libstdc++-v3/testsuite/std/simd/simd_bit.cc

// { dg-do run { target c++26 } }
// { dg-require-effective-target x86 }
// { dg-additional-options "-msse2" }

#include "test_setup.h"
#include <climits>

template <typename V>
  struct CheckInvocable
  {
    using T = typename V::value_type;
    static constexpr bool unsigned_integer
      = any_type_of<T, unsigned char, unsigned short, unsigned int, unsigned long,
		    unsigned long long>;
    static_assert(std::integral<T> == requires(V x) { std::byteswap(x); });
    static_assert(unsigned_integer == requires(V x) { std::bit_ceil(x); });
    static_assert(unsigned_integer == requires(V x) { std::bit_floor(x); });
    static_assert(unsigned_integer == requires(V x) { std::has_single_bit(x); });
    static_assert(unsigned_integer == requires(V x, V y) { std::rotl(x, y); });
    static_assert(unsigned_integer == requires(V x, int y) { std::rotl(x, y); });
    static_assert(unsigned_integer == requires(V x, V y) { std::rotr(x, y); });
    static_assert(unsigned_integer == requires(V x, int y) { std::rotr(x, y); });
    static_assert(unsigned_integer == requires(V x) { std::bit_width(x); });
    static_assert(unsigned_integer == requires(V x) { std::countl_zero(x); });
    static_assert(unsigned_integer == requires(V x) { std::countl_one(x); });
    static_assert(unsigned_integer == requires(V x) { std::countr_zero(x); });
    static_assert(unsigned_integer == requires(V x) { std::countr_one(x); });
    static_assert(unsigned_integer == requires(V x) { std::popcount(x); });
  };

template <typename V>
  requires std::integral<typename V::value_type>
  struct Tests<V> : CheckInvocable<V>
  {
    using T = typename V::value_type;
    using M = typename V::mask_type;

    static constexpr T msb = T(std::make_unsigned_t<T>(1) << (sizeof(T) * CHAR_BIT - 1));

    ADD_TEST(Byteswap) {
      std::tuple {test_iota<V>, V(T(0x01'02'03'04'05'06'07'08LL))},
      [](auto& t, const V a, const V b) {
	if constexpr (sizeof(T) == 1)
	  t.verify_equal(std::byteswap(a), a);
	else
	  {
	    auto x = std::byteswap(a);
	    for (int i = 0; i < V::size(); ++i)
	      t.verify_equal(x[i], std::byteswap(a[i]));
	    auto y = std::simd::byteswap(b);
	    for (int i = 0; i < V::size(); ++i)
	      t.verify_equal(y[i], std::byteswap(b[i]));
	  }
      }
    };

    ADD_TEST(BitCeil, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V, 0, msb < test_iota_max<V> ? msb : test_iota_max<V>>,
		  T(1024), T(msb + 1)},
      [](auto& t, const V a, const V b, const V c) {
	t.verify_precondition_failure("bit_ceil result is not representable", [&] {
	  bit_ceil(c);
	});
	t.verify_equal(bit_ceil(b), select(b == T(), T(1), b));
	t.verify_equal(std::bit_ceil(a), bit_ceil(a));
	t.verify_equal(std::simd::bit_ceil(a), bit_ceil(a));
	t.verify_equal(bit_ceil(a), V([&](int i) { return std::bit_ceil(a[i]); }));
      }
    };

    ADD_TEST(BitFloor, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, T(1024), T(msb + 1)},
      [](auto& t, const V a, const V b, const V c) {
	t.verify_equal(bit_floor(c), msb);
	t.verify_equal(bit_floor(b), b);
	t.verify_equal(std::bit_floor(a), bit_floor(a));
	t.verify_equal(std::simd::bit_floor(a), bit_floor(a));
	t.verify_equal(bit_floor(a), V([&](int i) { return std::bit_floor(a[i]); }));
      }
    };

    ADD_TEST(HasSingleBit, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, msb, T(msb + 1)},
      [](auto& t, const V a, const V b, const V c) {
	t.verify(all_of(has_single_bit(b)));
	t.verify(none_of(has_single_bit(c)));
	t.verify_equal(std::has_single_bit(a), has_single_bit(a));
	t.verify_equal(std::simd::has_single_bit(a), has_single_bit(a));
	t.verify_equal(has_single_bit(a), a != T() && a == bit_floor(a));
      }
    };

    ADD_TEST(FullRotate, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V, 0, 0>},
      [](auto& t, const V a) {
	constexpr int digits = std::numeric_limits<T>::digits;
	template for (int n : {0, digits, 5 * digits})
	  {
	    t.verify_equal(rotl(a, n), a);
	    t.verify_equal(std::rotl(a, n), a);
	    t.verify_equal(std::simd::rotl(a, n), a);
	    t.verify_equal(rotr(a, n), a);
	    t.verify_equal(std::rotr(a, n), a);
	    t.verify_equal(std::simd::rotr(a, n), a);
	  }
      }
    };

    using I = std::make_signed_t<T>;
    using IV = std::simd::rebind_t<I, V>;

