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      1 /* ===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------===
      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 __fixunsxfsi 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 int, 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  *             su_int is a 32 bit integral type
     25  *             value in long double is representable in su_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 su_int
     34 __fixunsxfsi(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     return fb.u.low.s.high >> (31 - e);
     42 }
     43 
     44 #endif /* !_ARCH_PPC */
     45