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      1 /* ===-- fixunssfsi.c - Implement __fixunssfsi -----------------------------===
      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 __fixunssfsi for the compiler_rt library.
     11  *
     12  * ===----------------------------------------------------------------------===
     13  */
     14 
     15 #include "int_lib.h"
     16 
     17 /* Returns: convert a to a unsigned int, rounding toward zero.
     18  *          Negative values all become zero.
     19  */
     20 
     21 /* Assumption: float is a IEEE 32 bit floating point type
     22  *             su_int is a 32 bit integral type
     23  *             value in float is representable in su_int or is negative
     24  *                 (no range checking performed)
     25  */
     26 
     27 /* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
     28 
     29 ARM_EABI_FNALIAS(f2uiz, fixunssfsi)
     30 
     31 COMPILER_RT_ABI su_int
     32 __fixunssfsi(float a)
     33 {
     34     float_bits fb;
     35     fb.f = a;
     36     int e = ((fb.u & 0x7F800000) >> 23) - 127;
     37     if (e < 0 || (fb.u & 0x80000000))
     38         return 0;
     39     su_int r = (fb.u & 0x007FFFFF) | 0x00800000;
     40     if (e > 23)
     41         r <<= (e - 23);
     42     else
     43         r >>= (23 - e);
     44     return r;
     45 }
     46