Module Name:	basesrc
Committed By:	itohy
Date:		Wed Aug 28 15:34:37 UTC 2002

Modified Files:
	basesrc/lib/libc/arch/sh3/string: ffs.S
	syssrc/sys/lib/libkern/arch/sh3: ffs.S

Log Message:
Slightly improved version of ffs(3).
Partially from SHIMIZU Ryo <ryo@iij.ad.jp>.  Thanks.
Some cases are slower, but other most cases are faster.

Here's a benchmark on SH-4 200MHz.

return value	C version	previous vers	this version	speed ratio
of ffs()	(ns/call) *1	(ns/call)	(ns/call) *2	(*1/*2)
------------	------------	-------------	------------	-----------
 0		  86		 86		 81		1.06
 1		 110		 86		106 *(slower)	1.04
 2		 132		 86		106 *		1.25
 3		 165		105		117 *		1.41
 4		 201		104		116 *		1.73
 5		 237		111		107		2.21
 6		 271		111		106		2.56
 7		 307		126		116		2.65
 8		 342		125		116		2.95
 9		 376		122		126 *		2.98
10		 410		121		127 *		3.23
11		 446		139		136		3.28
12		 483		140		134		3.60
13		 518		146		125		4.14
14		 551		146		126		4.37
15		 587		161		135		4.35
16		 624		162		136		4.59
17		 658		141		139		4.73
18		 694		142		140		4.96
19		 727		160		148		4.91
20		 764		161		150		5.09
21		 799		167		141		5.67
22		 834		167		142		5.87
23		 868		181		152		5.71
24		 903		181		153		5.90
25		 939		146		140		6.71
26		 974		146		141		6.91
27		1009		166		152		6.64
28		1044		165		148		7.05
29		1080		171		141		7.66
30		1115		171		141		7.91
31		1151		185		151		7.62
32		1185		186		151		7.85


To generate a diff of this commit:
cvs rdiff -r1.2 -r1.3 basesrc/lib/libc/arch/sh3/string/ffs.S
cvs rdiff -r1.2 -r1.3 syssrc/sys/lib/libkern/arch/sh3/ffs.S

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.