cavis/libnd4j/include/ops/declarable/helpers/cpu/lstm.cpp

372 lines
17 KiB
C++

/*******************************************************************************
* Copyright (c) 2015-2019 Skymind, Inc.
*
* This program and the accompanying materials are made available under the
* terms of the Apache License, Version 2.0 which is available at
* https://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
* SPDX-License-Identifier: Apache-2.0
******************************************************************************/
//
// @author Yurii Shyrma, created on 14.02.2018
//
// implementation of operation for LSTM cell with peep hole connections:
// http://www.bioinf.jku.at/publications/older/2604.pdf
// S. Hochreiter and J. Schmidhuber. "Long Short-Term Memory". Neural Computation, 9(8):1735-1780, 1997.
// and
// https://research.google.com/pubs/archive/43905.pdf
// Hasim Sak, Andrew Senior, and Francoise Beaufays. "Long short-term memory recurrent neural network architectures for large scale acoustic modeling." INTERSPEECH, 2014.
#include<ops/declarable/helpers/lstm.h>
#include <VariableSpace.h>
#include <ops/declarable/CustomOperations.h>
#include<ops/declarable/helpers/transforms.h>
#include <ops/declarable/helpers/legacy_helpers.h>
#include <array/NDArrayList.h>
#include <iterator>
#include <MmulHelper.h>
namespace nd4j {
namespace ops {
namespace helpers {
//////////////////////////////////////////////////////////////////////////
static FORCEINLINE NDArray sigmoid(const NDArray& arr) {
return (const_cast<NDArray&>(arr)).transform(transform::Sigmoid);
}
static FORCEINLINE void sigmoidInplace(const NDArray& arr) {
(const_cast<NDArray&>(arr)).applyTransform(transform::Sigmoid);
}
//////////////////////////////////////////////////////////////////////////
static FORCEINLINE NDArray tanh(const NDArray& arr) {
return (const_cast<NDArray&>(arr)).transform(transform::Tanh);
}
static FORCEINLINE void tanhInplace(const NDArray& arr) {
(const_cast<NDArray&>(arr)).applyTransform(transform::Tanh);
}
//////////////////////////////////////////////////////////////////////////
static NDArray* timeSubset(const NDArray* arr, const int t, const int dataFormat){
if(dataFormat == 0){
//TNS: shape [timeLength, numExamples, inOutSize]
auto x = (*arr)({t,t+1, 0,0, 0,0});
const std::vector<Nd4jLong> newShape({arr->sizeAt(1),arr->sizeAt(2)});
return x.reshape(arr->ordering(), newShape);
} else if(dataFormat == 1){
//NST: shape [numExamples, inOutSize, timeLength]
auto x = (*arr)({0,0, 0,0, t,t+1});
const std::vector<Nd4jLong> newShape({arr->sizeAt(0),arr->sizeAt(1)});
return x.reshape(arr->ordering(), newShape);
} else {
//NTS: shape [numExamples, timeLength, inOutSize] - TF "time_major=false" layout
auto x = (*arr)({0,0, t,t+1, 0,0});
const std::vector<Nd4jLong> newShape({arr->sizeAt(0),arr->sizeAt(2)});
return x.reshape(arr->ordering(), newShape);
}
}
//////////////////////////////////////////////////////////////////////////
template <typename T>
static void clipping(NDArray* arr, T limit) {
arr->applyScalar(scalar::LstmClip, limit);
}
//////////////////////////////////////////////////////////////////////////
void lstmCell(nd4j::LaunchContext * context, const NDArray* xt, const NDArray* ht_1, const NDArray* ct_1, const NDArray* Wx, const NDArray* Wh, const NDArray* Wc, const NDArray* Wp, const NDArray* b,
NDArray* ht, NDArray* ct, const std::vector<double>& params) {
// xt input [bS x inSize]
// ht_1 previous cell output [bS x numProj], that is at previous time step t-1, in case of projection=false -> numProj=numUnits!!!
