FreeBSD kernel libkern code
ashldi3.c
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1 /*-
2  * Copyright (c) 1992, 1993
3  * The Regents of the University of California. All rights reserved.
4  *
5  * This software was developed by the Computer Systems Engineering group
6  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7  * contributed to Berkeley.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  * notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  * notice, this list of conditions and the following disclaimer in the
16  * documentation and/or other materials provided with the distribution.
17  * 4. Neither the name of the University nor the names of its contributors
18  * may be used to endorse or promote products derived from this software
19  * without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$BSDSUniX$");
36 
37 #include <libkern/quad.h>
38 
39 /*
40  * Shift a (signed) quad value left (arithmetic shift left).
41  * This is the same as logical shift left!
42  */
43 quad_t
44 __ashldi3(a, shift)
45  quad_t a;
46  qshift_t shift;
47 {
48  union uu aa;
49 
50  aa.q = a;
51  if (shift >= LONG_BITS) {
52  aa.ul[H] = shift >= QUAD_BITS ? 0 :
53  aa.ul[L] << (shift - LONG_BITS);
54  aa.ul[L] = 0;
55  } else if (shift > 0) {
56  aa.ul[H] = (aa.ul[H] << shift) |
57  (aa.ul[L] >> (LONG_BITS - shift));
58  aa.ul[L] <<= shift;
59  }
60  return (aa.q);
61 }
Definition: quad.h:65
#define H
Definition: quad.h:75
u_long ul[2]
Definition: quad.h:69
#define QUAD_BITS
Definition: quad.h:83
#define L
Definition: quad.h:76
quad_t q
Definition: quad.h:66
unsigned int qshift_t
Definition: quad.h:100
#define LONG_BITS
Definition: quad.h:84
quad_t __ashldi3(quad_t a, qshift_t shift)
Definition: ashldi3.c:44
__FBSDID("$BSDSUniX$")