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From: Akinobu Mita <mita@miraclelinux.com>
To: linux-kernel@vger.kernel.org
Cc: Richard Henderson <rth@twiddle.net>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Russell King <rmk@arm.linux.org.uk>, Ian Molton <spyro@f2s.com>,
	dev-etrax@axis.com, David Howells <dhowells@redhat.com>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Linus Torvalds <torvalds@osdl.org>,
	linux-ia64@vger.kernel.org,
	Hirokazu Takata <takata@linux-m32r.org>,
	linux-m68k@vger.kernel.org, Greg Ungerer <gerg@uclinux.org>,
	linux-mips@linux-mips.org, parisc-linux@parisc-linux.org,
	linuxppc-dev@ozlabs.org, linux390@de.ibm.com,
	linuxsh-dev@lists.sourceforge.net,
	linuxsh-shmedia-dev@lists.sourceforge.net,
	sparclinux@vger.kernel.org, ultralinux@vger.kernel.org,
	Miles Bader <uclinux-v850@lsi.nec.co.jp>, Andi Kleen <ak@suse.de>,
	Chris Zankel <chris@zankel.net>,
	Akinobu Mita <mita@miraclelinux.com>
Subject: [patch 14/44] generic hweight{64,32,16,8}()
Date: Wed, 01 Feb 2006 18:02:38 +0900	[thread overview]
Message-ID: <20060201090325.905071000@localhost.localdomain> (raw)
In-Reply-To: 20060201090224.536581000@localhost.localdomain

[-- Attachment #1: hweight-bitops.patch --]
[-- Type: text/plain, Size: 2626 bytes --]


This patch introduces the C-language equivalents of the functions below:

unsigned int hweight32(unsigned int w);
unsigned int hweight16(unsigned int w);
unsigned int hweight8(unsigned int w);
unsigned long hweight64(__u64 w);

In include/asm-generic/bitops/hweight.h

This code largely copied from:
include/linux/bitops.h

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
 include/asm-generic/bitops/hweight.h |   54 +++++++++++++++++++++++++++++++++++
 1 files changed, 54 insertions(+)

Index: 2.6-git/include/asm-generic/bitops/hweight.h
===================================================================
--- /dev/null
+++ 2.6-git/include/asm-generic/bitops/hweight.h
@@ -0,0 +1,54 @@
+#ifndef _ASM_GENERIC_BITOPS_HWEIGHT_H_
+#define _ASM_GENERIC_BITOPS_HWEIGHT_H_
+
+#include <asm/types.h>
+
+/**
+ * hweightN - returns the hamming weight of a N-bit word
+ * @x: the word to weigh
+ *
+ * The Hamming Weight of a number is the total number of bits set in it.
+ */
+
+static inline unsigned int hweight32(unsigned int w)
+{
+        unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
+        res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+        res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
+        res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
+        return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
+}
+
+static inline unsigned int hweight16(unsigned int w)
+{
+        unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
+        res = (res & 0x3333) + ((res >> 2) & 0x3333);
+        res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
+        return (res & 0x00FF) + ((res >> 8) & 0x00FF);
+}
+
+static inline unsigned int hweight8(unsigned int w)
+{
+        unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
+        res = (res & 0x33) + ((res >> 2) & 0x33);
+        return (res & 0x0F) + ((res >> 4) & 0x0F);
+}
+
+static inline unsigned long hweight64(__u64 w)
+{
+#if BITS_PER_LONG == 32
+	return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w);
+#elif BITS_PER_LONG == 64
+	u64 res;
+	res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul);
+	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
+	res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful);
+	res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul);
+	res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul);
+	return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul);
+#else
+#error BITS_PER_LONG not defined
+#endif
+}
+
+#endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */

