Serban Constantinescu | 86797a7 | 2014-06-19 16:17:56 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "gtest/gtest.h" |
| 18 | #include "memcmp16.h" |
| 19 | |
| 20 | class RandGen { |
| 21 | public: |
| 22 | explicit RandGen(uint32_t seed) : val_(seed) {} |
| 23 | |
| 24 | uint32_t next() { |
| 25 | val_ = val_ * 48271 % 2147483647 + 13; |
| 26 | return val_; |
| 27 | } |
| 28 | |
| 29 | uint32_t val_; |
| 30 | }; |
| 31 | |
| 32 | class MemCmp16Test : public testing::Test { |
| 33 | }; |
| 34 | |
| 35 | // A simple implementation to compare against. |
| 36 | // Note: this version is equivalent to the generic one used when no optimized version is available. |
| 37 | int32_t memcmp16_compare(const uint16_t* s0, const uint16_t* s1, size_t count) { |
| 38 | for (size_t i = 0; i < count; i++) { |
| 39 | if (s0[i] != s1[i]) { |
| 40 | return static_cast<int32_t>(s0[i]) - static_cast<int32_t>(s1[i]); |
| 41 | } |
| 42 | } |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | static constexpr size_t kMemCmp16Rounds = 100000; |
| 47 | |
| 48 | static void CheckSeparate(size_t max_length, size_t min_length) { |
| 49 | RandGen r(0x1234); |
| 50 | size_t range_of_tests = 7; // All four (weighted) tests active in the beginning. |
| 51 | |
| 52 | for (size_t round = 0; round < kMemCmp16Rounds; ++round) { |
| 53 | size_t type = r.next() % range_of_tests; |
| 54 | size_t count1, count2; |
| 55 | uint16_t *s1, *s2; // Use raw pointers to simplify using clobbered addresses |
| 56 | |
| 57 | switch (type) { |
| 58 | case 0: // random, non-zero lengths of both strings |
| 59 | case 1: |
| 60 | case 2: |
| 61 | case 3: |
| 62 | count1 = (r.next() % max_length) + min_length; |
| 63 | count2 = (r.next() % max_length) + min_length; |
| 64 | break; |
| 65 | |
| 66 | case 4: // random non-zero length of first, second is zero |
| 67 | count1 = (r.next() % max_length) + min_length; |
| 68 | count2 = 0U; |
| 69 | break; |
| 70 | |
| 71 | case 5: // random non-zero length of second, first is zero |
| 72 | count1 = 0U; |
| 73 | count2 = (r.next() % max_length) + min_length; |
| 74 | break; |
| 75 | |
| 76 | case 6: // both zero-length |
| 77 | count1 = 0U; |
| 78 | count2 = 0U; |
| 79 | range_of_tests = 6; // Don't do zero-zero again. |
| 80 | break; |
| 81 | |
| 82 | default: |
| 83 | ASSERT_TRUE(false) << "Should not get here."; |
| 84 | continue; |
| 85 | } |
| 86 | |
| 87 | if (count1 > 0U) { |
| 88 | s1 = new uint16_t[count1]; |
| 89 | } else { |
| 90 | // Leave a random pointer, should not be touched. |
| 91 | s1 = reinterpret_cast<uint16_t*>(0xebad1001); |
| 92 | } |
| 93 | |
| 94 | if (count2 > 0U) { |
| 95 | s2 = new uint16_t[count2]; |
| 96 | } else { |
| 97 | // Leave a random pointer, should not be touched. |
| 98 | s2 = reinterpret_cast<uint16_t*>(0xebad2002); |
| 99 | } |
| 100 | |
| 101 | size_t min = count1 < count2 ? count1 : count2; |
| 102 | bool fill_same = r.next() % 1 == 1; |
| 103 | |
| 104 | if (fill_same) { |
| 105 | for (size_t i = 0; i < min; ++i) { |
| 106 | s1[i] = static_cast<uint16_t>(r.next() & 0xFFFF); |
| 107 | s2[i] = s1[i]; |
| 108 | } |
| 109 | for (size_t i = min; i < count1; ++i) { |
| 110 | s1[i] = static_cast<uint16_t>(r.next() & 0xFFFF); |
| 111 | } |
| 112 | for (size_t i = min; i < count2; ++i) { |
| 113 | s2[i] = static_cast<uint16_t>(r.next() & 0xFFFF); |
| 114 | } |
| 115 | } else { |
| 116 | for (size_t i = 0; i < count1; ++i) { |
| 117 | s1[i] = static_cast<uint16_t>(r.next() & 0xFFFF); |
| 118 | } |
| 119 | for (size_t i = 0; i < count2; ++i) { |
| 120 | s2[i] = static_cast<uint16_t>(r.next() & 0xFFFF); |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | uint16_t* s1_pot_unaligned = s1; |
| 125 | uint16_t* s2_pot_unaligned = s2; |
| 126 | size_t c1_mod = count1; |
| 127 | size_t c2_mod = count2; |
| 128 | |
| 129 | if (!fill_same) { // Don't waste a good "long" test. |
| 130 | if (count1 > 1 && r.next() % 10 == 0) { |
| 131 | c1_mod--; |
| 132 | s1_pot_unaligned++; |
| 133 | } |
| 134 | if (count2 > 1 && r.next() % 10 == 0) { |
| 135 | c2_mod--; |
| 136 | s2_pot_unaligned++; |
| 137 | } |
| 138 | } |
| 139 | size_t mod_min = c1_mod < c2_mod ? c1_mod : c2_mod; |
| 140 | |
| 141 | int32_t expected = memcmp16_compare(s1_pot_unaligned, s2_pot_unaligned, mod_min); |
Andreas Gampe | 29b3841 | 2014-08-13 00:15:43 -0700 | [diff] [blame] | 142 | int32_t computed = art::testing::MemCmp16Testing(s1_pot_unaligned, s2_pot_unaligned, mod_min); |
Serban Constantinescu | 86797a7 | 2014-06-19 16:17:56 +0100 | [diff] [blame] | 143 | |
| 144 | ASSERT_EQ(expected, computed) << "Run " << round << ", c1=" << count1 << " c2=" << count2; |
| 145 | |
| 146 | if (count1 > 0U) { |
| 147 | delete s1; |
| 148 | } |
| 149 | if (count2 > 0U) { |
| 150 | delete s2; |
| 151 | } |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | TEST_F(MemCmp16Test, RandomSeparateShort) { |
| 156 | CheckSeparate(5U, 1U); |
| 157 | } |
| 158 | |
| 159 | TEST_F(MemCmp16Test, RandomSeparateLong) { |
| 160 | CheckSeparate(64U, 32U); |
| 161 | } |
| 162 | |
| 163 | // TODO: What's a good test for overlapping memory. Is it important? |
| 164 | // TEST_F(MemCmp16Test, RandomOverlay) { |
| 165 | // |
| 166 | // } |