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[breaking] Drop single precision histogram (#7892)

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Co-authored-by: Philip Hyunsu Cho <chohyu01@cs.washington.edu>
This commit is contained in:
Jiaming Yuan
2022-05-13 19:54:55 +08:00
committed by GitHub
parent c8f9d4b6e6
commit 1b6538b4e5
18 changed files with 171 additions and 407 deletions
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131
src/common/hist_util.cc
View File

@@ -36,78 +36,51 @@ HistogramCuts::HistogramCuts() {
/*!
* \brief fill a histogram by zeros in range [begin, end)
*/
template<typename GradientSumT>
void InitilizeHistByZeroes(GHistRow<GradientSumT> hist, size_t begin, size_t end) {
void InitilizeHistByZeroes(GHistRow hist, size_t begin, size_t end) {
#if defined(XGBOOST_STRICT_R_MODE) && XGBOOST_STRICT_R_MODE == 1
std::fill(hist.begin() + begin, hist.begin() + end,
xgboost::detail::GradientPairInternal<GradientSumT>());
std::fill(hist.begin() + begin, hist.begin() + end, xgboost::GradientPairPrecise());
#else // defined(XGBOOST_STRICT_R_MODE) && XGBOOST_STRICT_R_MODE == 1
memset(hist.data() + begin, '\0', (end-begin)*
sizeof(xgboost::detail::GradientPairInternal<GradientSumT>));
memset(hist.data() + begin, '\0', (end - begin) * sizeof(xgboost::GradientPairPrecise));
#endif // defined(XGBOOST_STRICT_R_MODE) && XGBOOST_STRICT_R_MODE == 1
}
template void InitilizeHistByZeroes(GHistRow<float> hist, size_t begin,
size_t end);
template void InitilizeHistByZeroes(GHistRow<double> hist, size_t begin,
size_t end);
/*!
* \brief Increment hist as dst += add in range [begin, end)
*/
template<typename GradientSumT>
void IncrementHist(GHistRow<GradientSumT> dst, const GHistRow<GradientSumT> add,
size_t begin, size_t end) {
GradientSumT* pdst = reinterpret_cast<GradientSumT*>(dst.data());
const GradientSumT* padd = reinterpret_cast<const GradientSumT*>(add.data());
void IncrementHist(GHistRow dst, const GHistRow add, size_t begin, size_t end) {
double* pdst = reinterpret_cast<double*>(dst.data());
const double *padd = reinterpret_cast<const double *>(add.data());
for (size_t i = 2 * begin; i < 2 * end; ++i) {
pdst[i] += padd[i];
}
}
template void IncrementHist(GHistRow<float> dst, const GHistRow<float> add,
size_t begin, size_t end);
template void IncrementHist(GHistRow<double> dst, const GHistRow<double> add,
size_t begin, size_t end);
/*!
* \brief Copy hist from src to dst in range [begin, end)
*/
template<typename GradientSumT>
void CopyHist(GHistRow<GradientSumT> dst, const GHistRow<GradientSumT> src,
size_t begin, size_t end) {
GradientSumT* pdst = reinterpret_cast<GradientSumT*>(dst.data());
const GradientSumT* psrc = reinterpret_cast<const GradientSumT*>(src.data());
void CopyHist(GHistRow dst, const GHistRow src, size_t begin, size_t end) {
double *pdst = reinterpret_cast<double *>(dst.data());
const double *psrc = reinterpret_cast<const double *>(src.data());
for (size_t i = 2 * begin; i < 2 * end; ++i) {
pdst[i] = psrc[i];
}
}
template void CopyHist(GHistRow<float> dst, const GHistRow<float> src,
size_t begin, size_t end);
template void CopyHist(GHistRow<double> dst, const GHistRow<double> src,
size_t begin, size_t end);
/*!
