/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ #ifndef _ALPHA_SWAB_H #define _ALPHA_SWAB_H #include <linux/types.h> #include <linux/compiler.h> #include <asm/compiler.h> #ifdef __GNUC__ static inline __attribute_const__ __u32 __arch_swab32(__u32 x) { /* * Unfortunately, we can't use the 6 instruction sequence * on ev6 since the latency of the UNPKBW is 3, which is * pretty hard to hide. Just in case a future implementation * has a lower latency, here's the sequence (also by Mike Burrows) * * UNPKBW a0, v0 v0: 00AA00BB00CC00DD * SLL v0, 24, a0 a0: BB00CC00DD000000 * BIS v0, a0, a0 a0: BBAACCBBDDCC00DD * EXTWL a0, 6, v0 v0: 000000000000BBAA * ZAP a0, 0xf3, a0 a0: 00000000DDCC0000 * ADDL a0, v0, v0 v0: ssssssssDDCCBBAA */ __u64 t0, t1, t2, t3; t0 = __kernel_inslh(x, 7); /* t0 : 0000000000AABBCC */ t1 = __kernel_inswl(x, 3); /* t1 : 000000CCDD000000 */ t1 |= t0; /* t1 : 000000CCDDAABBCC */ t2 = t1 >> 16; /* t2 : 0000000000CCDDAA */ t0 = t1 & 0xFF00FF00; /* t0 : 00000000DD00BB00 */ t3 = t2 & 0x00FF00FF; /* t3 : 0000000000CC00AA */ t1 = t0 + t3; /* t1 : ssssssssDDCCBBAA */ return t1; } #define __arch_swab32 __arch_swab32 #endif /* __GNUC__ */ #endif /* _ALPHA_SWAB_H */