[Bug middle-end/12524] [tree-ssa] Slow-down and memory consumption increased 6x (C++ code, -O3)

["amacleod at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12524



------- Additional Comments From amacleod at redhat dot com  2003-10-07 20:05 -------
Some further investigation appears to point the finger at gimplification. I've
run this while watching memory use in a monitor.. mainline slowly builds and
peaks at about 170MB or so. tree-ssa climbs quicker, and peaks around 450MB, and
spends most of the time hovering around 400MB. If I disable SSA completely, that
only drops to about 400MB for a peak, so we dont see a lot of change (now that
SSA is using less memory in CCP :-)

So the question is, why are we using so much more memory.. is it because
gimplification is producing so many more instructions and temporaries? is there
a fix for this?  Perhaps Jaosn is the best one to take a look at this since he's
the one intimately familiar with the gimplification process.