1 /*
2 * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef OS_CPU_LINUX_X86_BYTES_LINUX_X86_HPP
26 #define OS_CPU_LINUX_X86_BYTES_LINUX_X86_HPP
27
28 #include <byteswap.h>
29
30 // Efficient swapping of data bytes from Java byte
31 // ordering to native byte ordering and vice versa.
swap_u2(u2 x)32 inline u2 Bytes::swap_u2(u2 x) {
33 #ifdef AMD64
34 return bswap_16(x);
35 #else
36 u2 ret;
37 __asm__ __volatile__ (
38 "movw %0, %%ax;"
39 "xchg %%al, %%ah;"
40 "movw %%ax, %0"
41 :"=r" (ret) // output : register 0 => ret
42 :"0" (x) // input : x => register 0
43 :"ax", "0" // clobbered registers
44 );
45 return ret;
46 #endif // AMD64
47 }
48
swap_u4(u4 x)49 inline u4 Bytes::swap_u4(u4 x) {
50 #ifdef AMD64
51 return bswap_32(x);
52 #else
53 u4 ret;
54 __asm__ __volatile__ (
55 "bswap %0"
56 :"=r" (ret) // output : register 0 => ret
57 :"0" (x) // input : x => register 0
58 :"0" // clobbered register
59 );
60 return ret;
61 #endif // AMD64
62 }
63
64 #ifdef AMD64
swap_u8(u8 x)65 inline u8 Bytes::swap_u8(u8 x) {
66 return bswap_64(x);
67 }
68 #else
69 // Helper function for swap_u8
swap_u8_base(u4 x,u4 y)70 inline u8 Bytes::swap_u8_base(u4 x, u4 y) {
71 return (((u8)swap_u4(x))<<32) | swap_u4(y);
72 }
73
swap_u8(u8 x)74 inline u8 Bytes::swap_u8(u8 x) {
75 return swap_u8_base(*(u4*)&x, *(((u4*)&x)+1));
76 }
77 #endif // !AMD64
78
79 #endif // OS_CPU_LINUX_X86_BYTES_LINUX_X86_HPP
80