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/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "memcmp16.h"
#include "gtest/gtest.h"
class RandGen {
public:
explicit RandGen(uint32_t seed) : val_(seed) {}
uint32_t next() {
val_ = val_ * 48271 % 2147483647 + 13;
return val_;
}
uint32_t val_;
};
class MemCmp16Test : public testing::Test {
};
// A simple implementation to compare against.
// Note: this version is equivalent to the generic one used when no optimized version is available.
int32_t memcmp16_compare(const uint16_t* s0, const uint16_t* s1, size_t count) {
for (size_t i = 0; i < count; i++) {
if (s0[i] != s1[i]) {
return static_cast<int32_t>(s0[i]) - static_cast<int32_t>(s1[i]);
}
}
return 0;
}
static constexpr size_t kMemCmp16Rounds = 100000;
static void CheckSeparate(size_t max_length, size_t min_length) {
RandGen r(0x1234);
size_t range_of_tests = 7; // All four (weighted) tests active in the beginning.
for (size_t round = 0; round < kMemCmp16Rounds; ++round) {
size_t type = r.next() % range_of_tests;
size_t count1, count2;
uint16_t *s1, *s2; // Use raw pointers to simplify using clobbered addresses
switch (type) {
case 0: // random, non-zero lengths of both strings
case 1:
case 2:
case 3:
count1 = (r.next() % max_length) + min_length;
count2 = (r.next() % max_length) + min_length;
break;
case 4: // random non-zero length of first, second is zero
count1 = (r.next() % max_length) + min_length;
count2 = 0U;
break;
case 5: // random non-zero length of second, first is zero
count1 = 0U;
count2 = (r.next() % max_length) + min_length;
break;
case 6: // both zero-length
count1 = 0U;
count2 = 0U;
range_of_tests = 6; // Don't do zero-zero again.
break;
default:
ASSERT_TRUE(false) << "Should not get here.";
continue;
}
if (count1 > 0U) {
s1 = new uint16_t[count1];
} else {
// Leave a random pointer, should not be touched.
s1 = reinterpret_cast<uint16_t*>(0xebad1001);
}
if (count2 > 0U) {
s2 = new uint16_t[count2];
} else {
// Leave a random pointer, should not be touched.
s2 = reinterpret_cast<uint16_t*>(0xebad2002);
}
size_t min = count1 < count2 ? count1 : count2;
bool fill_same = r.next() % 2 == 1;
if (fill_same) {
for (size_t i = 0; i < min; ++i) {
s1[i] = static_cast<uint16_t>(r.next() & 0xFFFF);
s2[i] = s1[i];
}
for (size_t i = min; i < count1; ++i) {
s1[i] = static_cast<uint16_t>(r.next() & 0xFFFF);
}
for (size_t i = min; i < count2; ++i) {
s2[i] = static_cast<uint16_t>(r.next() & 0xFFFF);
}
} else {
for (size_t i = 0; i < count1; ++i) {
s1[i] = static_cast<uint16_t>(r.next() & 0xFFFF);
}
for (size_t i = 0; i < count2; ++i) {
s2[i] = static_cast<uint16_t>(r.next() & 0xFFFF);
}
}
uint16_t* s1_pot_unaligned = s1;
uint16_t* s2_pot_unaligned = s2;
size_t c1_mod = count1;
size_t c2_mod = count2;
if (!fill_same) { // Don't waste a good "long" test.
if (count1 > 1 && r.next() % 10 == 0) {
c1_mod--;
s1_pot_unaligned++;
}
if (count2 > 1 && r.next() % 10 == 0) {
c2_mod--;
s2_pot_unaligned++;
}
}
size_t mod_min = c1_mod < c2_mod ? c1_mod : c2_mod;
int32_t expected = memcmp16_compare(s1_pot_unaligned, s2_pot_unaligned, mod_min);
int32_t computed = art::testing::MemCmp16Testing(s1_pot_unaligned, s2_pot_unaligned, mod_min);
ASSERT_EQ(expected, computed) << "Run " << round << ", c1=" << count1 << " c2=" << count2;
if (count1 > 0U) {
delete[] s1;
}
if (count2 > 0U) {
delete[] s2;
}
}
}
TEST_F(MemCmp16Test, RandomSeparateShort) {
CheckSeparate(5U, 1U);
}
TEST_F(MemCmp16Test, RandomSeparateLong) {
CheckSeparate(64U, 32U);
}
// TODO: What's a good test for overlapping memory. Is it important?
// TEST_F(MemCmp16Test, RandomOverlay) {
//
// }
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