1 /* ===-- fixunssfsi.c - Implement __fixunssfsi -----------------------------===
2 *
3 * The LLVM Compiler Infrastructure
4 *
5 * This file is distributed under the University of Illinois Open Source
6 * License. See LICENSE.TXT for details.
7 *
8 * ===----------------------------------------------------------------------===
9 *
10 * This file implements __fixunssfsi for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15 #include "int_lib.h"
16
17 /* Returns: convert a to a unsigned int, rounding toward zero.
18 * Negative values all become zero.
19 */
20
21 /* Assumption: float is a IEEE 32 bit floating point type
22 * su_int is a 32 bit integral type
23 * value in float is representable in su_int or is negative
24 * (no range checking performed)
25 */
26
27 /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
28
29 su_int
__fixunssfsi(float a)30 __fixunssfsi(float a)
31 {
32 float_bits fb;
33 fb.f = a;
34 int e = ((fb.u & 0x7F800000) >> 23) - 127;
35 if (e < 0 || (fb.u & 0x80000000))
36 return 0;
37 su_int r = (fb.u & 0x007FFFFF) | 0x00800000;
38 if (e > 23)
39 r <<= (e - 23);
40 else
41 r >>= (23 - e);
42 return r;
43 }
44