xref: /linux/arch/sh/include/asm/word-at-a-time.h (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
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 #include <linux/bitops.h>
9 #include <linux/wordpart.h>
10 /*
11  * Little-endian version cribbed from x86.
12  */
13 struct word_at_a_time {
14 	const unsigned long one_bits, high_bits;
15 };
16 
17 #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
18 
19 /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
count_masked_bytes(long mask)20 static inline long count_masked_bytes(long mask)
21 {
22 	/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
23 	long a = (0x0ff0001+mask) >> 23;
24 	/* Fix the 1 for 00 case */
25 	return a & mask;
26 }
27 
28 /* Return nonzero if it has a zero */
has_zero(unsigned long a,unsigned long * bits,const struct word_at_a_time * c)29 static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
30 {
31 	unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
32 	*bits = mask;
33 	return mask;
34 }
35 
prep_zero_mask(unsigned long a,unsigned long bits,const struct word_at_a_time * c)36 static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
37 {
38 	return bits;
39 }
40 
create_zero_mask(unsigned long bits)41 static inline unsigned long create_zero_mask(unsigned long bits)
42 {
43 	bits = (bits - 1) & ~bits;
44 	return bits >> 7;
45 }
46 
47 /* The mask we created is directly usable as a bytemask */
48 #define zero_bytemask(mask) (mask)
49 
find_zero(unsigned long mask)50 static inline unsigned long find_zero(unsigned long mask)
51 {
52 	return count_masked_bytes(mask);
53 }
54 #endif
55 
56 #endif
57