> Hmm, it seems to be because we do not value-number loads that
> satisfy stmt_could_throw_p (for whatever reason ...).  Seems to date
> back to rev. 131610, the fix for PR34648.  Looking at that bug it
> seems that we could at least allow stmts that only throw externally
> (but generally CSE should still work, so value-number them when
> we are doing FRE but not PRE).

OK.  The annoying thing is that it's optimized if you have y_1(D)->i2:

  t$F$i2_9 = y_1(D)->i2;
  D.1579_3 = y_1(D)->i2;

and this is equivalent wrt throwing (in particular TREE_THIS_NOTRAP is not set 
anywhere).

-- 
Eric Botcazou

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