[Bug tree-optimization/26854] [4.3/4.4/4.5 Regression] Inordinate compile times on large routines

[bonzini at gnu dot org]

------- Comment #108 from bonzini at gnu dot org  2009-06-15 16:30 -------
http://gcc.gnu.org/bugzilla/attachment.cgi?id=17968
This is the current state of -ftime-report/-fmem-report after the proposed
reimplementation of fwprop's dataflow.

Remaining hogs are:

1) Accounting for TV_ALIAS_STMT_WALKING is expensive.  Waiting for info from
Brad as to how much of the cost is paid without -ftime-report.  If it turns out
to be noticeable, Richi preapproved the trivial patch to remove the timevar.

2) CFG cleanup uses heavily the iterative fixing of dominators in
remove_edge_and_dominated_blocks, which on this testcase is very expensive. 
Probably we should make sure no dominators are there in some key cfgcleanup
passes, or just kill dominators at the beginning of CFG cleanup if the testcase
is particularly large.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26854