[PATCH] D16382: Add LoopSimplifyCFG pass

[David Majnemer via llvm-commits]

majnemer added a subscriber: majnemer.

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Comment at: lib/Transforms/Scalar/LoopSimplifyCFG.cpp:105
@@ +104,3 @@
+      L->moveToHeader(Succ);
+    LI->removeBlock(Pred);
+    MergeBasicBlockIntoOnlyPred(Succ, DT);
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escha wrote:
> sanjoy wrote:
> > Won't this invalidate `E`?
> I don't *think* so? This only modifies things earlier in the list, not later. Should I recalculate E on each iteration just to be sure?
`Loop::block_end` accesses the end iterator of a vector. `LoopInfo::removeBlock` calls `Loop::removeBlockFromLoop` which will `erase` an element from the vector.  `std::vector::erase` invalidates all iterators at or beyond the point of the erase including the vector's `end` iterator.


Repository:
  rL LLVM

http://reviews.llvm.org/D16382