1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2*4882a593Smuzhiyun #ifndef _ALPHA_SWAB_H
3*4882a593Smuzhiyun #define _ALPHA_SWAB_H
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <linux/types.h>
6*4882a593Smuzhiyun #include <linux/compiler.h>
7*4882a593Smuzhiyun #include <asm/compiler.h>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #ifdef __GNUC__
10*4882a593Smuzhiyun
__arch_swab32(__u32 x)11*4882a593Smuzhiyun static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
12*4882a593Smuzhiyun {
13*4882a593Smuzhiyun /*
14*4882a593Smuzhiyun * Unfortunately, we can't use the 6 instruction sequence
15*4882a593Smuzhiyun * on ev6 since the latency of the UNPKBW is 3, which is
16*4882a593Smuzhiyun * pretty hard to hide. Just in case a future implementation
17*4882a593Smuzhiyun * has a lower latency, here's the sequence (also by Mike Burrows)
18*4882a593Smuzhiyun *
19*4882a593Smuzhiyun * UNPKBW a0, v0 v0: 00AA00BB00CC00DD
20*4882a593Smuzhiyun * SLL v0, 24, a0 a0: BB00CC00DD000000
21*4882a593Smuzhiyun * BIS v0, a0, a0 a0: BBAACCBBDDCC00DD
22*4882a593Smuzhiyun * EXTWL a0, 6, v0 v0: 000000000000BBAA
23*4882a593Smuzhiyun * ZAP a0, 0xf3, a0 a0: 00000000DDCC0000
24*4882a593Smuzhiyun * ADDL a0, v0, v0 v0: ssssssssDDCCBBAA
25*4882a593Smuzhiyun */
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun __u64 t0, t1, t2, t3;
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun t0 = __kernel_inslh(x, 7); /* t0 : 0000000000AABBCC */
30*4882a593Smuzhiyun t1 = __kernel_inswl(x, 3); /* t1 : 000000CCDD000000 */
31*4882a593Smuzhiyun t1 |= t0; /* t1 : 000000CCDDAABBCC */
32*4882a593Smuzhiyun t2 = t1 >> 16; /* t2 : 0000000000CCDDAA */
33*4882a593Smuzhiyun t0 = t1 & 0xFF00FF00; /* t0 : 00000000DD00BB00 */
34*4882a593Smuzhiyun t3 = t2 & 0x00FF00FF; /* t3 : 0000000000CC00AA */
35*4882a593Smuzhiyun t1 = t0 + t3; /* t1 : ssssssssDDCCBBAA */
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun return t1;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun #define __arch_swab32 __arch_swab32
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun #endif /* __GNUC__ */
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun #endif /* _ALPHA_SWAB_H */
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