[Bug middle-end/32758] [4.3 Regression] ecj1 hangs

["paolo dot bonzini at lu dot unisi dot ch" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #24 from paolo dot bonzini at lu dot unisi dot ch  2007-08-29 12:15 -------
Subject: Re:  [4.3 Regression] ecj1 hangs

> Here is what I will try to regtest (already verified it fixes the testcase).

This is wrong, because local_live changes during execution of 
dce_process_block.  The {eh,regular}_block_artificial_uses must always 
be set (they are live throughout, not just at the bottom of the basic 
block).

> Alternatively, artificial_live could be a pointer bitmap which would just
> point to one of the &df->*_block_artificial_uses bitmap, though not sure
> if that ever could or in some register that wasn't originally set in
> local_live.

Much better, and would have the same effect as dce_simulate_fixup_sets.

> Certainly calling df_has_eh_preds just once per bb rather than per insn is IMHO
> worthwhile.

A patch to do so if preapproved if you add a comment saying

/* Calling df_simulate_fixup_sets has the disadvantage of calling
    df_has_eh_preds once per insn, so we cache the information here.  */

before the place where you set artificial_live.

Thanks!


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32758