aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-generic/bitops
diff options
context:
space:
mode:
authorCatalin Marinas <catalin.marinas@arm.com>2012-09-12 17:00:53 -0400
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-14 12:15:41 -0400
commit048fa2df92c325cb4425dccd66c8922c8342b507 (patch)
treea76ddbd3f05752f27e0867906a34e102cb76b4e4 /include/asm-generic/bitops
parent0753f70f07fbbd23a48d61ffea37028bd0bd6c7d (diff)
generic: Implement generic ffs/fls using __builtin_* functions
This patch implements ffs, __ffs, fls, __fls using __builtin_* gcc functions. These header files can be used by other architectures that rely on the gcc builtins. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'include/asm-generic/bitops')
-rw-r--r--include/asm-generic/bitops/builtin-__ffs.h15
-rw-r--r--include/asm-generic/bitops/builtin-__fls.h15
-rw-r--r--include/asm-generic/bitops/builtin-ffs.h17
-rw-r--r--include/asm-generic/bitops/builtin-fls.h16
4 files changed, 63 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/builtin-__ffs.h b/include/asm-generic/bitops/builtin-__ffs.h
new file mode 100644
index 000000000000..90041e3a41f0
--- /dev/null
+++ b/include/asm-generic/bitops/builtin-__ffs.h
@@ -0,0 +1,15 @@
1#ifndef _ASM_GENERIC_BITOPS_BUILTIN___FFS_H_
2#define _ASM_GENERIC_BITOPS_BUILTIN___FFS_H_
3
4/**
5 * __ffs - find first bit in word.
6 * @word: The word to search
7 *
8 * Undefined if no bit exists, so code should check against 0 first.
9 */
10static __always_inline unsigned long __ffs(unsigned long word)
11{
12 return __builtin_ctzl(word);
13}
14
15#endif
diff --git a/include/asm-generic/bitops/builtin-__fls.h b/include/asm-generic/bitops/builtin-__fls.h
new file mode 100644
index 000000000000..0248f386635f
--- /dev/null
+++ b/include/asm-generic/bitops/builtin-__fls.h
@@ -0,0 +1,15 @@
1#ifndef _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
2#define _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
3
4/**
5 * __fls - find last (most-significant) set bit in a long word
6 * @word: the word to search
7 *
8 * Undefined if no set bit exists, so code should check against 0 first.
9 */
10static __always_inline unsigned long __fls(unsigned long word)
11{
12 return (sizeof(word) * 8) - 1 - __builtin_clzl(word);
13}
14
15#endif
diff --git a/include/asm-generic/bitops/builtin-ffs.h b/include/asm-generic/bitops/builtin-ffs.h
new file mode 100644
index 000000000000..064825829e1c
--- /dev/null
+++ b/include/asm-generic/bitops/builtin-ffs.h
@@ -0,0 +1,17 @@
1#ifndef _ASM_GENERIC_BITOPS_BUILTIN_FFS_H_
2#define _ASM_GENERIC_BITOPS_BUILTIN_FFS_H_
3
4/**
5 * ffs - find first bit set
6 * @x: the word to search
7 *
8 * This is defined the same way as
9 * the libc and compiler builtin ffs routines, therefore
10 * differs in spirit from the above ffz (man ffs).
11 */
12static __always_inline int ffs(int x)
13{
14 return __builtin_ffs(x);
15}
16
17#endif
diff --git a/include/asm-generic/bitops/builtin-fls.h b/include/asm-generic/bitops/builtin-fls.h
new file mode 100644
index 000000000000..eda652d0ac7f
--- /dev/null
+++ b/include/asm-generic/bitops/builtin-fls.h
@@ -0,0 +1,16 @@
1#ifndef _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
2#define _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
3
4/**
5 * fls - find last (most-significant) bit set
6 * @x: the word to search
7 *
8 * This is defined the same way as ffs.
9 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
10 */
11static __always_inline int fls(int x)
12{
13 return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
14}
15
16#endif