LXR linux/arch/alpha/include/asm/word-at-a-time.h

   1#ifndef _ASM_WORD_AT_A_TIME_H
   2#define _ASM_WORD_AT_A_TIME_H
   3
   4#include <asm/compiler.h>
   5
   6/*
   7 * word-at-a-time interface for Alpha.
   8 */
   9
  10/*
  11 * We do not use the word_at_a_time struct on Alpha, but it needs to be
  12 * implemented to humour the generic code.
  13 */
  14struct word_at_a_time {
  15        const unsigned long unused;
  16};
  17
  18#define WORD_AT_A_TIME_CONSTANTS { 0 }
  19
  20/* Return nonzero if val has a zero */
  21static inline unsigned long has_zero(unsigned long val, unsigned long *bits, const struct word_at_a_time *c)
  22{
  23        unsigned long zero_locations = __kernel_cmpbge(0, val);
  24        *bits = zero_locations;
  25        return zero_locations;
  26}
  27
  28static inline unsigned long prep_zero_mask(unsigned long val, unsigned long bits, const struct word_at_a_time *c)
  29{
  30        return bits;
  31}
  32
  33#define create_zero_mask(bits) (bits)
  34
  35static inline unsigned long find_zero(unsigned long bits)
  36{
  37#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
  38        /* Simple if have CIX instructions */
  39        return __kernel_cttz(bits);
  40#else
  41        unsigned long t1, t2, t3;
  42        /* Retain lowest set bit only */
  43        bits &= -bits;
  44        /* Binary search for lowest set bit */
  45        t1 = bits & 0xf0;
  46        t2 = bits & 0xcc;
  47        t3 = bits & 0xaa;
  48        if (t1) t1 = 4;
  49        if (t2) t2 = 2;
  50        if (t3) t3 = 1;
  51        return t1 + t2 + t3;
  52#endif
  53}
  54
  55#endif /* _ASM_WORD_AT_A_TIME_H */
  56