* \brief Compute Subtraction: dst = src1 - src2 in range [begin, end)
*/
template<typename GradientSumT>
void SubtractionHist(GHistRow<GradientSumT> dst, const GHistRow<GradientSumT> src1,
const GHistRow<GradientSumT> src2,
size_t begin, size_t end) {
GradientSumT* pdst = reinterpret_cast<GradientSumT*>(dst.data());
const GradientSumT* psrc1 = reinterpret_cast<const GradientSumT*>(src1.data());
const GradientSumT* psrc2 = reinterpret_cast<const GradientSumT*>(src2.data());
void SubtractionHist(GHistRow dst, const GHistRow src1, const GHistRow src2, size_t begin,
size_t end) {
double* pdst = reinterpret_cast<double*>(dst.data());
const double* psrc1 = reinterpret_cast<const double*>(src1.data());
const double* psrc2 = reinterpret_cast<const double*>(src2.data());
for (size_t i = 2 * begin; i < 2 * end; ++i) {
pdst[i] = psrc1[i] - psrc2[i];
}
}
template void SubtractionHist(GHistRow<float> dst, const GHistRow<float> src1,
const GHistRow<float> src2,
size_t begin, size_t end);
template void SubtractionHist(GHistRow<double> dst, const GHistRow<double> src1,
const GHistRow<double> src2,
size_t begin, size_t end);
struct Prefetch {
public:
@@ -132,11 +105,10 @@ struct Prefetch {
constexpr size_t Prefetch::kNoPrefetchSize;
template <typename FPType, bool do_prefetch, typename BinIdxType,
bool first_page, bool any_missing = true>
template <bool do_prefetch, typename BinIdxType, bool first_page, bool any_missing = true>
void BuildHistKernel(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat, GHistRow<FPType> hist) {
const RowSetCollection::Elem row_indices, const GHistIndexMatrix &gmat,
GHistRow hist) {
const size_t size = row_indices.Size();
const size_t *rid = row_indices.begin;
auto const *pgh = reinterpret_cast<const float *>(gpair.data());
@@ -154,7 +126,7 @@ void BuildHistKernel(const std::vector<GradientPair> &gpair,
const size_t n_features =
get_row_ptr(row_indices.begin[0] + 1) - get_row_ptr(row_indices.begin[0]);
auto hist_data = reinterpret_cast<FPType *>(hist.data());
auto hist_data = reinterpret_cast<double *>(hist.data());
const uint32_t two{2}; // Each element from 'gpair' and 'hist' contains
// 2 FP values: gradient and hessian.
// So we need to multiply each row-index/bin-index by 2
@@ -195,24 +167,21 @@ void BuildHistKernel(const std::vector<GradientPair> &gpair,
}
}
template <typename FPType, bool do_prefetch, bool any_missing>
template <bool do_prefetch, bool any_missing>
void BuildHistDispatch(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat, GHistRow<FPType> hist) {
const RowSetCollection::Elem row_indices, const GHistIndexMatrix &gmat,
GHistRow hist) {
auto first_page = gmat.base_rowid == 0;
if (first_page) {
switch (gmat.index.GetBinTypeSize()) {
case kUint8BinsTypeSize:
BuildHistKernel<FPType, do_prefetch, uint8_t, true, any_missing>(
gpair, row_indices, gmat, hist);
BuildHistKernel<do_prefetch, uint8_t, true, any_missing>(gpair, row_indices, gmat, hist);
break;
case kUint16BinsTypeSize:
BuildHistKernel<FPType, do_prefetch, uint16_t, true, any_missing>(
gpair, row_indices, gmat, hist);
BuildHistKernel<do_prefetch, uint16_t, true, any_missing>(gpair, row_indices, gmat, hist);
break;
case kUint32BinsTypeSize:
BuildHistKernel<FPType, do_prefetch, uint32_t, true, any_missing>(
gpair, row_indices, gmat, hist);
BuildHistKernel<do_prefetch, uint32_t, true, any_missing>(gpair, row_indices, gmat, hist);
break;
default:
CHECK(false); // no default behavior
@@ -220,16 +189,13 @@ void BuildHistDispatch(const std::vector<GradientPair> &gpair,
} else {
switch (gmat.index.GetBinTypeSize()) {
case kUint8BinsTypeSize:
BuildHistKernel<FPType, do_prefetch, uint8_t, false, any_missing>(
gpair, row_indices, gmat, hist);
BuildHistKernel<do_prefetch, uint8_t, false, any_missing>(gpair, row_indices, gmat, hist);
break;
case kUint16BinsTypeSize:
BuildHistKernel<FPType, do_prefetch, uint16_t, false, any_missing>(
gpair, row_indices, gmat, hist);
BuildHistKernel<do_prefetch, uint16_t, false, any_missing>(gpair, row_indices, gmat, hist);
