libc/src/__support/FPUtil/multiply_add.h

   1 //===-- Common header for multiply-add implementations ----------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIBC_SRC_SUPPORT_FPUTIL_MULTIPLY_ADD_H
  10 #define LLVM_LIBC_SRC_SUPPORT_FPUTIL_MULTIPLY_ADD_H
  11
  12 #include "src/__support/common.h"
  13 #include "src/__support/macros/properties/architectures.h"
  14 #include "src/__support/macros/properties/cpu_features.h" // LIBC_TARGET_CPU_HAS_FMA
  15
  16 namespace __llvm_libc {
  17 namespace fputil {
  18
  19 // Implement a simple wrapper for multiply-add operation:
  20 //   multiply_add(x, y, z) = x*y + z
  21 // which uses FMA instructions to speed up if available.
  22
  23 template <typename T> LIBC_INLINE T multiply_add(T x, T y, T z) {
  24   return x * y + z;
  25 }
  26
  27 } // namespace fputil
  28 } // namespace __llvm_libc
  29
  30 #if defined(LIBC_TARGET_CPU_HAS_FMA)
  31
  32 // FMA instructions are available.
  33 #include "FMA.h"
  34
  35 namespace __llvm_libc {
  36 namespace fputil {
  37
  38 template <> LIBC_INLINE float multiply_add<float>(float x, float y, float z) {
  39   return fma(x, y, z);
  40 }
  41
  42 template <>
  43 LIBC_INLINE double multiply_add<double>(double x, double y, double z) {
  44   return fma(x, y, z);
  45 }
  46
  47 } // namespace fputil
  48 } // namespace __llvm_libc
  49
  50 #endif // LIBC_TARGET_CPU_HAS_FMA
  51
  52 #endif // LLVM_LIBC_SRC_SUPPORT_FPUTIL_MULTIPLY_ADD_H