libc/test/src/math/smoke/atan2_test.cpp

//===-- Unittests for atan2 -----------------------------------------------===//
//
// 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 "src/math/atan2.h"
#include "test/UnitTest/FPMatcher.h"
#include "test/UnitTest/Test.h"

using LlvmLibcAtan2Test = LIBC_NAMESPACE::testing::FPTest<double>;

TEST_F(LlvmLibcAtan2Test, SpecialNumbers) {
  constexpr double PI = 0x1.921fb54442d18p+1;
  constexpr double PI_OVER_2 = 0x1.921fb54442d18p+0;
  constexpr double PI_OVER_4 = 0x1.921fb54442d18p-1;
  constexpr double THREE_PI_OVER_4 = 0x1.2d97c7f3321d2p+1;

  EXPECT_FP_EQ(PI, LIBC_NAMESPACE::atan2(zero, neg_zero));
  EXPECT_FP_EQ(-PI, LIBC_NAMESPACE::atan2(neg_zero, neg_zero));
  EXPECT_FP_EQ(PI, LIBC_NAMESPACE::atan2(zero, neg_inf));
  EXPECT_FP_EQ(-PI, LIBC_NAMESPACE::atan2(neg_zero, neg_inf));
  EXPECT_FP_EQ(PI_OVER_2, LIBC_NAMESPACE::atan2(inf, zero));
  EXPECT_FP_EQ(PI_OVER_2, LIBC_NAMESPACE::atan2(inf, neg_zero));
  EXPECT_FP_EQ(-PI_OVER_2, LIBC_NAMESPACE::atan2(neg_inf, zero));
  EXPECT_FP_EQ(-PI_OVER_2, LIBC_NAMESPACE::atan2(neg_inf, neg_zero));
  EXPECT_FP_EQ(PI_OVER_4, LIBC_NAMESPACE::atan2(inf, inf));
  EXPECT_FP_EQ(-PI_OVER_4, LIBC_NAMESPACE::atan2(neg_inf, inf));
  EXPECT_FP_EQ(THREE_PI_OVER_4, LIBC_NAMESPACE::atan2(inf, neg_inf));
  EXPECT_FP_EQ(-THREE_PI_OVER_4, LIBC_NAMESPACE::atan2(neg_inf, neg_inf));

  EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::atan2(sNaN, sNaN),
                              FE_INVALID);
  EXPECT_MATH_ERRNO(0);

  EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::atan2(sNaN, 1.0),
                              FE_INVALID);
  EXPECT_MATH_ERRNO(0);

  EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::atan2(1.0, sNaN),
                              FE_INVALID);
  EXPECT_MATH_ERRNO(0);

  EXPECT_FP_EQ_ALL_ROUNDING(aNaN, LIBC_NAMESPACE::atan2(aNaN, zero));
  EXPECT_FP_EQ_ALL_ROUNDING(aNaN, LIBC_NAMESPACE::atan2(1.0, aNaN));
  EXPECT_FP_EQ_ALL_ROUNDING(0.0, LIBC_NAMESPACE::atan2(zero, zero));
  EXPECT_FP_EQ_ALL_ROUNDING(-0.0, LIBC_NAMESPACE::atan2(-0.0, zero));
  EXPECT_FP_EQ_ALL_ROUNDING(0.0, LIBC_NAMESPACE::atan2(1.0, inf));
  EXPECT_FP_EQ_ALL_ROUNDING(-0.0, LIBC_NAMESPACE::atan2(-1.0, inf));
}

#ifdef LIBC_TEST_FTZ_DAZ

using namespace LIBC_NAMESPACE::testing;

TEST_F(LlvmLibcAtan2Test, FTZMode) {
  ModifyMXCSR mxcsr(FTZ);

  EXPECT_FP_EQ(0x1.921fb54442d18p-1,
               LIBC_NAMESPACE::atan2(min_denormal, min_denormal));
  EXPECT_FP_EQ(0x1.0000000000001p-52,
               LIBC_NAMESPACE::atan2(min_denormal, max_denormal));
  EXPECT_FP_EQ(0x1.921fb54442d17p0,
               LIBC_NAMESPACE::atan2(max_denormal, min_denormal));
  EXPECT_FP_EQ(0x1.921fb54442d18p-1,
               LIBC_NAMESPACE::atan2(max_denormal, max_denormal));
}

TEST_F(LlvmLibcAtan2Test, DAZMode) {
  ModifyMXCSR mxcsr(DAZ);

  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(min_denormal, min_denormal));
  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(min_denormal, max_denormal));
  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(max_denormal, min_denormal));
  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(max_denormal, max_denormal));
}

TEST_F(LlvmLibcAtan2Test, FTZDAZMode) {
  ModifyMXCSR mxcsr(FTZ | DAZ);

  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(min_denormal, min_denormal));
  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(min_denormal, max_denormal));
  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(max_denormal, min_denormal));
  EXPECT_FP_EQ(0.0, LIBC_NAMESPACE::atan2(max_denormal, max_denormal));
}

#endif