src/libcompiler_builtins/compiler-rt/lib/builtins/negvsi2.c

   1 /* ===-- negvsi2.c - Implement __negvsi2 -----------------------------------===
   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 __negvsi2 for the compiler_rt library.
  11  *
  12  * ===----------------------------------------------------------------------===
  13  */
  14
  15 #include "int_lib.h"
  16
  17 /* Returns: -a */
  18
  19 /* Effects: aborts if -a overflows */
  20
  21 COMPILER_RT_ABI si_int
  22 __negvsi2(si_int a)
  23 {
  24     const si_int MIN = (si_int)1 << ((int)(sizeof(si_int) * CHAR_BIT)-1);
  25     if (a == MIN)
  26         compilerrt_abort();
  27     return -a;
  28 }