xref: /minix3/sys/external/bsd/compiler_rt/dist/lib/builtins/fixunsxfsi.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc /* ===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------===
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 __fixunsxfsi for the compiler_rt library.
11*0a6a1f1dSLionel Sambuc  *
12*0a6a1f1dSLionel Sambuc  * ===----------------------------------------------------------------------===
13*0a6a1f1dSLionel Sambuc  */
14*0a6a1f1dSLionel Sambuc 
15*0a6a1f1dSLionel Sambuc #if !_ARCH_PPC
16*0a6a1f1dSLionel Sambuc 
17*0a6a1f1dSLionel Sambuc #include "int_lib.h"
18*0a6a1f1dSLionel Sambuc 
19*0a6a1f1dSLionel Sambuc /* Returns: convert a to a unsigned int, rounding toward zero.
20*0a6a1f1dSLionel Sambuc  *          Negative values all become zero.
21*0a6a1f1dSLionel Sambuc  */
22*0a6a1f1dSLionel Sambuc 
23*0a6a1f1dSLionel Sambuc /* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
24*0a6a1f1dSLionel Sambuc  *             su_int is a 32 bit integral type
25*0a6a1f1dSLionel Sambuc  *             value in long double is representable in su_int or is negative
26*0a6a1f1dSLionel Sambuc  *                 (no range checking performed)
27*0a6a1f1dSLionel Sambuc  */
28*0a6a1f1dSLionel Sambuc 
29*0a6a1f1dSLionel Sambuc /* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
30*0a6a1f1dSLionel Sambuc  * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
31*0a6a1f1dSLionel Sambuc  */
32*0a6a1f1dSLionel Sambuc 
33*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI su_int
__fixunsxfsi(long double a)34*0a6a1f1dSLionel Sambuc __fixunsxfsi(long double a)
35*0a6a1f1dSLionel Sambuc {
36*0a6a1f1dSLionel Sambuc     long_double_bits fb;
37*0a6a1f1dSLionel Sambuc     fb.f = a;
38*0a6a1f1dSLionel Sambuc     int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
39*0a6a1f1dSLionel Sambuc     if (e < 0 || (fb.u.high.s.low & 0x00008000))
40*0a6a1f1dSLionel Sambuc         return 0;
41*0a6a1f1dSLionel Sambuc     return fb.u.low.s.high >> (31 - e);
42*0a6a1f1dSLionel Sambuc }
43*0a6a1f1dSLionel Sambuc 
44*0a6a1f1dSLionel Sambuc #endif /* !_ARCH_PPC */
45