1/* asm/arch/bitops.h for Linux/CRISv10 */
2
3#ifndef _CRIS_ARCH_BITOPS_H
4#define _CRIS_ARCH_BITOPS_H
5
6/*
7 * Helper functions for the core of the ff[sz] functions, wrapping the
8 * syntactically awkward asms.  The asms compute the number of leading
9 * zeroes of a bits-in-byte and byte-in-word and word-in-dword-swapped
10 * number.  They differ in that the first function also inverts all bits
11 * in the input.
12 */
13static inline unsigned long cris_swapnwbrlz(unsigned long w)
14{
15	/* Let's just say we return the result in the same register as the
16	   input.  Saying we clobber the input but can return the result
17	   in another register:
18	   !  __asm__ ("swapnwbr %2\n\tlz %2,%0"
19	   !	      : "=r,r" (res), "=r,X" (dummy) : "1,0" (w));
20	   confuses gcc (sched.c, gcc from cris-dist-1.14).  */
21
22	unsigned long res;
23	__asm__ ("swapnwbr %0 \n\t"
24		 "lz %0,%0"
25		 : "=r" (res) : "0" (w));
26	return res;
27}
28
29static inline unsigned long cris_swapwbrlz(unsigned long w)
30{
31	unsigned res;
32	__asm__ ("swapwbr %0 \n\t"
33		 "lz %0,%0"
34		 : "=r" (res)
35		 : "0" (w));
36	return res;
37}
38
39/*
40 * ffz = Find First Zero in word. Undefined if no zero exists,
41 * so code should check against ~0UL first..
42 */
43static inline unsigned long ffz(unsigned long w)
44{
45	return cris_swapnwbrlz(w);
46}
47
48/**
49 * __ffs - find first bit in word.
50 * @word: The word to search
51 *
52 * Undefined if no bit exists, so code should check against 0 first.
53 */
54static inline unsigned long __ffs(unsigned long word)
55{
56	return cris_swapnwbrlz(~word);
57}
58
59/**
60 * ffs - find first bit set
61 * @x: the word to search
62 *
63 * This is defined the same way as
64 * the libc and compiler builtin ffs routines, therefore
65 * differs in spirit from the above ffz (man ffs).
66 */
67
68static inline unsigned long kernel_ffs(unsigned long w)
69{
70	return w ? cris_swapwbrlz (w) + 1 : 0;
71}
72
73#endif
74