bitops: Optimize hweight() by making use of compile-time evaluation
Rename the extisting runtime hweight() implementations to
__arch_hweight(), rename the compile-time versions to __const_hweight()
and then have hweight() pick between them.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100318111929.GB11152@aftab>
Acked-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <1265028224.24455.154.camel@laptop>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/alpha/include/asm/bitops.h b/arch/alpha/include/asm/bitops.h
index 15f3ae2..296da1d 100644
--- a/arch/alpha/include/asm/bitops.h
+++ b/arch/alpha/include/asm/bitops.h
@@ -405,29 +405,31 @@
#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
/* Whee. EV67 can calculate it directly. */
-static inline unsigned long hweight64(unsigned long w)
+static inline unsigned long __arch_hweight64(unsigned long w)
{
return __kernel_ctpop(w);
}
-static inline unsigned int hweight32(unsigned int w)
+static inline unsigned int __arch_weight32(unsigned int w)
{
- return hweight64(w);
+ return __arch_hweight64(w);
}
-static inline unsigned int hweight16(unsigned int w)
+static inline unsigned int __arch_hweight16(unsigned int w)
{
- return hweight64(w & 0xffff);
+ return __arch_hweight64(w & 0xffff);
}
-static inline unsigned int hweight8(unsigned int w)
+static inline unsigned int __arch_hweight8(unsigned int w)
{
- return hweight64(w & 0xff);
+ return __arch_hweight64(w & 0xff);
}
#else
-#include <asm-generic/bitops/hweight.h>
+#include <asm-generic/bitops/arch_hweight.h>
#endif
+#include <asm-generic/bitops/const_hweight.h>
+
#endif /* __KERNEL__ */
#include <asm-generic/bitops/find.h>
diff --git a/arch/ia64/include/asm/bitops.h b/arch/ia64/include/asm/bitops.h
index 6ebc229..9da3df6 100644
--- a/arch/ia64/include/asm/bitops.h
+++ b/arch/ia64/include/asm/bitops.h
@@ -437,17 +437,18 @@
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
*/
-static __inline__ unsigned long
-hweight64 (unsigned long x)
+static __inline__ unsigned long __arch_hweight64(unsigned long x)
{
unsigned long result;
result = ia64_popcnt(x);
return result;
}
-#define hweight32(x) (unsigned int) hweight64((x) & 0xfffffffful)
-#define hweight16(x) (unsigned int) hweight64((x) & 0xfffful)
-#define hweight8(x) (unsigned int) hweight64((x) & 0xfful)
+#define __arch_hweight32(x) ((unsigned int) __arch_hweight64((x) & 0xfffffffful))
+#define __arch_hweight16(x) ((unsigned int) __arch_hweight64((x) & 0xfffful))
+#define __arch_hweight8(x) ((unsigned int) __arch_hweight64((x) & 0xfful))
+
+#include <asm-generic/bitops/const_hweight.h>
#endif /* __KERNEL__ */
diff --git a/arch/sparc/include/asm/bitops_64.h b/arch/sparc/include/asm/bitops_64.h
index e72ac9c..766121a 100644
--- a/arch/sparc/include/asm/bitops_64.h
+++ b/arch/sparc/include/asm/bitops_64.h
@@ -44,7 +44,7 @@
#ifdef ULTRA_HAS_POPULATION_COUNT
-static inline unsigned int hweight64(unsigned long w)
+static inline unsigned int __arch_hweight64(unsigned long w)
{
unsigned int res;
@@ -52,7 +52,7 @@
return res;
}
-static inline unsigned int hweight32(unsigned int w)
+static inline unsigned int __arch_hweight32(unsigned int w)
{
unsigned int res;
@@ -60,7 +60,7 @@
return res;
}
-static inline unsigned int hweight16(unsigned int w)
+static inline unsigned int __arch_hweight16(unsigned int w)
{
unsigned int res;
@@ -68,7 +68,7 @@
return res;
}
-static inline unsigned int hweight8(unsigned int w)
+static inline unsigned int __arch_hweight8(unsigned int w)
{
unsigned int res;
@@ -78,9 +78,10 @@
#else
-#include <asm-generic/bitops/hweight.h>
+#include <asm-generic/bitops/arch_hweight.h>
#endif
+#include <asm-generic/bitops/const_hweight.h>
#include <asm-generic/bitops/lock.h>
#endif /* __KERNEL__ */