Select64Test.cpp File Reference

#include <folly/experimental/Select64.h>
#include <cstddef>
#include <cstdint>
#include <folly/experimental/Instructions.h>
#include <folly/portability/GTest.h>

Go to the source code of this file.

Classes
class	Select64Test

Typedefs
using	TestArch = folly::compression::instructions::Default

Functions
uint64_t	check_select64_default (uint64_t x, uint64_t k)
uint64_t	check_select64_haswell (uint64_t x, uint64_t k)
	TEST_F (Select64Test, SelectInByteTable)
	TEST_F (Select64Test, Select64)

Typedef Documentation

using TestArch = folly::compression::instructions::Default

Definition at line 35 of file Select64Test.cpp.

Function Documentation

uint64_t check_select64_default	(	uint64_t	x,
		uint64_t	k
	)

Definition at line 26 of file Select64Test.cpp.

References k, and x.

                                                                   {
  return folly::select64<folly::compression::instructions::Default>(x, k);
}

uint64_t check_select64_haswell	(	uint64_t	x,
		uint64_t	k
	)

Definition at line 29 of file Select64Test.cpp.

References k, and x.

                                                                   {
  return folly::select64<folly::compression::instructions::Haswell>(x, k);
}

TEST_F	(	Select64Test	,
		SelectInByteTable
	)

Definition at line 37 of file Select64Test.cpp.

References EXPECT_EQ, i, folly::detail::kSelectInByte, and uint8_t.

                                        {
  for (size_t i = 0u; i < 256u; ++i) {
    uint8_t decoded = 0;
    for (size_t j = 0u; j < 8u; ++j) {
      auto const entry = folly::detail::kSelectInByte[j][i];
      decoded |= uint8_t(entry != 8) << entry;
    }
    EXPECT_EQ(i, decoded);
  }
}

TEST_F	(	Select64Test	,
		Select64
	)

Definition at line 48 of file Select64Test.cpp.

References i, k, folly::popcount(), uint64_t, and x.

                               {
  using instr = TestArch;
  constexpr uint64_t kPrime = uint64_t(-59);
  for (uint64_t x = kPrime, i = 0; i < (1 << 20); x *= kPrime, i += 1) {
    auto const w = instr::popcount(x);
    for (size_t k = 0; k < w; ++k) {
      auto const pos = folly::select64<instr>(x, k);
      CHECK_EQ((x >> pos) & 1, 1);
      CHECK_EQ(instr::popcount(x & ((uint64_t(1) << pos) - 1)), k);
    }
  }
}