Files
Jungfraujoch/image_analysis/indexing/IndexerFactory.cpp
T
leonarski_f ea383f9e83 FFBIDXIndexerCPU: the fast-feedback indexer on the CPU, used where there is no GPU
A port of the fast-feedback indexer's CUDA kernels to plain C++/Eigen: the same half-sphere and
rotation samples, the same scores and the same 32 output cells for Refine(). The loops are
reorganised so the inner one runs over samples and vectorises (GCC/Clang, no intrinsics), and the
cell search separates the rotation about the candidate vector out of the per-spot terms. The
vector refinement reproduces the library's warp sums - partial sums its shuffle reduction leaves in
the other lanes carry into the next round - and its float arithmetic (FMA contraction, the
Fibonacci points in float), because the candidates searched depend on it: on the library's 27 test
spot lists and 4 synthetic stills the CPU and GPU best cells agree to ~1e-6 relative, the top-32
sets in 30 of 31 cases completely.

FFBIDX now resolves to the GPU library where a GPU is visible and to the CPU port otherwise (no
GPU, --no-gpu, or a build without CUDA); Auto takes FFBIDX for stills whenever a cell is known,
also without a GPU, instead of FFTW. With a GPU nothing changes (a stills set and a rotation set
reproduce the baseline exactly). Without a GPU the stills indexer pool gets one indexer per worker
instead of eight, since the CPU indexer holds no card memory.

Single core, synthetic still, loaded 5950X: ~8 ms per call at 30 spots, ~15 ms at 80, ~35 ms at
250; 16 threads ~1300/700/330 calls/s.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015CeEGgpKdfkCTJb3YNMJcu
(cherry picked from commit 9a8eb8669d1be6c3ec16db6786280affd6830ee5)
2026-10-23 17:56:50 +02:00

45 lines
1.3 KiB
C++

// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only
#include "IndexerFactory.h"
#include "FFBIDXIndexerCPU.h"
#include "../../common/CUDAWrapper.h"
#ifdef JFJOCH_USE_CUDA
#include "FFBIDXIndexer.h"
#include "FFTIndexerGPU.h"
#endif
#ifdef JFJOCH_USE_FFTW
#include "FFTIndexerCPU.h"
#endif
std::unique_ptr<Indexer> CreateIndexer(const DiffractionExperiment& experiment) {
std::unique_ptr<Indexer> indexer;
switch (experiment.GetIndexingAlgorithm()) {
case IndexingAlgorithmEnum::FFBIDX:
#ifdef JFJOCH_USE_CUDA
if (get_gpu_count() > 0)
indexer = std::make_unique<FFBIDXIndexer>();
#endif
if (!indexer)
indexer = std::make_unique<FFBIDXIndexerCPU>();
indexer->Setup(experiment);
break;
case IndexingAlgorithmEnum::FFTW:
#ifdef JFJOCH_USE_FFTW
indexer = std::make_unique<FFTIndexerCPU>(experiment.GetIndexingSettings());
indexer->Setup(experiment);
#endif
break;
case IndexingAlgorithmEnum::FFT:
#ifdef JFJOCH_USE_CUDA
indexer = std::make_unique<FFTIndexerGPU>(experiment.GetIndexingSettings());
indexer->Setup(experiment);
#endif
break;
default:
break;
}
return indexer;
}