930cf1cb9f
Depends on D90805. Reviewed By: lntue Differential Revision: https://reviews.llvm.org/D90806
123 lines
3.3 KiB
C++
123 lines
3.3 KiB
C++
//===-- Floating-point manipulation functions -------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_UTILS_FPUTIL_MANIPULATION_FUNCTIONS_H
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#define LLVM_LIBC_UTILS_FPUTIL_MANIPULATION_FUNCTIONS_H
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#include "FPBits.h"
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#include "NearestIntegerOperations.h"
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#include "NormalFloat.h"
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#include "include/math.h"
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#include "utils/CPP/TypeTraits.h"
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#include <limits.h>
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namespace __llvm_libc {
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namespace fputil {
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template <typename T,
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cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
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static inline T frexp(T x, int &exp) {
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FPBits<T> bits(x);
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if (bits.isInfOrNaN())
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return x;
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if (bits.isZero()) {
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exp = 0;
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return x;
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}
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NormalFloat<T> normal(bits);
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exp = normal.exponent + 1;
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normal.exponent = -1;
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return normal;
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}
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template <typename T,
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cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
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static inline T modf(T x, T &iptr) {
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FPBits<T> bits(x);
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if (bits.isZero() || bits.isNaN()) {
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iptr = x;
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return x;
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} else if (bits.isInf()) {
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iptr = x;
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return bits.sign ? FPBits<T>::negZero() : FPBits<T>::zero();
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} else {
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iptr = trunc(x);
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if (x == iptr) {
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// If x is already an integer value, then return zero with the right
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// sign.
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return bits.sign ? FPBits<T>::negZero() : FPBits<T>::zero();
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} else {
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return x - iptr;
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}
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}
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}
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template <typename T,
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cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
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static inline T copysign(T x, T y) {
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FPBits<T> xbits(x);
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xbits.sign = FPBits<T>(y).sign;
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return xbits;
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}
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template <typename T,
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cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
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static inline int ilogb(T x) {
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// TODO: Raise appropriate floating point exceptions and set errno to the
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// an appropriate error value wherever relevant.
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FPBits<T> bits(x);
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if (bits.isZero()) {
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return FP_ILOGB0;
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} else if (bits.isNaN()) {
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return FP_ILOGBNAN;
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} else if (bits.isInf()) {
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return INT_MAX;
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}
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NormalFloat<T> normal(bits);
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// The C standard does not specify the return value when an exponent is
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// out of int range. However, XSI conformance required that INT_MAX or
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// INT_MIN are returned.
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// NOTE: It is highly unlikely that exponent will be out of int range as
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// the exponent is only 15 bits wide even for the 128-bit floating point
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// format.
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if (normal.exponent > INT_MAX)
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return INT_MAX;
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else if (normal.exponent < INT_MIN)
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return INT_MIN;
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else
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return normal.exponent;
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}
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template <typename T,
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cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
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static inline T logb(T x) {
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FPBits<T> bits(x);
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if (bits.isZero()) {
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// TODO(Floating point exception): Raise div-by-zero exception.
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// TODO(errno): POSIX requires setting errno to ERANGE.
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return FPBits<T>::negInf();
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} else if (bits.isNaN()) {
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return x;
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} else if (bits.isInf()) {
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// Return positive infinity.
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return FPBits<T>::inf();
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}
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NormalFloat<T> normal(bits);
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return normal.exponent;
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}
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} // namespace fputil
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} // namespace __llvm_libc
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#endif // LLVM_LIBC_UTILS_FPUTIL_MANIPULATION_FUNCTIONS_H
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