[PATCH] D28073: Preserve domtree and loop-simplify for runtime unrolling.

Michael Kuperstein via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Dec 27 11:33:28 PST 2016


mkuper added inline comments.


================
Comment at: lib/Transforms/Utils/LoopUnroll.cpp:55
+static cl::opt<bool>
+UnrollVerifyDomtree("unroll-verify-domtree", cl::init(false), cl::Hidden,
+                    cl::desc("Verify domtree after unrolling"));
----------------
We want to enforce this being on in new tests too, I assume?


================
Comment at: lib/Transforms/Utils/LoopUnroll.cpp:619
+      if (BB == LatchBlock) {
+        // The latch is special because we emit unconditional branches in
+        // some cases.  Since the latch is always at the bottom of the loop,
----------------
Isn't it the case that when the latch ends with an unconditional branch, that branch is towards the header block?
If so, we should not have any children outside the loop.


Repository:
  rL LLVM

https://reviews.llvm.org/D28073





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