Make the User::value_op_iterator a random access iterator. I had written

this code ages ago and lost track of it. Seems worth doing though --
this thing can get called from places that would benefit from knowing
that std::distance is O(1). Also add a very fledgeling unittest for
Users and make sure various aspects of this seem to work reasonably.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206453 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 97 insertions, 0 deletions

diff --git a/unittests/IR/CMakeLists.txt b/unittests/IR/CMakeLists.txt
index 7368a24051..b439d59dec 100644
--- a/unittests/IR/CMakeLists.txt
+++ b/unittests/IR/CMakeLists.txt
@@ -21,6 +21,7 @@ set(IRSources
   PatternMatch.cpp
   TypeBuilderTest.cpp
   TypesTest.cpp
+  UserTest.cpp
   ValueHandleTest.cpp
   ValueMapTest.cpp
   ValueTest.cpp
diff --git a/unittests/IR/UserTest.cpp b/unittests/IR/UserTest.cpp
new file mode 100644
index 0000000000..9c0e7b2750
--- /dev/null
+++ b/unittests/IR/UserTest.cpp
@@ -0,0 +1,96 @@
+//===- llvm/unittest/IR/UserTest.cpp - User unit tests --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/User.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/Support/SourceMgr.h"
+#include "gtest/gtest.h"
+using namespace llvm;
+
+namespace {
+
+TEST(UserTest, ValueOpIteration) {
+  LLVMContext C;
+
+  const char *ModuleString = "define void @f(i32 %x, i32 %y) {\n"
+                             "entry:\n"
+                             "  switch i32 undef, label %s0\n"
+                             "      [ i32 1, label %s1\n"
+                             "        i32 2, label %s2\n"
+                             "        i32 3, label %s3\n"
+                             "        i32 4, label %s4\n"
+                             "        i32 5, label %s5\n"
+                             "        i32 6, label %s6\n"
+                             "        i32 7, label %s7\n"
+                             "        i32 8, label %s8\n"
+                             "        i32 9, label %s9 ]\n"
+                             "\n"
+                             "s0:\n"
+                             "  br label %exit\n"
+                             "s1:\n"
+                             "  br label %exit\n"
+                             "s2:\n"
+                             "  br label %exit\n"
+                             "s3:\n"
+                             "  br label %exit\n"
+                             "s4:\n"
+                             "  br label %exit\n"
+                             "s5:\n"
+                             "  br label %exit\n"
+                             "s6:\n"
+                             "  br label %exit\n"
+                             "s7:\n"
+                             "  br label %exit\n"
+                             "s8:\n"
+                             "  br label %exit\n"
+                             "s9:\n"
+                             "  br label %exit\n"
+                             "\n"
+                             "exit:\n"
+                             "  %phi = phi i32 [ 0, %s0 ], [ 1, %s1 ],\n"
+                             "                 [ 2, %s2 ], [ 3, %s3 ],\n"
+                             "                 [ 4, %s4 ], [ 5, %s5 ],\n"
+                             "                 [ 6, %s6 ], [ 7, %s7 ],\n"
+                             "                 [ 8, %s8 ], [ 9, %s9 ]\n"
+                             "  ret void\n"
+                             "}\n";
+  SMDiagnostic Err;
+  Module *M = ParseAssemblyString(ModuleString, NULL, Err, C);
+
+  Function *F = M->getFunction("f");
+  BasicBlock &ExitBB = F->back();
+  PHINode &P = cast<PHINode>(ExitBB.front());
+  EXPECT_TRUE(P.value_op_begin() == P.value_op_begin());
+  EXPECT_FALSE(P.value_op_begin() == P.value_op_end());
+  EXPECT_TRUE(P.value_op_begin() != P.value_op_end());
+  EXPECT_FALSE(P.value_op_end() != P.value_op_end());
+  EXPECT_TRUE(P.value_op_begin() < P.value_op_end());
+  EXPECT_FALSE(P.value_op_begin() < P.value_op_begin());
+  EXPECT_TRUE(P.value_op_end() > P.value_op_begin());
+  EXPECT_FALSE(P.value_op_begin() > P.value_op_begin());
+  EXPECT_TRUE(P.value_op_begin() <= P.value_op_begin());
+  EXPECT_FALSE(P.value_op_end() <= P.value_op_begin());
+  EXPECT_TRUE(P.value_op_begin() >= P.value_op_begin());
+  EXPECT_FALSE(P.value_op_begin() >= P.value_op_end());
+  EXPECT_EQ(10, std::distance(P.value_op_begin(), P.value_op_end()));
+
+  User::value_op_iterator I = P.value_op_begin();
+  I += 3;
+  EXPECT_EQ(std::next(P.value_op_begin(), 3), I);
+  EXPECT_EQ(P.getOperand(3), *I);
+  I++;
+  EXPECT_EQ(P.getOperand(6), I[2]);
+  EXPECT_EQ(P.value_op_end(), (I - 2) + 8);
+}
+
+} // end anonymous namespace