1214152Sed/* ===-- fixunsdfti.c - Implement __fixunsdfti -----------------------------===
2214152Sed *
3214152Sed *                     The LLVM Compiler Infrastructure
4214152Sed *
5222656Sed * This file is dual licensed under the MIT and the University of Illinois Open
6222656Sed * Source Licenses. See LICENSE.TXT for details.
7214152Sed *
8214152Sed * ===----------------------------------------------------------------------===
9214152Sed *
10214152Sed * This file implements __fixunsdfti for the compiler_rt library.
11214152Sed *
12214152Sed * ===----------------------------------------------------------------------===
13214152Sed */
14214152Sed
15239138Sandrew#include "int_lib.h"
16239138Sandrew
17263763Sdim#ifdef CRT_HAS_128BIT
18214152Sed
19214152Sed/* Returns: convert a to a unsigned long long, rounding toward zero.
20214152Sed *          Negative values all become zero.
21214152Sed */
22214152Sed
23214152Sed/* Assumption: double is a IEEE 64 bit floating point type
24214152Sed *             tu_int is a 64 bit integral type
25214152Sed *             value in double is representable in tu_int or is negative
26214152Sed *                 (no range checking performed)
27214152Sed */
28214152Sed
29214152Sed/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
30214152Sed
31214152Sedtu_int
32214152Sed__fixunsdfti(double a)
33214152Sed{
34214152Sed    double_bits fb;
35214152Sed    fb.f = a;
36214152Sed    int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
37214152Sed    if (e < 0 || (fb.u.s.high & 0x80000000))
38214152Sed        return 0;
39214152Sed    tu_int r = 0x0010000000000000uLL | (fb.u.all & 0x000FFFFFFFFFFFFFuLL);
40214152Sed    if (e > 52)
41214152Sed        r <<= (e - 52);
42214152Sed    else
43214152Sed        r >>= (52 - e);
44214152Sed    return r;
45214152Sed}
46214152Sed
47263763Sdim#endif /* CRT_HAS_128BIT */
48