "It was discovered that since December 2014, the "
                "tensor_format parameter was ignored and the equivalent of "
                "'bc01' is always used.  Since your code seems to be using "
                "another value, this might have affected previous results "
                "ran with this code.")
        DnnBase.__init__(self)
        self.tensor_format = tensor_format

        if algo == 'log' and version() < (3000, 3000):
            raise RuntimeError("CuDNN log-softmax requires CuDNN v3")

        assert(algo in ('fast', 'accurate', 'log'))
        self.algo = algo

        assert(mode in ('instance', 'channel'))
        self.mode = mode

        self.tensor_4d_descs = [softmax_input
                                for softmax_input in self.softmax_inputs]
        self.tensor_4d_descs.append('softmax_output')

    def infer_shape(self, node, shape):
        if self.direction == 'forward':
            return [shape[0]]
        else:
            return [shape[1]]

    def _define_tensor4d_desc(self, name, id):
        return """
cudnnTensorDescriptor_t %(id)s_%(name)s;
""" % dict(name=name, id=id)

    def _init_tensor4d_desc(self, name, id, fail):
        return """
%(id)s_%(name)s = NULL;
if ((err%(name)s = cudnnCreateTensorDescriptor(&%(id)s_%(name)s)) != CUDNN_STATUS_SUCCESS) {
  PyErr_Format(PyExc_MemoryError, "could not allocate tensor descriptor "
               ": %%s", cudnnGetErrorString(err%(name)s));
  %(fail)s
}
""" % dict(name=name, id=id, fail=fail)

    def _clean_tensor4d_desc(self, name, id):
        return """
if(%(id)s_%(name)s!= NULL)
  cudnnDestroyTensorDescriptor(%(id)s_%(name)s);
""" % dict(name=name, id=id)

    def c_support_code_struct(self, node, name):
        result = ''
        for id in self.tensor_4d_descs:
            result += self._define_tensor4d_desc(name, id)
        return result

    def c_init_code_struct(self, node, name, sub):
        result = """
cudnnStatus_t err%(name)s;
""" % dict(name=name)

        for id in self.tensor_4d_descs:
            result += self._init_tensor4d_desc(name, id, sub['fail'])
        return result

    def c_cleanup_code_struct(self, node, name):
        result = ''
        for id in self.tensor_4d_descs:
            result += self._clean_tensor4d_desc(name, id)
        return result

    def c_code(self, node, name, inputs, outputs, sub):
        ins = inputs
        outs, = outputs

        if self.tensor_format == 'b01c':
            tensor_format = 1
        else:
            tensor_format = 0

        if self.mode == 'instance':
            mode = 1
        else:
            mode = 0

        if self.algo == 'fast':
            algo = "CUDNN_SOFTMAX_FAST"
        elif self.algo == "log":
            algo = "CUDNN_SOFTMAX_LOG"
        else:
            algo = "CUDNN_SOFTMAX_ACCURATE"

        # Setup configuration variables.
        result = """
cudnnStatus_t err%(name)s;
cudnnTensorFormat_t format%(name)s = CUDNN_TENSOR_NCHW;
if (%(tensor_format)d == 1)
  format%(name)s = CUDNN_TENSOR_NHWC;

cudnnSoftmaxAlgorithm_t algo%(name)s = %(algo)s;

cudnnSoftmaxMode_t mode%(name)s = CUDNN_SOFTMAX_MODE_CHANNEL;
if (%(mode)d == 1)
  mode%(name)s = CUDNN_SOFTMAX_MODE_INSTANCE;
""" % dict(name=name, tensor_format=tensor_format, mode=mode, algo=algo)

        # Validate the input and build the input variables.
        for input_idx, input_name in enumerate(self.softmax_inputs):
            result += c_set_tensor4d(ins[input_idx], input_name + "_" + name,
                                     "err" + name, sub['fail'])

        subs = dict(ins=ins[-1], outs=outs, fail=sub['fail'],
                    name=name)

        for idx, softmax_input in enumerate(self.softmax_inputs):
            subs['name%d' % idx] = softmax_input
            subs['ins%d' % idx] = inputs[idx]

        # Build and prepare the output variable.
        result += """
if (CudaNdarray_prep_output(&%(outs)s, 4, CudaNdarray_HOST_DIMS(%(ins)s)) != 0)
{
  %(fail)s
}
""" % subs
        result += c_set_tensor4d(outs,
                                 "softmax_output_" + name,
                                 "err" + name, sub['fail'])

        # Add on a call to the method that does the actual work.
        result += self.method() % subs

        return result

    def c_code_cache_version(self):
        return (0, 6, version())

    def method(self):
        raise NotImplementedError('GpuDnnSoftmaxBase::method')


class GpuDnnSoftmax(GpuDnnSoftmaxBase):
    """
    Op for the cuDNN Softmax.

