[Bug tree-optimization/26830] [4.1/4.2 Regression] Insane amount of compile-time / memory needed at -O1 and above

[rguenth at gcc dot gnu dot org]

------- Comment #17 from rguenth at gcc dot gnu dot org  2006-03-24 16:33 -------
Now compare numbers from 4.0.3 (i686 again):

 tree PHI insertion    :   6.50 (12%) usr   0.06 ( 2%) sys   6.99 (11%) wall
 tree SSA rewrite      :   8.25 (15%) usr   0.02 ( 1%) sys   8.75 (14%) wall
 tree SSA other        :   3.18 ( 6%) usr   0.20 ( 6%) sys   5.07 ( 8%) wall
 dominator optimization:   8.73 (16%) usr   0.06 ( 2%) sys   8.87 (14%) wall
 global alloc          :   4.58 ( 8%) usr   0.27 ( 9%) sys   5.28 ( 8%) wall
 TOTAL                 :  53.96             3.08            63.37

the usual and expected offender, DOM.  But you can also imagine the big PHIs
there.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26830