| 1 | /* ===-- subvsi3.c - Implement __subvsi3 -----------------------------------=== |
| 2 | * |
| 3 | * The LLVM Compiler Infrastructure |
| 4 | * |
| 5 | * This file is dual licensed under the MIT and the University of Illinois Open |
| 6 | * Source Licenses. See LICENSE.TXT for details. |
| 7 | * |
| 8 | * ===----------------------------------------------------------------------=== |
| 9 | * |
| 10 | * This file implements __subvsi3 for the compiler_rt library. |
| 11 | * |
| 12 | * ===----------------------------------------------------------------------=== |
| 13 | */ |
| 14 | |
| 15 | #include "int_lib.h" |
| 16 | |
| 17 | /* Returns: a - b */ |
| 18 | |
| 19 | /* Effects: aborts if a - b overflows */ |
| 20 | |
| 21 | COMPILER_RT_ABI si_int |
| 22 | __subvsi3(si_int a, si_int b) |
| 23 | { |
| 24 | si_int s = (su_int) a - (su_int) b; |
| 25 | if (b >= 0) |
| 26 | { |
| 27 | if (s > a) |
| 28 | compilerrt_abort(); |
| 29 | } |
| 30 | else |
| 31 | { |
| 32 | if (s <= a) |
| 33 | compilerrt_abort(); |
| 34 | } |
| 35 | return s; |
| 36 | } |
| 37 | |