Abseil Common Libraries (C++) (grcp 依赖)
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566 lines
20 KiB
566 lines
20 KiB
4 years ago
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// Copyright 2020 The Abseil Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "absl/numeric/bits.h"
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#include <limits>
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#include "gmock/gmock.h"
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#include "gtest/gtest.h"
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#include "absl/random/random.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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namespace {
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TEST(Rotate, Left) {
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static_assert(rotl(uint8_t{0x12}, 0) == uint8_t{0x12}, "");
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static_assert(rotl(uint16_t{0x1234}, 0) == uint16_t{0x1234}, "");
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static_assert(rotl(uint32_t{0x12345678UL}, 0) == uint32_t{0x12345678UL}, "");
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static_assert(rotl(uint64_t{0x12345678ABCDEF01ULL}, 0) ==
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uint64_t{0x12345678ABCDEF01ULL},
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"");
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EXPECT_EQ(rotl(uint8_t{0x12}, 0), uint8_t{0x12});
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EXPECT_EQ(rotl(uint16_t{0x1234}, 0), uint16_t{0x1234});
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EXPECT_EQ(rotl(uint32_t{0x12345678UL}, 0), uint32_t{0x12345678UL});
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EXPECT_EQ(rotl(uint64_t{0x12345678ABCDEF01ULL}, 0),
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uint64_t{0x12345678ABCDEF01ULL});
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EXPECT_EQ(rotl(uint8_t{0x12}, 8), uint8_t{0x12});
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EXPECT_EQ(rotl(uint16_t{0x1234}, 16), uint16_t{0x1234});
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EXPECT_EQ(rotl(uint32_t{0x12345678UL}, 32), uint32_t{0x12345678UL});
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EXPECT_EQ(rotl(uint64_t{0x12345678ABCDEF01ULL}, 64),
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uint64_t{0x12345678ABCDEF01ULL});
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EXPECT_EQ(rotl(uint8_t{0x12}, -8), uint8_t{0x12});
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EXPECT_EQ(rotl(uint16_t{0x1234}, -16), uint16_t{0x1234});
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EXPECT_EQ(rotl(uint32_t{0x12345678UL}, -32), uint32_t{0x12345678UL});
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EXPECT_EQ(rotl(uint64_t{0x12345678ABCDEF01ULL}, -64),
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uint64_t{0x12345678ABCDEF01ULL});
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EXPECT_EQ(rotl(uint8_t{0x12}, 4), uint8_t{0x21});
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EXPECT_EQ(rotl(uint16_t{0x1234}, 4), uint16_t{0x2341});
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EXPECT_EQ(rotl(uint32_t{0x12345678UL}, 4), uint32_t{0x23456781UL});
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EXPECT_EQ(rotl(uint64_t{0x12345678ABCDEF01ULL}, 4),
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uint64_t{0x2345678ABCDEF011ULL});
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EXPECT_EQ(rotl(uint8_t{0x12}, -4), uint8_t{0x21});
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EXPECT_EQ(rotl(uint16_t{0x1234}, -4), uint16_t{0x4123});
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EXPECT_EQ(rotl(uint32_t{0x12345678UL}, -4), uint32_t{0x81234567UL});
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EXPECT_EQ(rotl(uint64_t{0x12345678ABCDEF01ULL}, -4),
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uint64_t{0x112345678ABCDEF0ULL});
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}
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TEST(Rotate, Right) {
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static_assert(rotr(uint8_t{0x12}, 0) == uint8_t{0x12}, "");
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static_assert(rotr(uint16_t{0x1234}, 0) == uint16_t{0x1234}, "");
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static_assert(rotr(uint32_t{0x12345678UL}, 0) == uint32_t{0x12345678UL}, "");
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static_assert(rotr(uint64_t{0x12345678ABCDEF01ULL}, 0) ==
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uint64_t{0x12345678ABCDEF01ULL},
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"");
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EXPECT_EQ(rotr(uint8_t{0x12}, 0), uint8_t{0x12});
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EXPECT_EQ(rotr(uint16_t{0x1234}, 0), uint16_t{0x1234});
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EXPECT_EQ(rotr(uint32_t{0x12345678UL}, 0), uint32_t{0x12345678UL});
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EXPECT_EQ(rotr(uint64_t{0x12345678ABCDEF01ULL}, 0),
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uint64_t{0x12345678ABCDEF01ULL});
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EXPECT_EQ(rotr(uint8_t{0x12}, 8), uint8_t{0x12});
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EXPECT_EQ(rotr(uint16_t{0x1234}, 16), uint16_t{0x1234});
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EXPECT_EQ(rotr(uint32_t{0x12345678UL}, 32), uint32_t{0x12345678UL});
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EXPECT_EQ(rotr(uint64_t{0x12345678ABCDEF01ULL}, 64),
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uint64_t{0x12345678ABCDEF01ULL});
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EXPECT_EQ(rotr(uint8_t{0x12}, -8), uint8_t{0x12});
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EXPECT_EQ(rotr(uint16_t{0x1234}, -16), uint16_t{0x1234});
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EXPECT_EQ(rotr(uint32_t{0x12345678UL}, -32), uint32_t{0x12345678UL});
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EXPECT_EQ(rotr(uint64_t{0x12345678ABCDEF01ULL}, -64),
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uint64_t{0x12345678ABCDEF01ULL});
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EXPECT_EQ(rotr(uint8_t{0x12}, 4), uint8_t{0x21});
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EXPECT_EQ(rotr(uint16_t{0x1234}, 4), uint16_t{0x4123});
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EXPECT_EQ(rotr(uint32_t{0x12345678UL}, 4), uint32_t{0x81234567UL});
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EXPECT_EQ(rotr(uint64_t{0x12345678ABCDEF01ULL}, 4),
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uint64_t{0x112345678ABCDEF0ULL});
