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      1      1.1  joerg /* ===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------===
      2      1.1  joerg  *
      3      1.1  joerg  *                     The LLVM Compiler Infrastructure
      4      1.1  joerg  *
      5      1.1  joerg  * This file is dual licensed under the MIT and the University of Illinois Open
      6      1.1  joerg  * Source Licenses. See LICENSE.TXT for details.
      7      1.1  joerg  *
      8      1.1  joerg  * ===----------------------------------------------------------------------===
      9      1.1  joerg  *
     10      1.1  joerg  * This file implements __fixunsxfsi for the compiler_rt library.
     11      1.1  joerg  *
     12      1.1  joerg  * ===----------------------------------------------------------------------===
     13      1.1  joerg  */
     14      1.1  joerg 
     15      1.1  joerg #if !_ARCH_PPC
     16      1.1  joerg 
     17      1.1  joerg #include "int_lib.h"
     18      1.1  joerg 
     19      1.1  joerg /* Returns: convert a to a unsigned int, rounding toward zero.
     20      1.1  joerg  *          Negative values all become zero.
     21      1.1  joerg  */
     22      1.1  joerg 
     23      1.1  joerg /* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
     24      1.1  joerg  *             su_int is a 32 bit integral type
     25      1.1  joerg  *             value in long double is representable in su_int or is negative
     26      1.1  joerg  */
     27      1.1  joerg 
     28      1.1  joerg /* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
     29      1.1  joerg  * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
     30      1.1  joerg  */
     31      1.1  joerg 
     32  1.1.1.2  joerg COMPILER_RT_ABI su_int
     33      1.1  joerg __fixunsxfsi(long double a)
     34      1.1  joerg {
     35      1.1  joerg     long_double_bits fb;
     36      1.1  joerg     fb.f = a;
     37      1.1  joerg     int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
     38      1.1  joerg     if (e < 0 || (fb.u.high.s.low & 0x00008000))
     39      1.1  joerg         return 0;
     40  1.1.1.3  joerg     if ((unsigned)e > sizeof(su_int) * CHAR_BIT)
     41  1.1.1.3  joerg         return ~(su_int)0;
     42      1.1  joerg     return fb.u.low.s.high >> (31 - e);
     43      1.1  joerg }
     44      1.1  joerg 
     45      1.1  joerg #endif /* !_ARCH_PPC */
     46