arch/sh/include/asm/word-at-a-time.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_SH_WORD_AT_A_TIME_H
   3 #define __ASM_SH_WORD_AT_A_TIME_H
   4
   5 #ifdef CONFIG_CPU_BIG_ENDIAN
   6 # include <asm-generic/word-at-a-time.h>
   7 #else
   8 /*
   9  * Little-endian version cribbed from x86.
  10  */
  11 struct word_at_a_time {
  12         const unsigned long one_bits, high_bits;
  13 };
  14
  15 #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
  16
  17 /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
  18 static inline long count_masked_bytes(long mask)
  19 {
  20         /* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
  21         long a = (0x0ff0001+mask) >> 23;
  22         /* Fix the 1 for 00 case */
  23         return a & mask;
  24 }
  25
  26 /* Return nonzero if it has a zero */
  27 static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
  28 {
  29         unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
  30         *bits = mask;
  31         return mask;
  32 }
  33
  34 static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
  35 {
  36         return bits;
  37 }
  38
  39 static inline unsigned long create_zero_mask(unsigned long bits)
  40 {
  41         bits = (bits - 1) & ~bits;
  42         return bits >> 7;
  43 }
  44
  45 /* The mask we created is directly usable as a bytemask */
  46 #define zero_bytemask(mask) (mask)
  47
  48 static inline unsigned long find_zero(unsigned long mask)
  49 {
  50         return count_masked_bytes(mask);
  51 }
  52 #endif
  53
  54 #endif