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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [include/] [asm-cris/] [arch-v10/] [bitops.h] - Rev 3
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/* asm/arch/bitops.h for Linux/CRISv10 */ #ifndef _CRIS_ARCH_BITOPS_H #define _CRIS_ARCH_BITOPS_H /* * Helper functions for the core of the ff[sz] functions, wrapping the * syntactically awkward asms. The asms compute the number of leading * zeroes of a bits-in-byte and byte-in-word and word-in-dword-swapped * number. They differ in that the first function also inverts all bits * in the input. */ static inline unsigned long cris_swapnwbrlz(unsigned long w) { /* Let's just say we return the result in the same register as the input. Saying we clobber the input but can return the result in another register: ! __asm__ ("swapnwbr %2\n\tlz %2,%0" ! : "=r,r" (res), "=r,X" (dummy) : "1,0" (w)); confuses gcc (sched.c, gcc from cris-dist-1.14). */ unsigned long res; __asm__ ("swapnwbr %0 \n\t" "lz %0,%0" : "=r" (res) : "0" (w)); return res; } static inline unsigned long cris_swapwbrlz(unsigned long w) { unsigned res; __asm__ ("swapwbr %0 \n\t" "lz %0,%0" : "=r" (res) : "0" (w)); return res; } /* * ffz = Find First Zero in word. Undefined if no zero exists, * so code should check against ~0UL first.. */ static inline unsigned long ffz(unsigned long w) { return cris_swapnwbrlz(w); } /** * __ffs - find first bit in word. * @word: The word to search * * Undefined if no bit exists, so code should check against 0 first. */ static inline unsigned long __ffs(unsigned long word) { return cris_swapnwbrlz(~word); } /** * ffs - find first bit set * @x: the word to search * * This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from the above ffz (man ffs). */ static inline unsigned long kernel_ffs(unsigned long w) { return w ? cris_swapwbrlz (w) + 1 : 0; } #endif