break;
case kUint32BinsTypeSize:
BuildHistKernel<FPType, do_prefetch, uint32_t, false, any_missing>(
gpair, row_indices, gmat, hist);
BuildHistKernel<do_prefetch, uint32_t, false, any_missing>(gpair, row_indices, gmat, hist);
break;
default:
CHECK(false); // no default behavior
@@ -237,12 +203,10 @@ void BuildHistDispatch(const std::vector<GradientPair> &gpair,
}
}
template <typename GradientSumT>
template <bool any_missing>
void GHistBuilder<GradientSumT>::BuildHist(
const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices, const GHistIndexMatrix &gmat,
GHistRowT hist) const {
void GHistBuilder::BuildHist(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices, const GHistIndexMatrix &gmat,
GHistRow hist) const {
const size_t nrows = row_indices.Size();
const size_t no_prefetch_size = Prefetch::NoPrefetchSize(nrows);
@@ -252,7 +216,7 @@ void GHistBuilder<GradientSumT>::BuildHist(
if (contiguousBlock) {
// contiguous memory access, built-in HW prefetching is enough
BuildHistDispatch<GradientSumT, false, any_missing>(gpair, row_indices,
BuildHistDispatch<false, any_missing>(gpair, row_indices,
gmat, hist);
} else {
const RowSetCollection::Elem span1(row_indices.begin,
@@ -260,33 +224,18 @@ void GHistBuilder<GradientSumT>::BuildHist(
const RowSetCollection::Elem span2(row_indices.end - no_prefetch_size,
row_indices.end);
BuildHistDispatch<GradientSumT, true, any_missing>(gpair, span1, gmat,
hist);
BuildHistDispatch<true, any_missing>(gpair, span1, gmat, hist);
// no prefetching to avoid loading extra memory
BuildHistDispatch<GradientSumT, false, any_missing>(gpair, span2, gmat,
hist);
BuildHistDispatch<false, any_missing>(gpair, span2, gmat, hist);
}
}
template void
GHistBuilder<float>::BuildHist<true>(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat,
GHistRow<float> hist) const;
template void
GHistBuilder<float>::BuildHist<false>(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat,
GHistRow<float> hist) const;
template void
GHistBuilder<double>::BuildHist<true>(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat,
GHistRow<double> hist) const;
template void
GHistBuilder<double>::BuildHist<false>(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat,
GHistRow<double> hist) const;
template void GHistBuilder::BuildHist<true>(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat, GHistRow hist) const;
template void GHistBuilder::BuildHist<false>(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat, GHistRow hist) const;
} // namespace common
} // namespace xgboost

59
src/common/hist_util.h
View File

@@ -322,56 +322,44 @@ bst_bin_t XGBOOST_HOST_DEV_INLINE BinarySearchBin(size_t begin, size_t end,
return -1;
}
template<typename GradientSumT>
using GHistRow = Span<xgboost::detail::GradientPairInternal<GradientSumT> >;
using GHistRow = Span<xgboost::GradientPairPrecise>;
/*!
* \brief fill a histogram by zeros
*/
template<typename GradientSumT>
void InitilizeHistByZeroes(GHistRow<GradientSumT> hist, size_t begin, size_t end);
void InitilizeHistByZeroes(GHistRow hist, size_t begin, size_t end);
/*!
* \brief Increment hist as dst += add in range [begin, end)
*/
template<typename GradientSumT>
void IncrementHist(GHistRow<GradientSumT> dst, const GHistRow<GradientSumT> add,
size_t begin, size_t end);
void IncrementHist(GHistRow dst, const GHistRow add, size_t begin, size_t end);
/*!
* \brief Copy hist from src to dst in range [begin, end)
*/
template<typename GradientSumT>
void CopyHist(GHistRow<GradientSumT> dst, const GHistRow<GradientSumT> src,
size_t begin, size_t end);
void CopyHist(GHistRow dst, const GHistRow src, size_t begin, size_t end);
/*!
* \brief Compute Subtraction: dst = src1 - src2 in range [begin, end)
*/
template<typename GradientSumT>
void SubtractionHist(GHistRow<GradientSumT> dst, const GHistRow<GradientSumT> src1,
const GHistRow<GradientSumT> src2,
size_t begin, size_t end);
void SubtractionHist(GHistRow dst, const GHistRow src1, const GHistRow src2, size_t begin,
size_t end);
/*!
