1 /* ===-- fixsfdi.c - Implement __fixsfdi -----------------------------------===
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 __fixsfdi 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: float is a IEEE 32 bit floating point type
20 * su_int is a 32 bit integral type
21 * value in float is representable in di_int (no range checking performed)
22 */
23
24 /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
25
26 di_int
__fixsfdi(float a)27 __fixsfdi(float a)
28 {
29 float_bits fb;
30 fb.f = a;
31 int e = ((fb.u & 0x7F800000) >> 23) - 127;
32 if (e < 0)
33 return 0;
34 di_int s = (si_int)(fb.u & 0x80000000) >> 31;
35 di_int r = (fb.u & 0x007FFFFF) | 0x00800000;
36 if (e > 23)
37 r <<= (e - 23);
38 else
39 r >>= (23 - e);
40 return (r ^ s) - s;
41 }
42