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Diffstat (limited to 'llvm/unittests/FuzzMutate/ReservoirSamplerTest.cpp')
-rw-r--r-- | llvm/unittests/FuzzMutate/ReservoirSamplerTest.cpp | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/llvm/unittests/FuzzMutate/ReservoirSamplerTest.cpp b/llvm/unittests/FuzzMutate/ReservoirSamplerTest.cpp deleted file mode 100644 index d246ba1428b..00000000000 --- a/llvm/unittests/FuzzMutate/ReservoirSamplerTest.cpp +++ /dev/null @@ -1,69 +0,0 @@ -//===- ReservoirSampler.cpp - Tests for the ReservoirSampler --------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// - -#include "llvm/FuzzMutate/Random.h" -#include "gtest/gtest.h" -#include <random> - -using namespace llvm; - -TEST(ReservoirSamplerTest, OneItem) { - std::mt19937 Rand; - auto Sampler = makeSampler(Rand, 7, 1); - ASSERT_FALSE(Sampler.isEmpty()); - ASSERT_EQ(7, Sampler.getSelection()); -} - -TEST(ReservoirSamplerTest, NoWeight) { - std::mt19937 Rand; - auto Sampler = makeSampler(Rand, 7, 0); - ASSERT_TRUE(Sampler.isEmpty()); -} - -TEST(ReservoirSamplerTest, Uniform) { - std::mt19937 Rand; - - // Run three chi-squared tests to check that the distribution is reasonably - // uniform. - std::vector<int> Items = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; - - int Failures = 0; - for (int Run = 0; Run < 3; ++Run) { - std::vector<int> Counts(Items.size(), 0); - - // We need $np_s > 5$ at minimum, but we're better off going a couple of - // orders of magnitude larger. - int N = Items.size() * 5 * 100; - for (int I = 0; I < N; ++I) { - auto Sampler = makeSampler(Rand, Items); - Counts[Sampler.getSelection()] += 1; - } - - // Knuth. TAOCP Vol. 2, 3.3.1 (8): - // $V = \frac{1}{n} \sum_{s=1}^{k} \left(\frac{Y_s^2}{p_s}\right) - n$ - double Ps = 1.0 / Items.size(); - double Sum = 0.0; - for (int Ys : Counts) - Sum += Ys * Ys / Ps; - double V = (Sum / N) - N; - - assert(Items.size() == 10 && "Our chi-squared values assume 10 items"); - // Since we have 10 items, there are 9 degrees of freedom and the table of - // chi-squared values is as follows: - // - // | p=1% | 5% | 25% | 50% | 75% | 95% | 99% | - // v=9 | 2.088 | 3.325 | 5.899 | 8.343 | 11.39 | 16.92 | 21.67 | - // - // Check that we're in the likely range of results. - //if (V < 2.088 || V > 21.67) - if (V < 2.088 || V > 21.67) - ++Failures; - } - EXPECT_LT(Failures, 3) << "Non-uniform distribution?"; -} |