Index: lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
===================================================================
--- lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -354,6 +354,32 @@
   return true;
 }
 
+
+static bool GetBranchWeights(BranchInst *BI, uint64_t &LeftWeight,
+                             uint64_t &RightWeight) {
+  MDNode *MD = BI->getMetadata(LLVMContext::MD_prof);
+  if (!MD || MD->getNumOperands() != 3)
+    return false;
+
+  MDString* MDS = dyn_cast_or_null<MDString>(MD->getOperand(0));
+  if (!MDS || !MDS->getString().equals("branch_weights"))
+    return false;
+
+  ConstantInt *LeftCI = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
+  ConstantInt *RightCI = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
+
+  if (!LeftCI || LeftCI->getValue().getBitWidth() > 64)
+    return false;
+
+  if (!RightCI || RightCI->getValue().getBitWidth() > 64)
+    return false;
+
+  LeftWeight = LeftCI->getZExtValue();
+  RightWeight = RightCI->getZExtValue();
+
+  return true;
+}
+
 InductiveRangeCheck *
 InductiveRangeCheck::create(InductiveRangeCheck::AllocatorTy &A, BranchInst *BI,
                             Loop *L, ScalarEvolution &SE) {
@@ -361,6 +387,21 @@
   if (BI->isUnconditional() || BI->getParent() == L->getLoopLatch())
     return nullptr;
 
+  uint64_t LeftWeight = 0, RightWeight = 0;
+
+  if (!GetBranchWeights(BI, LeftWeight, RightWeight))
+    return nullptr;
+
+  const int LikelyRatio = 16;
+  // LikelyRatio = LikelyBranchWeight / UnlikelyBranchWeight, from
+  // LowerExpectIntrinsic.cpp
+
+  bool TrueVeryLikely = (RightWeight == 0 && LeftWeight != 0) ||
+    (LeftWeight / RightWeight >= LikelyRatio);
+
+  if (!TrueVeryLikely)
+    return nullptr;
+
   Value *Length = nullptr;
   const SCEV *IndexSCEV = nullptr;
 
Index: test/Transforms/IRCE/multiple-access-no-preloop.ll
===================================================================
--- test/Transforms/IRCE/multiple-access-no-preloop.ll
+++ test/Transforms/IRCE/multiple-access-no-preloop.ll
@@ -13,13 +13,13 @@
   %idx = phi i32 [ 0, %entry ] , [ %idx.next, %in.bounds.b ]
   %idx.next = add i32 %idx, 1
   %abc.a = icmp slt i32 %idx, %len.a
-  br i1 %abc.a, label %in.bounds.a, label %out.of.bounds
+  br i1 %abc.a, label %in.bounds.a, label %out.of.bounds, !prof !1
 
  in.bounds.a:
   %addr.a = getelementptr i32* %arr_a, i32 %idx
   store i32 0, i32* %addr.a
   %abc.b = icmp slt i32 %idx, %len.b
-  br i1 %abc.b, label %in.bounds.b, label %out.of.bounds
+  br i1 %abc.b, label %in.bounds.b, label %out.of.bounds, !prof !1
 
  in.bounds.b:
   %addr.b = getelementptr i32* %arr_b, i32 %idx
@@ -57,3 +57,4 @@
 ; CHECK: br i1 %next.postloop, label %loop.postloop, label %exit.loopexit
 
