generic: implement __fls on all 64-bit archs
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@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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 @@
}
#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 @@
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 @@
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 @@
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 a99a749..897eade 100644
--- a/include/asm-powerpc/bitops.h
+++ b/include/asm-powerpc/bitops.h
@@ -313,6 +313,11 @@
return 32 - lz;
}
+static __inline__ unsigned long __fls(unsigned long x)
+{
+ return __ilog2(x);
+}
+
/*
* 64-bit can do this using one cntlzd (count leading zeroes doubleword)
* instruction; for 32-bit we use the generic version, which does two
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 @@
}
#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 @@
#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 @@
#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__