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1 /* ===-- fixunsxfdi.c - Implement __fixunsxfdi -----------------------------===
2  *
3  *                     The LLVM Compiler Infrastructure
4  *
5  * This file is dual licensed under the MIT and the University of Illinois Open
6  * Source Licenses. See LICENSE.TXT for details.
7  *
8  * ===----------------------------------------------------------------------===
9  *
10  * This file implements __fixunsxfdi for the compiler_rt library.
11  *
12  * ===----------------------------------------------------------------------===
13  */
14 
15 #if !_ARCH_PPC
16 
17 #include "int_lib.h"
18 
19 /* Returns: convert a to a unsigned long long, rounding toward zero.
20  *          Negative values all become zero.
21  */
22 
23 /* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
24  *             du_int is a 64 bit integral type
25  *             value in long double is representable in du_int or is negative
26  *                 (no range checking performed)
27  */
28 
29 /* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
30  * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
31  */
32 
33 COMPILER_RT_ABI du_int
__fixunsxfdi(long double a)34 __fixunsxfdi(long double a)
35 {
36     long_double_bits fb;
37     fb.f = a;
38     int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
39     if (e < 0 || (fb.u.high.s.low & 0x00008000))
40         return 0;
41     if ((unsigned)e > sizeof(du_int) * CHAR_BIT)
42         return ~(du_int)0;
43     return fb.u.low.all >> (63 - e);
44 }
45 
46 #endif
47