 !0 = !{i32 0, i32 2147483647}
+!1 = !{!"branch_weights", i32 64, i32 4}
Index: test/Transforms/IRCE/no-branch-weight.ll
===================================================================
--- /dev/null
+++ test/Transforms/IRCE/no-branch-weight.ll
@@ -0,0 +1,40 @@
+; RUN: opt -verify-loop-info -irce-print-changed-loops -irce < %s 2>&1 | FileCheck %s
+
+; CHECK-NOT: constrained Loop
+
+define void @multiple_access_no_preloop(
+    i32* %arr_a, i32* %a_len_ptr, i32* %arr_b, i32* %b_len_ptr, i32 %n) {
+
+ entry:
+  %len.a = load i32* %a_len_ptr, !range !0
+  %len.b = load i32* %b_len_ptr, !range !0
+  %first.itr.check = icmp sgt i32 %n, 0
+  br i1 %first.itr.check, label %loop, label %exit
+
+ loop:
+  %idx = phi i32 [ 0, %entry ] , [ %idx.next, %in.bounds.b ]
+  %idx.next = add i32 %idx, 1
+  %abc.a = icmp slt i32 %idx, %len.a
+  br i1 %abc.a, label %in.bounds.a, label %out.of.bounds
+
+ in.bounds.a:
+  %addr.a = getelementptr i32* %arr_a, i32 %idx
+  store i32 0, i32* %addr.a
+  %abc.b = icmp slt i32 %idx, %len.b
+  br i1 %abc.b, label %in.bounds.b, label %out.of.bounds
+
+ in.bounds.b:
+  %addr.b = getelementptr i32* %arr_b, i32 %idx
+  store i32 -1, i32* %addr.b
+  %next = icmp slt i32 %idx.next, %n
+  br i1 %next, label %loop, label %exit
+
+ out.of.bounds:
+  ret void
+
+ exit:
+  ret void
+}
+
+!0 = !{i32 0, i32 2147483647}
+
Index: test/Transforms/IRCE/single-access-no-preloop.ll
===================================================================
--- test/Transforms/IRCE/single-access-no-preloop.ll
+++ test/Transforms/IRCE/single-access-no-preloop.ll
@@ -10,7 +10,7 @@
   %idx = phi i32 [ 0, %entry ] , [ %idx.next, %in.bounds ]
   %idx.next = add i32 %idx, 1
   %abc = icmp slt i32 %idx, %len
-  br i1 %abc, label %in.bounds, label %out.of.bounds
+  br i1 %abc, label %in.bounds, label %out.of.bounds, !prof !1
 
  in.bounds:
   %addr = getelementptr i32* %arr, i32 %idx
@@ -65,7 +65,7 @@
   %idx.next = add i32 %idx, 1
   %idx.for.abc = add i32 %idx, 4
   %abc = icmp slt i32 %idx.for.abc, %len
-  br i1 %abc, label %in.bounds, label %out.of.bounds
+  br i1 %abc, label %in.bounds, label %out.of.bounds, !prof !1
 
  in.bounds:
   %addr = getelementptr i32* %arr, i32 %idx.for.abc
@@ -108,3 +108,4 @@
 ; CHECK: br i1 %next.postloop, label %loop.postloop, label %exit.loopexit
 
 !0 = !{i32 0, i32 2147483647}
+!1 = !{!"branch_weights", i32 64, i32 4}
Index: test/Transforms/IRCE/single-access-with-preloop.ll
===================================================================
--- test/Transforms/IRCE/single-access-with-preloop.ll
+++ test/Transforms/IRCE/single-access-with-preloop.ll
@@ -13,7 +13,7 @@
   %abc.high = icmp slt i32 %array.idx, %len
   %abc.low = icmp sge i32 %array.idx, 0
   %abc = and i1 %abc.low, %abc.high
-  br i1 %abc, label %in.bounds, label %out.of.bounds
+  br i1 %abc, label %in.bounds, label %out.of.bounds, !prof !1
 
  in.bounds:
   %addr = getelementptr i32* %arr, i32 %array.idx
@@ -57,3 +57,4 @@
 ; CHECK: br i1 %next.postloop, label %loop.postloop, label %exit.loopexit
 
 !0 = !{i32 0, i32 2147483647}
+!1 = !{!"branch_weights", i32 64, i32 4}
Index: test/Transforms/IRCE/with-parent-loops.ll
===================================================================
--- test/Transforms/IRCE/with-parent-loops.ll
+++ test/Transforms/IRCE/with-parent-loops.ll
@@ -16,7 +16,7 @@
   %idx = phi i32 [ 0, %entry ], [ %idx.next, %in.bounds ]
   %idx.next = add i32 %idx, 1
   %abc = icmp slt i32 %idx, %len
-  br i1 %abc, label %in.bounds, label %out.of.bounds
+  br i1 %abc, label %in.bounds, label %out.of.bounds, !prof !1
 
 in.bounds:                                        ; preds = %loop
   %addr = getelementptr i32* %arr, i32 %idx
@@ -50,7 +50,7 @@
   %idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %in.bounds.i ]
   %idx.next.i = add i32 %idx.i, 1
   %abc.i = icmp slt i32 %idx.i, %len.i
-  br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i
+  br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i, !prof !1
 
