linux-sg2042/include/asm-cris/arch-v32/bitops.h

65 lines
1.2 KiB
C

#ifndef _ASM_CRIS_ARCH_BITOPS_H
#define _ASM_CRIS_ARCH_BITOPS_H
/*
* Helper functions for the core of the ff[sz] functions. They compute the
* number of leading zeroes of a bits-in-byte, 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)
{
unsigned long res;
__asm__ __volatile__ ("swapnwbr %0\n\t"
"lz %0,%0"
: "=r" (res) : "0" (w));
return res;
}
static inline unsigned long
cris_swapwbrlz(unsigned long w)
{
unsigned long res;
__asm__ __volatile__ ("swapwbr %0\n\t"
"lz %0,%0"
: "=r" (res) : "0" (w));
return res;
}
/*
* Find First Zero in word. Undefined if no zero exist, so the caller should
* check against ~0 first.
*/
static inline unsigned long
ffz(unsigned long w)
{
return cris_swapnwbrlz(w);
}
/*
* Find First Set bit in word. Undefined if no 1 exist, so the caller
* should check against 0 first.
*/
static inline unsigned long
__ffs(unsigned long w)
{
return cris_swapnwbrlz(~w);
}
/*
* Find First Bit that is set.
*/
static inline unsigned long
kernel_ffs(unsigned long w)
{
return w ? cris_swapwbrlz (w) + 1 : 0;
}
#endif /* _ASM_CRIS_ARCH_BITOPS_H */