search for: storingglobalv

...ominates the block and if we haven't processed it yet, // do so now. We can't handle the case where the store doesn't dominate a // block because there may be a path between the store and the use, but we // may need to insert phi nodes to handle dominance properly. if (!StoringGlobalVal && !dominates(OnlyStore->getParent(), UseBlock)) continue; This prevents mem2reg from forwarding the single store to uses that it does not dominate. Why is this only prevented when NOT storing to global values? I would think it would be exactly the opposite. A global value ma...

...'s well-defined, it's always correct to use the value stored, because undef can be anything. The reason for the check is question is that the stored value might not dominate the use. This is only possible, however, if the stored value is an instruction; dominance doesn't make sense if StoringGlobalVal is true. -Eli

...se undef can be > anything. I agree. > The reason for the check is question is that the stored value might > not dominate the use. This is only possible, however, if the stored Yes, that's the case I am seeing. > value is an instruction; dominance doesn't make sense if > StoringGlobalVal is true. Ok, so you're saying that because we're storing a global value, by definition it DOES dominate the use because it's a global (and thus live-in to the Function). Is that right? In the case I'm seeing, the "global value" is a constant. So I guess it's ok t...