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EXPECT_EQ(rotr(uint8_t{0x12}, -4), uint8_t{0x21});
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EXPECT_EQ(rotr(uint16_t{0x1234}, -4), uint16_t{0x2341});
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EXPECT_EQ(rotr(uint32_t{0x12345678UL}, -4), uint32_t{0x23456781UL});
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EXPECT_EQ(rotr(uint64_t{0x12345678ABCDEF01ULL}, -4),
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uint64_t{0x2345678ABCDEF011ULL});
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}
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TEST(Rotate, Symmetry) {
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// rotr(x, s) is equivalent to rotl(x, -s)
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absl::BitGen rng;
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constexpr int kTrials = 100;
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for (int i = 0; i < kTrials; ++i) {
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uint8_t value = absl::Uniform(rng, std::numeric_limits<uint8_t>::min(),
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std::numeric_limits<uint8_t>::max());
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int shift = absl::Uniform(rng, -2 * std::numeric_limits<uint8_t>::digits,
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2 * std::numeric_limits<uint8_t>::digits);
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EXPECT_EQ(rotl(value, shift), rotr(value, -shift));
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}
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for (int i = 0; i < kTrials; ++i) {
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uint16_t value = absl::Uniform(rng, std::numeric_limits<uint16_t>::min(),
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std::numeric_limits<uint16_t>::max());
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int shift = absl::Uniform(rng, -2 * std::numeric_limits<uint16_t>::digits,
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2 * std::numeric_limits<uint16_t>::digits);
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EXPECT_EQ(rotl(value, shift), rotr(value, -shift));
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}
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for (int i = 0; i < kTrials; ++i) {
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uint32_t value = absl::Uniform(rng, std::numeric_limits<uint32_t>::min(),
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std::numeric_limits<uint32_t>::max());
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int shift = absl::Uniform(rng, -2 * std::numeric_limits<uint32_t>::digits,
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2 * std::numeric_limits<uint32_t>::digits);
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EXPECT_EQ(rotl(value, shift), rotr(value, -shift));
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}
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for (int i = 0; i < kTrials; ++i) {
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uint64_t value = absl::Uniform(rng, std::numeric_limits<uint64_t>::min(),
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std::numeric_limits<uint64_t>::max());
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int shift = absl::Uniform(rng, -2 * std::numeric_limits<uint64_t>::digits,
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2 * std::numeric_limits<uint64_t>::digits);
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EXPECT_EQ(rotl(value, shift), rotr(value, -shift));
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}
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}
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TEST(Counting, LeadingZeroes) {
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#if ABSL_INTERNAL_HAS_CONSTEXPR_CLZ
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static_assert(countl_zero(uint8_t{}) == 8, "");
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static_assert(countl_zero(static_cast<uint8_t>(-1)) == 0, "");
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static_assert(countl_zero(uint16_t{}) == 16, "");
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static_assert(countl_zero(static_cast<uint16_t>(-1)) == 0, "");
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static_assert(countl_zero(uint32_t{}) == 32, "");
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static_assert(countl_zero(~uint32_t{}) == 0, "");
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static_assert(countl_zero(uint64_t{}) == 64, "");
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static_assert(countl_zero(~uint64_t{}) == 0, "");
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#endif
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EXPECT_EQ(countl_zero(uint8_t{}), 8);
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EXPECT_EQ(countl_zero(static_cast<uint8_t>(-1)), 0);
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EXPECT_EQ(countl_zero(uint16_t{}), 16);
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EXPECT_EQ(countl_zero(static_cast<uint16_t>(-1)), 0);
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EXPECT_EQ(countl_zero(uint32_t{}), 32);
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EXPECT_EQ(countl_zero(~uint32_t{}), 0);
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EXPECT_EQ(countl_zero(uint64_t{}), 64);
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EXPECT_EQ(countl_zero(~uint64_t{}), 0);
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for (int i = 0; i < 8; i++) {
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EXPECT_EQ(countl_zero(static_cast<uint8_t>(1u << i)), 7 - i);
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}
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for (int i = 0; i < 16; i++) {
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EXPECT_EQ(countl_zero(static_cast<uint16_t>(1u << i)), 15 - i);
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}
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for (int i = 0; i < 32; i++) {
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EXPECT_EQ(countl_zero(uint32_t{1} << i), 31 - i);
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}
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for (int i = 0; i < 64; i++) {
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EXPECT_EQ(countl_zero(uint64_t{1} << i), 63 - i);
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}
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}
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TEST(Counting, LeadingOnes) {
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#if ABSL_INTERNAL_HAS_CONSTEXPR_CLZ
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static_assert(countl_one(uint8_t{}) == 0, "");
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static_assert(countl_one(static_cast<uint8_t>(-1)) == 8, "");
