1 /* ===-- fixunssfti.c - Implement __fixunssfti -----------------------------===
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 __fixunssfti for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15 #include "int_lib.h"
16
17 #ifdef CRT_HAS_128BIT
18
19 /* Returns: convert a to a unsigned long long, rounding toward zero.
20 * Negative values all become zero.
21 */
22
23 /* Assumption: float is a IEEE 32 bit floating point type
24 * tu_int is a 64 bit integral type
25 * value in float is representable in tu_int or is negative
26 * (no range checking performed)
27 */
28
29 /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
30
31 COMPILER_RT_ABI tu_int
__fixunssfti(float a)32 __fixunssfti(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 tu_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
47 #endif /* CRT_HAS_128BIT */
48