DFA scheduler in GCC

[David Edelsohn]

	Does the new scheduler produce any significant performance
improvement in the code GCC generates commensurate with its compile-time
cost?

	Both my experience with the new DFA scheduler targeted at PowerPC
delivered with GNUPro and the GCC for IA-64 Summit minutes report that the
scheduler compile time was no faster than the Haifa Scheduler and the
scheduler did it not generate faster code.  The software pipelining did
not seem to be effective either, mainly because of dependency information
infrastructure still lacking in GCC.

	In theory, the DFA scheduler and software pipelining should be
much better.  Until the new work demonstrates an improvement and is shown
to be robust, I think it should be on a branch, as GCC's development
policy specifies.

	What evidence shows that the DFA scheduler and software pipeliner
have evolved beyond a work in progress?

David