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1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.2// See https://llvm.org/LICENSE.txt for license information.3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception4 5// long double __floatunditf(unsigned long long x);6// This file implements the PowerPC unsigned long long -> long double conversion7 8#include "DD.h"9 10long double __floatunditf(uint64_t a) {11 12 // Begins with an exact copy of the code from __floatundidf13 14 static const double twop52 = 0x1.0p52;15 static const double twop84 = 0x1.0p84;16 static const double twop84_plus_twop52 = 0x1.00000001p84;17 18 doublebits high = {.d = twop84};19 doublebits low = {.d = twop52};20 21 high.x |= a >> 32; // 0x1.0p84 + high 32 bits of a22 low.x |= a & UINT64_C(0x00000000ffffffff); // 0x1.0p52 + low 32 bits of a23 24 const double high_addend = high.d - twop84_plus_twop52;25 26 // At this point, we have two double precision numbers27 // high_addend and low.d, and we wish to return their sum28 // as a canonicalized long double:29 30 // This implementation sets the inexact flag spuriously.31 // This could be avoided, but at some substantial cost.32 33 DD result;34 35 result.s.hi = high_addend + low.d;36 result.s.lo = (high_addend - result.s.hi) + low.d;37 38 return result.ld;39}40