1//===-- subvsi3.c - Implement __subvsi3 -----------------------------------===//
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 __subvsi3 for the compiler_rt library.
10//
11//===----------------------------------------------------------------------===//
12
13#include "int_lib.h"
14
15// Returns: a - b
16
17// Effects: aborts if a - b overflows
18
19COMPILER_RT_ABI si_int __subvsi3(si_int a, si_int b) {
20 si_int s = (su_int)a - (su_int)b;
21 if (b >= 0) {
22 if (s > a)
23 compilerrt_abort();
24 } else {
25 if (s <= a)
26 compilerrt_abort();
27 }
28 return s;
29}
30

source code of compiler-rt/lib/builtins/subvsi3.c