xref: /aosp_15_r20/external/compiler-rt/lib/builtins/absvti2.c (revision 7c3d14c8b49c529e04be81a3ce6f5cc23712e4c6)
1*7c3d14c8STreehugger Robot /* ===-- absvti2.c - Implement __absvdi2 -----------------------------------===
2*7c3d14c8STreehugger Robot  *
3*7c3d14c8STreehugger Robot  *                     The LLVM Compiler Infrastructure
4*7c3d14c8STreehugger Robot  *
5*7c3d14c8STreehugger Robot  * This file is dual licensed under the MIT and the University of Illinois Open
6*7c3d14c8STreehugger Robot  * Source Licenses. See LICENSE.TXT for details.
7*7c3d14c8STreehugger Robot  *
8*7c3d14c8STreehugger Robot  * ===----------------------------------------------------------------------===
9*7c3d14c8STreehugger Robot  *
10*7c3d14c8STreehugger Robot  * This file implements __absvti2 for the compiler_rt library.
11*7c3d14c8STreehugger Robot  *
12*7c3d14c8STreehugger Robot  * ===----------------------------------------------------------------------===
13*7c3d14c8STreehugger Robot  */
14*7c3d14c8STreehugger Robot 
15*7c3d14c8STreehugger Robot #include "int_lib.h"
16*7c3d14c8STreehugger Robot 
17*7c3d14c8STreehugger Robot #ifdef CRT_HAS_128BIT
18*7c3d14c8STreehugger Robot 
19*7c3d14c8STreehugger Robot /* Returns: absolute value */
20*7c3d14c8STreehugger Robot 
21*7c3d14c8STreehugger Robot /* Effects: aborts if abs(x) < 0 */
22*7c3d14c8STreehugger Robot 
23*7c3d14c8STreehugger Robot COMPILER_RT_ABI ti_int
__absvti2(ti_int a)24*7c3d14c8STreehugger Robot __absvti2(ti_int a)
25*7c3d14c8STreehugger Robot {
26*7c3d14c8STreehugger Robot     const int N = (int)(sizeof(ti_int) * CHAR_BIT);
27*7c3d14c8STreehugger Robot     if (a == ((ti_int)1 << (N-1)))
28*7c3d14c8STreehugger Robot         compilerrt_abort();
29*7c3d14c8STreehugger Robot     const ti_int s = a >> (N - 1);
30*7c3d14c8STreehugger Robot     return (a ^ s) - s;
31*7c3d14c8STreehugger Robot }
32*7c3d14c8STreehugger Robot 
33*7c3d14c8STreehugger Robot #endif /* CRT_HAS_128BIT */
34*7c3d14c8STreehugger Robot 
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