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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.
*/
extern 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;
}
extern 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..
*/
extern 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.
*/
extern 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).
*/
extern inline unsigned long kernel_ffs(unsigned long w)
{
return w ? cris_swapwbrlz (w) + 1 : 0;
}
#endif
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