[2/3] Implement __fls on all 64-bit archs

From: Alexander van Heukelum
Date: Sat Mar 15 2008 - 13:35:53 EST


Implement __fls on all 64-bit archs:

alpha has an implementation of fls64.
Added __fls(x) = fls64(x) - 1.

ia64 has fls, but not __fls.
Added __fls based on code of fls.

mips and powerpc have __ilog2, which is the same as __fls.
Added __fls = __ilog2.

parisc, s390, sh and sparc64:
Include generic __fls.

x86_64 already has __fls.

Signed-off-by: Alexander van Heukelum <heukelum@xxxxxxxxxxx>
---
include/asm-alpha/bitops.h | 5 +++++
include/asm-ia64/bitops.h | 16 ++++++++++++++++
include/asm-mips/bitops.h | 5 +++++
include/asm-parisc/bitops.h | 1 +
include/asm-powerpc/bitops.h | 5 +++++
include/asm-s390/bitops.h | 1 +
include/asm-sh/bitops.h | 1 +
include/asm-sparc64/bitops.h | 1 +
8 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/include/asm-alpha/bitops.h b/include/asm-alpha/bitops.h
index 9e19a70..15f3ae2 100644
--- a/include/asm-alpha/bitops.h
+++ b/include/asm-alpha/bitops.h
@@ -388,6 +388,11 @@ static inline int fls64(unsigned long x)
}
#endif

+static inline unsigned long __fls(unsigned long x)
+{
+ return fls64(x) - 1;
+}
+
static inline int fls(int x)
{
return fls64((unsigned int) x);
diff --git a/include/asm-ia64/bitops.h b/include/asm-ia64/bitops.h
index 953d3df..e2ca800 100644
--- a/include/asm-ia64/bitops.h
+++ b/include/asm-ia64/bitops.h
@@ -407,6 +407,22 @@ fls (int t)
return ia64_popcnt(x);
}

+/*
+ * Find the last (most significant) bit set. Undefined for x==0.
+ * Bits are numbered from 0..63 (e.g., __fls(9) == 3).
+ */
+static inline unsigned long
+__fls (unsigned long x)
+{
+ x |= x >> 1;
+ x |= x >> 2;
+ x |= x >> 4;
+ x |= x >> 8;
+ x |= x >> 16;
+ x |= x >> 32;
+ return ia64_popcnt(x) - 1;
+}
+
#include <asm-generic/bitops/fls64.h>

/*
diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h
index ec75ce4..c2bd126 100644
--- a/include/asm-mips/bitops.h
+++ b/include/asm-mips/bitops.h
@@ -591,6 +591,11 @@ static inline int __ilog2(unsigned long x)
return 63 - lz;
}

+static inline unsigned long __fls(unsigned long x)
+{
+ return __ilog2(x);
+}
+
#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)

/*
diff --git a/include/asm-parisc/bitops.h b/include/asm-parisc/bitops.h
index f8eebcb..7a6ea10 100644
--- a/include/asm-parisc/bitops.h
+++ b/include/asm-parisc/bitops.h
@@ -210,6 +210,7 @@ static __inline__ int fls(int x)
return ret;
}

+#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
diff --git a/include/asm-powerpc/bitops.h b/include/asm-powerpc/bitops.h
index 220d9a7..2fc0c45 100644
--- a/include/asm-powerpc/bitops.h
+++ b/include/asm-powerpc/bitops.h
@@ -312,6 +312,11 @@ static __inline__ int fls(unsigned int x)
asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
return 32 - lz;
}
+
+static __inline__ unsigned long __fls(unsigned long x)
+{
+ return __ilog2(x);
+}
#include <asm-generic/bitops/fls64.h>

#include <asm-generic/bitops/hweight.h>
diff --git a/include/asm-s390/bitops.h b/include/asm-s390/bitops.h
index 965394e..b4eb24a 100644
--- a/include/asm-s390/bitops.h
+++ b/include/asm-s390/bitops.h
@@ -769,6 +769,7 @@ static inline int sched_find_first_bit(unsigned long *b)
}

#include <asm-generic/bitops/fls.h>
+#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>

#include <asm-generic/bitops/hweight.h>
diff --git a/include/asm-sh/bitops.h b/include/asm-sh/bitops.h
index b6ba5a6..d7d382f 100644
--- a/include/asm-sh/bitops.h
+++ b/include/asm-sh/bitops.h
@@ -95,6 +95,7 @@ static inline unsigned long ffz(unsigned long word)
#include <asm-generic/bitops/ext2-atomic.h>
#include <asm-generic/bitops/minix.h>
#include <asm-generic/bitops/fls.h>
+#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>

#endif /* __KERNEL__ */
diff --git a/include/asm-sparc64/bitops.h b/include/asm-sparc64/bitops.h
index 982ce89..11f9d81 100644
--- a/include/asm-sparc64/bitops.h
+++ b/include/asm-sparc64/bitops.h
@@ -34,6 +34,7 @@ extern void change_bit(unsigned long nr, volatile unsigned long *addr);
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/__ffs.h>
#include <asm-generic/bitops/fls.h>
+#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>

#ifdef __KERNEL__

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