Index: lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
===================================================================
--- lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
+++ lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
@@ -764,6 +764,9 @@
       Val->getScalarType()->isIntegerTy(64))
     return ((Index % 2 == 0) ? 1 : 0);
 
+  if (Opcode == Instruction::ExtractElement)
+    return ((Val->getScalarSizeInBits() == 1) ? 2 /*+test-under-mask*/ : 1);
+
   return BaseT::getVectorInstrCost(Opcode, Val, Index);
 }
 
Index: lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- lib/Transforms/Vectorize/LoopVectorize.cpp
+++ lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2105,6 +2105,10 @@
   /// pairs.
   typedef DenseMap<Instruction *, unsigned> ScalarCostsTy;
 
+  /// A set containing all BasicBlocks that are known to present after
+  /// vectorization as a predicated block.
+  SmallPtrSet<BasicBlock *, 4> PredicatedBBsAfterVectorization;
+
   /// A map holding scalar costs for different vectorization factors. The
   /// presence of a cost for an instruction in the mapping indicates that the
   /// instruction will be scalarized when vectorizing with the associated
@@ -6757,6 +6761,9 @@
         ScalarCostsTy ScalarCosts;
         if (computePredInstDiscount(&I, ScalarCosts, VF) >= 0)
           ScalarCostsVF.insert(ScalarCosts.begin(), ScalarCosts.end());
+
+        // Remember that BB will remain after vectorization.
+        PredicatedBBsAfterVectorization.insert(BB);
       }
   }
 }
@@ -7203,7 +7210,31 @@
     // instruction cost.
     return 0;
   case Instruction::Br: {
-    return TTI.getCFInstrCost(I->getOpcode());
+    // In cases of scalarized and predicated instructions, there will be VF
+    // predicated blocks in the vectorized loop. Each branch around these
+    // blocks requires also an extract of its vector compare i1 element.
+    bool ScalarPredicatedBB = false;
+    BranchInst *BI = cast<BranchInst>(I);
+    if (VF > 1 && BI->isConditional() &&
+        (PredicatedBBsAfterVectorization.count(BI->getSuccessor(0)) ||
+         PredicatedBBsAfterVectorization.count(BI->getSuccessor(1))))
+      ScalarPredicatedBB = true;
+
+    if (ScalarPredicatedBB) {
+      // Return cost for branches around scalarized and predicated blocks.
+      Type *Vec_i1Ty =
+          VectorType::get(IntegerType::getInt1Ty(RetTy->getContext()), VF);
+      return (TTI.getScalarizationOverhead(Vec_i1Ty, false, true) +
+              (TTI.getCFInstrCost(Instruction::Br) * VF));
+    } else if (I->getParent() == TheLoop->getLoopLatch() || VF == 1)
+      // The back-edge branch will remain, as will all scalar branches.
+      return TTI.getCFInstrCost(Instruction::Br);
+    else
+      // This branch will be eliminated by if-conversion.
+      return 0;
+    // Note: We currently assume zero cost for an unconditional branch inside
+    // a predicated block since it will become a fall-through, although we
+    // may decide in the future to call TTI for all branches.
   }
   case Instruction::PHI: {
     auto *Phi = cast<PHINode>(I);
Index: test/Transforms/LoopVectorize/SystemZ/branch-for-predicated-block.ll
===================================================================
--- /dev/null
+++ test/Transforms/LoopVectorize/SystemZ/branch-for-predicated-block.ll
@@ -0,0 +1,38 @@
+; REQUIRES: asserts
+; RUN: opt -mtriple=s390x-unknown-linux -mcpu=z13 -loop-vectorize \
+; RUN:   -force-vector-width=2 -debug-only=loop-vectorize \
+; RUN:   -disable-output < %s 2>&1 | FileCheck %s
+
+; Check costs for branches inside a vectorized loop around predicated
+; blocks. Each such branch will be guarded with an extractelement from the
+; vector compare plus a test under mask instruction. This cost is modelled on
+; the extractelement of i1.
+
+define void @fun(i32* %arr, i64 %trip.count) {
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
+  %arrayidx = getelementptr inbounds i32, i32* %arr, i64 %indvars.iv
+  %l = load i32, i32* %arrayidx, align 4
+  %cmp55 = icmp sgt i32 %l, 0
+  br i1 %cmp55, label %if.then, label %for.inc
+
+if.then:
+  %sub = sub nsw i32 0, %l
+  store i32 %sub, i32* %arrayidx, align 4
+  br label %for.inc
+
+for.inc:
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, %trip.count
+  br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+  ret void
+
+; CHECK: LV: Found an estimated cost of 4 for VF 2 For instruction:   br i1 %cmp55, label %if.then, label %for.inc
+; CHECK: LV: Found an estimated cost of 0 for VF 2 For instruction:   br label %for.inc
+; CHECK: LV: Found an estimated cost of 0 for VF 2 For instruction:   br i1 %exitcond, label %for.end.loopexit, label %for.body
+}