RCQ search microbenchmark (#3863)

Summary:

add RCQ search microbenchmark with parameters similar to the ones provided by ivansopin in D62529163

Differential Revision: D62769834

Author: Mengdi Lin

faiss/perf_tests/bench_no_multithreading_rcq_search.cpp

@@ -0,0 +1,65 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gflags/gflags.h>
+
+#include <benchmark/benchmark.h>
+#include <faiss/IndexAdditiveQuantizer.h> // @manual=//faiss:faiss_no_multithreading
+#include <faiss/utils/random.h>
+
+using namespace faiss;
+DEFINE_uint32(iterations, 20, "iterations");
+DEFINE_uint32(nprobe, 1, "nprobe");
+DEFINE_uint32(batch_size, 1, "batch_size");
+DEFINE_double(beam_factor, 4.0, "beam factor");
+
+static void bench_search(
+        benchmark::State& state,
+        int batch_size,
+        int nprobe,
+        float beam_factor) {
+    int d = 512;
+    int nt = 2 << 15;
+    std::vector<float> xt(d * nt);
+
+    float_rand(xt.data(), d * nt, 12345);
+    ResidualCoarseQuantizer rq(d, {16, 8});
+    rq.verbose = false;
+    rq.train(nt, xt.data());
+
+    std::vector<float> xq(d * batch_size);
+    float_rand(xq.data(), d * batch_size, 12345);
+
+    std::vector<float> distances(nprobe * batch_size);
+    std::vector<int64_t> clusterIndices(nprobe * batch_size);
+    SearchParametersResidualCoarseQuantizer param;
+    param.beam_factor = beam_factor;
+    for (auto _ : state) {
+        rq.search(
+                batch_size,
+                xq.data(),
+                nprobe,
+                distances.data(),
+                clusterIndices.data(),
+                &param);
+    }
+}
+
+int main(int argc, char** argv) {
+    benchmark::Initialize(&argc, argv);
+    gflags::AllowCommandLineReparsing();
+    gflags::ParseCommandLineFlags(&argc, &argv, true);
+    int iterations = FLAGS_iterations;
+    int nprobe = FLAGS_nprobe;
+    float beam_factor = FLAGS_beam_factor;
+    int batch_size = FLAGS_batch_size;
+    benchmark::RegisterBenchmark(
+            "search", bench_search, batch_size, nprobe, beam_factor)
+            ->Iterations(iterations);
+    benchmark::RunSpecifiedBenchmarks();
+    benchmark::Shutdown();
+}