// ct_1 previous cell state [bS x numUnits], that is at previous time step t-1
// Wx input-to-hidden weights, [inSize x 4*numUnits]
// Wh hidden-to-hidden weights, [numProj x 4*numUnits]
// Wc diagonal weights for peephole connections [3*numUnits]
// Wp projection weights [numUnits x numProj]
// b biases, [4*numUnits]
// ht current cell output [bS x numProj], that is at current time step t
// ct current cell state [bS x numUnits], that is at current time step t
const bool peephole = (bool)params[0]; // if true, provide peephole connections
const bool projection = (bool)params[1]; // if true, then projection is performed, if false then numProj==numUnits is mandatory!!!!
double clippingCellValue = params[2]; // clipping value for ct, if it is not equal to zero, then cell state is clipped
double clippingProjValue = params[3]; // clipping value for projected ht, if it is not equal to zero, then projected cell output is clipped
const double forgetBias = params[4];
const int bS = xt->sizeAt(0);
const int inSize = xt->sizeAt(1);
const int numProj = ht_1->sizeAt(1);
const int numUnits = ct_1->sizeAt(1);
auto z = mmul(*xt, *Wx) + mmul(*ht_1, *Wh) + *b; // [bS x 4*numUnits] + [bS x 4*numUnits] + [1 x 4*numUnits] = [bS x 4*numUnits]
auto zit = z({0,0, 0, numUnits}); // z for input gate, = mmul(Wxi,xt) + mmul(Whi,ht_1) + bi = [bS x numUnits]
auto zft = z({0,0, numUnits, 2*numUnits}); // z for forget gate, = mmul(Wxf,xt) + mmul(Whf,ht_1) + bf = [bS x numUnits]
auto zct = z({0,0, 2*numUnits, 3*numUnits}); // z for cell state, = mmul(Wxc,xt) + mmul(Whc,ht_1) + bc = [bS x numUnits]
auto zot = z({0,0, 3*numUnits, 4*numUnits}); // z for output gate, = mmul(Wxo,xt) + mmul(Who,ht_1) + bo = [bS x numUnits]
if(peephole) { // add peephole connections: z + ct_1*Wc
zit += (*ct_1) * (*Wc)({0, numUnits}); // add peephole connections to input gate
zft += (*ct_1) * (*Wc)({numUnits, 2*numUnits}); // add peephole connections to forget gate
}
// current sell state = ft*ct_1 + it*tanh(mmul(Wxc,xt) + mmul(Whc,ht_1) + bc
ct->assign( sigmoid(zft + forgetBias) * (*ct_1) + sigmoid(zit) * tanh(zct) );
// if clipping value is provided then cell state is clipped by this value prior to the cell output activation
if(clippingCellValue > 0.0)
clipping(ct, clippingCellValue);
if(peephole)
zot += (*ct) * (*Wc)({{2*numUnits, 3*numUnits}}); // add peephole connections to output gate zot + ct*Wc
// current cell output = ot*tanh(ct)
auto htNoPeepHole = sigmoid(zot) * tanh(*ct); // = [bS x numUnits]
// apply projection
if(projection) {
ht->assign( mmul(htNoPeepHole, *Wp) ); // [bS x numUnits] * [ numUnits x numProj] = [bS x numProj]
// if clipping projection is provided then projected cell output state is clipped by this value
if(clippingProjValue != 0.)
clipping(ht, clippingProjValue);
}
else
ht->assign(&htNoPeepHole);
}
template <typename T>
static void fusedTanh(NDArray *z, NDArray *i, NDArray *c, const NDArray *cLast, NDArray *f, NDArray *h) {
//cell state = blockInput .* inputGate + prevCellState .* forgetGate
/*
z->applyPairwiseTransform(pairwise::Multiply, i, c, nullptr); //c = z * i
auto temp = (*f) * (*cLast);
*c += temp; //c = (i * z) + (zf * (*cLast))
c->applyTransform(transform::Tanh, h); //h = tanh(c)
*/
auto uLen = static_cast<uint>(z->lengthOf());
auto c_ = c->bufferAsT<T>();
auto z_ = z->bufferAsT<T>();
auto i_ = i->bufferAsT<T>();
auto f_ = f->bufferAsT<T>();
auto cLast_ = cLast->bufferAsT<T>();
auto h_ = h->bufferAsT<T>();
PRAGMA_OMP_PARALLEL_FOR_SIMD
for (uint e = 0; e < uLen; e++) {
c_[e] = z_[e] * i_[e] + (f_[e] * cLast_[e]);
h_[e] = nd4j::math::nd4j_tanh<T,T>(c_[e]);
}
}
//////////////////////////////////////////////////////////////////////////
void lstmBlockCell(const NDArray* xt, const NDArray* cLast, const NDArray* yLast,
const NDArray* W, const NDArray* Wci, const NDArray* Wcf, const NDArray* Wco, const NDArray* b,
