------- Comment #16 from sergeid at il dot ibm dot com 2008-12-21 07:44 ------- (In reply to comment #15) > Re. comment #14: Yes, I suppose so. Why do you want to remove gcse-las from > mainline. Not that I'm against it -- ideally RTL gcse.c would not work on > memory at all anymore -- but I wouldn't remove gcse-las until we catch in the > GIMPLE optimizers as much as possible of the things we still need gcse-las > for.
For the time being this is the only case I've found out which is missed by tree-PRE and caught by GCSE-LAS. As you pointed out, GCSE-LAS doesn't seem to help much. > It seems to me, btw, that it might be easier to teach GIMPLE loop invariant > code motion about this transformation. Adding this in GIMPLE PRE might be a > little too expensive...? That may be; I was just noting that such redundancies should be caught somewhere at the GIMPLE stage. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38401