* \brief histogram of gradient statistics for multiple nodes
*/
template<typename GradientSumT>
class HistCollection {
public:
using GHistRowT = GHistRow<GradientSumT>;
using GradientPairT = xgboost::detail::GradientPairInternal<GradientSumT>;
// access histogram for i-th node
GHistRowT operator[](bst_uint nid) const {
GHistRow operator[](bst_uint nid) const {
constexpr uint32_t kMax = std::numeric_limits<uint32_t>::max();
const size_t id = row_ptr_.at(nid);
CHECK_NE(id, kMax);
GradientPairT* ptr = nullptr;
GradientPairPrecise* ptr = nullptr;
if (contiguous_allocation_) {
ptr = const_cast<GradientPairT*>(data_[0].data() + nbins_*id);
ptr = const_cast<GradientPairPrecise*>(data_[0].data() + nbins_*id);
} else {
ptr = const_cast<GradientPairT*>(data_[id].data());
ptr = const_cast<GradientPairPrecise*>(data_[id].data());
}
return {ptr, nbins_};
}
@@ -431,7 +419,7 @@ class HistCollection {
/*! \brief flag to identify contiguous memory allocation */
bool contiguous_allocation_ = false;
std::vector<std::vector<GradientPairT>> data_;
std::vector<std::vector<GradientPairPrecise>> data_;
/*! \brief row_ptr_[nid] locates bin for histogram of node nid */
std::vector<size_t> row_ptr_;
@@ -442,11 +430,8 @@ class HistCollection {
* Supports processing multiple tree-nodes for nested parallelism
* Able to reduce histograms across threads in efficient way
*/
template<typename GradientSumT>
class ParallelGHistBuilder {
public:
using GHistRowT = GHistRow<GradientSumT>;
void Init(size_t nbins) {
if (nbins != nbins_) {
hist_buffer_.Init(nbins);
@@ -457,7 +442,7 @@ class ParallelGHistBuilder {
// Add new elements if needed, mark all hists as unused
// targeted_hists - already allocated hists which should contain final results after Reduce() call
void Reset(size_t nthreads, size_t nodes, const BlockedSpace2d& space,
const std::vector<GHistRowT>& targeted_hists) {
const std::vector<GHistRow>& targeted_hists) {
hist_buffer_.Init(nbins_);
tid_nid_to_hist_.clear();
threads_to_nids_map_.clear();
@@ -478,7 +463,7 @@ class ParallelGHistBuilder {
}
// Get specified hist, initialize hist by zeros if it wasn't used before
GHistRowT GetInitializedHist(size_t tid, size_t nid) {
GHistRow GetInitializedHist(size_t tid, size_t nid) {
CHECK_LT(nid, nodes_);
CHECK_LT(tid, nthreads_);
@@ -486,7 +471,7 @@ class ParallelGHistBuilder {
if (idx >= 0) {
hist_buffer_.AllocateData(idx);
}
GHistRowT hist = idx == -1 ? targeted_hists_[nid] : hist_buffer_[idx];
GHistRow hist = idx == -1 ? targeted_hists_[nid] : hist_buffer_[idx];
if (!hist_was_used_[tid * nodes_ + nid]) {
InitilizeHistByZeroes(hist, 0, hist.size());
@@ -501,7 +486,7 @@ class ParallelGHistBuilder {
CHECK_GT(end, begin);
CHECK_LT(nid, nodes_);
GHistRowT dst = targeted_hists_[nid];
GHistRow dst = targeted_hists_[nid];
bool is_updated = false;
for (size_t tid = 0; tid < nthreads_; ++tid) {
@@ -509,7 +494,7 @@ class ParallelGHistBuilder {
is_updated = true;
int idx = tid_nid_to_hist_.at({tid, nid});
GHistRowT src = idx == -1 ? targeted_hists_[nid] : hist_buffer_[idx];
GHistRow src = idx == -1 ? targeted_hists_[nid] : hist_buffer_[idx];
if (dst.data() != src.data()) {
IncrementHist(dst, src, begin, end);
@@ -595,7 +580,7 @@ class ParallelGHistBuilder {
/*! \brief number of nodes which will be processed in parallel */
size_t nodes_ = 0;
/*! \brief Buffer for additional histograms for Parallel processing */
HistCollection<GradientSumT> hist_buffer_;
HistCollection hist_buffer_;
/*!
* \brief Marks which hists were used, it means that they should be merged.
* Contains only {true or false} values
@@ -606,7 +591,7 @@ class ParallelGHistBuilder {
/*! \brief Buffer for additional histograms for Parallel processing */
std::vector<bool> threads_to_nids_map_;
/*! \brief Contains histograms for final results */
std::vector<GHistRowT> targeted_hists_;
std::vector<GHistRow> targeted_hists_;
/*!
* \brief map pair {tid, nid} to index of allocated histogram from hist_buffer_ and targeted_hists_,
* -1 is reserved for targeted_hists_
@@ -617,19 +602,15 @@ class ParallelGHistBuilder {
/*!
* \brief builder for histograms of gradient statistics
*/
template<typename GradientSumT>
class GHistBuilder {
public:
using GHistRowT = GHistRow<GradientSumT>;
GHistBuilder() = default;
explicit GHistBuilder(uint32_t nbins): nbins_{nbins} {}
// construct a histogram via histogram aggregation
template <bool any_missing>
void BuildHist(const std::vector<GradientPair> &gpair,
const RowSetCollection::Elem row_indices,
const GHistIndexMatrix &gmat, GHistRowT hist) const;
void BuildHist(const std::vector<GradientPair>& gpair, const RowSetCollection::Elem row_indices,
const GHistIndexMatrix& gmat, GHistRow hist) const;
uint32_t GetNumBins() const {
return nbins_;
}