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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: Zenning and the Flexible Mind</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: Zenning and the Flexible Mind</title>
<meta name="chapter" content="22" />
<meta name="pages" content="417-418" />
<!--UNASSIGNED1//-->
<!--UNASSIGNED2//-->
</head>
<body>
@ -37,7 +30,7 @@
<p><br /></p>
<p><b>LISTING 22.2 L22-2.ASM</b></p><!-- CODE //-->
<p><b>LISTING 22.2 L22-2.ASM</b></p>
<pre>
ClearS proc near
push bp ;save caller&rsquo;s BP
@ -60,7 +53,7 @@ Bye:
pop bp ;restore caller&rsquo;s BP
ret EndMrk-RetAddr-2 ;return, clearing the parms from the stack
ClearS endp
</pre><!-- END CODE //-->
</pre>
<p>(The <b>OnStack</b> structure definition doesn&rsquo;t change in any of our examples, so I&rsquo;m not going clutter up this chapter by reproducing it for each new version of <b>ClearS</b>.)</p>
@ -68,7 +61,7 @@ ClearS endp
<p>Well, <b>LES</b> would serve better than two <b>MOV</b> instructions for loading ES and DI as shown in Listing 22.3.</p>
<p><b>LISTING 22.3 L22-3.ASM</b></p><!-- CODE //-->
<p><b>LISTING 22.3 L22-3.ASM</b></p>
<pre>
ClearS proc near
push bp ;save caller&rsquo;s BP
@ -91,13 +84,13 @@ Bye:
pop bp ;restore caller&rsquo;s BP
ret EndMrk-RetAddr-2 ;return, clearing the parms from the stack
ClearS endp
</pre><!-- END CODE //-->
</pre>
<p>That&rsquo;s good for another three bytes. We&rsquo;re down to 43 bytes, and counting.</p>
<p>We can save 3 more bytes by clearing the low and high bytes of AX and BX, respectively, by using <b>SUB <i>reg8,reg8</i></b> rather than ANDing 16-bit values as shown in Listing 22.4.</p>
<p><b>LISTING 22.4 L22-4.ASM</b></p><!-- CODE //-->
<p><b>LISTING 22.4 L22-4.ASM</b></p>
<pre>
ClearS proc near
push bp ;save caller&rsquo;s BP
@ -120,7 +113,7 @@ Bye:
pop bp ;restore caller&rsquo;s BP
ret EndMrk-RetAddr-2 ;return, clearing the parms from the stack
ClearS endp
</pre><!-- END CODE //-->
</pre>
<p>Now we&rsquo;re down to 40 bytes&mdash;more than 20 percent smaller than the original code. That&rsquo;s pretty much it for simple instruction optimizations. Now let&rsquo;s look for instruction optimizations.</p>
@ -145,10 +138,6 @@ ClearS endp
<div align="center">
Graphics Programming Black Book &copy; 2001 Michael Abrash
</div><!-- all of the reference materials (books) have the footer and subfoot reveresed -->
<!-- reference_subfoot = footer -->
<!-- reference_footer = subfoot -->
<!-- BEGIN SUB FOOTER -->
<!-- END FOOTER -->
</div>
</body>
</html>