subvsi3.c revision 2d1fdb26e458c4ddc04155c1d421bced3ba90cd0 
1/* ===-- subvsi3.c - Implement __subvsi3 -----------------------------------===
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 __subvsi3 for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15#include "int_lib.h"
16
17/* Returns: a - b */
18
19/* Effects: aborts if a - b overflows */
20
21COMPILER_RT_ABI si_int
22__subvsi3(si_int a, si_int b)
23{
24    si_int s = a - b;
25    if (b >= 0)
26    {
27        if (s > a)
28            compilerrt_abort();
29    }
30    else
31    {
32        if (s <= a)
33            compilerrt_abort();
34    }
35    return s;
36}
37