xref: /minix3/sys/external/bsd/compiler_rt/dist/lib/builtins/fixunsdfsi.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc /* ===-- fixunsdfsi.c - Implement __fixunsdfsi -----------------------------===
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 __fixunsdfsi 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 /* Returns: convert a to a unsigned int, rounding toward zero.
18*0a6a1f1dSLionel Sambuc  *          Negative values all become zero.
19*0a6a1f1dSLionel Sambuc  */
20*0a6a1f1dSLionel Sambuc 
21*0a6a1f1dSLionel Sambuc /* Assumption: double is a IEEE 64 bit floating point type
22*0a6a1f1dSLionel Sambuc  *             su_int is a 32 bit integral type
23*0a6a1f1dSLionel Sambuc  *             value in double is representable in su_int or is negative
24*0a6a1f1dSLionel Sambuc  *                 (no range checking performed)
25*0a6a1f1dSLionel Sambuc  */
26*0a6a1f1dSLionel Sambuc 
27*0a6a1f1dSLionel Sambuc /* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
28*0a6a1f1dSLionel Sambuc 
ARM_EABI_FNALIAS(d2uiz,fixunsdfsi)29*0a6a1f1dSLionel Sambuc ARM_EABI_FNALIAS(d2uiz, fixunsdfsi)
30*0a6a1f1dSLionel Sambuc 
31*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI su_int
32*0a6a1f1dSLionel Sambuc __fixunsdfsi(double a)
33*0a6a1f1dSLionel Sambuc {
34*0a6a1f1dSLionel Sambuc     double_bits fb;
35*0a6a1f1dSLionel Sambuc     fb.f = a;
36*0a6a1f1dSLionel Sambuc     int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
37*0a6a1f1dSLionel Sambuc     if (e < 0 || (fb.u.s.high & 0x80000000))
38*0a6a1f1dSLionel Sambuc         return 0;
39*0a6a1f1dSLionel Sambuc     return (
40*0a6a1f1dSLionel Sambuc                 0x80000000u                      |
41*0a6a1f1dSLionel Sambuc                 ((fb.u.s.high & 0x000FFFFF) << 11) |
42*0a6a1f1dSLionel Sambuc                 (fb.u.s.low >> 21)
43*0a6a1f1dSLionel Sambuc            ) >> (31 - e);
44*0a6a1f1dSLionel Sambuc }
45