diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -6437,24 +6437,36 @@
       auto Op2Info = getOperandInfo(VL, OpIdx);
 
       SmallVector<const Value *, 4> Operands(VL0->operand_values());
-      InstructionCost ScalarEltCost =
-          TTI->getArithmeticInstrCost(E->getOpcode(), ScalarTy, CostKind,
-                                      Op1Info, Op2Info,
-                                      Operands, VL0);
+      InstructionCost ScalarCost = 0;
+      for (const Value *V : VL) {
+        ScalarCost += TTI->getArithmeticInstrCost(
+            E->getOpcode(), ScalarTy, CostKind, Op1Info, Op2Info, Operands,
+            isa<Instruction>(V) ? cast<Instruction>(V) : nullptr);
+      }
+
       if (NeedToShuffleReuses) {
-        CommonCost -= (EntryVF - VL.size()) * ScalarEltCost;
+        CommonCost -=
+            (EntryVF - VL.size()) *
+            TTI->getArithmeticInstrCost(E->getOpcode(), ScalarTy, CostKind,
+                                        Op1Info, Op2Info, Operands);
       }
-      InstructionCost ScalarCost = VecTy->getNumElements() * ScalarEltCost;
+
       for (unsigned I = 0, Num = VL0->getNumOperands(); I < Num; ++I) {
         if (all_of(VL, [I](Value *V) {
               return isConstant(cast<Instruction>(V)->getOperand(I));
             }))
           Operands[I] = ConstantVector::getNullValue(VecTy);
       }
+
+      // Populate vector with context instructions.
+      SmallVector<const Instruction *> OpsForVector = {VL0};
+      for (const Value *V : VL.drop_front())
+        OpsForVector.push_back(cast<Instruction>(V));
+
       InstructionCost VecCost =
-          TTI->getArithmeticInstrCost(E->getOpcode(), VecTy, CostKind,
-                                      Op1Info, Op2Info,
-                                      Operands, VL0);
+          TTI->getArithmeticInstrCost(E->getOpcode(), VecTy, CostKind, Op1Info,
+                                      Op2Info, Operands, OpsForVector);
+
       LLVM_DEBUG(dumpTreeCosts(E, CommonCost, VecCost, ScalarCost));
       return CommonCost + VecCost - ScalarCost;
     }