| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| |
| // long double __floatunditf(unsigned long long x); |
| // This file implements the PowerPC unsigned long long -> long double conversion |
| |
| #include "DD.h" |
| |
| long double __floatunditf(uint64_t a) { |
| |
| // Begins with an exact copy of the code from __floatundidf |
| |
| static const double twop52 = 0x1.0p52; |
| static const double twop84 = 0x1.0p84; |
| static const double twop84_plus_twop52 = 0x1.00000001p84; |
| |
| doublebits high = {.d = twop84}; |
| doublebits low = {.d = twop52}; |
| |
| high.x |= a >> 32; // 0x1.0p84 + high 32 bits of a |
| low.x |= a & UINT64_C(0x00000000ffffffff); // 0x1.0p52 + low 32 bits of a |
| |
| const double high_addend = high.d - twop84_plus_twop52; |
| |
| // At this point, we have two double precision numbers |
| // high_addend and low.d, and we wish to return their sum |
| // as a canonicalized long double: |
| |
| // This implementation sets the inexact flag spuriously. |
| // This could be avoided, but at some substantial cost. |
| |
| DD result; |
| |
| result.s.hi = high_addend + low.d; |
| result.s.lo = (high_addend - result.s.hi) + low.d; |
| |
| return result.ld; |
| } |