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/CPP/type_traits.h" 13 #include "src/__support/common.h" 14 #include "src/__support/macros/config.h" 15 #include "src/__support/macros/properties/architectures.h" 16 #include "src/__support/macros/properties/cpu_features.h" // LIBC_TARGET_CPU_HAS_FMA 17 18 namespace LIBC_NAMESPACE_DECL { 19 namespace fputil { 20 21 // Implement a simple wrapper for multiply-add operation: 22 // multiply_add(x, y, z) = x*y + z 23 // which uses FMA instructions to speed up if available. 24 25 template <typename T> 26 LIBC_INLINE cpp::enable_if_t<(sizeof(T) > sizeof(void *)), T> 27 multiply_add(const T &x, const T &y, const T &z) { 28 return x * y + z; 29 } 30 31 template <typename T> 32 LIBC_INLINE cpp::enable_if_t<(sizeof(T) <= sizeof(void *)), T> 33 multiply_add(T x, T y, T z) { 34 return x * y + z; 35 } 36 37 } // namespace fputil 38 } // namespace LIBC_NAMESPACE_DECL 39 40 #if defined(LIBC_TARGET_CPU_HAS_FMA) 41 42 // FMA instructions are available. 43 // We use builtins directly instead of including FMA.h to avoid a circular 44 // dependency: multiply_add.h -> FMA.h -> generic/FMA.h -> dyadic_float.h. 45 46 namespace LIBC_NAMESPACE_DECL { 47 namespace fputil { 48 49 LIBC_INLINE float multiply_add(float x, float y, float z) { 50 return __builtin_fmaf(x, y, z); 51 } 52 53 LIBC_INLINE double multiply_add(double x, double y, double z) { 54 return __builtin_fma(x, y, z); 55 } 56 57 } // namespace fputil 58 } // namespace LIBC_NAMESPACE_DECL 59 60 #endif // LIBC_TARGET_CPU_HAS_FMA 61 62 #endif // LLVM_LIBC_SRC___SUPPORT_FPUTIL_MULTIPLY_ADD_H 63