    Parameters
    ----------
    tensor_format
        Always set to 'bc01'.
    algo
        'fast' or 'accurate' indicating whether computations should be
        optimized for speed or accuracy respectively.
    mode
        'instance' or 'channel' indicating whether the softmax should
        be computed per image across 'c01' or per spatial location '01' per
        image across 'c'.

    """

    direction = 'forward'
    softmax_inputs = ['softmax_input']

    def make_node(self, x):
        x = as_cuda_ndarray_variable(x)
        assert x.ndim == 4
        return Apply(self, [x], [x.type()])

    def method(self):
        return """
#ifndef CUDNN_VERSION
err%(name)s = cudnnSoftmaxForward(
  _handle,
  algo%(name)s,
  mode%(name)s,
  softmax_input_%(name)s,
  CudaNdarray_DEV_DATA(%(ins)s),
  softmax_output_%(name)s,
  CudaNdarray_DEV_DATA(%(outs)s)
);
#else
{
const float alpha = 1.;
const float beta = 0.;
err%(name)s = cudnnSoftmaxForward(
  _handle,
  algo%(name)s,
  mode%(name)s,
  (void*) &alpha,
  softmax_input_%(name)s,
  CudaNdarray_DEV_DATA(%(ins)s),
  (void*) &beta,
  softmax_output_%(name)s,
  CudaNdarray_DEV_DATA(%(outs)s)
);
}
#endif
"""

    def grad(self, inp, grads):
        x, = inp
        g_sm, = grads
        sm = self.make_node(x).outputs[0]
        return [GpuDnnSoftmaxGrad(
            self.tensor_format,
            self.algo,
            self.mode
        )(g_sm, sm)]


class GpuDnnSoftmaxGrad(GpuDnnSoftmaxBase):
    """
    Op for the cuDNN SoftmaxGrad.

    Parameters
    ----------
    tensor_format
        Always set to 'bc01'.
    algo
        'fast' or 'accurate' indicating whether computations should be
        optimized for speed or accuracy respectively.
    mode
        'instance' or 'channel' indicating whether the softmax should
        be computed per image across 'c01' or per spatial location '01' per
        image across 'c'.

    """

    direction = 'backward'
    softmax_inputs = ['softmax_gout', 'softmax_input']

    def make_node(self, dy, sm):
        dy = as_cuda_ndarray_variable(dy)
        sm = as_cuda_ndarray_variable(sm)
        assert dy.ndim == 4
        assert sm.ndim == 4
        return Apply(self, [dy, sm], [sm.type()])

    def method(self):
        return """
#ifndef CUDNN_VERSION
err%(name)s = cudnnSoftmaxBackward(
  _handle,
  algo%(name)s,
  mode%(name)s,
  %(name1)s_%(name)s,
  CudaNdarray_DEV_DATA(%(ins1)s),
  %(name0)s_%(name)s,
  CudaNdarray_DEV_DATA(%(ins0)s),
  softmax_output_%(name)s,
  CudaNdarray_DEV_DATA(%(outs)s)
);
#else
{
const float alpha = 1.;
const float beta = 0.;
err%(name)s = cudnnSoftmaxBackward(
  _handle,
  algo%(name)s,
  mode%(name)s,
  (void*) &alpha,
  %(name1)s_%(name)s,
  CudaNdarray_DEV_DATA(%(ins1)s),
  %(name0)s_%(name)s,
  CudaNdarray_DEV_DATA(%(ins0)s),
  (void*) &beta,
  softmax_output_%(name)s,
  CudaNdarray_DEV_DATA(%(outs)s)
);
}
#endif
        """


# Intentation for history
if True:
    # @register_opt('cudnn')  # this optimizer is registered in opt.py instead.
    @local_optimizer([GpuConv])
    def local_conv_dnn(node):
        if not dnn_available():
            return
        if isinstance(node.op, GpuConv):
            if node.op.border_mode not in ['full', 'valid']:
                return
            img, kern = node.inputs
            border_mode = node.op.border_mode
            subsample = node.op.subsample
            direction_hint = node.op.direction_hint
            rval = dnn_conv(img, kern,
                            border_mode=border_mode, subsample=subsample,
                            direction_hint=direction_hint)
            if node.outputs[0].broadcastable != rval.broadcastable:
                rval = tensor.patternbroadcast(
                    rval, node.outputs[0].type.broadcastable)
            return [rval]

