1 /* ===-- fixsfti.c - Implement __fixsfti -----------------------------------===
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 __fixsfti 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 signed long long, rounding toward zero. */
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 ti_int (no range checking performed)
24 */
25
26 /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
27
28 COMPILER_RT_ABI ti_int
__fixsfti(float a)29 __fixsfti(float a)
30 {
31 float_bits fb;
32 fb.f = a;
33 int e = ((fb.u & 0x7F800000) >> 23) - 127;
34 if (e < 0)
35 return 0;
36 ti_int s = (si_int)(fb.u & 0x80000000) >> 31;
37 ti_int r = (fb.u & 0x007FFFFF) | 0x00800000;
38 if (e > 23)
39 r <<= (e - 23);
40 else
41 r >>= (23 - e);
42 return (r ^ s) - s;
43 }
44
45 #endif /* CRT_HAS_128BIT */
46