diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp
--- a/llvm/lib/Analysis/LoopInfo.cpp
+++ b/llvm/lib/Analysis/LoopInfo.cpp
@@ -396,7 +396,26 @@
   BasicBlock *GuardOtherSucc = (GuardBI->getSuccessor(0) == Preheader)
                                    ? GuardBI->getSuccessor(1)
                                    : GuardBI->getSuccessor(0);
-  return (GuardOtherSucc == ExitFromLatchSucc) ? GuardBI : nullptr;
+  if (GuardOtherSucc != ExitFromLatchSucc)
+    return nullptr;
+
+  auto IsSafeToSpeculativelyExecute = [](const BasicBlock &BB) {
+    return llvm::all_of(BB, [&BB](const Instruction &I) {
+      if (BB.getTerminator() == &I)
+        return true;
+
+      if (const PHINode *PN = dyn_cast<PHINode>(&I))
+        if (PN->hasConstantValue())
+          return true;
+
+      return isSafeToSpeculativelyExecute(&I);
+    });
+  };
+
+  return (IsSafeToSpeculativelyExecute(*Preheader) &&
+          IsSafeToSpeculativelyExecute(*ExitFromLatch))
+             ? GuardBI
+             : nullptr;
 }
 
 bool Loop::isCanonical(ScalarEvolution &SE) const {
diff --git a/llvm/unittests/Analysis/LoopInfoTest.cpp b/llvm/unittests/Analysis/LoopInfoTest.cpp
--- a/llvm/unittests/Analysis/LoopInfoTest.cpp
+++ b/llvm/unittests/Analysis/LoopInfoTest.cpp
@@ -1373,6 +1373,96 @@
       });
 }
 
+TEST(LoopInfoTest, LoopPreheaderNotSafe) {
+  const char *ModuleStr =
+      "define void @foo(i64 %N) {\n"
+      "entry:\n"
+      "  %guard = icmp slt i64 0, %N\n"
+      "  br i1 %guard, label %for.preheader, label %for.end\n"
+      "for.preheader:\n"
+      "  call void @bar()\n"
+      "  br label %for.body\n"
+      "for.body:\n"
+      "  %i = phi i64 [ %inc, %for.body ], [ 0, %for.preheader ]\n"
+      "  call void @bar()\n"
+      "  %inc = add nsw i64 %i, 1\n"
+      "  %cmp = icmp slt i64 %inc, %N\n"
+      "  br i1 %cmp, label %for.body, label %for.exit\n"
+      "for.exit:\n"
+      "  br label %for.end\n"
+      "for.end:\n"
+      "  ret void\n"
+      "}\n"
+      "declare void @bar()\n";
+
+  // Parse the module.
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+
+  runWithLoopInfoPlus(
+      *M, "foo",
+      [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
+        Function::iterator FI = F.begin();
+        // First two basic block are entry and for.preheader - skip them.
+        ++FI;
+        BasicBlock *Header = &*(++FI);
+        assert(Header && "No header");
+        Loop *L = LI.getLoopFor(Header);
+        EXPECT_NE(L, nullptr);
+        EXPECT_TRUE(L->isLoopSimplifyForm());
+
+        // No loop guard becuase loop preheader contains instructions not safe
+	//to execute speculatively.
+        EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
+        EXPECT_FALSE(L->isGuarded());
+      });
+}
+
+TEST(LoopInfoTest, LoopExitNotSafe) {
+  const char *ModuleStr =
+      "define void @foo(i64 %N) {\n"
+      "entry:\n"
+      "  %guard = icmp slt i64 0, %N\n"
+      "  br i1 %guard, label %for.preheader, label %for.end\n"
+      "for.preheader:\n"
+      "  br label %for.body\n"
+      "for.body:\n"
+      "  %i = phi i64 [ %inc, %for.body ], [ 0, %for.preheader ]\n"
+      "  call void @bar()\n"
+      "  %inc = add nsw i64 %i, 1\n"
+      "  %cmp = icmp slt i64 %inc, %N\n"
+      "  br i1 %cmp, label %for.body, label %for.exit\n"
+      "for.exit:\n"
+      "  call void @bar()\n"
+      "  br label %for.end\n"
+      "for.end:\n"
+      "  ret void\n"
+      "}\n"
+      "declare void @bar()\n";
+
+  // Parse the module.
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
+
+  runWithLoopInfoPlus(
+      *M, "foo",
+      [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
+        Function::iterator FI = F.begin();
+        // First two basic block are entry and for.preheader - skip them.
+        ++FI;
+        BasicBlock *Header = &*(++FI);
+        assert(Header && "No header");
+        Loop *L = LI.getLoopFor(Header);
+        EXPECT_NE(L, nullptr);
+        EXPECT_TRUE(L->isLoopSimplifyForm());
+
+        // No loop guard becuase loop exit contains instructions not safe to
+	// execute speculatively.
+        EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
+        EXPECT_FALSE(L->isGuarded());
+      });
+}
+
 // Examine getUniqueExitBlocks/getUniqueNonLatchExitBlocks functions.
 TEST(LoopInfoTest, LoopUniqueExitBlocks) {
   const char *ModuleStr =