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

37 lines
852 B
C

/* ===-- subvsi3.c - Implement __subvsi3 -----------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* 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;
}