8d7b50e572
This patch implements the `RandomGenerator`, a new input generator that enables conformance testing for functions with large input spaces (e.g., double-precision math functions). **Architectural Refactoring** To support different generation strategies in a clean and extensible way, the existing `ExhaustiveGenerator` was refactored into a new class hierarchy: * A new abstract base class, `RangeBasedGenerator`, was introduced using the Curiously Recurring Template Pattern (CRTP). It contains the common logic for generators that operate on a sequence of ranges. * `ExhaustiveGenerator` now inherits from this base class, simplifying its implementation. **New Components** * The new `RandomGenerator` class also inherits from `RangeBasedGenerator`. It implements a strategy that randomly samples a specified number of points from the total input space. * Random number generation is handled by a new, self-contained `RandomState` class (a `xorshift64*` PRNG seeded with `splitmix64`) to ensure deterministic and reproducible random streams for testing. **Example Usage** As a first use case and demonstration of this new capability, this patch also adds the first double-precision conformance test for the `log` function. This test uses the new `RandomGenerator` to validate the implementations from the `llvm-libm`, `cuda-math`, and `hip-math` providers.
54 lines
1.5 KiB
C++
54 lines
1.5 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, 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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//
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//===----------------------------------------------------------------------===//
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///
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/// \file
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/// This file contains the definition of the RandomState class, a fast and
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/// lightweight pseudo-random number generator.
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///
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/// The implementation is based on the xorshift* generator, seeded using the
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/// SplitMix64 generator for robust initialization. For more details on the
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/// algorithm, see: https://en.wikipedia.org/wiki/Xorshift
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///
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//===----------------------------------------------------------------------===//
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#ifndef MATHTEST_RANDOMSTATE_HPP
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#define MATHTEST_RANDOMSTATE_HPP
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#include <cstdint>
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struct SeedTy {
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uint64_t Value;
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};
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class [[nodiscard]] RandomState {
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uint64_t State;
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[[nodiscard]] static constexpr uint64_t splitMix64(uint64_t X) noexcept {
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X += 0x9E3779B97F4A7C15ULL;
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X = (X ^ (X >> 30)) * 0xBF58476D1CE4E5B9ULL;
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X = (X ^ (X >> 27)) * 0x94D049BB133111EBULL;
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X = (X ^ (X >> 31));
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return X ? X : 0x9E3779B97F4A7C15ULL;
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}
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public:
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explicit constexpr RandomState(SeedTy Seed) noexcept
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: State(splitMix64(Seed.Value)) {}
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inline uint64_t next() noexcept {
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uint64_t X = State;
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X ^= X >> 12;
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X ^= X << 25;
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X ^= X >> 27;
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State = X;
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return X * 0x2545F4914F6CDD1DULL;
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}
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};
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#endif // MATHTEST_RANDOMSTATE_HPP
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