xref: /minix3/sys/external/bsd/compiler_rt/dist/lib/builtins/fixxfti.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc /* ===-- fixxfti.c - Implement __fixxfti -----------------------------------===
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 __fixxfti 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 signed long long, rounding toward zero. */
20*0a6a1f1dSLionel Sambuc 
21*0a6a1f1dSLionel Sambuc /* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
22*0a6a1f1dSLionel Sambuc  *             su_int is a 32 bit integral type
23*0a6a1f1dSLionel Sambuc  *             value in long double is representable in ti_int (no range checking performed)
24*0a6a1f1dSLionel Sambuc  */
25*0a6a1f1dSLionel Sambuc 
26*0a6a1f1dSLionel Sambuc /* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
27*0a6a1f1dSLionel Sambuc  * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
28*0a6a1f1dSLionel Sambuc  */
29*0a6a1f1dSLionel Sambuc 
30*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI ti_int
__fixxfti(long double a)31*0a6a1f1dSLionel Sambuc __fixxfti(long double a)
32*0a6a1f1dSLionel Sambuc {
33*0a6a1f1dSLionel Sambuc     long_double_bits fb;
34*0a6a1f1dSLionel Sambuc     fb.f = a;
35*0a6a1f1dSLionel Sambuc     int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
36*0a6a1f1dSLionel Sambuc     if (e < 0)
37*0a6a1f1dSLionel Sambuc         return 0;
38*0a6a1f1dSLionel Sambuc     ti_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15);
39*0a6a1f1dSLionel Sambuc     ti_int r = fb.u.low.all;
40*0a6a1f1dSLionel Sambuc     if (e > 63)
41*0a6a1f1dSLionel Sambuc         r <<= (e - 63);
42*0a6a1f1dSLionel Sambuc     else
43*0a6a1f1dSLionel Sambuc         r >>= (63 - e);
44*0a6a1f1dSLionel Sambuc     return (r ^ s) - s;
45*0a6a1f1dSLionel Sambuc }
46*0a6a1f1dSLionel Sambuc 
47*0a6a1f1dSLionel Sambuc #endif /* CRT_HAS_128BIT */
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