llvm-project/libc/src/__support/FPUtil/BasicOperations.h

81 lines
2.1 KiB
C++

//===-- Basic operations on floating point numbers --------------*- 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_BASIC_OPERATIONS_H
#define LLVM_LIBC_SRC_SUPPORT_FPUTIL_BASIC_OPERATIONS_H
#include "FPBits.h"
#include "src/__support/CPP/type_traits.h"
namespace __llvm_libc {
namespace fputil {
template <typename T, cpp::enable_if_t<cpp::is_floating_point_v<T>, int> = 0>
static inline T abs(T x) {
FPBits<T> bits(x);
bits.set_sign(0);
return T(bits);
}
template <typename T, cpp::enable_if_t<cpp::is_floating_point_v<T>, int> = 0>
static inline T fmin(T x, T y) {
FPBits<T> bitx(x), bity(y);
if (bitx.is_nan()) {
return y;
} else if (bity.is_nan()) {
return x;
} else if (bitx.get_sign() != bity.get_sign()) {
// To make sure that fmin(+0, -0) == -0 == fmin(-0, +0), whenever x and
// y has different signs and both are not NaNs, we return the number
// with negative sign.
return (bitx.get_sign() ? x : y);
} else {
return (x < y ? x : y);
}
}
template <typename T, cpp::enable_if_t<cpp::is_floating_point_v<T>, int> = 0>
static inline T fmax(T x, T y) {
FPBits<T> bitx(x), bity(y);
if (bitx.is_nan()) {
return y;
} else if (bity.is_nan()) {
return x;
} else if (bitx.get_sign() != bity.get_sign()) {
// To make sure that fmax(+0, -0) == +0 == fmax(-0, +0), whenever x and
// y has different signs and both are not NaNs, we return the number
// with positive sign.
return (bitx.get_sign() ? y : x);
} else {
return (x > y ? x : y);
}
}
template <typename T, cpp::enable_if_t<cpp::is_floating_point_v<T>, int> = 0>
static inline T fdim(T x, T y) {
FPBits<T> bitx(x), bity(y);
if (bitx.is_nan()) {
return x;
}
if (bity.is_nan()) {
return y;
}
return (x > y ? x - y : 0);
}
} // namespace fputil
} // namespace __llvm_libc
#endif // LLVM_LIBC_SRC_SUPPORT_FPUTIL_BASIC_OPERATIONS_H