<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 2008 (1.71) original version by: Nikos Drakos, CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>8.1.3 Copy-Propagation</TITLE> <META NAME="description" CONTENT="8.1.3 Copy-Propagation"> <META NAME="keywords" CONTENT="sdccman"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META NAME="Generator" CONTENT="LaTeX2HTML v2008"> <META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> <LINK REL="STYLESHEET" HREF="sdccman.css"> <LINK REL="next" HREF="node173.html"> <LINK REL="previous" HREF="node171.html"> <LINK REL="up" HREF="node169.html"> <LINK REL="next" HREF="node173.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html3399" HREF="node173.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html3393" HREF="node169.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html3387" HREF="node171.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html3395" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <A NAME="tex2html3397" HREF="node191.html"> <IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="index.png"></A> <BR> <B> Next:</B> <A NAME="tex2html3400" HREF="node173.html">8.1.4 Loop Optimizations</A> <B> Up:</B> <A NAME="tex2html3394" HREF="node169.html">8.1 Optimizations</A> <B> Previous:</B> <A NAME="tex2html3388" HREF="node171.html">8.1.2 Dead-Code Elimination</A> <B> <A NAME="tex2html3396" HREF="node1.html">Contents</A></B> <B> <A NAME="tex2html3398" HREF="node191.html">Index</A></B> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION00913000000000000000"></A><A NAME="4020"></A> <BR> 8.1.3 Copy-Propagation </H2> <BLOCKQUOTE> <TT>int f() { </TT> <BR><TT> int i, j; </TT> <BR><TT> i = 10; </TT> <BR><TT> j = i; </TT> <BR><TT> return j; </TT> <BR><TT>}</TT> </BLOCKQUOTE> will be changed to <BLOCKQUOTE> <TT>int f() { </TT> <BR><TT> int i, j; </TT> <BR><TT> i = 10; </TT> <BR><TT> j = 10; </TT> <BR><TT> return 10; </TT> <BR><TT>}</TT> </BLOCKQUOTE> Note: the dead stores created by this copy propagation will be eliminated by dead-code elimination. <P> <BR><HR> <ADDRESS> 2011-03-20 </ADDRESS> </BODY> </HTML>