compiler-rt/lib/builtins/absvti2.c

   1 //===-- absvti2.c - Implement __absvdi2 -----------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements __absvti2 for the compiler_rt library.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "int_lib.h"
  14
  15 #ifdef CRT_HAS_128BIT
  16
  17 // Returns: absolute value
  18
  19 // Effects: aborts if abs(x) < 0
  20
  21 COMPILER_RT_ABI ti_int __absvti2(ti_int a) {
  22   const int N = (int)(sizeof(ti_int) * CHAR_BIT);
  23   if (a == ((ti_int)1 << (N - 1)))
  24     compilerrt_abort();
  25   const ti_int s = a >> (N - 1);
  26   return (a ^ s) - s;
  27 }
  28
  29 #endif // CRT_HAS_128BIT