xref: /minix3/sys/external/bsd/compiler_rt/dist/lib/builtins/absvdi2.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc /*===-- absvdi2.c - Implement __absvdi2 -----------------------------------===
2*0a6a1f1dSLionel Sambuc  *
3*0a6a1f1dSLionel Sambuc  *                     The LLVM Compiler Infrastructure
4*0a6a1f1dSLionel Sambuc  *
5*0a6a1f1dSLionel Sambuc  * This file is dual licensed under the MIT and the University of Illinois Open
6*0a6a1f1dSLionel Sambuc  * Source Licenses. See LICENSE.TXT for details.
7*0a6a1f1dSLionel Sambuc  *
8*0a6a1f1dSLionel Sambuc  *===----------------------------------------------------------------------===
9*0a6a1f1dSLionel Sambuc  *
10*0a6a1f1dSLionel Sambuc  * This file implements __absvdi2 for the compiler_rt library.
11*0a6a1f1dSLionel Sambuc  *
12*0a6a1f1dSLionel Sambuc  *===----------------------------------------------------------------------===
13*0a6a1f1dSLionel Sambuc  */
14*0a6a1f1dSLionel Sambuc 
15*0a6a1f1dSLionel Sambuc #include "int_lib.h"
16*0a6a1f1dSLionel Sambuc 
17*0a6a1f1dSLionel Sambuc /* Returns: absolute value */
18*0a6a1f1dSLionel Sambuc 
19*0a6a1f1dSLionel Sambuc /* Effects: aborts if abs(x) < 0 */
20*0a6a1f1dSLionel Sambuc 
21*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI di_int
__absvdi2(di_int a)22*0a6a1f1dSLionel Sambuc __absvdi2(di_int a)
23*0a6a1f1dSLionel Sambuc {
24*0a6a1f1dSLionel Sambuc     const int N = (int)(sizeof(di_int) * CHAR_BIT);
25*0a6a1f1dSLionel Sambuc     if (a == ((di_int)1 << (N-1)))
26*0a6a1f1dSLionel Sambuc         compilerrt_abort();
27*0a6a1f1dSLionel Sambuc     const di_int t = a >> (N - 1);
28*0a6a1f1dSLionel Sambuc     return (a ^ t) - t;
29*0a6a1f1dSLionel Sambuc }
30