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-exception 4 5 // long double __floatditf(long long x); 6 // This file implements the PowerPC long long -> long double conversion 7 8 #include "DD.h" 9 10 long double __floatditf(int64_t a) { 11 12 static const double twop32 = 0x1.0p32; 13 static const double twop52 = 0x1.0p52; 14 15 doublebits low = {.d = twop52}; 16 low.x |= a & UINT64_C(0x00000000ffffffff); // 0x1.0p52 + low 32 bits of a. 17 18 const double high_addend = (double)((int32_t)(a >> 32)) * twop32 - twop52; 19 20 // At this point, we have two double precision numbers 21 // high_addend and low.d, and we wish to return their sum 22 // as a canonicalized long double: 23 24 // This implementation sets the inexact flag spuriously. 25 // This could be avoided, but at some substantial cost. 26 27 DD result; 28 29 result.s.hi = high_addend + low.d; 30 result.s.lo = (high_addend - result.s.hi) + low.d; 31 32 return result.ld; 33 } 34