xref: /optee_os/lib/libutils/isoc/arch/arm/arm32_aeabi_shift.c (revision 1bb929836182ecb96d2d9d268daa807c67596396)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2015, Linaro Limited
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright notice,
10  * this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright notice,
13  * this list of conditions and the following disclaimer in the documentation
14  * and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 union dword {
30 	unsigned long long dw;
31 	unsigned long w[2];
32 };
33 
34 long long __aeabi_llsl(long long a, int shift);
35 long long __aeabi_llsl(long long a, int shift)
36 {
37 	union dword dword = { .dw = a };
38 	unsigned long hi = dword.w[1];
39 	unsigned long lo = dword.w[0];
40 
41 	if (shift >= 32) {
42 		hi = lo << (shift - 32);
43 		lo = 0;
44 	} else if (shift > 0) {
45 		hi = (hi << shift) | (lo >> (32 - shift));
46 		lo = lo << shift;
47 	}
48 
49 	dword.w[1] = hi;
50 	dword.w[0] = lo;
51 	return dword.dw;
52 }
53 
54 long long __aeabi_llsr(long long a, int shift);
55 long long __aeabi_llsr(long long a, int shift)
56 {
57 	union dword dword = { .dw = a };
58 	unsigned long hi = dword.w[1];
59 	unsigned long lo = dword.w[0];
60 
61 	if (shift >= 32) {
62 		lo = hi >> (shift - 32);
63 		hi = 0;
64 	} else if (shift > 0) {
65 		lo = (lo >> shift) | (hi << (32 - shift));
66 		hi = hi >> shift;
67 	}
68 
69 	dword.w[1] = hi;
70 	dword.w[0] = lo;
71 	return dword.dw;
72 }
73