faiss/benchs/bench_6bit_codec.cpp

83 lines
2.1 KiB
C++

/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include <omp.h>
#include <cstdio>
#include <benchmark/benchmark.h>
#include <faiss/impl/ScalarQuantizer.h>
#include <faiss/utils/distances.h>
#include <faiss/utils/random.h>
#include <faiss/utils/utils.h>
using namespace faiss;
static void bench(benchmark::State& state) {
int d = 128;
int n = 2000;
state.SetLabel(faiss::get_compile_options());
std::vector<float> x(d * n);
float_rand(x.data(), d * n, 12345);
// make sure it's idempotent
ScalarQuantizer sq(d, ScalarQuantizer::QT_6bit);
omp_set_num_threads(1);
sq.train(n, x.data());
size_t code_size = sq.code_size;
state.counters["code_size"] = sq.code_size;
// encode
std::vector<uint8_t> codes(code_size * n);
sq.compute_codes(x.data(), codes.data(), n);
// decode
std::vector<float> x2(d * n);
sq.decode(codes.data(), x2.data(), n);
state.counters["sql2_recons_error"] =
fvec_L2sqr(x.data(), x2.data(), n * d) / n;
// encode again
std::vector<uint8_t> codes2(code_size * n);
sq.compute_codes(x2.data(), codes2.data(), n);
size_t ndiff = 0;
for (size_t i = 0; i < codes.size(); i++) {
if (codes[i] != codes2[i])
ndiff++;
}
state.counters["ndiff_for_idempotence"] = ndiff;
state.counters["code_size_two"] = codes.size();
std::unique_ptr<ScalarQuantizer::SQDistanceComputer> dc(
sq.get_distance_computer());
dc->codes = codes.data();
dc->code_size = sq.code_size;
state.counters["code_size_three"] = dc->code_size;
for (auto _ : state) {
float sum_dis = 0;
for (int i = 0; i < n; i++) {
dc->set_query(&x[i * d]);
for (int j = 0; j < n; j++) {
benchmark::DoNotOptimize(sum_dis += (*dc)(j));
}
}
}
}
// I think maybe n and d should be input arguments
// for things to really make sense, idk.
BENCHMARK(bench)->Iterations(20);
BENCHMARK_MAIN();