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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-01-22 17:59:29 +0300
committerIngo Molnar <mingo@elte.hu>2010-01-29 11:01:39 +0300
commit9f41699ed067fa695faff8e2e9981b2550abec62 (patch)
treed579511fdefee2dff6d113f7afac1149a3bb6b0d /include/linux/bitops.h
parent8433be1184e4f22c37d4b8ed36cde529a47882f4 (diff)
downloadlinux-9f41699ed067fa695faff8e2e9981b2550abec62.tar.xz
bitops: Provide compile time HWEIGHT{8,16,32,64}
Provide compile time versions of hweight. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20100122155535.797688466@chello.nl> [ Remove some whitespace damage while we are at it ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/bitops.h')
-rw-r--r--include/linux/bitops.h18
1 files changed, 16 insertions, 2 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index c05a29cb9bb2..ba0fd1eb4af7 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -25,7 +25,7 @@
static __inline__ int get_bitmask_order(unsigned int count)
{
int order;
-
+
order = fls(count);
return order; /* We could be slightly more clever with -1 here... */
}
@@ -33,7 +33,7 @@ static __inline__ int get_bitmask_order(unsigned int count)
static __inline__ int get_count_order(unsigned int count)
{
int order;
-
+
order = fls(count) - 1;
if (count & (count - 1))
order++;
@@ -45,6 +45,20 @@ static inline unsigned long hweight_long(unsigned long w)
return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
}
+#define HWEIGHT8(w) \
+ ( (!!((w) & (1ULL << 0))) + \
+ (!!((w) & (1ULL << 1))) + \
+ (!!((w) & (1ULL << 2))) + \
+ (!!((w) & (1ULL << 3))) + \
+ (!!((w) & (1ULL << 4))) + \
+ (!!((w) & (1ULL << 5))) + \
+ (!!((w) & (1ULL << 6))) + \
+ (!!((w) & (1ULL << 7))) )
+
+#define HWEIGHT16(w) (HWEIGHT8(w) + HWEIGHT8(w >> 8))
+#define HWEIGHT32(w) (HWEIGHT16(w) + HWEIGHT16(w >> 16))
+#define HWEIGHT64(w) (HWEIGHT32(w) + HWEIGHT32(w >> 32))
+
/**
* rol32 - rotate a 32-bit value left
* @word: value to rotate