    ADD_TEST_N(RotateN, 12, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V, 0, 0>},
      []<int N>(auto& t, const V x) {
	constexpr int shift = 11 * N;
	constexpr int rshift = I(sizeof(T) * CHAR_BIT) - shift;
	const IV vshift = I(shift);
	const IV vshiftx = vshift ^ IV(x & T(1));
	V ref([](T i) -> T { return std::rotl(i, shift); });
	V refx([](T i) -> T { return std::rotl(i, shift ^ (i & 1)); });
	const V l1 = rotl(x, shift);
	const V lv = rotl(x, vshift);
	const V lx = rotl(x, vshiftx);
	t.verify_equal(l1, ref);
	t.verify_equal(lv, ref);
	t.verify_equal(lx, refx);
	t.verify_equal(rotr(x, rshift), ref);
	t.verify_equal(rotr(x, I(rshift)), ref);
	t.verify_equal(rotr(x, I(sizeof(T) * CHAR_BIT) - vshiftx), refx);
      }
    };

    // The value-type of reference is always going to be 'int', forcing a conversion in verify_equal
    // (unless V::value_type is 'unsigned int'). That's intentional, since we thus can find
    // (hypothetical) cases of value-changing conversions in the implementation.
#define REFERENCE(x, fun) simd::rebind_t<decltype(fun(x[0])), V>([&](int i) { return fun(x[i]); })

    ADD_TEST(BitWidth, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, msb - test_iota<V>},
      [](auto& t, const V x, const V y) {
	t.verify_equal(std::bit_width(x), REFERENCE(x, std::bit_width));
	t.verify_equal(simd::bit_width(x), REFERENCE(x, std::bit_width));
	t.verify_equal(std::bit_width(y), REFERENCE(y, std::bit_width));
	t.verify_equal(simd::bit_width(y), REFERENCE(y, std::bit_width));
      }
    };

    ADD_TEST(CountLZero, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, msb - test_iota<V>},
      [](auto& t, const V x, const V y) {
	t.verify_equal(std::countl_zero(x), REFERENCE(x, std::countl_zero));
	t.verify_equal(simd::countl_zero(x), REFERENCE(x, std::countl_zero));
	t.verify_equal(std::countl_zero(y), REFERENCE(y, std::countl_zero));
	t.verify_equal(simd::countl_zero(y), REFERENCE(y, std::countl_zero));
      }
    };

    ADD_TEST(CountLOne, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, msb - test_iota<V>},
      [](auto& t, const V x, const V y) {
	t.verify_equal(std::countl_one(x), REFERENCE(x, std::countl_one));
	t.verify_equal(simd::countl_one(x), REFERENCE(x, std::countl_one));
	t.verify_equal(std::countl_one(y), REFERENCE(y, std::countl_one));
	t.verify_equal(simd::countl_one(y), REFERENCE(y, std::countl_one));
      }
    };

    ADD_TEST(CountRZero, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, msb - test_iota<V>},
      [](auto& t, const V x, const V y) {
	t.verify_equal(std::countr_zero(x), REFERENCE(x, std::countr_zero));
	t.verify_equal(simd::countr_zero(x), REFERENCE(x, std::countr_zero));
	t.verify_equal(std::countr_zero(y), REFERENCE(y, std::countr_zero));
	t.verify_equal(simd::countr_zero(y), REFERENCE(y, std::countr_zero));
      }
    };

    ADD_TEST(CountROne, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, msb - test_iota<V>},
      [](auto& t, const V x, const V y) {
	t.verify_equal(std::countr_one(x), REFERENCE(x, std::countr_one));
	t.verify_equal(simd::countr_one(x), REFERENCE(x, std::countr_one));
	t.verify_equal(std::countr_one(y), REFERENCE(y, std::countr_one));
	t.verify_equal(simd::countr_one(y), REFERENCE(y, std::countr_one));
      }
    };

    ADD_TEST(PopCount, std::__unsigned_integer<T>) {
      std::tuple {test_iota<V>, msb - test_iota<V>},
      [](auto& t, const V x, const V y) {
	t.verify_equal(std::popcount(x), REFERENCE(x, std::popcount));
	t.verify_equal(simd::popcount(x), REFERENCE(x, std::popcount));
	t.verify_equal(std::popcount(y), REFERENCE(y, std::popcount));
	t.verify_equal(simd::popcount(y), REFERENCE(y, std::popcount));
      }
    };
  };

template <typename V>
  struct Tests : CheckInvocable<V>
  {};

#include "create_tests.h"