Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame^] | 1 | /*===-- absvdi2.c - Implement __absvdi2 -----------------------------------=== |
| 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 __absvdi2 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 | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame^] | 18 | /* Returns: absolute value */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 19 | |
Edward O'Callaghan | 37a6a45 | 2009-08-07 20:30:09 +0000 | [diff] [blame^] | 20 | /* Effects: aborts if abs(x) < 0 */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 21 | |
| 22 | di_int |
| 23 | __absvdi2(di_int a) |
| 24 | { |
| 25 | const int N = (int)(sizeof(di_int) * CHAR_BIT); |
| 26 | if (a == ((di_int)1 << (N-1))) |
| 27 | abort(); |
| 28 | const di_int t = a >> (N - 1); |
| 29 | return (a ^ t) - t; |
| 30 | } |