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authorAlexander van Heukelum <heukelum@mailshack.com>2008-03-15 18:31:49 +0100
committerIngo Molnar <mingo@elte.hu>2008-04-26 19:21:16 +0200
commit56a6b1eb7bfb5ace0b5cb9c149f502fbd101b8ab (patch)
tree46d3781050938b0649fc89cd8e7f612cacb66984 /include/asm-ia64/bitops.h
parent7d9dff22e8ad06ad330968c9e3d3a2fb55a5f9c3 (diff)
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>
Diffstat (limited to 'include/asm-ia64/bitops.h')
-rw-r--r--include/asm-ia64/bitops.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/include/asm-ia64/bitops.h b/include/asm-ia64/bitops.h
index 953d3df9dd2..e2ca8003733 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>
/*