| #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 */ |
