On Wed, Nov 26, 2014 at 11:14:36AM -0700, Jeff Law wrote: > >Are you talking about create_log_links? There can be no duplicates there > >(anymore), that would be multiple defs of the same reg in the same insn, > >indeed. > Yes, I was referring to the code in create_log_links. You dropped the > check for duplicate links. It caught my eye when reading the changes, > but then I realized the check may no longer be necessary. > > Hmm, what about an insn that has two destinations, which happen to be > upper and lower SUBREGs of a pseudo. Would that create duplicate links > after your change?
Yes it would. And I'm not so certain distribute_log_links handles that situation gracefully. Rats. IMNSHO such RTL should be invalid (it can always be written simpler as one SET); but there seems to be no such rule. I'll add the check back. Wouldn't it be lovely if we could just use DF here... Segher
