Index: llvm/lib/Transforms/Utils/LoopPeel.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopPeel.cpp
+++ llvm/lib/Transforms/Utils/LoopPeel.cpp
@@ -460,27 +460,30 @@
   if (L->getHeader()->getParent()->hasProfileData()) {
     if (violatesLegacyMultiExitLoopCheck(L))
       return;
-    Optional<unsigned> PeelCount = getLoopEstimatedTripCount(L);
-    if (!PeelCount)
+    Optional<unsigned> EstimatedTripCount = getLoopEstimatedTripCount(L);
+    if (!EstimatedTripCount)
       return;
 
-    LLVM_DEBUG(dbgs() << "Profile-based estimated trip count is " << *PeelCount
-                      << "\n");
-
-    if (*PeelCount) {
-      if ((*PeelCount + AlreadyPeeled <= UnrollPeelMaxCount) &&
-          (LoopSize * (*PeelCount + 1) <= Threshold)) {
-        LLVM_DEBUG(dbgs() << "Peeling first " << *PeelCount
-                          << " iterations.\n");
-        PP.PeelCount = *PeelCount;
+    LLVM_DEBUG(dbgs() << "Profile-based estimated trip count is "
+                      << *EstimatedTripCount << "\n");
+
+    if (*EstimatedTripCount) {
+      // Even if we cannot peel all estimated iterations, partial peeling also
+      // seems beneficial, but only to some extent.
+      if (*EstimatedTripCount + AlreadyPeeled <= MaxPeelCount * 2 &&
+          AlreadyPeeled < MaxPeelCount) {
+        unsigned PeelCount =
+            std::min(*EstimatedTripCount, MaxPeelCount - AlreadyPeeled);
+        LLVM_DEBUG(dbgs() << "Peeling first " << PeelCount << " iterations.\n");
+        PP.PeelCount = PeelCount;
         return;
       }
-      LLVM_DEBUG(dbgs() << "Requested peel count: " << *PeelCount << "\n");
       LLVM_DEBUG(dbgs() << "Already peel count: " << AlreadyPeeled << "\n");
       LLVM_DEBUG(dbgs() << "Max peel count: " << UnrollPeelMaxCount << "\n");
-      LLVM_DEBUG(dbgs() << "Peel cost: " << LoopSize * (*PeelCount + 1)
-                        << "\n");
+      LLVM_DEBUG(dbgs() << "Loop cost: " << LoopSize << "\n");
       LLVM_DEBUG(dbgs() << "Max peel cost: " << Threshold << "\n");
+      LLVM_DEBUG(dbgs() << "Max peel count by cost: "
+                        << (Threshold / LoopSize - 1) << "\n");
     }
   }
 }
Index: llvm/test/Transforms/LoopUnroll/peel-loop-conditions-pgo-2.ll
===================================================================
--- llvm/test/Transforms/LoopUnroll/peel-loop-conditions-pgo-2.ll
+++ llvm/test/Transforms/LoopUnroll/peel-loop-conditions-pgo-2.ll
@@ -7,8 +7,8 @@
 
 ; Check that we can peel off iterations that make conditions true.
 ; The second invocation of loop-unroll will NOT do profile based peeling of
-; remained iterations because the total number of peeled iterations exceeds
-; threashold specified with -unroll-peel-max-count=7.
+; remaining iterations because the total number of iterations exceeds the
+; doubled threshold specified with -unroll-peel-max-count=7.
 define void @test2(i32 %k) !prof !4 {
 ; CHECK: Loop Unroll: F[test2] Loop %for.body
 ; CHECK: PEELING loop %for.body with iteration count 2!
@@ -39,5 +39,5 @@
 }
 
 !1 = distinct !{!1}
-!3 = !{!"branch_weights", i32 8, i32 1}
+!3 = !{!"branch_weights", i32 14, i32 1}
 !4 = !{!"function_entry_count", i64 1}
Index: llvm/test/Transforms/LoopUnroll/peel-loop-conditions-pgo-3.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopUnroll/peel-loop-conditions-pgo-3.ll
@@ -0,0 +1,43 @@
+; RUN: opt < %s -S -loop-unroll -loop-unroll -verify-dom-info -debug-only=loop-unroll -unroll-peel-max-count=7 2>&1 | FileCheck %s
+; REQUIRES: asserts
+
+declare void @f1()
+declare void @f2()
+
+; Check that we can peel off iterations that make conditions true.
+; The second invocation of loop-unroll will do profile-based peeling of remaining
+; iterations and will partially peel them so that the total number of peeled
+; iterations does not exceed the threshold specified with -unroll-peel-max-count=7.
+define void @test2(i32 %k) !prof !4 {
+; CHECK: Loop Unroll: F[test2] Loop %for.body
+; CHECK: PEELING loop %for.body with iteration count 2!
+; CHECK: PEELING loop %for.body with iteration count 5!
+; CHECK: llvm.loop.unroll.disable
+for.body.lr.ph:
+  br label %for.body
+
+for.body:
+  %i.05 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.inc ]
+  %cmp1 = icmp ult i32 %i.05, 2
+  br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+  call void @f1()
+  br label %for.inc
+
+if.else:
+  call void @f2()
+  br label %for.inc
+
+for.inc:
+  %inc = add nsw i32 %i.05, 1
+  %cmp = icmp slt i32 %inc, %k
+  br i1 %cmp, label %for.body, label %for.end, !llvm.loop !1, !prof !3
+
+for.end:
+  ret void
+}
+
+!1 = distinct !{!1}
+!3 = !{!"branch_weights", i32 13, i32 1}
+!4 = !{!"function_entry_count", i64 1}