[Bug c++/13776] [tree-ssa] Many C++ compile-time regression in 3.5-tree-ssa 040120

[dberlin at gcc dot gnu dot org]

------- Additional Comments From dberlin at gcc dot gnu dot org  2004-03-14 04:47 -------
There are about 100 functions here with > a couple thousand bb's.
PRE takes about 2-3 seconds for each of these functions.
Which means i have to microoptimize it in order to get rid of the cumulative time effect.
A lot of is it simply iterating over large lists looking for certain types of nodes (like EPHiS), where the 
lists are O(n_basic_blocks), and we only need to look at 10 entries or so.  This doesn't matter when the 
numbers are close, but when you have 8000 bb's to walk 20 times, instead of walking 40 entries 20 
times, it matters.



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13776