 in.bounds.i:                                      ; preds = %loop.i
   %addr.i = getelementptr i32* %arr, i32 %idx.i
@@ -96,7 +96,7 @@
   %idx.i.i = phi i32 [ 0, %loop.i ], [ %idx.next.i.i, %in.bounds.i.i ]
   %idx.next.i.i = add i32 %idx.i.i, 1
   %abc.i.i = icmp slt i32 %idx.i.i, %len.i.i
-  br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i
+  br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i, !prof !1
 
 in.bounds.i.i:                                    ; preds = %loop.i.i
   %addr.i.i = getelementptr i32* %arr, i32 %idx.i.i
@@ -140,7 +140,7 @@
   %idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %in.bounds.i ]
   %idx.next.i = add i32 %idx.i, 1
   %abc.i = icmp slt i32 %idx.i, %len.i
-  br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i
+  br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i, !prof !1
 
 in.bounds.i:                                      ; preds = %loop.i
   %addr.i = getelementptr i32* %arr, i32 %idx.i
@@ -163,7 +163,7 @@
   %idx.i3 = phi i32 [ 0, %inner_loop.exit ], [ %idx.next.i4, %in.bounds.i9 ]
   %idx.next.i4 = add i32 %idx.i3, 1
   %abc.i5 = icmp slt i32 %idx.i3, %len.i1
-  br i1 %abc.i5, label %in.bounds.i9, label %out.of.bounds.i10
+  br i1 %abc.i5, label %in.bounds.i9, label %out.of.bounds.i10, !prof !1
 
 in.bounds.i9:                                     ; preds = %loop.i6
   %addr.i7 = getelementptr i32* %arr, i32 %idx.i3
@@ -210,7 +210,7 @@
   %idx.i.i = phi i32 [ 0, %loop.i ], [ %idx.next.i.i, %in.bounds.i.i ]
   %idx.next.i.i = add i32 %idx.i.i, 1
   %abc.i.i = icmp slt i32 %idx.i.i, %len.i.i
-  br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i
+  br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i, !prof !1
 
 in.bounds.i.i:                                    ; preds = %loop.i.i
   %addr.i.i = getelementptr i32* %arr, i32 %idx.i.i
@@ -242,7 +242,7 @@
   %idx.i.i7 = phi i32 [ 0, %loop.i6 ], [ %idx.next.i.i8, %in.bounds.i.i13 ]
   %idx.next.i.i8 = add i32 %idx.i.i7, 1
   %abc.i.i9 = icmp slt i32 %idx.i.i7, %len.i.i4
-  br i1 %abc.i.i9, label %in.bounds.i.i13, label %out.of.bounds.i.i14
+  br i1 %abc.i.i9, label %in.bounds.i.i13, label %out.of.bounds.i.i14, !prof !1
 
 in.bounds.i.i13:                                  ; preds = %loop.i.i10
   %addr.i.i11 = getelementptr i32* %arr, i32 %idx.i.i7
@@ -286,7 +286,7 @@
   %idx.i = phi i32 [ 0, %loop ], [ %idx.next.i, %in.bounds.i ]
   %idx.next.i = add i32 %idx.i, 1
   %abc.i = icmp slt i32 %idx.i, %len.i
-  br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i
+  br i1 %abc.i, label %in.bounds.i, label %out.of.bounds.i, !prof !1
 
 in.bounds.i:                                      ; preds = %loop.i
   %addr.i = getelementptr i32* %arr, i32 %idx.i
@@ -315,7 +315,7 @@
   %idx.i.i = phi i32 [ 0, %loop.i4 ], [ %idx.next.i.i, %in.bounds.i.i ]
   %idx.next.i.i = add i32 %idx.i.i, 1
   %abc.i.i = icmp slt i32 %idx.i.i, %len.i.i
-  br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i
+  br i1 %abc.i.i, label %in.bounds.i.i, label %out.of.bounds.i.i, !prof !1
 
 in.bounds.i.i:                                    ; preds = %loop.i.i
   %addr.i.i = getelementptr i32* %arr, i32 %idx.i.i
@@ -342,3 +342,4 @@
 attributes #0 = { alwaysinline }
 
 !0 = !{i32 0, i32 2147483647}
+!1 = !{!"branch_weights", i32 64, i32 4}