[Bug middle-end/28071] [4.1/4.2 regression] A file that can not be compiled in reasonable time/space

amacleod at redhat dot com gcc-bugzilla@gcc.gnu.org
Fri Aug 25 01:43:00 GMT 2006



------- Comment #48 from amacleod at redhat dot com  2006-08-25 01:42 -------
Created an attachment (id=12136)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12136&action=view)
Patch for the remaining SSA to Normal time issues

I've attached a patch to address the slowdowns in TER. Again, not sure this is
stage 3, but I'll send a note to gcc-patches with the full breakdown, but
basically I replaced the expression linked lists with bitmaps.

This patch has been bootstrapped on 1686-pc-linux-gnu with no new regressions.

at -O2 timings go from:
   tree SSA to normal    :  30.79 (19%) usr   0.06 ( 2%) sys  31.89 (19%) wall
to
   tree SSA to normal    :   1.33 ( 1%) usr   0.02 ( 1%) sys   1.86 ( 1%) wall

and at -O3:
   tree SSA to normal    :  32.08 (35%) usr   0.08 ( 1%) sys  32.92 (28%) wall
to
   tree SSA to normal    :  18.75 (24%) usr   0.06 ( 1%) sys  18.83 (23%) wall

when combined with the previous live on entry/exit patch, I get the following
times at -O2 :
   tree SSA to normal    :  30.79 (19%) usr   0.06 ( 2%) sys  31.89 (19%) wall
to
   tree SSA to normal    :   1.16 ( 1%) usr   0.01 ( 0%) sys   1.17 ( 1%) wall

and at -O3:
   tree SSA to normal    :  32.08 (35%) usr   0.08 ( 1%) sys  32.92 (28%) wall
to
   tree SSA to normal    :   2.50 ( 4%) usr   0.08 ( 1%) sys   2.61 ( 2%) wall


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28071



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