1 /** @file
2 Compiler intrinsic for 32--bit unsigned division, ported from LLVM code.
3
4
5 Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
6
7 This program and the accompanying materials
8 are licensed and made available under the terms and conditions of the BSD License
9 which accompanies this distribution. The full text of the license may be found at
10 http://opensource.org/licenses/bsd-license.php
11
12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
14
15 **/
16 /**
17 University of Illinois/NCSA
18 Open Source License
19
20 Copyright (c) 2003-2008 University of Illinois at Urbana-Champaign.
21 All rights reserved.
22
23 Developed by:
24
25 LLVM Team
26
27 University of Illinois at Urbana-Champaign
28
29 http://llvm.org
30
31 Permission is hereby granted, free of charge, to any person obtaining a copy of
32 this software and associated documentation files (the "Software"), to deal with
33 the Software without restriction, including without limitation the rights to
34 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
35 of the Software, and to permit persons to whom the Software is furnished to do
36 so, subject to the following conditions:
37
38 * Redistributions of source code must retain the above copyright notice,
39 this list of conditions and the following disclaimers.
40
41 * Redistributions in binary form must reproduce the above copyright notice,
42 this list of conditions and the following disclaimers in the
43 documentation and/or other materials provided with the distribution.
44
45 * Neither the names of the LLVM Team, University of Illinois at
46 Urbana-Champaign, nor the names of its contributors may be used to
47 endorse or promote products derived from this Software without specific
48 prior written permission.
49
50 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
51 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
52 FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
53 CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
54 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
55 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
56 SOFTWARE.
57 **/
58
59
60 #include "Llvm_int_lib.h"
61
62 UINT32 __udivsi3(UINT32 n, UINT32 d);
63
64 // Returns: a / b
65
66 INT32
__divsi3(INT32 a,INT32 b)67 __divsi3(INT32 a, INT32 b)
68 {
69 const int bits_in_word_m1 = (int)(sizeof(INT32) * CHAR_BIT) - 1;
70 INT32 s_a = a >> bits_in_word_m1; // s_a = a < 0 ? -1 : 0
71 INT32 s_b = b >> bits_in_word_m1; // s_b = b < 0 ? -1 : 0
72 a = (a ^ s_a) - s_a; // negate if s_a == -1
73 b = (b ^ s_b) - s_b; // negate if s_b == -1
74 s_a ^= s_b; // sign of quotient
75 return (__udivsi3(a, b) ^ s_a) - s_a; // negate if s_a == -1
76 }
77
78
79