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1//===----------------------------------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9// Define a hexfloat literal emulator since we can't depend on being able to10// for hexfloat literals11 12// 0x10.F5p-10 == hexfloat<double>(0x10, 0xF5, -10)13 14#ifndef HEXFLOAT_H15#define HEXFLOAT_H16 17#include <climits>18#include <cmath>19#include <cstddef>20 21template <class T>22class hexfloat23{24 T value_;25 26 static int CountLeadingZeros(unsigned long long n) {27 const std::size_t Digits = sizeof(unsigned long long) * CHAR_BIT;28 const unsigned long long TopBit = 1ull << (Digits - 1);29 if (n == 0) return Digits;30 int LeadingZeros = 0;31 while ((n & TopBit) == 0) {32 ++LeadingZeros;33 n <<= 1;34 }35 return LeadingZeros;36 }37 38public:39 hexfloat(long long m1, unsigned long long m0, int exp)40 {41 const std::size_t Digits = sizeof(unsigned long long) * CHAR_BIT;42 int s = m1 < 0 ? -1 : 1;43 int exp2 = -static_cast<int>(Digits - CountLeadingZeros(m0)/4*4);44 value_ = std::ldexp(m1 + s * std::ldexp(T(m0), exp2), exp);45 }46 47 operator T() const {return value_;}48};49 50#endif51