diff --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -734,16 +734,23 @@
       return MaybeAlign(CI->getLimitedValue());
     }
   } else if (auto *CstPtr = dyn_cast<Constant>(this)) {
-    if (auto *CstInt = dyn_cast_or_null<ConstantInt>(ConstantExpr::getPtrToInt(
-            const_cast<Constant *>(CstPtr), DL.getIntPtrType(getType()),
-            /*OnlyIfReduced=*/true))) {
+    MaybeAlign Alignment(llvm::None);
+    // NOTE: getPtrToInt call may create extra constant operator
+    Constant *CstPTI = ConstantExpr::getPtrToInt(const_cast<Constant *>(CstPtr),
+                                                 DL.getIntPtrType(getType()),
+                                                 /*OnlyIfReduced=*/true);
+    if (auto *CstInt = dyn_cast_or_null<ConstantInt>(CstPTI)) {
       size_t TrailingZeros = CstInt->getValue().countTrailingZeros();
       // While the actual alignment may be large, elsewhere we have
-      // an arbitrary upper alignmet limit, so let's clamp to it.
-      return Align(TrailingZeros < Value::MaxAlignmentExponent
-                       ? uint64_t(1) << TrailingZeros
-                       : Value::MaximumAlignment);
+      // an arbitrary upper alignment limit, so let's clamp to it.
+      Alignment = Align(TrailingZeros < Value::MaxAlignmentExponent
+                            ? uint64_t(1) << TrailingZeros
+                            : Value::MaximumAlignment);
     }
+    // Remove unused ptrtoint operator if it has been created
+    if (CstPTI && !CstPTI->isConstantUsed())
+      CstPTI->destroyConstant();
+    return Alignment;
   }
   return llvm::None;
 }
diff --git a/llvm/unittests/IR/ConstantsTest.cpp b/llvm/unittests/IR/ConstantsTest.cpp
--- a/llvm/unittests/IR/ConstantsTest.cpp
+++ b/llvm/unittests/IR/ConstantsTest.cpp
@@ -638,5 +638,33 @@
   EXPECT_FALSE(CP00U->isElementWiseEqual(CP00U0));
 }
 
+TEST(ConstantsTest, GlobalValueImmutabilityOnGetPtrAlignmentTest) {
+  LLVMContext Context;
+  SMDiagnostic Error;
+  std::unique_ptr<Module> M = parseAssemblyString(
+      "@gs = common global [8 x i32] zeroinitializer, align 8 "
+      "define void @f() { "
+      "entry: "
+      "  %0 = load i32, i32* getelementptr inbounds "
+      "         ([8 x i32], [8 x i32]* @gs, i64 0, i64 0), align 8 "
+      "  ret void "
+      "}",
+      Error, Context);
+
+  const Function *F = M->getFunction("f");
+  const BasicBlock &BB = F->getEntryBlock();
+  const Instruction &I = BB.front();
+  const Value *GEP = I.getOperand(0);
+  EXPECT_TRUE(isa<Constant>(GEP));
+
+  GlobalVariable *GV = M->getGlobalVariable("gs");
+  unsigned GVUsesNumBefore = GV->getNumUses();
+
+  MaybeAlign Align = GEP->getPointerAlignment(DataLayout(""));
+  (void)Align;
+
+  ASSERT_EQ(GVUsesNumBefore, GV->getNumUses());
+}
+
 }  // end anonymous namespace
 }  // end namespace llvm