56fd68e7dd
CCCL (CUDA C++ Core Libraries) provides: - CUB: device/block/warp-level GPU primitives (reduce, scan, sort, topk) - Thrust: high-level parallel algorithms (transform_reduce, sort, scan) - libcudacxx: CUDA C++ standard library (atomics, barriers, memory) - cudax: experimental features (memory resources, allocators) - Tuning policies: per-SM hardware-specific algorithm parameters Competition optimization vectors mapped to CCCL: - Output TPS (83% weight): warp_reduce, block_reduce, device_topk - Input TPS (14% weight): device_scan, block_load, prefetch - Cache TPS (3% weight): prefix caching strategy patterns - Memory (0.9 util): pooled/cached/buddy allocators Source: https://github.com/NVIDIA/cccl (shallow clone, HEAD only) License: Apache-2.0
59 lines
2.9 KiB
Plaintext
59 lines
2.9 KiB
Plaintext
//===----------------------------------------------------------------------===//
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//
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// Part of CUDA Experimental in CUDA C++ Core Libraries,
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// under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES.
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//
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//===----------------------------------------------------------------------===//
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#include <cuda/std/cstddef>
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#include <cuda/experimental/__cuco/capacity.cuh>
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#include <cuda/experimental/__cuco/hash_functions.cuh>
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#include <cuda/experimental/__cuco/probing_scheme.cuh>
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#include <testing.cuh>
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namespace cudax = cuda::experimental;
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C2H_TEST("cuco make_valid_capacity rounding and validation", "[capacity]")
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{
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using probing = cudax::cuco::double_hashing<1, cudax::cuco::hash<int>>;
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[[maybe_unused]] constexpr int bucket = 1;
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static_assert(cudax::cuco::is_double_hashing_v<probing>, "scheme is double hashing");
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// make_valid_capacity rounds up and is idempotent; is_valid_capacity is derived from it
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constexpr auto valid = cudax::cuco::make_valid_capacity<probing, bucket>(::cuda::std::size_t{1000});
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static_assert(valid >= 1000, "rounds up");
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static_assert(cudax::cuco::is_valid_capacity<probing, bucket>(valid), "result is valid");
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static_assert(cudax::cuco::make_valid_capacity<probing, bucket>(valid) == valid, "idempotent");
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// 1000 is not a valid double-hashing capacity; it rounds up to a prime-cycle capacity
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static_assert(!cudax::cuco::is_valid_capacity<probing, bucket>(::cuda::std::size_t{1000}), "1000 is not valid");
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// equal-rounding requests produce the same valid capacity
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static_assert(cudax::cuco::make_valid_capacity<probing, bucket>(::cuda::std::size_t{1000})
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== cudax::cuco::make_valid_capacity<probing, bucket>(::cuda::std::size_t{1008}),
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"requests that round to the same capacity agree");
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// cuCollections extent_test parity: double hashing, cg_size 2, bucket_size 4.
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// 1234 rounds up to next_prime(ceil(1234 / 8) = 155) = 157, times the stride 8 -> 1256.
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using dh4 = cudax::cuco::double_hashing<2, cudax::cuco::hash<int>>;
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[[maybe_unused]] constexpr int bucket4 = 4;
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static_assert(cudax::cuco::make_valid_capacity<dh4, bucket4>(::cuda::std::size_t{1234}) == ::cuda::std::size_t{1256},
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"compile-time valid capacity matches the cuCollections extent test");
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REQUIRE(cudax::cuco::make_valid_capacity<dh4, bucket4>(::cuda::std::size_t{1234}) == ::cuda::std::size_t{1256});
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// a desired load factor outside (0, 1] is rejected
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using lp4 = cudax::cuco::linear_probing<2, cudax::cuco::hash<int>>;
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auto bad_lf = [](double __lf) {
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[[maybe_unused]] auto __r = cudax::cuco::make_valid_capacity<lp4, bucket4>(::cuda::std::size_t{1000}, __lf);
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};
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REQUIRE_THROWS(bad_lf(0.0));
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REQUIRE_THROWS(bad_lf(-0.5));
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REQUIRE_THROWS(bad_lf(1.5));
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}
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