Index: lib/Analysis/ScalarEvolution.cpp
===================================================================
--- lib/Analysis/ScalarEvolution.cpp
+++ lib/Analysis/ScalarEvolution.cpp
@@ -5250,20 +5250,22 @@
     break;
 
     case Instruction::AShr:
-      // For a two-shift sext-inreg, use sext(trunc(x)) as the SCEV expression.
-      if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->RHS))
-        if (Operator *L = dyn_cast<Operator>(BO->LHS))
-          if (L->getOpcode() == Instruction::Shl &&
-              L->getOperand(1) == BO->RHS) {
-            uint64_t BitWidth = getTypeSizeInBits(BO->LHS->getType());
-
-            // If the shift count is not less than the bitwidth, the result of
-            // the shift is undefined. Don't try to analyze it, because the
-            // resolution chosen here may differ from the resolution chosen in
-            // other parts of the compiler.
-            if (CI->getValue().uge(BitWidth))
-              break;
+      ConstantInt *CI = dyn_cast<ConstantInt>(BO->RHS);
+      Operator *L = dyn_cast<Operator>(BO->LHS);
+      if (CI && L) {
+        if (L->getOpcode() == Instruction::Shl) {
+          uint64_t BitWidth = getTypeSizeInBits(BO->LHS->getType());
+          // If the shift count is not less than the bitwidth, the result of
+          // the shift is undefined. Don't try to analyze it, because the
+          // resolution chosen here may differ from the resolution chosen in
+          // other parts of the compiler.
+          if (CI->getValue().uge(BitWidth))
+            break;
 
+          Value *LOp1 = L->getOperand(1);
+
+          // For a two-shift sext-inreg, use sext(trunc(x)) as the SCEV expression.
+          if (LOp1 == BO->RHS) {
             uint64_t Amt = BitWidth - CI->getZExtValue();
             if (Amt == BitWidth)
               return getSCEV(L->getOperand(0)); // shift by zero --> noop
@@ -5271,7 +5273,28 @@
                 getTruncateExpr(getSCEV(L->getOperand(0)),
                                 IntegerType::get(getContext(), Amt)),
                 BO->LHS->getType());
+          } else if (ConstantInt *LCI = dyn_cast<ConstantInt>(LOp1)) {
+            // %y = shl %x, n
+            // %z = ashr %y, m
+            // where n != m
+            if (LCI->getValue().uge(BitWidth))
+              break;
+
+            uint64_t AshrAmt = CI->getZExtValue();
+            uint64_t LshAmt = LCI->getZExtValue();
+            if (AshrAmt > LshAmt)
+              // n < m
+              //TODO: udiv(x, 2^(m-n))
+              break;
+            // n > m
+            // Use mul(x, 2^(n-m))) as the SCEV expression.
+            uint64_t Mul = 1 << (LshAmt - AshrAmt);
+            Value *MulOp = ConstantInt::get(CI->getType(), Mul);
+            return getMulExpr(getSCEV(L->getOperand(0)),
+                              getSCEV(MulOp));
           }
+        }
+      }
       break;
     }
   }
Index: test/Analysis/ScalarEvolution/sext-mul.ll
===================================================================
--- /dev/null
+++ test/Analysis/ScalarEvolution/sext-mul.ll
@@ -0,0 +1,42 @@
+; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
+
+; CHECK:  %12 = ashr exact i64 %11, 32
+; CHECK:  -->  {0,+,2}<%9> U: [0,-1) S: [-9223372036854775808,9223372036854775807)              Exits: (-2 + (2 * (zext i32 %2 to i64)))<nsw>           LoopDispositions: { %9: Computable }
+; CHECK:  %13 = getelementptr inbounds i32, i32* %0, i64 %12
+; CHECK:  -->  {%0,+,8}<%9> U: full-set S: full-set             Exits: (-8 + (8 * (zext i32 %2 to i64)) + %0)           LoopDispositions: { %9: Computable }
+; CHECK:  %16 = or i64 %12, 1
+; CHECK:  -->  {1,+,2}<%9> U: full-set S: full-set              Exits: (-1 + (2 * (zext i32 %2 to i64)))                LoopDispositions: { %9: Computable }
+; CHECK:  %17 = getelementptr inbounds i32, i32* %0, i64 %16
+; CHECK:  -->  {(4 + %0)<nsw>,+,8}<%9> U: full-set S: full-set          Exits: (-4 + (8 * (zext i32 %2 to i64)) + %0)           LoopDispositions: { %9: Computable }
+
+define void @foo(i32* nocapture, i32, i32) {
+  %4 = icmp sgt i32 %2, 0
+  br i1 %4, label %5, label %8
+
+; <label>:5:                                      ; preds = %3
+  %6 = zext i32 %2 to i64
+  br label %9
+
+; <label>:7:                                      ; preds = %9
+  br label %8
+
+; <label>:8:                                      ; preds = %7, %3
+  ret void
+
+; <label>:9:                                      ; preds = %9, %5
+  %10 = phi i64 [ %20, %9 ], [ 0, %5 ]
+  %11 = shl i64 %10, 33
+  %12 = ashr exact i64 %11, 32
+  %13 = getelementptr inbounds i32, i32* %0, i64 %12
+  %14 = load i32, i32* %13, align 4
+  %15 = sub nsw i32 %14, %1
+  store i32 %15, i32* %13, align 4
+  %16 = or i64 %12, 1
+  %17 = getelementptr inbounds i32, i32* %0, i64 %16
+  %18 = load i32, i32* %17, align 4
+  %19 = mul nsw i32 %18, %1
+  store i32 %19, i32* %17, align 4
+  %20 = add nuw nsw i64 %10, 1
+  %21 = icmp eq i64 %20, %6
+  br i1 %21, label %7, label %9
+}