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Strip comments and inline ids onto h*

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James Gregory 2013-12-30 15:11:04 +11:00
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@ -10,16 +10,9 @@
<meta name="vspubdate" content="07/01/97" />
<meta name="vscategory" content="Web and Software Development: Game Development,Web and Software Development: Graphics and Multimedia Development" />
<title>Michael Abrash's Graphics Programming Black Book Special Edition: Boyer-Moore String Searching</title><!-- HEADER -->
<!-- Empty Reference Subhead -->
<!--ISBN=1576101746//-->
<!--TITLE=Michael Abrash's Graphics Programming Black Book Special Edition//-->
<!--AUTHOR=Michael Abrash//-->
<!--PUBLISHER=The Coriolis Group, Inc.//-->
<title>Michael Abrash's Graphics Programming Black Book Special Edition: Boyer-Moore String Searching</title>
<meta name="chapter" content="14" />
<meta name="pages" content="268-271" />
<!--UNASSIGNED1//-->
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</head>
<body>
@ -37,7 +30,7 @@
<p><br /></p>
<p><b>LISTING 14.1 L14-1.C</b></p><!-- CODE //-->
<p><b>LISTING 14.1 L14-1.C</b></p>
<pre>
/* Searches a buffer for a specified pattern. In case of a mismatch,
uses the value of the mismatched byte to skip across as many
@ -124,9 +117,9 @@ unsigned char * FindString(unsigned char * BufferPtr,
BufferPtr += Skip;
}
}
</pre><!-- END CODE //-->
</pre>
<p><b>LISTING 14.2 L14-2.C</b></p><!-- CODE //-->
<p><b>LISTING 14.2 L14-2.C</b></p>
<pre>
/* Program to exercise buffer-search routines in Listings 14.1 &amp; 14.3.
(Must be modified to put copy of pattern as sentinel at end of the
@ -182,7 +175,7 @@ void main() {
}
exit(0);
}
</pre><!-- END CODE //-->
</pre>
<p>Well, architecture carries a lot of weight, but it sure as heck isn&rsquo;t destiny. I had simply fallen into the trap of figuring that the algorithm was so clever that I didn&rsquo;t have to do any thinking myself. The path leading to <b>REPNZ SCASB</b> from the original brute-force approach of <b>REPZ CMPSB</b> at every location had been based on my observation that the first character comparison at each buffer location usually fails. Why not apply the same concept to Boyer-Moore? Listing 14.3 is just like the standard implementation&mdash;except that it&rsquo;s optimized to handle a first-comparison mismatch as quickly as possible in the loop at <b>QuickSearchLoop</b>, much as <b>REPNZ SCASB</b> optimizes first-comparison mismatches for the brute-force approach. The results in Table 14.1 speak for themselves; Listing 14.3 is more than twice as fast as what I assure you was already a nice, tight assembly implementation (and unrolling <b>QuickSearchLoop</b> could boost performance by up to 10 percent more). Listing 14.3 is also <i>four times</i> faster than <b>REPNZ SCASB</b> in one case.</p>
@ -203,10 +196,6 @@ void main() {
<div align="center">
Graphics Programming Black Book &copy; 2001 Michael Abrash
</div><!-- all of the reference materials (books) have the footer and subfoot reveresed -->
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</div>
</body>
</html>