lib/builtins/absvti2.c

   1 /* ===-- absvti2.c - Implement __absvdi2 -----------------------------------===
   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 __absvti2 for the compiler_rt library.
  11  *
  12  * ===----------------------------------------------------------------------===
  13  */
  14
  15 #include "int_lib.h"
  16
  17 #ifdef CRT_HAS_128BIT
  18
  19 /* Returns: absolute value */
  20
  21 /* Effects: aborts if abs(x) < 0 */
  22
  23 COMPILER_RT_ABI ti_int
  24 __absvti2(ti_int a)
  25 {
  26     const int N = (int)(sizeof(ti_int) * CHAR_BIT);
  27     if (a == ((ti_int)1 << (N-1)))
  28         compilerrt_abort();
  29     const ti_int s = a >> (N - 1);
  30     return (a ^ s) - s;
  31 }
  32
  33 #endif /* CRT_HAS_128BIT */
  34