1250003Sadrian/* ===-- subvsi3.c - Implement __subvsi3 -----------------------------------===
2250003Sadrian *
3250003Sadrian *                The LLVM Compiler Infrastructure
4250003Sadrian *
5250003Sadrian * This file is dual licensed under the MIT and the University of Illinois Open
6250003Sadrian * Source Licenses. See LICENSE.TXT for details.
7250003Sadrian *
8250003Sadrian * ===----------------------------------------------------------------------===
9250003Sadrian *
10250003Sadrian * This file implements __subvsi3 for the compiler_rt library.
11250003Sadrian *
12250003Sadrian * ===----------------------------------------------------------------------===
13250003Sadrian */
14250003Sadrian
15250003Sadrian#include "int_lib.h"
16250003Sadrian
17250003Sadrian/* Returns: a - b */
18250003Sadrian
19250003Sadrian/* Effects: aborts if a - b overflows */
20250003Sadrian
21250003SadrianCOMPILER_RT_ABI si_int
22250003Sadrian__subvsi3(si_int a, si_int b)
23250003Sadrian{
24250003Sadrian    si_int s = (su_int) a - (su_int) b;
25250003Sadrian    if (b >= 0)
26250003Sadrian    {
27250003Sadrian        if (s > a)
28250003Sadrian            compilerrt_abort();
29250003Sadrian    }
30250003Sadrian    else
31250003Sadrian    {
32250003Sadrian        if (s <= a)
33250003Sadrian            compilerrt_abort();
34250003Sadrian    }
35250003Sadrian    return s;
36250003Sadrian}
37250003Sadrian