1 files changed, 67 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/nsan/tests/NSanUnitTest.cpp b/contrib/llvm-project/compiler-rt/lib/nsan/tests/NSanUnitTest.cpp
new file mode 100644
index 000000000000..d121292c3668
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/nsan/tests/NSanUnitTest.cpp
@@ -0,0 +1,67 @@
+// 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
+
+// Do not attempt to use LLVM ostream etc from gtest.
+// #define GTEST_NO_LLVM_SUPPORT 1
+
+#include "../nsan.h"
+#include "gtest/gtest.h"
+
+#include <cmath>
+
+namespace __nsan {
+
+template <typename FT, auto next> void TestFT() {
+  // Basic local tests anchored at 0.0.
+  ASSERT_EQ(GetULPDiff<FT>(0.0, 0.0), 0);
+  ASSERT_EQ(GetULPDiff<FT>(-0.0, 0.0), 0);
+  ASSERT_EQ(GetULPDiff<FT>(next(-0.0, -1.0), 0.0), 1);
+  ASSERT_EQ(GetULPDiff<FT>(next(0.0, 1.0), -0.0), 1);
+  ASSERT_EQ(GetULPDiff<FT>(next(-0.0, -1.0), next(0.0, 1.0)), 2);
+  // Basic local tests anchored at 2.0.
+  ASSERT_EQ(GetULPDiff<FT>(next(2.0, 1.0), 2.0), 1);
+  ASSERT_EQ(GetULPDiff<FT>(next(2.0, 3.0), 2.0), 1);
+  ASSERT_EQ(GetULPDiff<FT>(next(2.0, 1.0), next(2.0, 3.0)), 2);
+
+  ASSERT_NE(GetULPDiff<FT>(-0.01, 0.01), kMaxULPDiff);
+
+  // Basic local tests anchored at a random number.
+  const FT X = 4863.5123;
+  const FT To = 2 * X;
+  FT Y = X;
+  ASSERT_EQ(GetULPDiff<FT>(X, Y), 0);
+  ASSERT_EQ(GetULPDiff<FT>(-X, -Y), 0);
+  Y = next(Y, To);
+  ASSERT_EQ(GetULPDiff<FT>(X, Y), 1);
+  ASSERT_EQ(GetULPDiff<FT>(-X, -Y), 1);
+  Y = next(Y, To);
+  ASSERT_EQ(GetULPDiff<FT>(X, Y), 2);
+  ASSERT_EQ(GetULPDiff<FT>(-X, -Y), 2);
+  Y = next(Y, To);
+  ASSERT_EQ(GetULPDiff<FT>(X, Y), 3);
+  ASSERT_EQ(GetULPDiff<FT>(-X, -Y), 3);
+
+  // Values with larger differences.
+  static constexpr const __sanitizer::u64 MantissaSize =
+      __sanitizer::u64{1} << FTInfo<FT>::kMantissaBits;
+  ASSERT_EQ(GetULPDiff<FT>(1.0, next(2.0, 1.0)), MantissaSize - 1);
+  ASSERT_EQ(GetULPDiff<FT>(1.0, 2.0), MantissaSize);
+  ASSERT_EQ(GetULPDiff<FT>(1.0, next(2.0, 3.0)), MantissaSize + 1);
+  ASSERT_EQ(GetULPDiff<FT>(1.0, 3.0), (3 * MantissaSize) / 2);
+}
+
+TEST(NSanTest, Float) { TestFT<float, nextafterf>(); }
+
+TEST(NSanTest, Double) {
+  TestFT<double, static_cast<double (*)(double, double)>(nextafter)>();
+}
+
+TEST(NSanTest, Float128) {
+  // Very basic tests. FIXME: improve when we have nextafter<__float128>.
+  ASSERT_EQ(GetULPDiff<__float128>(0.0, 0.0), 0);
+  ASSERT_EQ(GetULPDiff<__float128>(-0.0, 0.0), 0);
+  ASSERT_NE(GetULPDiff<__float128>(-0.01, 0.01), kMaxULPDiff);
+}
+
+} // end namespace __nsan