    # This optimizer is registered in opt.py as part of the meta-optimizer.
    # It tries exactly the opposite code path of what local_conv_dnn() uses,
    # because for some input/kernel shape configurations, this is faster.
    @local_optimizer([GpuConv])
    def local_conv_dnn_alternative(node):
        if not dnn_available():
            return
        if isinstance(node.op, GpuConv):
            border_mode = node.op.border_mode
            subsample = node.op.subsample
            if border_mode not in ['full', 'valid'] or subsample != (1, 1):
                return
            img, kern = node.inputs
            direction_hint = node.op.direction_hint
            if border_mode == 'full':
                # for a full convolution, try using the forward pass instead
                # of the backward pass wrt. inputs and vice versa
                if direction_hint == 'bprop inputs':
                    direction_hint = 'forward'
                else:
                    direction_hint = 'bprop inputs'
            elif border_mode == 'valid':
                # for a valid convolution, try using the backward pass wrt.
                # weights instead of the forward pass and vice versa
                if direction_hint == 'bprop weights':
                    direction_hint = 'forward'
                else:
                    direction_hint = 'bprop weights'
            rval = dnn_conv(img, kern,
                            border_mode=border_mode, subsample=subsample,
                            direction_hint=direction_hint)
            if node.outputs[0].broadcastable != rval.broadcastable:
                rval = tensor.patternbroadcast(
                    rval, node.outputs[0].type.broadcastable)
            return [rval]

    @local_optimizer([GpuDnnConv], inplace=True)
    def local_dnn_conv_inplace(node):
        if type(node.op) != GpuDnnConv or node.op.inplace:
            return
        inputs = list(node.inputs)
        dest = inputs[2]
        if (dest.owner and
                isinstance(dest.owner.op, GpuAllocEmpty) and
                len(dest.clients) > 1):
            inputs[2] = gpu_alloc_empty(*dest.owner.inputs)
        return [GpuDnnConv(algo=node.op.algo, inplace=True)(*inputs)]

    @local_optimizer([GpuDnnConvGradW], inplace=True)
    def local_dnn_convgw_inplace(node):
        if type(node.op) != GpuDnnConvGradW or node.op.inplace:
            return
        inputs = list(node.inputs)
        dest = inputs[2]
        if (dest.owner and
                isinstance(dest.owner.op, GpuAllocEmpty) and
                len(dest.clients) > 1):
            inputs[2] = gpu_alloc_empty(*dest.owner.inputs)
        return [GpuDnnConvGradW(inplace=True)(*inputs)]

    @local_optimizer([GpuDnnConvGradI], inplace=True)
    def local_dnn_convgi_inplace(node):
        if type(node.op) != GpuDnnConvGradI or node.op.inplace:
            return
        inputs = list(node.inputs)
        dest = inputs[2]
        if (dest.owner and
                isinstance(dest.owner.op, GpuAllocEmpty) and
                len(dest.clients) > 1):
            inputs[2] = gpu_alloc_empty(*dest.owner.inputs)
        return [GpuDnnConvGradI(inplace=True)(*inputs)]

    optdb.register('local_dnn_conv_inplace',
                   tensor.opt.in2out(local_dnn_conv_inplace,
                                     local_dnn_convgw_inplace,
                                     local_dnn_convgi_inplace,
                                     name="local_dnn_conv_inplace"),
                   70.0, 'fast_run', 'inplace', 'gpu', 'cudnn')

    @register_opt('cudnn')
    @alpha_merge(GpuDnnConv, alpha_in=4, beta_in=5, nd=4)
    def local_dnn_conv_alpha_merge(node, *inputs):
        if not dnn_available() or version() == -1:
            return None
        return [GpuDnnConv(algo=node.op.algo)(*inputs)]

    @register_opt('cudnn')
    @alpha_merge(GpuDnnConvGradW, alpha_in=4, beta_in=5, nd=4)
    def local_dnn_convw_alpha_merge(node, *inputs):
        if not dnn_available() or version() == -1:
            return None
        return [GpuDnnConvGradW()(*inputs)]

    @register_opt('cudnn')
    @alpha_merge(GpuDnnConvGradI, alpha_in=4, beta_in=5, nd=4)
    def local_dnn_convi_alpha_merge(node, *inputs):
        if not dnn_available() or version() == -1:
            return None
        return [GpuDnnConvGradI()(*inputs)]

    @register_opt('cudnn')
    @output_merge(GpuDnnConv, alpha_in=4, beta_in=5, out_in=2, nd=4)
    def local_dnn_conv_output_merge(node, *inputs):
        inputs = inputs[0:2] + (gpu_contiguous(inputs[2]),) + inputs[3:]
        return [GpuDnnConv(algo=node.op.algo)(*inputs)]

