search for: onlystore

...oads and stores > > within the block. > > This is a simpler approach and should have the same effect. I'll code it > up. Urk. After looking at doing this today, I realized it won't work. The problem is that RewriteSingleStoreAlloca has this loop: for (; &*I != OnlyStore; ++I) { // scan block for store. if (isa<LoadInst>(I) && I->getOperand(0) == AI) break; It's looking for a load that matches the address of the single store. This is the loop that's taking all the time. What I did with the original patch was to make...

On Saturday 04 October 2008 17:05, Chris Lattner wrote: > Looking more closely at the approach, I infer that the (logical in > hindsight) issue are cases where mem2reg scans a BB to see the > relative ordering of two instructions. For example, the single store Correct. > case. I could imagine that if you saw lots of single store allocas in > the middle of a large BB that

On Oct 4, 2008, at 2:51 PM, Chris Lattner wrote: >>> I like your approach of using the use lists but I'm not sure the >>> ordering >>> is guaranteed. If it is, your approach is superior. >> >> I got my patch updated to work with TOT. Here it is. Comments >> welcome. > > Hi Dave, > > Great. I'd like to get this in, but would

...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 may have some value coming into the...

...; >> This is a simpler approach and should have the same effect. I'll >> code it >> up. > > Urk. After looking at doing this today, I realized it won't work. > The > problem is that RewriteSingleStoreAlloca has this loop: > > for (; &*I != OnlyStore; ++I) { // scan block for store. > if (isa<LoadInst>(I) && I->getOperand(0) == AI) > break; > > It's looking for a load that matches the address of the single > store. This > is the loop that's taking all the time. What I did with the...