1214152Sed/* ===-- fixdfti.c - Implement __fixdfti -----------------------------------===
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 __fixdfti 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 signed long long, rounding toward zero. */
20214152Sed
21214152Sed/* Assumption: double is a IEEE 64 bit floating point type
22214152Sed *             su_int is a 32 bit integral type
23214152Sed *             value in double is representable in ti_int (no range checking performed)
24214152Sed */
25214152Sed
26214152Sed/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
27214152Sed
28214152Sedti_int
29214152Sed__fixdfti(double a)
30214152Sed{
31214152Sed    double_bits fb;
32214152Sed    fb.f = a;
33214152Sed    int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
34214152Sed    if (e < 0)
35214152Sed        return 0;
36214152Sed    ti_int s = (si_int)(fb.u.s.high & 0x80000000) >> 31;
37214152Sed    ti_int r = 0x0010000000000000uLL | (0x000FFFFFFFFFFFFFuLL & fb.u.all);
38214152Sed    if (e > 52)
39214152Sed        r <<= (e - 52);
40214152Sed    else
41214152Sed        r >>= (52 - e);
42214152Sed    return (r ^ s) - s;
43214152Sed}
44214152Sed
45263763Sdim#endif /* CRT_HAS_128BIT */
46