fixunssfdi.c revision 222656 
1/* ===-- fixunssfdi.c - Implement __fixunssfdi -----------------------------===
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 __fixunssfdi for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14#include "abi.h"
15
16#include "int_lib.h"
17/* Returns: convert a to a unsigned long long, rounding toward zero.
18 *          Negative values all become zero.
19 */
20
21/* Assumption: float is a IEEE 32 bit floating point type
22 *             du_int is a 64 bit integral type
23 *             value in float is representable in du_int or is negative
24 *                 (no range checking performed)
25 */
26
27/* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
28
29ARM_EABI_FNALIAS(f2ulz, fixunssfdi);
30
31COMPILER_RT_ABI du_int
32__fixunssfdi(float a)
33{
34    float_bits fb;
35    fb.f = a;
36    int e = ((fb.u & 0x7F800000) >> 23) - 127;
37    if (e < 0 || (fb.u & 0x80000000))
38        return 0;
39    du_int r = (fb.u & 0x007FFFFF) | 0x00800000;
40    if (e > 23)
41        r <<= (e - 23);
42    else
43        r >>= (23 - e);
44    return r;
45}
46