1 /* ===-- fixunsdfdi.c - Implement __fixunsdfdi -----------------------------===
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 __fixunsdfdi for the compiler_rt library.
11  *
12  * ===----------------------------------------------------------------------===
13  */
14 
15 #include "int_lib.h"
16 
17 /* Returns: convert a to a unsigned long long, rounding toward zero.
18  *          Negative values all become zero.
19  */
20 
21 /* Assumption: double is a IEEE 64 bit floating point type
22  *             du_int is a 64 bit integral type
23  *             value in double is representable in du_int or is negative
24  *                 (no range checking performed)
25  */
26 
27 /* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
28 
29 ARM_EABI_FNALIAS(d2ulz, fixunsdfdi)
30 
31 COMPILER_RT_ABI du_int
32 __fixunsdfdi(double a)
33 {
34     double_bits fb;
35     fb.f = a;
36     int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
37     if (e < 0 || (fb.u.s.high & 0x80000000))
38         return 0;
39     udwords r;
40     r.s.high = (fb.u.s.high & 0x000FFFFF) | 0x00100000;
41     r.s.low = fb.u.s.low;
42     if (e > 52)
43         r.all <<= (e - 52);
44     else
45         r.all >>= (52 - e);
46     return r.all;
47 }
48