1 /*!
2 * Copyright 2021 by Contributors
3 */
4 #include "xgboost/span.h"
5 #include "xgboost/generic_parameters.h"
6 #include "xgboost/linalg.h"
7 #include "../common/device_helpers.cuh"
8
9 namespace xgboost {
10 namespace gbm {
11
GPUCopyGradient(HostDeviceVector<GradientPair> const * in_gpair,bst_group_t n_groups,bst_group_t group_id,HostDeviceVector<GradientPair> * out_gpair)12 void GPUCopyGradient(HostDeviceVector<GradientPair> const *in_gpair,
13 bst_group_t n_groups, bst_group_t group_id,
14 HostDeviceVector<GradientPair> *out_gpair) {
15 MatrixView<GradientPair const> in{
16 in_gpair,
17 {n_groups, 1ul},
18 {in_gpair->Size() / n_groups, static_cast<size_t>(n_groups)},
19 in_gpair->DeviceIdx()};
20 auto v_in = VectorView<GradientPair const>{in, group_id};
21 out_gpair->Resize(v_in.Size());
22 auto d_out = out_gpair->DeviceSpan();
23 dh::LaunchN(v_in.Size(), [=] __device__(size_t i) { d_out[i] = v_in[i]; });
24 }
25
GPUDartPredictInc(common::Span<float> out_predts,common::Span<float> predts,float tree_w,size_t n_rows,bst_group_t n_groups,bst_group_t group)26 void GPUDartPredictInc(common::Span<float> out_predts,
27 common::Span<float> predts, float tree_w, size_t n_rows,
28 bst_group_t n_groups, bst_group_t group) {
29 dh::LaunchN(n_rows, [=] XGBOOST_DEVICE(size_t ridx) {
30 const size_t offset = ridx * n_groups + group;
31 out_predts[offset] += (predts[offset] * tree_w);
32 });
33 }
34
GPUDartInplacePredictInc(common::Span<float> out_predts,common::Span<float> predts,float tree_w,size_t n_rows,float base_score,bst_group_t n_groups,bst_group_t group)35 void GPUDartInplacePredictInc(common::Span<float> out_predts,
36 common::Span<float> predts, float tree_w,
37 size_t n_rows, float base_score,
38 bst_group_t n_groups, bst_group_t group) {
39 dh::LaunchN(n_rows, [=] XGBOOST_DEVICE(size_t ridx) {
40 const size_t offset = ridx * n_groups + group;
41 out_predts[offset] += (predts[offset] - base_score) * tree_w;
42 });
43 }
44 } // namespace gbm
45 } // namespace xgboost
46