    @register_opt('cudnn')
    @output_merge(GpuDnnConvGradW, alpha_in=4, beta_in=5, out_in=2, nd=4)
    def local_dnn_convw_output_merge(node, *inputs):
        inputs = inputs[0:2] + (gpu_contiguous(inputs[2]),) + inputs[3:]
        return [GpuDnnConvGradW()(*inputs)]

    @register_opt('cudnn')
    @output_merge(GpuDnnConvGradI, alpha_in=4, beta_in=5, out_in=2, nd=4)
    def local_dnn_convi_output_merge(node, *inputs):
        inputs = inputs[0:2] + (gpu_contiguous(inputs[2]),) + inputs[3:]
        return [GpuDnnConvGradI()(*inputs)]

    @register_opt('cudnn')
    @local_optimizer([GpuDownsampleFactorMax])
    def local_pool_dnn(node):
        if not dnn_available():
            return
        if isinstance(node.op, GpuDownsampleFactorMax):
            if not node.op.ignore_border:
                return
            img, = node.inputs
            ds = node.op.ds
            return [dnn_pool(gpu_contiguous(img), ds, ds)]

    @register_opt('cudnn')
    @local_optimizer([DownsampleFactorMax])
    def local_pool_dnn_alternative(node):
        if not dnn_available():
            return
        if isinstance(node.op, DownsampleFactorMax):
            if not node.op.ignore_border:
                return
            img, = node.inputs
            ds = node.op.ds
            stride = node.op.st
            pad = node.op.padding
            mode = node.op.mode
            if (img.owner and isinstance(img.owner.op, HostFromGpu)):
                ret = dnn_pool(gpu_contiguous(img.owner.inputs[0]),
                               ds, stride=stride, pad=pad, mode=mode)
                return [host_from_gpu(ret)]

    @register_opt('cudnn')
    @local_optimizer([GpuDownsampleFactorMaxGrad])
    def local_pool_dnn_grad(node):
        if not dnn_available():
            return
        if isinstance(node.op, GpuDownsampleFactorMaxGrad):
            if not node.op.ignore_border:
                return
            inp, out, inp_grad = node.inputs
            ds = node.op.ds

            desc = GpuDnnPoolDesc(ws=ds, stride=ds, mode="max")()
            return [GpuDnnPoolGrad()(gpu_contiguous(inp),
                                     gpu_contiguous(out),
                                     gpu_contiguous(inp_grad),
                                     desc)]

    @register_opt('cudnn')
    @local_optimizer([MaxPoolGrad])
    def local_pool_dnn_grad_stride(node):
        if not dnn_available():
            return
        if isinstance(node.op, MaxPoolGrad):
            if not node.op.ignore_border:
                return
            inp, out, inp_grad = node.inputs
            ds = node.op.ds
            st = node.op.st
            pad = node.op.padding
            mode = node.op.mode

            if ((inp.owner and isinstance(inp.owner.op, HostFromGpu)) or
                (out.owner and isinstance(out.owner.op, HostFromGpu)) or
                (inp_grad.owner and isinstance(inp_grad.owner.op,
                                               HostFromGpu))):
                desc = GpuDnnPoolDesc(ws=ds, stride=st, mode=mode, pad=pad)()
                ret = GpuDnnPoolGrad()(gpu_contiguous(inp),
                                       gpu_contiguous(out),
                                       gpu_contiguous(inp_grad),
                                       desc)
                return [host_from_gpu(ret)]

    @register_opt('cudnn')
    @local_optimizer([AveragePoolGrad])
    def local_avgpool_dnn_grad_stride(node):
        if not dnn_available():
            return
        if isinstance(node.op, AveragePoolGrad):
            if not node.op.ignore_border:
                return
            inp, inp_grad = node.inputs
            ds = node.op.ds
            st = node.op.st
            pad = node.op.padding
            mode = node.op.mode

            if ((inp.owner and isinstance(inp.owner.op, HostFromGpu)) or
                (inp_grad.owner and isinstance(inp_grad.owner.op,
                                               HostFromGpu))):
                desc = GpuDnnPoolDesc(ws=ds, stride=st, mode=mode, pad=pad)()
                contiguous_inp_grad = gpu_contiguous(inp_grad)
                ret = GpuDnnPoolGrad()(gpu_contiguous(inp),
                                       contiguous_inp_grad,
                                       contiguous_inp_grad,
                                       desc)
                return [host_from_gpu(ret)]

