[IR] Adding const_value_op_iterator for IR/User.h

const value op iterator is missing from User.h class.

Differential Revision: https://reviews.llvm.org/D28464

llvm-svn: 291443
diff --git a/llvm/unittests/IR/UserTest.cpp b/llvm/unittests/IR/UserTest.cpp
index 7d875aa..7ba6840 100644
--- a/llvm/unittests/IR/UserTest.cpp
+++ b/llvm/unittests/IR/UserTest.cpp
@@ -84,6 +84,22 @@
   EXPECT_FALSE(P.value_op_begin() >= P.value_op_end());
   EXPECT_EQ(10, std::distance(P.value_op_begin(), P.value_op_end()));
 
+  // const value op iteration
+  const PHINode *IP = &P;
+  EXPECT_TRUE(IP->value_op_begin() == IP->value_op_begin());
+  EXPECT_FALSE(IP->value_op_begin() == IP->value_op_end());
+  EXPECT_TRUE(IP->value_op_begin() != IP->value_op_end());
+  EXPECT_FALSE(IP->value_op_end() != IP->value_op_end());
+  EXPECT_TRUE(IP->value_op_begin() < IP->value_op_end());
+  EXPECT_FALSE(IP->value_op_begin() < IP->value_op_begin());
+  EXPECT_TRUE(IP->value_op_end() > IP->value_op_begin());
+  EXPECT_FALSE(IP->value_op_begin() > IP->value_op_begin());
+  EXPECT_TRUE(IP->value_op_begin() <= IP->value_op_begin());
+  EXPECT_FALSE(IP->value_op_end() <= IP->value_op_begin());
+  EXPECT_TRUE(IP->value_op_begin() >= IP->value_op_begin());
+  EXPECT_FALSE(IP->value_op_begin() >= IP->value_op_end());
+  EXPECT_EQ(10, std::distance(IP->value_op_begin(), IP->value_op_end()));
+
   User::value_op_iterator I = P.value_op_begin();
   I += 3;
   EXPECT_EQ(std::next(P.value_op_begin(), 3), I);
@@ -91,6 +107,15 @@
   I++;
   EXPECT_EQ(P.getOperand(6), I[2]);
   EXPECT_EQ(P.value_op_end(), (I - 2) + 8);
+
+  // const value op
+  User::const_value_op_iterator CI = IP->value_op_begin();
+  CI += 3;
+  EXPECT_EQ(std::next(IP->value_op_begin(), 3), CI);
+  EXPECT_EQ(IP->getOperand(3), *CI);
+  CI++;
+  EXPECT_EQ(IP->getOperand(6), CI[2]);
+  EXPECT_EQ(IP->value_op_end(), (CI - 2) + 8);
 }
 
 TEST(UserTest, PersonalityUser) {