Edward O'Callaghan | 2bf6272 | 2009-08-05 04:02:56 +0000 | [diff] [blame^] | 1 | /* ===-- subvsi3.c - Implement __subvsi3 -----------------------------------=== |
| 2 | * |
| 3 | * The LLVM Compiler Infrastructure |
| 4 | * |
| 5 | * This file is distributed under the University of Illinois Open Source |
| 6 | * License. See LICENSE.TXT for details. |
| 7 | * |
| 8 | * ===----------------------------------------------------------------------=== |
| 9 | * |
| 10 | * This file implements __subvsi3 for the compiler_rt library. |
| 11 | * |
| 12 | * ===----------------------------------------------------------------------=== |
| 13 | */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 14 | |
| 15 | #include "int_lib.h" |
| 16 | #include <stdlib.h> |
| 17 | |
Edward O'Callaghan | 2bf6272 | 2009-08-05 04:02:56 +0000 | [diff] [blame^] | 18 | /* Returns: a - b */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 19 | |
Edward O'Callaghan | 2bf6272 | 2009-08-05 04:02:56 +0000 | [diff] [blame^] | 20 | /* Effects: aborts if a - b overflows */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 21 | |
| 22 | si_int |
| 23 | __subvsi3(si_int a, si_int b) |
| 24 | { |
| 25 | si_int s = a - b; |
| 26 | if (b >= 0) |
| 27 | { |
| 28 | if (s > a) |
| 29 | abort(); |
| 30 | } |
| 31 | else |
| 32 | { |
| 33 | if (s <= a) |
| 34 | abort(); |
| 35 | } |
| 36 | return s; |
| 37 | } |