[PATCH] D18158: Adding ability to unroll loops using epilogue remainder.

[Z. Zheng via llvm-commits]

zzheng added a comment.

I've seen 'unrolling loop' in comments, personally I prefer 'unrolled loop' for clarity.


================
Comment at: lib/Transforms/Utils/LoopUnroll.cpp:297
@@ -292,2 +296,3 @@
+  // Don't output the runtime loop remainder if Count is a multiple of
   // TripMultiple.  Such a prolog is never needed, and is unsafe if the loop
   // contains a convergent instruction.
----------------
'prolog'?

I recommend changing prolog/remainder here to 'leftover'

================
Comment at: lib/Transforms/Utils/LoopUnrollRuntime.cpp:146
@@ +145,3 @@
+/// - Update PHI nodes at the unrolling loop exit and epilog loop exit
+/// - Create PHI nodes at the unrolling loop exit to combine
+///   values that exit the unrolling loop code and jump around it.
----------------
You mean 'unrolled loop', right?

================
Comment at: lib/Transforms/Utils/LoopUnrollRuntime.cpp:191
@@ +190,3 @@
+    // NewExit was spilt 1 more time to get EpilogPreHeader.
+    assert(PN->hasOneUse() && "The phi should have 1 use");
+    PHINode *EpilogPN = cast<PHINode> (PN->use_begin()->getUser());
----------------
PN shoudl have 2 uses, right? One in epilogue loop or its preheader and one in Exit.

Please clarify it only has 1 use for now as we'll add the use in epilogue later.


http://reviews.llvm.org/D18158