NDArray* i, NDArray* c, NDArray* f, NDArray* o, NDArray* z, NDArray* h, NDArray* y, const std::vector<double>& params) {
/* Input arrays:
* 0: xt - input [bS, inSize] at time t
* 1: cLast (cs_prev) - previous cell state [bS, numUnits], time t-1
* 2: yLast (h_prev) - previous output [bS, numUnits], time t-1
* 3: W - Weights - concatenated (input-to-hidden, hidden-to-hidden weights) weights, [(inSize+numUnits), 4*numUnits]
* 4: Wci - weights - cell peephole (t-1) connections to input modulation gate, [numUnits]
* 5: Wcf - weights - cell peephole (t-1) connections to forget gate, [numUnits]
* 6: Wco - weights - cell peephole (t) connections to output gate, [numUnits]
* 7: b - biases, [4*numUnits]
*
* Input integer arguments:
* 0: if not zero, provide peephole connections
*
* Input float arguments:
* 0: the bias added to forget gates in order to reduce the scale of forgetting in the beginning of the training
* 1: clipping value for cell state, if it is not equal to zero, then cell state is clipped
*
* Output arrays:
* 0: i - Input modulation gate activations [bS, numUnits]
* 1: c (cs) - Cell state (pre tanh) [bs, numUnits] (cs)
* 2: f - Output - forget gate activations [bs, numUnits]
* 3: o - Output - output gate activations [bs, numUnits]
* 4: z (ci) - Output - block input [bs, numUnits]
* 5: h (co) - Cell state, post tanh [bs, numUnits]
* 6: y (h) - Current cell output [bS, numUnits], time t
*/
const bool peephole = (bool)params[0]; // if true, provide peephole connections
const double forgetBias = params[1];
const double clippingCellValue = params[2]; // clipping value for ct, if it is not equal to zero, then cell state is clipped
const int bS = xt->sizeAt(0);
const int inSize = xt->sizeAt(1);
const int numUnits = cLast->sizeAt(1);
//Concat inputs: [xt, yt-1]: concat([bs,nIn],[bs,nOut]) -> [bs, (nIn+nOut)]
nd4j::ops::concat concat;
Context cContext(119);
auto concatOut = NDArrayFactory::create(xt->ordering(), {xt->sizeAt(0), xt->sizeAt(1) + yLast->sizeAt(1)}, xt->dataType(), xt->getContext());
cContext.setInputArray(0, const_cast<NDArray*>(xt), false);
cContext.setInputArray(1, const_cast<NDArray*>(yLast), false);
cContext.setOutputArray(0, &concatOut, false);
cContext.getIArguments()->emplace_back(1);
concat.execute(&cContext);
//NDArray* NDArrayFactory::create_( const char order, const std::vector<Nd4jLong> &shape, nd4j::DataType dataType, nd4j::memory::Workspace* workspace) {
std::vector<Nd4jLong> shape = {bS, 4*numUnits};
auto m = NDArrayFactory::create_('c', shape, xt->dataType(), nullptr);
MmulHelper::mmul(&concatOut, W, m, 1.0f, 0.0f, 'c'); //mmul: [bs, (nIn+numUnits)]* [(inSize+numUnits), 4*numUnits] = [bs, 4*numUnits] - C result array
*m += (*b); //addiRowVector
//Note: weights are ordered [inputGate, blockInput, forgetGate, outputGate] to match TF (TF code comments state [i,f,z/ci,o] but behaviour is [i,z,f,o])
auto zi = (*m)({0,0, 0, numUnits}); // z for input modulation gate, [bS, numUnits]
auto zz = (*m)({0,0, numUnits, 2*numUnits}); // z for block input, [bS, numUnits]
auto zf = (*m)({0,0, 2*numUnits, 3*numUnits}); // z for forget gate, [bS, numUnits]
auto zo = (*m)({0,0, 3*numUnits, 4*numUnits}); // z for output gate, [bS, numUnits]
if(peephole) { // add peephole connections: z + ct_1*Wc
zi += (*cLast) * (*Wci); // add peephole connections to input gate
zf += (*cLast) * (*Wcf); // add peephole connections to forget gate
}
// current sell state = ft*cLast + it*tanh(mmul(Wxc,xt) + mmul(Whc,ht_1) + bc
if(forgetBias != 0.0){
zf += forgetBias;
}
PRAGMA_OMP_PARALLEL
#pragma omp single
{
#pragma omp task
zz.applyTransform(transform::Tanh, z); //z = tanh(zz)
#pragma omp task
zi.applyTransform(transform::Sigmoid, i); //i = sigmoid(zi)
#pragma omp task
zf.applyTransform(transform::Sigmoid, f); //f = sigmoid(zf);
}
