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From: "law at redhat dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/62217] [4.9/5 Regression] DOM confuses complete unrolling which in turn causes VRP to warn
Date: Tue, 17 Feb 2015 20:01:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62217

--- Comment #14 from Jeffrey A. Law <law at redhat dot com> ---
WRT the patch in c#12, it looks reasonable for the same reasons as we avoid
propagating in 23821.  I can confirm that it prevents the unwanted cprop into
array reference.   By DOM2 we have the following array references:


  g_x[0] = *x2_9(D);
  g_x[0] = *x1_7(D);
  g_x[1] = *x2_9(D);
  g_x[1] = *x1_7(D);
  g_x[2] = *x2_9(D);
  g_x[2] = *x1_7(D);
  g_x[3] = *x1_7(D);
  g_x[3] = *x2_9(D);


Assuming it bootstraps and regression tests, I'd go with it.