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References: <bug-18046-280@http.gcc.gnu.org/bugzilla/>
Subject: [Bug tree-optimization/18046] Missed jump threading optimization
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From: "steven at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
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------- Comment #12 from steven at gcc dot gnu dot org  2008-09-21 13:58 -------
tree PRE now *does* handle the partially redundant global variable load. This
is the .final_cleanup dump:


;; Function bar (bar)

bar ()
{
  int prephitmp.13;

<bb 2>:
  prephitmp.13 = i;
  switch (prephitmp.13) <default: <L1>, case 0: <L0>>

<L0>:
  foo ();
  prephitmp.13 = i;

<L1>:
  switch (prephitmp.13) <default: <L5>, case 0: <L4>>

<L4>:
  foo (); [tail call]

<L5>:
  return;

}


But we still miss the jump threading opportunity.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18046