if (z->ews() == 1 && i->ews() == 1 && c->ews() == 1 && cLast->ews() == 1 && f->ews() == 1 && h->ews() == 1 &&
z->ordering() == i->ordering() && z->ordering() == c->ordering() && z->ordering() == cLast->ordering() && z->ordering() == f->ordering() && z->ordering() == h->ordering()) {
//cell state = blockInput .* inputGate + prevCellState .* forgetGate
BUILD_SINGLE_SELECTOR(z->dataType(), fusedTanh, (z, i, c, cLast, f, h), FLOAT_TYPES);
} else {
//cell state = blockInput .* inputGate + prevCellState .* forgetGate
z->applyPairwiseTransform(pairwise::Multiply, i, c, nullptr); //c = z * i
auto temp = (*f) * (*cLast);
*c += temp; //c = (i * z) + (zf * (*cLast))
c->applyTransform(transform::Tanh, h); //h = tanh(c)
}
// if clipping value is provided then cell state is clipped by this value prior to the cell output activation
if(clippingCellValue > 0.0) {
clipping(c, clippingCellValue);
}
if(peephole) {
// add peephole connections to output gate zot + ct*Wc
auto prod = *c * (*Wco);
zo += prod;
}
zo.applyTransform(transform::Sigmoid, o); // o = sigmoid(zo)
// current cell output = ot*tanh(ct)
c->applyTransform(transform::Tanh, h); //h = tanh(c)
o->applyPairwiseTransform(pairwise::Multiply, h, y, nullptr); //y = o * h
}
//////////////////////////////////////////////////////////////////////////
void lstmTimeLoop(nd4j::LaunchContext * context, const NDArray* x, const NDArray* h0, const NDArray* c0, const NDArray* Wx, const NDArray* Wh, const NDArray* Wc, const NDArray* Wp, const NDArray* b,
NDArray* h, NDArray* c, const std::vector<double>& params) {
// x input [time x bS x inSize]
// h0 initial cell output (at time step = 0) [bS x numProj], in case of projection=false -> numProj == numUnits !!!
// c0 initial cell state (at time step = 0) [bS x numUnits],
// Wx input-to-hidden weights, [inSize x 4*numUnits]
// Wh hidden-to-hidden weights, [numProj x 4*numUnits]
// Wc diagonal weights for peephole connections [3*numUnits]
// Wp projection weights [numUnits x numProj]
// b biases, [4*numUnits]
// h cell outputs [time x bS x numProj], that is per each time step
// c cell states [time x bS x numUnits] that is per each time step
const int time = x->sizeAt(0);
NDArray currentH(*h0);
NDArray currentC(*c0);
// loop through time steps
for (int t = 0; t < time; ++t) {
auto xt = (*x)({t,t+1, 0,0, 0,0});
auto ht = (*h)({t,t+1, 0,0, 0,0});
auto ct = (*c)({t,t+1, 0,0, 0,0});
helpers::lstmCell(context, &xt,&currentH,&currentC, Wx,Wh,Wc,Wp, b, &ht, &ct, params);
currentH.assign(ht);
currentC.assign(ct);
}
}
/////////////////////////////////////////////////////////////////////////////
void lstmBlockTimeLoop(const NDArray* maxSeqLength, const NDArray* xSeq, const NDArray* c0, const NDArray* y0,
const NDArray* W, const NDArray* Wci, const NDArray* Wcf, const NDArray* Wco, const NDArray* b,
const NDArray* iSeq, const NDArray* cSeq, const NDArray* fSeq, const NDArray* oSeq, const NDArray* zSeq,
const NDArray* hSeq, const NDArray* ySeq, const std::vector<double>& params, const int dataFormat){
const int seqLen = xSeq->sizeAt(0);
const int mb = xSeq->sizeAt(1);
const int inSize = xSeq->sizeAt(2);
const int outSize = iSeq->sizeAt(2);
const std::vector<Nd4jLong> inSliceShape({mb,inSize});
const std::vector<Nd4jLong> outSliceShape({mb,outSize});
NDArray* c_t1 = const_cast<NDArray*>(c0);
NDArray* y_t1 = const_cast<NDArray*>(y0);
// loop through time steps
for (int t = 0; t <seqLen; ++t) {
auto xt = timeSubset(xSeq, t, dataFormat);
auto it = timeSubset(iSeq, t, dataFormat);
auto ct = timeSubset(cSeq, t, dataFormat);
auto ft = timeSubset(fSeq, t, dataFormat);
auto ot = timeSubset(oSeq, t, dataFormat);
auto zt = timeSubset(zSeq, t, dataFormat);
auto ht = timeSubset(hSeq, t, dataFormat);
auto yt = timeSubset(ySeq, t, dataFormat);
helpers::lstmBlockCell(xt, c_t1, y_t1, W, Wci, Wcf, Wco, b, it, ct, ft, ot, zt, ht, yt, params);
c_t1 = ct;
y_t1 = yt;
}
}
}
}
}