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From: agk@sourceware.org
To: lvm-devel@redhat.com, lvm2-cvs@sourceware.org
Subject: LVM2 ./WHATS_NEW_DM libdm/datastruct/bitset.c
Date: Mon, 19 Apr 2010 17:17:00 -0000 [thread overview]
Message-ID: <20100419171756.25085.qmail@sourceware.org> (raw)
CVSROOT: /cvs/lvm2
Module name: LVM2
Changes by: agk@sourceware.org 2010-04-19 17:17:55
Modified files:
. : WHATS_NEW_DM
libdm/datastruct: bitset.c
Log message:
Speed up dm_bit_get_next with ffs().
Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW_DM.diff?cvsroot=lvm2&r1=1.356&r2=1.357
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/libdm/datastruct/bitset.c.diff?cvsroot=lvm2&r1=1.5&r2=1.6
--- LVM2/WHATS_NEW_DM 2010/04/14 21:47:48 1.356
+++ LVM2/WHATS_NEW_DM 2010/04/19 17:17:55 1.357
@@ -1,5 +1,6 @@
Version 1.02.47 -
=================================
+ Speed up dm_bit_get_next with ffs().
Version 1.02.46 - 14th April 2010
=================================
--- LVM2/libdm/datastruct/bitset.c 2008/11/03 18:59:59 1.5
+++ LVM2/libdm/datastruct/bitset.c 2010/04/19 17:17:55 1.6
@@ -52,18 +52,11 @@
out[i] = in1[i] | in2[i];
}
-/*
- * FIXME: slow
- */
-static inline int _test_word(uint32_t test, int bit)
+static int _test_word(uint32_t test, int bit)
{
- while (bit < (int) DM_BITS_PER_INT) {
- if (test & (0x1 << bit))
- return bit;
- bit++;
- }
+ int next_set_bit;
- return -1;
+ return ((next_set_bit = ffs(test >> bit)) ? next_set_bit + bit - 1 : -1);
}
int dm_bit_get_next(dm_bitset_t bs, int last_bit)
next reply other threads:[~2010-04-19 17:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-19 17:17 agk [this message]
2010-04-19 21:10 agk
2010-04-19 21:23 agk
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