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229 lines (193 loc) · 7.95 KB
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/***************************************************************************
* Copyright (c) Johan Mabille, Sylvain Corlay, Wolf Vollprecht and *
* Martin Renou *
* Copyright (c) QuantStack *
* Copyright (c) Serge Guelton *
* *
* Distributed under the terms of the BSD 3-Clause License. *
* *
* The full license is in the file LICENSE, distributed with this software. *
****************************************************************************/
#include "xsimd/xsimd.hpp"
#ifndef XSIMD_NO_SUPPORTED_ARCHITECTURE
#include "test_utils.hpp"
template <class T>
struct bit_test
{
using value_type = T;
using bits = std::integral_constant<int, sizeof(T) * CHAR_BIT>;
void test_popcount()
{
// Zero
CHECK_EQ(xsimd::detail::popcount(T(0)), 0);
// All bits set
CHECK_EQ(xsimd::detail::popcount(T(~T(0))), bits::value);
// Single bit patterns - all should have popcount of 1
for (int i = 0; i < bits::value; ++i)
{
T value = T(T(1) << i);
INFO("popcount(1 << " << i << ")");
CHECK_EQ(xsimd::detail::popcount(value), 1);
}
// Powers of 2 minus 1 - known popcounts
for (int i = 1; i < bits::value; ++i)
{
T value = T((T(1) << i) - 1);
INFO("popcount((1 << " << i << ") - 1)");
CHECK_EQ(xsimd::detail::popcount(value), i);
}
// Alternating patterns
if (bits::value >= 8)
{
T pattern_aa = T(0);
T pattern_55 = T(0);
for (int i = 0; i < bits::value / 8; ++i)
{
pattern_aa |= T(0xAA) << (i * 8);
pattern_55 |= T(0x55) << (i * 8);
}
INFO("popcount(0xAA...)");
CHECK_EQ(xsimd::detail::popcount(pattern_aa), bits::value / 2);
INFO("popcount(0x55...)");
CHECK_EQ(xsimd::detail::popcount(pattern_55), bits::value / 2);
}
// Specific test cases
CHECK_EQ(xsimd::detail::popcount(T(1)), 1);
CHECK_EQ(xsimd::detail::popcount(T(3)), 2);
CHECK_EQ(xsimd::detail::popcount(T(7)), 3);
CHECK_EQ(xsimd::detail::popcount(T(15)), 4);
}
void test_countl_zero()
{
// Zero should have all leading zeros
CHECK_EQ(xsimd::detail::countl_zero(T(0)), bits::value);
// All bits set should have 0 leading zeros
CHECK_EQ(xsimd::detail::countl_zero(T(~T(0))), 0);
// MSB set should have 0 leading zeros
T msb = T(1) << (bits::value - 1);
CHECK_EQ(xsimd::detail::countl_zero(msb), 0);
// Powers of 2
for (int i = 0; i < bits::value; ++i)
{
T value = T(T(1) << i);
int expected = bits::value - i - 1;
INFO("countl_zero(1 << " << i << ")");
CHECK_EQ(xsimd::detail::countl_zero(value), expected);
}
// Sequential patterns (1, 3, 7, 15, ...)
