src/__support/FPUtil/multiply_add.h

//===-- Common header for multiply-add implementations ----------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIBC_SRC_SUPPORT_FPUTIL_MULTIPLY_ADD_H
#define LLVM_LIBC_SRC_SUPPORT_FPUTIL_MULTIPLY_ADD_H

#include "src/__support/common.h"
#include "src/__support/macros/properties/architectures.h"
#include "src/__support/macros/properties/cpu_features.h" // LIBC_TARGET_CPU_HAS_FMA

namespace __llvm_libc {
namespace fputil {

// Implement a simple wrapper for multiply-add operation:
//   multiply_add(x, y, z) = x*y + z
// which uses FMA instructions to speed up if available.

template <typename T> LIBC_INLINE T multiply_add(T x, T y, T z) {
  return x * y + z;
}

} // namespace fputil
} // namespace __llvm_libc

#if defined(LIBC_TARGET_CPU_HAS_FMA)

// FMA instructions are available.
#include "FMA.h"

namespace __llvm_libc {
namespace fputil {

template <> LIBC_INLINE float multiply_add<float>(float x, float y, float z) {
  return fma(x, y, z);
}

template <>
LIBC_INLINE double multiply_add<double>(double x, double y, double z) {
  return fma(x, y, z);
}

} // namespace fputil
} // namespace __llvm_libc

#endif // LIBC_TARGET_CPU_HAS_FMA

#endif // LLVM_LIBC_SRC_SUPPORT_FPUTIL_MULTIPLY_ADD_H