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      1 //===- llvm/unittest/ADT/PointerIntPairTest.cpp - Unit tests --------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #include "gtest/gtest.h"
     11 #include "llvm/ADT/PointerIntPair.h"
     12 #include <limits>
     13 using namespace llvm;
     14 
     15 namespace {
     16 
     17 // Test fixture
     18 class PointerIntPairTest : public testing::Test {
     19 };
     20 
     21 TEST_F(PointerIntPairTest, GetSet) {
     22   PointerIntPair<PointerIntPairTest *, 2> Pair(this, 1U);
     23   EXPECT_EQ(this, Pair.getPointer());
     24   EXPECT_EQ(1U, Pair.getInt());
     25 
     26   Pair.setInt(2);
     27   EXPECT_EQ(this, Pair.getPointer());
     28   EXPECT_EQ(2U, Pair.getInt());
     29 
     30   Pair.setPointer(nullptr);
     31   EXPECT_EQ(nullptr, Pair.getPointer());
     32   EXPECT_EQ(2U, Pair.getInt());
     33 
     34   Pair.setPointerAndInt(this, 3U);
     35   EXPECT_EQ(this, Pair.getPointer());
     36   EXPECT_EQ(3U, Pair.getInt());
     37 }
     38 
     39 TEST_F(PointerIntPairTest, DefaultInitialize) {
     40   PointerIntPair<PointerIntPairTest *, 2> Pair;
     41   EXPECT_EQ(nullptr, Pair.getPointer());
     42   EXPECT_EQ(0U, Pair.getInt());
     43 }
     44 
     45 TEST_F(PointerIntPairTest, ManyUnusedBits) {
     46   // In real code this would be a word-sized integer limited to 31 bits.
     47   struct Fixnum31 {
     48     uintptr_t Value;
     49   };
     50   class FixnumPointerTraits {
     51   public:
     52     static inline void *getAsVoidPointer(Fixnum31 Num) {
     53       return reinterpret_cast<void *>(Num.Value << NumLowBitsAvailable);
     54     }
     55     static inline Fixnum31 getFromVoidPointer(void *P) {
     56       // In real code this would assert that the value is in range.
     57       return { reinterpret_cast<uintptr_t>(P) >> NumLowBitsAvailable };
     58     }
     59     enum { NumLowBitsAvailable = std::numeric_limits<uintptr_t>::digits - 31 };
     60   };
     61 
     62   PointerIntPair<Fixnum31, 1, bool, FixnumPointerTraits> pair;
     63   EXPECT_EQ((uintptr_t)0, pair.getPointer().Value);
     64   EXPECT_FALSE(pair.getInt());
     65 
     66   pair.setPointerAndInt({ 0x7FFFFFFF }, true );
     67   EXPECT_EQ((uintptr_t)0x7FFFFFFF, pair.getPointer().Value);
     68   EXPECT_TRUE(pair.getInt());
     69 
     70   EXPECT_EQ(FixnumPointerTraits::NumLowBitsAvailable - 1,
     71             PointerLikeTypeTraits<decltype(pair)>::NumLowBitsAvailable);
     72 }
     73 
     74 } // end anonymous namespace
     75