xref: /linux/arch/sh/include/asm/word-at-a-time.h (revision bb9707077b4ee5f77bc9939b057ff8a0d410296f)
1 #ifndef __ASM_SH_WORD_AT_A_TIME_H
2 #define __ASM_SH_WORD_AT_A_TIME_H
3 
4 #ifdef CONFIG_CPU_BIG_ENDIAN
5 # include <asm-generic/word-at-a-time.h>
6 #else
7 /*
8  * Little-endian version cribbed from x86.
9  */
10 struct word_at_a_time {
11 	const unsigned long one_bits, high_bits;
12 };
13 
14 #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
15 
16 /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
17 static inline long count_masked_bytes(long mask)
18 {
19 	/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
20 	long a = (0x0ff0001+mask) >> 23;
21 	/* Fix the 1 for 00 case */
22 	return a & mask;
23 }
24 
25 /* Return nonzero if it has a zero */
26 static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
27 {
28 	unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
29 	*bits = mask;
30 	return mask;
31 }
32 
33 static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
34 {
35 	return bits;
36 }
37 
38 static inline unsigned long create_zero_mask(unsigned long bits)
39 {
40 	bits = (bits - 1) & ~bits;
41 	return bits >> 7;
42 }
43 
44 /* The mask we created is directly usable as a bytemask */
45 #define zero_bytemask(mask) (mask)
46 
47 static inline unsigned long find_zero(unsigned long mask)
48 {
49 	return count_masked_bytes(mask);
50 }
51 #endif
52 
53 #endif
54