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From: pashanhenlei@gmail.com
Newsgroups: comp.compilers
Subject: about the tiger book, reducible flow graph, Figure 18.2
Date: Sat, 19 Jan 2013 11:02:24 -0500 (EST)
Organization: Compilers Central
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Keywords: books, question, optimize
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Xref: csiph.com comp.compilers:845

i have a question: when we reduce Figure 18.2c to Figure 18.2a, why
should we first remove edge 6->9 and edge 5->4? i can't figure out the
rules behind.

can anyone help me? TIA.