xref: /minix3/sys/external/bsd/compiler_rt/dist/lib/builtins/fixunssfti.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc /* ===-- fixunssfti.c - Implement __fixunssfti -----------------------------===
2*0a6a1f1dSLionel Sambuc  *
3*0a6a1f1dSLionel Sambuc  *                     The LLVM Compiler Infrastructure
4*0a6a1f1dSLionel Sambuc  *
5*0a6a1f1dSLionel Sambuc  * This file is dual licensed under the MIT and the University of Illinois Open
6*0a6a1f1dSLionel Sambuc  * Source Licenses. See LICENSE.TXT for details.
7*0a6a1f1dSLionel Sambuc  *
8*0a6a1f1dSLionel Sambuc  * ===----------------------------------------------------------------------===
9*0a6a1f1dSLionel Sambuc  *
10*0a6a1f1dSLionel Sambuc  * This file implements __fixunssfti for the compiler_rt library.
11*0a6a1f1dSLionel Sambuc  *
12*0a6a1f1dSLionel Sambuc  * ===----------------------------------------------------------------------===
13*0a6a1f1dSLionel Sambuc  */
14*0a6a1f1dSLionel Sambuc 
15*0a6a1f1dSLionel Sambuc #include "int_lib.h"
16*0a6a1f1dSLionel Sambuc 
17*0a6a1f1dSLionel Sambuc #ifdef CRT_HAS_128BIT
18*0a6a1f1dSLionel Sambuc 
19*0a6a1f1dSLionel Sambuc /* Returns: convert a to a unsigned long long, rounding toward zero.
20*0a6a1f1dSLionel Sambuc  *          Negative values all become zero.
21*0a6a1f1dSLionel Sambuc  */
22*0a6a1f1dSLionel Sambuc 
23*0a6a1f1dSLionel Sambuc /* Assumption: float is a IEEE 32 bit floating point type
24*0a6a1f1dSLionel Sambuc  *             tu_int is a 64 bit integral type
25*0a6a1f1dSLionel Sambuc  *             value in float is representable in tu_int or is negative
26*0a6a1f1dSLionel Sambuc  *                 (no range checking performed)
27*0a6a1f1dSLionel Sambuc  */
28*0a6a1f1dSLionel Sambuc 
29*0a6a1f1dSLionel Sambuc /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
30*0a6a1f1dSLionel Sambuc 
31*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI tu_int
__fixunssfti(float a)32*0a6a1f1dSLionel Sambuc __fixunssfti(float a)
33*0a6a1f1dSLionel Sambuc {
34*0a6a1f1dSLionel Sambuc     float_bits fb;
35*0a6a1f1dSLionel Sambuc     fb.f = a;
36*0a6a1f1dSLionel Sambuc     int e = ((fb.u & 0x7F800000) >> 23) - 127;
37*0a6a1f1dSLionel Sambuc     if (e < 0 || (fb.u & 0x80000000))
38*0a6a1f1dSLionel Sambuc         return 0;
39*0a6a1f1dSLionel Sambuc     tu_int r = (fb.u & 0x007FFFFF) | 0x00800000;
40*0a6a1f1dSLionel Sambuc     if (e > 23)
41*0a6a1f1dSLionel Sambuc         r <<= (e - 23);
42*0a6a1f1dSLionel Sambuc     else
43*0a6a1f1dSLionel Sambuc         r >>= (23 - e);
44*0a6a1f1dSLionel Sambuc     return r;
45*0a6a1f1dSLionel Sambuc }
46*0a6a1f1dSLionel Sambuc 
47*0a6a1f1dSLionel Sambuc #endif /* CRT_HAS_128BIT */
48