xref: /minix3/sys/external/bsd/compiler_rt/dist/lib/builtins/fixunssfdi.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc /* ===-- fixunssfdi.c - Implement __fixunssfdi -----------------------------===
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 __fixunssfdi 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 /* Returns: convert a to a unsigned long long, rounding toward zero.
17*0a6a1f1dSLionel Sambuc  *          Negative values all become zero.
18*0a6a1f1dSLionel Sambuc  */
19*0a6a1f1dSLionel Sambuc 
20*0a6a1f1dSLionel Sambuc /* Assumption: float is a IEEE 32 bit floating point type
21*0a6a1f1dSLionel Sambuc  *             du_int is a 64 bit integral type
22*0a6a1f1dSLionel Sambuc  *             value in float is representable in du_int or is negative
23*0a6a1f1dSLionel Sambuc  *                 (no range checking performed)
24*0a6a1f1dSLionel Sambuc  */
25*0a6a1f1dSLionel Sambuc 
26*0a6a1f1dSLionel Sambuc /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
27*0a6a1f1dSLionel Sambuc 
ARM_EABI_FNALIAS(f2ulz,fixunssfdi)28*0a6a1f1dSLionel Sambuc ARM_EABI_FNALIAS(f2ulz, fixunssfdi)
29*0a6a1f1dSLionel Sambuc 
30*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI du_int
31*0a6a1f1dSLionel Sambuc __fixunssfdi(float a)
32*0a6a1f1dSLionel Sambuc {
33*0a6a1f1dSLionel Sambuc     float_bits fb;
34*0a6a1f1dSLionel Sambuc     fb.f = a;
35*0a6a1f1dSLionel Sambuc     int e = ((fb.u & 0x7F800000) >> 23) - 127;
36*0a6a1f1dSLionel Sambuc     if (e < 0 || (fb.u & 0x80000000))
37*0a6a1f1dSLionel Sambuc         return 0;
38*0a6a1f1dSLionel Sambuc     du_int r = (fb.u & 0x007FFFFF) | 0x00800000;
39*0a6a1f1dSLionel Sambuc     if (e > 23)
40*0a6a1f1dSLionel Sambuc         r <<= (e - 23);
41*0a6a1f1dSLionel Sambuc     else
42*0a6a1f1dSLionel Sambuc         r >>= (23 - e);
43*0a6a1f1dSLionel Sambuc     return r;
44*0a6a1f1dSLionel Sambuc }
45