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-exception
6 //
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_128BIT
16
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 6
21 // bytes tu_int is a 128 bit integral type value in long double is representable
22 // in tu_int or is negative
23
24 // gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee
25 // eeee | 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm
26 // mmmm mmmm mmmm
27
__fixunsxfti(xf_float a)28 COMPILER_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 else
40 r >>= (63 - e);
41 return r;
42 }
43
44 #endif // CRT_HAS_128BIT
45