diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index e890943c6a8..38a3fbb21f8 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -1397,13 +1397,61 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     SC.Done(&I);
   }
 
+  // \brief Handle multiplication by constant.
+  //
+  // Handle a special case of multiplication by constant that may have one or
+  // more zeros in the lower bits. This makes corresponding number of lower bits
+  // of the result zero as well. We model it by shifting the other operand
+  // shadow left by the required number of bits. Effectively, we transform
+  // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B).
+  // We use multiplication by 2**N instead of shift to cover the case of
+  // multiplication by 0, which may occur in some elements of a vector operand.
+  void handleMulByConstant(BinaryOperator &I, Constant *ConstArg,
+                           Value *OtherArg) {
+    Constant *ShadowMul;
+    Type *Ty = ConstArg->getType();
+    if (Ty->isVectorTy()) {
+      unsigned NumElements = Ty->getVectorNumElements();
+      Type *EltTy = Ty->getSequentialElementType();
+      SmallVector<Constant *, 16> Elements;
+      for (unsigned Idx = 0; Idx < NumElements; ++Idx) {
+        ConstantInt *Elt =
+            dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx));
+        APInt V = Elt->getValue();
+        APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
+        Elements.push_back(ConstantInt::get(EltTy, V2));
+      }
+      ShadowMul = ConstantVector::get(Elements);
+    } else {
+      ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg);
+      APInt V = Elt->getValue();
+      APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
+      ShadowMul = ConstantInt::get(Elt->getType(), V2);
+    }
+
+    IRBuilder<> IRB(&I);
+    setShadow(&I,
+              IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst"));
+    setOrigin(&I, getOrigin(OtherArg));
+  }
+
+  void visitMul(BinaryOperator &I) {
+    Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0));
+    Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1));
+    if (constOp0 && !constOp1)
+      handleMulByConstant(I, constOp0, I.getOperand(1));
+    else if (constOp1 && !constOp0)
+      handleMulByConstant(I, constOp1, I.getOperand(0));
+    else
+      handleShadowOr(I);
+  }
+
   void visitFAdd(BinaryOperator &I) { handleShadowOr(I); }
   void visitFSub(BinaryOperator &I) { handleShadowOr(I); }
   void visitFMul(BinaryOperator &I) { handleShadowOr(I); }
   void visitAdd(BinaryOperator &I) { handleShadowOr(I); }
   void visitSub(BinaryOperator &I) { handleShadowOr(I); }
   void visitXor(BinaryOperator &I) { handleShadowOr(I); }
-  void visitMul(BinaryOperator &I) { handleShadowOr(I); }
 
   void handleDiv(Instruction &I) {
     IRBuilder<> IRB(&I);
diff --git a/test/Instrumentation/MemorySanitizer/mul_by_constant.ll b/test/Instrumentation/MemorySanitizer/mul_by_constant.ll
new file mode 100644
index 00000000000..e068f69ae4b
--- /dev/null
+++ b/test/Instrumentation/MemorySanitizer/mul_by_constant.ll
@@ -0,0 +1,94 @@
+; RUN: opt < %s -msan -msan-check-access-address=0 -S | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Check instrumentation mul when one of the operands is a constant.
+
+define i64 @MulConst(i64 %x) sanitize_memory {
+entry:
+  %y = mul i64 %x, 42949672960000
+  ret i64 %y
+}
+
+; 42949672960000 = 2**32 * 10000
+; 36 trailing zero bits
+; 68719476736 = 2**36
+
+; CHECK-LABEL: @MulConst(
+; CHECK: [[A:%.*]] = load {{.*}} @__msan_param_tls
+; CHECK: [[B:%.*]] = mul i64 [[A]], 68719476736
+; CHECK: store i64 [[B]], i64* {{.*}} @__msan_retval_tls
+
+
+define i64 @MulZero(i64 %x) sanitize_memory {
+entry:
+  %y = mul i64 %x, 0
+  ret i64 %y
+}
+
+; CHECK-LABEL: @MulZero(
+; CHECK: [[A:%.*]] = load {{.*}} @__msan_param_tls
+; CHECK: [[B:%.*]] = mul i64 [[A]], 0{{$}}
+; CHECK: store i64 [[B]], i64* {{.*}} @__msan_retval_tls
+
+
+define i64 @MulNeg(i64 %x) sanitize_memory {
+entry:
+  %y = mul i64 %x, -16
+  ret i64 %y
+}
+
+; CHECK-LABEL: @MulNeg(
+; CHECK: [[A:%.*]] = load {{.*}} @__msan_param_tls
+; CHECK: [[B:%.*]] = mul i64 [[A]], 16
+; CHECK: store i64 [[B]], i64* {{.*}} @__msan_retval_tls
+
+
+define i64 @MulNeg2(i64 %x) sanitize_memory {
+entry:
+  %y = mul i64 %x, -48
+  ret i64 %y
+}
+
+; CHECK-LABEL: @MulNeg2(
+; CHECK: [[A:%.*]] = load {{.*}} @__msan_param_tls
+; CHECK: [[B:%.*]] = mul i64 [[A]], 16
+; CHECK: store i64 [[B]], i64* {{.*}} @__msan_retval_tls
+
+
+define i64 @MulOdd(i64 %x) sanitize_memory {
+entry:
+  %y = mul i64 %x, 12345
+  ret i64 %y
+}
+
+; CHECK-LABEL: @MulOdd(
+; CHECK: [[A:%.*]] = load {{.*}} @__msan_param_tls
+; CHECK: [[B:%.*]] = mul i64 [[A]], 1
+; CHECK: store i64 [[B]], i64* {{.*}} @__msan_retval_tls
+
+
+define i64 @MulLarge(i64 %x) sanitize_memory {
+entry:
+  %y = mul i64 %x, -9223372036854775808
+  ret i64 %y
+}
+
+; -9223372036854775808 = 0x7000000000000000
+
+; CHECK-LABEL: @MulLarge(
+; CHECK: [[A:%.*]] = load {{.*}} @__msan_param_tls
+; CHECK: [[B:%.*]] = mul i64 [[A]], -9223372036854775808
+; CHECK: store i64 [[B]], i64* {{.*}} @__msan_retval_tls
+
+define <4 x i32> @MulVectorConst(<4 x i32> %x) sanitize_memory {
+entry:
+  %y = mul <4 x i32> %x, <i32 3072, i32 0, i32 -16, i32 -48>
+  ret <4 x i32> %y
+}
+
+; CHECK-LABEL: @MulVectorConst(
+; CHECK: [[A:%.*]] = load {{.*}} @__msan_param_tls
+; CHECK: [[B:%.*]] = mul <4 x i32> [[A]], <i32 1024, i32 0, i32 16, i32 16>
+; CHECK: store <4 x i32> [[B]], <4 x i32>* {{.*}} @__msan_retval_tls