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      1 /* ===-- subvsi3.c - Implement __subvsi3 -----------------------------------===
      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 __subvsi3 for the compiler_rt library.
     11  *
     12  * ===----------------------------------------------------------------------===
     13  */
     14 
     15 #include "int_lib.h"
     16 
     17 /* Returns: a - b */
     18 
     19 /* Effects: aborts if a - b overflows */
     20 
     21 COMPILER_RT_ABI si_int
     22 __subvsi3(si_int a, si_int b)
     23 {
     24     si_int s = a - b;
     25     if (b >= 0)
     26     {
     27         if (s > a)
     28             compilerrt_abort();
     29     }
     30     else
     31     {
     32         if (s <= a)
     33             compilerrt_abort();
     34     }
     35     return s;
     36 }
     37