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//===-- Floating-point manipulation functions -------------------*- 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_UTILS_FPUTIL_MANIPULATION_FUNCTIONS_H
#define LLVM_LIBC_UTILS_FPUTIL_MANIPULATION_FUNCTIONS_H
#include "FPBits.h"
#include "NearestIntegerOperations.h"
#include "NormalFloat.h"
#include "utils/CPP/TypeTraits.h"
namespace __llvm_libc {
namespace fputil {
template <typename T,
cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
static inline T frexp(T x, int &exp) {
FPBits<T> bits(x);
if (bits.isInfOrNaN())
return x;
if (bits.isZero()) {
exp = 0;
return x;
}
NormalFloat<T> normal(bits);
exp = normal.exponent + 1;
normal.exponent = -1;
return normal;
}
template <typename T,
cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
static inline T modf(T x, T &iptr) {
FPBits<T> bits(x);
if (bits.isZero() || bits.isNaN()) {
iptr = x;
return x;
} else if (bits.isInf()) {
iptr = x;
return bits.sign ? FPBits<T>::negZero() : FPBits<T>::zero();
} else {
iptr = trunc(x);
if (x == iptr) {
// If x is already an integer value, then return zero with the right
// sign.
return bits.sign ? FPBits<T>::negZero() : FPBits<T>::zero();
} else {
return x - iptr;
}
}
}
template <typename T,
cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
static inline T copysign(T x, T y) {
FPBits<T> xbits(x);
xbits.sign = FPBits<T>(y).sign;
return xbits;
}
template <typename T,
cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
static inline T logb(T x) {
FPBits<T> bits(x);
if (bits.isZero()) {
// TODO(Floating point exception): Raise div-by-zero exception.
// TODO(errno): POSIX requires setting errno to ERANGE.
return FPBits<T>::negInf();
} else if (bits.isNaN()) {
return x;
} else if (bits.isInf()) {
// Return positive infinity.
return FPBits<T>::inf();
}
NormalFloat<T> normal(bits);
return normal.exponent;
}
} // namespace fputil
} // namespace __llvm_libc
#endif // LLVM_LIBC_UTILS_FPUTIL_MANIPULATION_FUNCTIONS_H