llvm-project/compiler-rt/lib/builtins/subvsi3.c

30 lines
819 B
C

//===-- subvsi3.c - Implement __subvsi3 -----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements __subvsi3 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "int_lib.h"
// Returns: a - b
// Effects: aborts if a - b overflows
COMPILER_RT_ABI si_int __subvsi3(si_int a, si_int b) {
si_int s = (su_int)a - (su_int)b;
if (b >= 0) {
if (s > a)
compilerrt_abort();
} else {
if (s <= a)
compilerrt_abort();
}
return s;
}