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
26 ARM_EABI_FNALIAS(d2lz, fixdfdi);
27
28 di_int
__fixdfdi(double a)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