//===-- Unittests for logf-----------------------------------------------===//
//
// 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/__support/FPUtil/FPBits.h"
#include "src/math/logf.h"
#include "utils/MPFRWrapper/MPFRUtils.h"
#include "utils/UnitTest/FPMatcher.h"
#include "utils/UnitTest/Test.h"
#include <math.h>

#include <errno.h>
#include <stdint.h>

namespace mpfr = __llvm_libc::testing::mpfr;

DECLARE_SPECIAL_CONSTANTS(float)

TEST(LlvmLibcLogfTest, SpecialNumbers) {
  EXPECT_FP_EQ(aNaN, __llvm_libc::logf(aNaN));
  EXPECT_FP_EQ(inf, __llvm_libc::logf(inf));
  EXPECT_TRUE(FPBits((__llvm_libc::logf(neg_inf))).is_nan());
  EXPECT_FP_EQ(neg_inf, __llvm_libc::logf(0.0f));
  EXPECT_FP_EQ(neg_inf, __llvm_libc::logf(-0.0f));
  EXPECT_TRUE(FPBits(__llvm_libc::logf(-1.0f)).is_nan());
  EXPECT_FP_EQ(zero, __llvm_libc::logf(1.0f));
}

TEST(LlvmLibcLogfTest, TrickyInputs) {
  constexpr int N = 24;
  constexpr uint32_t INPUTS[N] = {
      0x3509dcf6U, 0x3bf86ef0U, 0x3ca1c99fU, 0x3d13e105U, 0x3f7ff1f2U,
      0x3f7fffffU, 0x3f800006U, 0x3f800014U, 0x3f80001cU, 0x3f80c777U,
      0x3f80ce72U, 0x3f80d19fU, 0x3f80f7bfU, 0x3f80fcfeU, 0x3f81feb4U,
      0x3f83d731U, 0x3f90cb1dU, 0x3fc55379U, 0x3fd364d7U, 0x41178febU,
      0x4c5d65a5U, 0x4e85f412U, 0x65d890d3U, 0x6f31a8ecU};
  for (int i = 0; i < N; ++i) {
    float x = float(FPBits(INPUTS[i]));
    EXPECT_MPFR_MATCH(mpfr::Operation::Log, x, __llvm_libc::logf(x), 0.5);
  }
}

TEST(LlvmLibcLogfTest, InFloatRange) {
  constexpr uint32_t COUNT = 1000000;
  constexpr uint32_t STEP = UINT32_MAX / COUNT;
  for (uint32_t i = 0, v = 0; i <= COUNT; ++i, v += STEP) {
    float x = float(FPBits(v));
    if (isnan(x) || isinf(x))
      continue;
    errno = 0;
    float result = __llvm_libc::logf(x);
    // If the computation resulted in an error or did not produce valid result
    // in the single-precision floating point range, then ignore comparing with
    // MPFR result as MPFR can still produce valid results because of its
    // wider precision.
    if (isnan(result) || isinf(result) || errno != 0)
      continue;
    ASSERT_MPFR_MATCH(mpfr::Operation::Log, x, __llvm_libc::logf(x), 0.5);
  }
}