------- Comment #23 from ian at airs dot com 2007-06-30 17:57 ------- The patch in comment #19 of PR 32437 looks clearly correct. That patch should not be reverted, at least not by itself. I'm not clear on whether that was the patch that was reverted, but, if it was, I don't think it should have been. We are not in a time critical situation here. Let's take the time to figure out the right fix even if Richard doesn't have time to work on it.
This is DCE, not DSE. In DSE we can not eliminate frame related instructions, because the stores into the frame are used by code which dataflow doesn't see: the exception unwinder. That does not apply to DCE. In DCE, we should be able to eliminate changes to the stack pointer when the stack pointer is not used, even though those changes are frame related. So I think this patch should be unreverted, and I don't think you should add a test for frame relatedness. Then we should fix PR 32475. Further comments over there. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32437
