[PATCH] D147622: mark remainder loop can be unrolled

[Yashwant Singh via Phabricator via llvm-commits]

yassingh created this revision.
Herald added subscribers: zzheng, hiraditya.
Herald added a project: All.
yassingh requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D147622

Files:
  llvm/include/llvm/Analysis/LoopInfo.h
  llvm/lib/Analysis/LoopInfo.cpp
  llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp


Index: llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -1330,6 +1330,7 @@
                                         LLVMLoopUnrollFollowupRemainder});
     if (RemainderLoopID)
       RemainderLoop->setLoopID(*RemainderLoopID);
+    RemainderLoop->setLoopCanBeUnrolled();
   }
 
   if (UnrollResult != LoopUnrollResult::FullyUnrolled) {
Index: llvm/lib/Analysis/LoopInfo.cpp
===================================================================
--- llvm/lib/Analysis/LoopInfo.cpp
+++ llvm/lib/Analysis/LoopInfo.cpp
@@ -545,6 +545,17 @@
   setLoopID(NewLoopID);
 }
 
+void Loop::setLoopCanBeUnrolled() {
+  LLVMContext &Context = getHeader()->getContext();
+
+  MDNode *EnableUnrollMD =
+      MDNode::get(Context, MDString::get(Context, "llvm.loop.unroll.enable"));
+  MDNode *LoopID = getLoopID();
+  MDNode *NewLoopID = makePostTransformationMetadata(
+      Context, LoopID, {"llvm.loop.unroll."}, {EnableUnrollMD});
+  setLoopID(NewLoopID);
+}
+
 void Loop::setLoopMustProgress() {
   LLVMContext &Context = getHeader()->getContext();
 
Index: llvm/include/llvm/Analysis/LoopInfo.h
===================================================================
--- llvm/include/llvm/Analysis/LoopInfo.h
+++ llvm/include/llvm/Analysis/LoopInfo.h
@@ -872,6 +872,8 @@
   /// unrolling pass is run more than once (which it generally is).
   void setLoopAlreadyUnrolled();
 
+  void setLoopCanBeUnrolled();
+
   /// Add llvm.loop.mustprogress to this loop's loop id metadata.
   void setLoopMustProgress();
 


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