Index: llvm/lib/Transforms/Utils/LoopUnroll.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -36,6 +36,7 @@
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
+#include "llvm-c/Core.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/DiagnosticInfo.h"
@@ -385,6 +386,25 @@
   // A conditional branch which exits the loop, which can be optimized to an
   // unconditional branch in the unrolled loop in some cases.
   bool LatchIsExiting = L->isLoopExiting(LatchBlock);
+
+  if (LatchBI && (LatchBI->isConditional() && LatchIsExiting)) {
+    // Insert block frequency for exit latch. This rearranges the basic blocks
+    // neatly.
+    LLVMMetadataRef branch_weights =
+        LLVMMDStringInContext2(LLVMGetGlobalContext(), "branch_weights", 14);
+    LLVMMetadataRef weight1 =
+        LLVMValueAsMetadata(LLVMConstInt(LLVMIntType(32), 20, 0));
+    LLVMMetadataRef weight2 =
+        LLVMValueAsMetadata(LLVMConstInt(LLVMIntType(32), 80, 0));
+    LLVMMetadataRef mds[] = {branch_weights, weight1, weight2};
+    LLVMMetadataRef metadata =
+        LLVMMDNodeInContext2(LLVMGetGlobalContext(), mds, 3);
+    LLVMValueRef metadata_value =
+        LLVMMetadataAsValue(LLVMGetGlobalContext(), metadata);
+
+    LLVMSetMetadata(wrap(LatchBI), LLVMGetMDKindID("prof", 4), metadata_value);
+  }
+
   if (!LatchBI || (LatchBI->isConditional() && !LatchIsExiting)) {
     LLVM_DEBUG(
         dbgs() << "Can't unroll; a conditional latch must exit the loop");