for (int i = 1; i < bits::value; ++i)
{
T value = T((T(1) << i) - 1);
int expected = bits::value - i;
INFO("countl_zero((1 << " << i << ") - 1)");
CHECK_EQ(xsimd::detail::countl_zero(value), expected);
}
// Specific values
CHECK_EQ(xsimd::detail::countl_zero(T(1)), bits::value - 1);
CHECK_EQ(xsimd::detail::countl_zero(T(2)), bits::value - 2);
CHECK_EQ(xsimd::detail::countl_zero(T(4)), bits::value - 3);
}
void test_countl_one()
{
// Zero should have 0 leading ones
CHECK_EQ(xsimd::detail::countl_one(T(0)), 0);
// All bits set should have all leading ones
CHECK_EQ(xsimd::detail::countl_one(T(~T(0))), bits::value);
// MSB clear, rest set should have 0 leading ones
T pattern = T(~(T(1) << (bits::value - 1)));
CHECK_EQ(xsimd::detail::countl_one(pattern), 0);
// Inverted powers of 2
for (int i = 0; i < bits::value; ++i)
{
T value = T(~(T(1) << i));
int expected = (i == bits::value - 1) ? 0 : bits::value - i - 1;
INFO("countl_one(~(1 << " << i << "))");
CHECK_EQ(xsimd::detail::countl_one(value), expected);
}
// Patterns with known leading ones
for (int i = 1; i <= bits::value; ++i)
{
T value = T(T(~T(0)) << (bits::value - i));
INFO("countl_one(~0 << " << (bits::value - i) << ")");
CHECK_EQ(xsimd::detail::countl_one(value), i);
}
// Specific values
CHECK_EQ(xsimd::detail::countl_one(T(~T(1))), bits::value - 1);
CHECK_EQ(xsimd::detail::countl_one(T(~T(3))), bits::value - 2);
}
void test_countr_zero()
{
// Zero should have all trailing zeros
CHECK_EQ(xsimd::detail::countr_zero(T(0)), bits::value);
// All bits set should have 0 trailing zeros
CHECK_EQ(xsimd::detail::countr_zero(T(~T(0))), 0);
// Odd numbers should have 0 trailing zeros
CHECK_EQ(xsimd::detail::countr_zero(T(1)), 0);
CHECK_EQ(xsimd::detail::countr_zero(T(3)), 0);
CHECK_EQ(xsimd::detail::countr_zero(T(5)), 0);
CHECK_EQ(xsimd::detail::countr_zero(T(7)), 0);
// Powers of 2
for (int i = 0; i < bits::value; ++i)
{
T value = T(1) << i;
INFO("countr_zero(1 << " << i << ")");
CHECK_EQ(xsimd::detail::countr_zero(value), i);
}
// Even numbers with known factors
CHECK_EQ(xsimd::detail::countr_zero(T(2)), 1);
CHECK_EQ(xsimd::detail::countr_zero(T(4)), 2);
CHECK_EQ(xsimd::detail::countr_zero(T(6)), 1);
CHECK_EQ(xsimd::detail::countr_zero(T(8)), 3);
CHECK_EQ(xsimd::detail::countr_zero(T(12)), 2);
CHECK_EQ(xsimd::detail::countr_zero(T(16)), 4);
// Specific patterns
for (int i = 1; i < bits::value; ++i)
{
T value = T(~T(0)) << i;
INFO("countr_zero(~0 << " << i << ")");
CHECK_EQ(xsimd::detail::countr_zero(value), i);
}
}
void test_countr_one()
{
// Zero should have 0 trailing ones
CHECK_EQ(xsimd::detail::countr_one(T(0)), 0);
// All bits set should have all trailing ones
CHECK_EQ(xsimd::detail::countr_one(T(~T(0))), bits::value);
// Even numbers should have 0 trailing ones
CHECK_EQ(xsimd::detail::countr_one(T(2)), 0);
CHECK_EQ(xsimd::detail::countr_one(T(4)), 0);
CHECK_EQ(xsimd::detail::countr_one(T(6)), 0);
// Powers of 2 minus 1
for (int i = 1; i < bits::value; ++i)
{
T value = T((T(1) << i) - 1);
INFO("countr_one((1 << " << i << ") - 1)");
CHECK_EQ(xsimd::detail::countr_one(value), i);
}
// Specific values
CHECK_EQ(xsimd::detail::countr_one(T(1)), 1);
CHECK_EQ(xsimd::detail::countr_one(T(3)), 2);
CHECK_EQ(xsimd::detail::countr_one(T(7)), 3);
CHECK_EQ(xsimd::detail::countr_one(T(15)), 4);
CHECK_EQ(xsimd::detail::countr_one(T(31)), 5);
// Inverted powers of 2 minus 1
for (int i = 1; i < bits::value; ++i)
{
T value = T(~((T(1) << i) - 1));
INFO("countr_one(~((1 << " << i << ") - 1))");
CHECK_EQ(xsimd::detail::countr_one(value), 0);
}
}
};
TEST_CASE_TEMPLATE("[bit operations]", T,
uint8_t, uint16_t, uint32_t, uint64_t)
{
bit_test<T> Test;
SUBCASE("popcount") { Test.test_popcount(); }
SUBCASE("countl_zero") { Test.test_countl_zero(); }
SUBCASE("countl_one") { Test.test_countl_one(); }
SUBCASE("countr_zero") { Test.test_countr_zero(); }
SUBCASE("countr_one") { Test.test_countr_one(); }
}
#endif