------- Comment #30 from steven at gcc dot gnu dot org 2006-01-08 16:08 ------- Other than VRP taking so much time for GCC 4.1, there are no surprises in the timings I just added in comment #29 for GCC 4.0 and GCC 4.1.
Computing dominance frontiers is just not a linear operation (especially not for a function with this many of them :-). "CPROP 1", "CPROP 2", and "bypass jumps" are all the same algorithm (const/copy propagation in gcse.c) which also has known non-linear algorithms for strange test cases like the one for this bug report. If only VRP wouldn't suck up so much time here, I would call this one FIXED... -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19097