    @register_opt('cudnn')
    @local_optimizer([GpuSoftmax])
    def local_softmax_dnn(node):
        if not dnn_available():
            return
        if isinstance(node.op, GpuSoftmax):
            ins = node.inputs[0].dimshuffle(0, 1, 'x', 'x')
            ins = gpu_contiguous(ins)
            out = GpuDnnSoftmax('bc01', 'accurate', 'channel')(ins)
            out = as_cuda_ndarray_variable(out.dimshuffle(0, 1))
            return [out]

    @register_opt('cudnn')
    @local_optimizer([GpuElemwise])
    def local_log_softmax_dnn(node):
        # The log-softmax implementation is only available starting at CuDNN V3
        if not dnn_available() or version() < (3000, 3000):
            return
        if (isinstance(node.op, GpuElemwise) and
                isinstance(node.op.scalar_op, Log) and
                node.inputs[0].owner and
                isinstance(node.inputs[0].owner.op, GpuDnnSoftmax) and
                len(node.inputs[0].owner.out.clients) == 1):

            log_input = node.inputs[0]
            softmax_node = log_input.owner

            new_softmax_node = GpuDnnSoftmax(softmax_node.op.tensor_format,
                                             'log', softmax_node.op.mode)
            new_log_softmax = new_softmax_node(softmax_node.inputs[0])
            return [new_log_softmax]

    class NoCuDNNRaise(Optimizer):
        def apply(self, fgraph):
            """ Raise a RuntimeError if cudnn can't be used"""
            if not dnn_available():
                # Make an assert error as we want Theano to fail, not
                # just skip this optimization.
                raise AssertionError(
                    "cuDNN optimization was enabled, but Theano was not able"
                    " to use it. We got this error: \n" +
                    dnn_available.msg)
    gpu_seqopt.register("NoCuDNNRaise", NoCuDNNRaise(), 0, 'cudnn')

    @register_opt('cudnn')
    @local_optimizer([SoftmaxGrad])
    def local_softmax_dnn_grad(node):
        if (isinstance(node.op, SoftmaxGrad) and
            ((node.inputs[0].owner and
              isinstance(node.inputs[0].owner.op, HostFromGpu)) or
             (node.inputs[1].owner and
                 isinstance(node.inputs[1].owner.op, HostFromGpu)))):
            if not dnn_available():
                return
            ins = []
            for n in node.inputs:
                if isinstance(n.owner.op, HostFromGpu):
                    n = n.owner.inputs[0]
                if n.ndim != 2:
                    return
                ins.append(n.dimshuffle(0, 1, 'x', 'x'))

            out = GpuDnnSoftmaxGrad(
                'bc01',
                'accurate',
                'channel'
            )(
                gpu_contiguous(ins[0]),
                gpu_contiguous(ins[1])
            )
            return [out.dimshuffle(0, 1)]

### AbstractConv Optimizations
@local_optimizer([AbstractConv2d, AbstractConv2d_gradWeights, AbstractConv2d_gradInputs])
def local_abstractconv_cudnn(node):
    inp1 = node.inputs[0]
    inp2 = node.inputs[1]

    if ((not isinstance(node.op, AbstractConv2d) or
         not isinstance(node.op, AbstractConv2d_gradWeights) or
         not isinstance(node.op, AbstractConv2d_gradInputs))):
        return None

    if not isinstance(inp1.type, CudaNdarrayType) or \
            not isinstance(inp2.type, CudaNdarrayType):
        return None
    if not dnn_available():
        return None

    if node.op.filters_flip:
        conv_mode = 'conv'
    else:
        conv_mode = 'cross'
    if (isinstance(node.op, AbstractConv2d)):
        rval = dnn_conv(inp1, inp2,
                        border_mode=node.op.border_mode,
                        subsample=node.op.subsample,
                        direction_hint='forward',
                        conv_mode = conv_mode)
        return [rval]
    if (isinstance(node.op, AbstractConv2d_gradWeights)):
        shape = (inp2.shape[1], inp1.shape[1], node.inputs[2][0], node.inputs[2][1])
        rval = dnn_gradweight(inp1, inp2, shape,
                              border_mode=node.op.border_mode,
                              subsample=node.op.subsample,
                              conv_mode = conv_mode)
        return [rval]
    if (isinstance(node.op, AbstractConv2d_gradInputs)):
        shape = (inp2.shape[0], inp1.shape[1], node.inputs[2][0], node.inputs[2][1])
        rval = dnn_gradinput(inp1, inp2, shape,
                             border_mode=node.op.border_mode,
                             subsample=node.op.subsample,
                             conv_mode = conv_mode)
        return [rval]