--

  parent reply	other threads:[~2006-02-01  9:16 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-02-01  9:02 [patch 00/44] generic bitops Akinobu Mita
2006-02-01  9:02 ` [patch 01/44] ia64: use cpu_set() instead of __set_bit() Akinobu Mita
2006-02-01  9:02 ` [patch 02/44] parisc: add ()-pair in __ffz() macro Akinobu Mita
2006-02-01  9:02 ` [patch 03/44] cris: remove unnecessary local_irq_restore() Akinobu Mita
2006-02-01  9:02 ` [patch 04/44] use non atomic operations for minix_*_bit() and ext2_*_bit() Akinobu Mita
2006-02-01  9:02 ` [patch 05/44] generic {,test_and_}{set,clear,change}_bit() Akinobu Mita
2006-02-03  9:55   ` Martin Waitz
2006-02-06 23:07     ` Russell King
2006-02-01  9:02 ` [patch 06/44] generic __{,test_and_}{set,clear,change}_bit() and test_bit() Akinobu Mita
2006-02-01  9:02 ` [patch 07/44] generic __ffs() Akinobu Mita
2006-02-01  9:02 ` [patch 08/44] generic ffz() Akinobu Mita
2006-02-01  9:02 ` [patch 09/44] generic fls() Akinobu Mita
2006-02-01  9:02 ` [patch 10/44] generic fls64() Akinobu Mita
2006-02-01  9:02 ` [patch 11/44] generic find_{next,first}{,_zero}_bit() Akinobu Mita
2006-02-01  9:02 ` [patch 12/44] generic sched_find_first_bit() Akinobu Mita
2006-02-03  3:58   ` [parisc-linux] " Grant Grundler
2006-02-01  9:02 ` [patch 13/44] generic ffs() Akinobu Mita
2006-02-01  9:02 ` Akinobu Mita [this message]
2006-02-01  9:06   ` [patch 14/44] generic hweight{64,32,16,8}() Andi Kleen
2006-02-01  9:26     ` Michael Tokarev
2006-02-01 10:24       ` Andi Kleen
2006-02-02 12:50         ` Akinobu Mita
2006-02-09  5:55           ` [PATCH] alpha: remove __alpha_cix__ and __alpha_fix__ Akinobu Mita
2006-02-09 19:12             ` Richard Henderson
2006-02-10  5:40               ` Akinobu Mita
2006-02-02  1:26   ` [patch 14/44] generic hweight{64,32,16,8}() Gabriel Paubert
2006-02-06 11:52     ` Akinobu Mita
2006-02-03  8:31   ` Ulrich Eckhardt
2006-02-01  9:02 ` [patch 15/44] generic ext2_{set,clear,test,find_first_zero,find_next_zero}_bit() Akinobu Mita
2006-02-01 11:27   ` Roman Zippel
2006-02-06 11:47     ` Akinobu Mita
2006-02-08 10:41     ` Akinobu Mita
2006-02-01  9:02 ` [patch 16/44] generic ext2_{set,clear}_bit_atomic() Akinobu Mita
2006-02-01  9:02 ` [patch 17/44] generic minix_{test,set,test_and_clear,test,find_first_zero}_bit() Akinobu Mita
2006-02-01  9:02 ` [patch 18/44] alpha: use generic bitops Akinobu Mita
2006-02-01  9:02 ` [patch 19/44] arm: " Akinobu Mita
2006-02-01  9:02 ` [patch 20/44] arm26: " Akinobu Mita
2006-02-01  9:02 ` [patch 21/44] cris: " Akinobu Mita
2006-02-01  9:02 ` [patch 22/44] frv: " Akinobu Mita
2006-02-01  9:02 ` [patch 23/44] h8300: " Akinobu Mita
2006-02-01  9:02 ` [patch 24/44] i386: " Akinobu Mita
2006-02-01  9:02 ` [patch 25/44] ia64: " Akinobu Mita
2006-02-01  9:02 ` [patch 26/44] m32r: " Akinobu Mita
2006-02-01  9:02 ` [patch 27/44] m68k: " Akinobu Mita
2006-02-01  9:02 ` [patch 28/44] m68knommu: " Akinobu Mita
2006-02-01  9:02 ` [patch 29/44] mips: " Akinobu Mita
2006-02-01  9:02 ` [patch 30/44] parisc: " Akinobu Mita
2006-02-01  9:02 ` [patch 31/44] powerpc: " Akinobu Mita
2006-02-01  9:02 ` [patch 32/44] s390: " Akinobu Mita
2006-02-01  9:02 ` [patch 33/44] sh: " Akinobu Mita
2006-02-01  9:02 ` [patch 34/44] sh64: " Akinobu Mita
2006-02-01  9:02 ` [patch 35/44] sparc: " Akinobu Mita
2006-02-01  9:03 ` [patch 36/44] sparc64: " Akinobu Mita
2006-02-01  9:03 ` [patch 37/44] v850: " Akinobu Mita
2006-02-01  9:03 ` [patch 38/44] x86_64: " Akinobu Mita
2006-02-01  9:03 ` [patch 39/44] xtensa: " Akinobu Mita
2006-02-01  9:03 ` [patch 40/44] update include/asm-generic/bitops.h Akinobu Mita
2006-02-01  9:03 ` [patch 41/44] make thread_info.flags an unsigned long Akinobu Mita
2006-02-01  9:03 ` [patch 42/44] ia64: make partial_page.bitmap " Akinobu Mita
2006-02-01  9:03 ` [patch 43/44] ntfs: remove generic_ffs() Akinobu Mita
2006-02-01  9:03 ` [patch 44/44] remove unused generic bitops in include/linux/bitops.h Akinobu Mita
2006-02-06 10:26 ` [patch 11/44] generic find_{next,first}{,_zero}_bit() David Howells
2006-02-07  2:02   ` Akinobu Mita

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