45 lines · c
1//===-- fixunsxfti.c - Implement __fixunsxfti -----------------------------===//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// This file implements __fixunsxfti for the compiler_rt library.10//11//===----------------------------------------------------------------------===//12 13#include "int_lib.h"14 15#ifdef CRT_HAS_128BIT16 17// Returns: convert a to a unsigned long long, rounding toward zero.18// Negative values all become zero.19 20// Assumption: long double is an intel 80 bit floating point type padded with 621// bytes tu_int is a 128 bit integral type value in long double is representable22// in tu_int or is negative23 24// gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee25// eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm26// mmmm mmmm mmmm27 28COMPILER_RT_ABI tu_int __fixunsxfti(xf_float a) {29 xf_bits fb;30 fb.f = a;31 int e = (fb.u.high.s.low & 0x00007FFF) - 16383;32 if (e < 0 || (fb.u.high.s.low & 0x00008000))33 return 0;34 if ((unsigned)e > sizeof(tu_int) * CHAR_BIT)35 return ~(tu_int)0;36 tu_int r = fb.u.low.all;37 if (e > 63)38 r <<= (e - 63);39 else40 r >>= (63 - e);41 return r;42}43 44#endif // CRT_HAS_128BIT45