libc/test/src/math/fmabf16_test.cpp

//===-- Unit test for fmabf16 ---------------------------------------===//
//
// 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/bfloat16.h"
#include "src/math/fmabf16.h"
#include "test/UnitTest/FPMatcher.h"
#include "test/UnitTest/Test.h"
#include "utils/MPFRWrapper/MPFRUtils.h"

using LlvmLibcFmaBf16Test = LIBC_NAMESPACE::testing::FPTest<bfloat16>;

namespace mpfr = LIBC_NAMESPACE::testing::mpfr;

// subnormal range (negative)
static constexpr uint16_t SUBNORM_NEG_START = 0x8001U;
static constexpr uint16_t SUBNORM_NEG_STOP = 0x807FU;

TEST_F(LlvmLibcFmaBf16Test, SubnormalNegativeRange) {
  constexpr bfloat16 Z_VALUES[] = {zero,    neg_zero,   inf,
                                   neg_inf, min_normal, max_normal};
  for (uint16_t v1 = SUBNORM_NEG_START; v1 <= SUBNORM_NEG_STOP; v1++) {
    for (uint16_t v2 = v1; v2 <= SUBNORM_NEG_STOP; v2++) {

      bfloat16 x = FPBits(v1).get_val();
      bfloat16 y = FPBits(v2).get_val();
      for (const bfloat16 &z : Z_VALUES) {
        mpfr::TernaryInput<bfloat16> input{x, y, z};

        EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Fma, input,
                                       LIBC_NAMESPACE::fmabf16(x, y, z), 0.5);
      }
      bfloat16 neg_xy = -(x * y);
      mpfr::TernaryInput<bfloat16> input{x, y, neg_xy};
      EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Fma, input,
                                     LIBC_NAMESPACE::fmabf16(x, y, neg_xy),
                                     0.5);
    }
  }
}

TEST_F(LlvmLibcFmaBf16Test, SpecialNumbers) {
  constexpr bfloat16 VALUES[] = {zero,    neg_zero,   inf,
                                 neg_inf, min_normal, max_normal};
  for (size_t i = 0; i < 6; ++i) {
    for (size_t j = i; j < 6; ++j) {
      bfloat16 x = VALUES[i];
      bfloat16 y = VALUES[j];
      for (const bfloat16 &z : VALUES) {
        mpfr::TernaryInput<bfloat16> input{x, y, z};

        EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Fma, input,
                                       LIBC_NAMESPACE::fmabf16(x, y, z), 0.5);
      }
      bfloat16 neg_xy = -(x * y);
      mpfr::TernaryInput<bfloat16> input{x, y, neg_xy};
      EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Fma, input,
                                     LIBC_NAMESPACE::fmabf16(x, y, neg_xy),
                                     0.5);
    }
  }
}