18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
28c2ecf20Sopenharmony_ci#ifndef _ALPHA_SWAB_H
38c2ecf20Sopenharmony_ci#define _ALPHA_SWAB_H
48c2ecf20Sopenharmony_ci
58c2ecf20Sopenharmony_ci#include <linux/types.h>
68c2ecf20Sopenharmony_ci#include <linux/compiler.h>
78c2ecf20Sopenharmony_ci#include <asm/compiler.h>
88c2ecf20Sopenharmony_ci
98c2ecf20Sopenharmony_ci#ifdef __GNUC__
108c2ecf20Sopenharmony_ci
118c2ecf20Sopenharmony_cistatic inline __attribute_const__ __u32 __arch_swab32(__u32 x)
128c2ecf20Sopenharmony_ci{
138c2ecf20Sopenharmony_ci	/*
148c2ecf20Sopenharmony_ci	 * Unfortunately, we can't use the 6 instruction sequence
158c2ecf20Sopenharmony_ci	 * on ev6 since the latency of the UNPKBW is 3, which is
168c2ecf20Sopenharmony_ci	 * pretty hard to hide.  Just in case a future implementation
178c2ecf20Sopenharmony_ci	 * has a lower latency, here's the sequence (also by Mike Burrows)
188c2ecf20Sopenharmony_ci	 *
198c2ecf20Sopenharmony_ci	 * UNPKBW a0, v0       v0: 00AA00BB00CC00DD
208c2ecf20Sopenharmony_ci	 * SLL v0, 24, a0      a0: BB00CC00DD000000
218c2ecf20Sopenharmony_ci	 * BIS v0, a0, a0      a0: BBAACCBBDDCC00DD
228c2ecf20Sopenharmony_ci	 * EXTWL a0, 6, v0     v0: 000000000000BBAA
238c2ecf20Sopenharmony_ci	 * ZAP a0, 0xf3, a0    a0: 00000000DDCC0000
248c2ecf20Sopenharmony_ci	 * ADDL a0, v0, v0     v0: ssssssssDDCCBBAA
258c2ecf20Sopenharmony_ci	 */
268c2ecf20Sopenharmony_ci
278c2ecf20Sopenharmony_ci	__u64 t0, t1, t2, t3;
288c2ecf20Sopenharmony_ci
298c2ecf20Sopenharmony_ci	t0 = __kernel_inslh(x, 7);	/* t0 : 0000000000AABBCC */
308c2ecf20Sopenharmony_ci	t1 = __kernel_inswl(x, 3);	/* t1 : 000000CCDD000000 */
318c2ecf20Sopenharmony_ci	t1 |= t0;			/* t1 : 000000CCDDAABBCC */
328c2ecf20Sopenharmony_ci	t2 = t1 >> 16;			/* t2 : 0000000000CCDDAA */
338c2ecf20Sopenharmony_ci	t0 = t1 & 0xFF00FF00;		/* t0 : 00000000DD00BB00 */
348c2ecf20Sopenharmony_ci	t3 = t2 & 0x00FF00FF;		/* t3 : 0000000000CC00AA */
358c2ecf20Sopenharmony_ci	t1 = t0 + t3;			/* t1 : ssssssssDDCCBBAA */
368c2ecf20Sopenharmony_ci
378c2ecf20Sopenharmony_ci	return t1;
388c2ecf20Sopenharmony_ci}
398c2ecf20Sopenharmony_ci#define __arch_swab32 __arch_swab32
408c2ecf20Sopenharmony_ci
418c2ecf20Sopenharmony_ci#endif /* __GNUC__ */
428c2ecf20Sopenharmony_ci
438c2ecf20Sopenharmony_ci#endif /* _ALPHA_SWAB_H */
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