Out-of-sight compile times for calculate_loop_depth

Jeffrey A Law law@cygnus.com
Mon Feb 7 15:25:00 GMT 2000


  In message < 14495.20749.161443.966173@ongaonga.elec.canterbury.ac.nz >you writ
e:
  > This testcase exposes problems with the dominator calculation
  > algorithm and with flow_loop_node_add.  The latter I never
  > particularly liked since it can exhibit quadratic behaviour.  As an
  > interim solution, adding the loops to the loop tree in reverse order
  > should reduce the insertion time.
There are certainly faster algorithms for computing dominators; I've
speculated that we'll eventually have to use one as we make more use of
dominance relationships.

The advantage of the existing dominator algorithm is that it's very
simple to understand and performs OK for reasonable code.

jeff



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