------- Additional Comments From steven at gcc dot gnu dot org 2005-01-31 12:39 ------- To get something started, I have done SPECint and SPECfp runs on AMD64 with CVS HEAD 20050130, unmodified vs. a cse.c with path following disabled (by setting the max-cse-path-length to 1). The overall scores go *up* (!!!) with that change, but some individual benchmarks regress. Still this is a lot better than half a year ago, when terminating CSE would cause an overall regression of more than 10%.
Diego Novillo also had his SPEC tester on i686 run, with CSE completely disabled, and there, too, the overall performance drop was not as large as one would maybe have expected. Note that completely disabling is a step further than setting the max-cse-path-length to 1. The latter effectively makes CSE a purely local pass. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19721
