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