xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/subvsi3.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-- subvsi3.c - Implement __subvsi3 -----------------------------------===//
2*0b57cec5SDimitry Andric //
3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*0b57cec5SDimitry Andric //
7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
8*0b57cec5SDimitry Andric //
9*0b57cec5SDimitry Andric // This file implements __subvsi3 for the compiler_rt library.
10*0b57cec5SDimitry Andric //
11*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
12*0b57cec5SDimitry Andric 
13*0b57cec5SDimitry Andric #include "int_lib.h"
14*0b57cec5SDimitry Andric 
15*0b57cec5SDimitry Andric // Returns: a - b
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric // Effects: aborts if a - b overflows
18*0b57cec5SDimitry Andric 
__subvsi3(si_int a,si_int b)19*0b57cec5SDimitry Andric COMPILER_RT_ABI si_int __subvsi3(si_int a, si_int b) {
20*0b57cec5SDimitry Andric   si_int s = (su_int)a - (su_int)b;
21*0b57cec5SDimitry Andric   if (b >= 0) {
22*0b57cec5SDimitry Andric     if (s > a)
23*0b57cec5SDimitry Andric       compilerrt_abort();
24*0b57cec5SDimitry Andric   } else {
25*0b57cec5SDimitry Andric     if (s <= a)
26*0b57cec5SDimitry Andric       compilerrt_abort();
27*0b57cec5SDimitry Andric   }
28*0b57cec5SDimitry Andric   return s;
29*0b57cec5SDimitry Andric }
30