110 lines
3.9 KiB
C++
110 lines
3.9 KiB
C++
//===-- Common operations on floating point numbers -------------*- 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_FLOAT_OPERATIONS_H
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#define LLVM_LIBC_UTILS_FPUTIL_FLOAT_OPERATIONS_H
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#include "BitPatterns.h"
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#include "FloatProperties.h"
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#include "utils/CPP/TypeTraits.h"
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namespace __llvm_libc {
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namespace fputil {
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// Return the bits of a float value.
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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 typename FloatProperties<T>::BitsType valueAsBits(T x) {
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using BitsType = typename FloatProperties<T>::BitsType;
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return *reinterpret_cast<BitsType *>(&x);
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}
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// Return the float value from bits.
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template <typename BitsType,
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cpp::EnableIfType<
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cpp::IsFloatingPointType<FloatTypeT<BitsType>>::Value, int> = 0>
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static inline FloatTypeT<BitsType> valueFromBits(BitsType bits) {
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return *reinterpret_cast<FloatTypeT<BitsType> *>(&bits);
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}
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// Return the bits of abs(x).
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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 typename FloatProperties<T>::BitsType absBits(T x) {
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return valueAsBits(x) & (~FloatProperties<T>::signMask);
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}
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// Return the zero adjusted exponent value of x.
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template <typename T,
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cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
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int getExponent(T x) {
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using Properties = FloatProperties<T>;
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using BitsType = typename Properties::BitsType;
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BitsType bits = absBits(x);
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int e = (bits >> Properties::mantissaWidth); // Shift out the mantissa.
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e -= Properties::exponentOffset; // Zero adjust.
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return e;
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}
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// Return true if x is infinity (positive or negative.)
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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 bool isInf(T x) {
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using Properties = FloatProperties<T>;
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using BitsType = typename FloatProperties<T>::BitsType;
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BitsType bits = valueAsBits(x);
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return ((bits & BitPatterns<T>::inf) == BitPatterns<T>::inf) &&
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((bits & Properties::mantissaMask) == 0);
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}
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// Return true if x is a NAN (quiet or signalling.)
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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 bool isNaN(T x) {
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using Properties = FloatProperties<T>;
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using BitsType = typename FloatProperties<T>::BitsType;
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BitsType bits = valueAsBits(x);
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return ((bits & BitPatterns<T>::inf) == BitPatterns<T>::inf) &&
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((bits & Properties::mantissaMask) != 0);
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}
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// Return true if x is a quiet NAN.
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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 bool isQuietNaN(T x) {
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using Properties = FloatProperties<T>;
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using BitsType = typename FloatProperties<T>::BitsType;
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BitsType bits = valueAsBits(x);
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return ((bits & BitPatterns<T>::inf) == BitPatterns<T>::inf) &&
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((bits & Properties::quietNaNMask) != 0);
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}
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// Return true if x is a quiet NAN with sign bit set.
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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 bool isNegativeQuietNaN(T x) {
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using Properties = FloatProperties<T>;
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using BitsType = typename FloatProperties<T>::BitsType;
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BitsType bits = valueAsBits(x);
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return ((bits & BitPatterns<T>::negInf) == BitPatterns<T>::negInf) &&
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((bits & Properties::quietNaNMask) != 0);
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}
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// Return the absolute value of x.
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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 abs(T x) {
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return valueFromBits(absBits(x));
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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_FLOAT_OPERATIONS_H
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