1/* ===-- fixdfdi.c - Implement __fixdfdi -----------------------------------===
2 *
3 *                     The LLVM Compiler Infrastructure
4 *
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
7 *
8 * ===----------------------------------------------------------------------===
9 *
10 * This file implements __fixdfdi for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15#include "int_lib.h"
16
17/* Returns: convert a to a signed long long, rounding toward zero. */
18
19/* Assumption: double is a IEEE 64 bit floating point type
20 *            su_int is a 32 bit integral type
21 *            value in double is representable in di_int (no range checking performed)
22 */
23
24/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
25
26ARM_EABI_FNALIAS(d2lz, fixdfdi)
27
28COMPILER_RT_ABI di_int
29__fixdfdi(double a)
30{
31    double_bits fb;
32    fb.f = a;
33    int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
34    if (e < 0)
35        return 0;
36    di_int s = (si_int)(fb.u.s.high & 0x80000000) >> 31;
37    dwords r;
38    r.s.high = (fb.u.s.high & 0x000FFFFF) | 0x00100000;
39    r.s.low = fb.u.s.low;
40    if (e > 52)
41        r.all <<= (e - 52);
42    else
43        r.all >>= (52 - e);
44    return (r.all ^ s) - s;
45}
46