| //===-- Benchmark memory specific tools -----------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "LibcMemoryBenchmark.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/MathExtras.h" |
| #include <algorithm> |
| |
| namespace llvm { |
| namespace libc_benchmarks { |
| |
| // Returns a distribution that samples the buffer to satisfy the required |
| // alignment. |
| // When alignment is set, the distribution is scaled down by `Factor` and scaled |
| // up again by the same amount during sampling. |
| static std::uniform_int_distribution<uint32_t> |
| GetOffsetDistribution(const StudyConfiguration &Conf) { |
| if (Conf.AddressAlignment && |
| *Conf.AddressAlignment > AlignedBuffer::Alignment) |
| report_fatal_error( |
| "AddressAlignment must be less or equal to AlignedBuffer::Alignment"); |
| if (!Conf.AddressAlignment) |
| return std::uniform_int_distribution<uint32_t>(0, 0); // Always 0. |
| // If we test up to Size bytes, the returned offset must stay under |
| // BuffersSize - Size. |
| int64_t MaxOffset = Conf.BufferSize; |
| MaxOffset -= Conf.Size.To; |
| MaxOffset -= 1; |
| if (MaxOffset < 0) |
| report_fatal_error( |
| "BufferSize too small to exercise specified Size configuration"); |
| MaxOffset /= Conf.AddressAlignment->value(); |
| return std::uniform_int_distribution<uint32_t>(0, MaxOffset); |
| } |
| |
| OffsetDistribution::OffsetDistribution(const StudyConfiguration &Conf) |
| : Distribution(GetOffsetDistribution(Conf)), |
| Factor(Conf.AddressAlignment.valueOrOne().value()) {} |
| |
| // Precomputes offset where to insert mismatches between the two buffers. |
| MismatchOffsetDistribution::MismatchOffsetDistribution( |
| const StudyConfiguration &Conf) |
| : MismatchAt(Conf.MemcmpMismatchAt) { |
| if (MismatchAt <= 1) |
| return; |
| const auto ToSize = Conf.Size.To; |
| for (size_t I = ToSize + 1; I < Conf.BufferSize; I += ToSize) |
| MismatchIndices.push_back(I); |
| if (MismatchIndices.empty()) |
| llvm::report_fatal_error("Unable to generate mismatch"); |
| MismatchIndexSelector = |
| std::uniform_int_distribution<size_t>(0, MismatchIndices.size() - 1); |
| } |
| |
| } // namespace libc_benchmarks |
| } // namespace llvm |