aboutsummaryrefslogtreecommitdiff
path: root/lib/builtins/fixunssfdi.c
blob: 69d5952e96078a1283327ecd683c0f15654da9aa (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
/* ===-- fixunssfdi.c - Implement __fixunssfdi -----------------------------===
 *
 *                     The LLVM Compiler Infrastructure
 *
 * This file is dual licensed under the MIT and the University of Illinois Open
 * Source Licenses. See LICENSE.TXT for details.
 *
 * ===----------------------------------------------------------------------===
 *
 * This file implements __fixunssfdi for the compiler_rt library.
 *
 * ===----------------------------------------------------------------------===
 */

#include "int_lib.h"
/* Returns: convert a to a unsigned long long, rounding toward zero.
 *          Negative values all become zero.
 */

/* Assumption: float is a IEEE 32 bit floating point type 
 *             du_int is a 64 bit integral type
 *             value in float is representable in du_int or is negative 
 *                 (no range checking performed)
 */

/* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */

ARM_EABI_FNALIAS(f2ulz, fixunssfdi)

COMPILER_RT_ABI du_int
__fixunssfdi(float a)
{
    float_bits fb;
    fb.f = a;
    int e = ((fb.u & 0x7F800000) >> 23) - 127;
    if (e < 0 || (fb.u & 0x80000000))
        return 0;
    du_int r = (fb.u & 0x007FFFFF) | 0x00800000;
    if (e > 23)
        r <<= (e - 23);
    else
        r >>= (23 - e);
    return r;
}