On Tue, 10 Sep 2013, Jeff Law wrote: > On 09/10/2013 07:23 AM, Richard Biener wrote: > > > > update-ssa for example just queues to release SSA names. But yes, > > re-using SSA names from a freelist has issues and advantages ;) > Yup. I've wondered from time to time if we could do away with the name > manager -- IIRCC it was written when we took everything out of SSA form after > jump threading then put everything back into SSA form. With the incremental > update we do now we could consider doing away with the manager entirely.
Well, it definitely helps to re-use the SSA namespace and keep it compact (helps for compile-time and memory-usage). The question is whether it helps within a pass. Once in the compilation (after early optimizations) we compact the namespace. We already have statistics in place btw, --enable-gather-detailed-mem-stats prints the number of re-used SSA_NAME nodes and the number of overall allocated ones. Richard.