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static_assert(countl_one(uint16_t{}) == 0, "");
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static_assert(countl_one(static_cast<uint16_t>(-1)) == 16, "");
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static_assert(countl_one(uint32_t{}) == 0, "");
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static_assert(countl_one(~uint32_t{}) == 32, "");
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static_assert(countl_one(uint64_t{}) == 0, "");
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static_assert(countl_one(~uint64_t{}) == 64, "");
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#endif
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EXPECT_EQ(countl_one(uint8_t{}), 0);
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EXPECT_EQ(countl_one(static_cast<uint8_t>(-1)), 8);
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EXPECT_EQ(countl_one(uint16_t{}), 0);
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EXPECT_EQ(countl_one(static_cast<uint16_t>(-1)), 16);
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EXPECT_EQ(countl_one(uint32_t{}), 0);
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EXPECT_EQ(countl_one(~uint32_t{}), 32);
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EXPECT_EQ(countl_one(uint64_t{}), 0);
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EXPECT_EQ(countl_one(~uint64_t{}), 64);
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}
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TEST(Counting, TrailingZeroes) {
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#if ABSL_INTERNAL_HAS_CONSTEXPR_CTZ
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static_assert(countr_zero(uint8_t{}) == 8, "");
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static_assert(countr_zero(static_cast<uint8_t>(-1)) == 0, "");
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static_assert(countr_zero(uint16_t{}) == 16, "");
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static_assert(countr_zero(static_cast<uint16_t>(-1)) == 0, "");
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static_assert(countr_zero(uint32_t{}) == 32, "");
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static_assert(countr_zero(~uint32_t{}) == 0, "");
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static_assert(countr_zero(uint64_t{}) == 64, "");
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static_assert(countr_zero(~uint64_t{}) == 0, "");
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#endif
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EXPECT_EQ(countr_zero(uint8_t{}), 8);
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EXPECT_EQ(countr_zero(static_cast<uint8_t>(-1)), 0);
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EXPECT_EQ(countr_zero(uint16_t{}), 16);
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EXPECT_EQ(countr_zero(static_cast<uint16_t>(-1)), 0);
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EXPECT_EQ(countr_zero(uint32_t{}), 32);
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EXPECT_EQ(countr_zero(~uint32_t{}), 0);
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EXPECT_EQ(countr_zero(uint64_t{}), 64);
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EXPECT_EQ(countr_zero(~uint64_t{}), 0);
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}
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TEST(Counting, TrailingOnes) {
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#if ABSL_INTERNAL_HAS_CONSTEXPR_CTZ
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static_assert(countr_one(uint8_t{}) == 0, "");
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static_assert(countr_one(static_cast<uint8_t>(-1)) == 8, "");
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static_assert(countr_one(uint16_t{}) == 0, "");
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static_assert(countr_one(static_cast<uint16_t>(-1)) == 16, "");
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static_assert(countr_one(uint32_t{}) == 0, "");
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static_assert(countr_one(~uint32_t{}) == 32, "");
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static_assert(countr_one(uint64_t{}) == 0, "");
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static_assert(countr_one(~uint64_t{}) == 64, "");
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#endif
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EXPECT_EQ(countr_one(uint8_t{}), 0);
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EXPECT_EQ(countr_one(static_cast<uint8_t>(-1)), 8);
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EXPECT_EQ(countr_one(uint16_t{}), 0);
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EXPECT_EQ(countr_one(static_cast<uint16_t>(-1)), 16);
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EXPECT_EQ(countr_one(uint32_t{}), 0);
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EXPECT_EQ(countr_one(~uint32_t{}), 32);
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EXPECT_EQ(countr_one(uint64_t{}), 0);
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EXPECT_EQ(countr_one(~uint64_t{}), 64);
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}
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TEST(Counting, Popcount) {
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#if ABSL_INTERNAL_HAS_CONSTEXPR_POPCOUNT
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static_assert(popcount(uint8_t{}) == 0, "");
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static_assert(popcount(uint8_t{1}) == 1, "");
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static_assert(popcount(static_cast<uint8_t>(-1)) == 8, "");
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static_assert(popcount(uint16_t{}) == 0, "");
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static_assert(popcount(uint16_t{1}) == 1, "");
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static_assert(popcount(static_cast<uint16_t>(-1)) == 16, "");
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static_assert(popcount(uint32_t{}) == 0, "");
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static_assert(popcount(uint32_t{1}) == 1, "");
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static_assert(popcount(~uint32_t{}) == 32, "");
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static_assert(popcount(uint64_t{}) == 0, "");
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static_assert(popcount(uint64_t{1}) == 1, "");
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static_assert(popcount(~uint64_t{}) == 64, "");
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#endif // ABSL_INTERNAL_HAS_CONSTEXPR_POPCOUNT
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EXPECT_EQ(popcount(uint8_t{}), 0);
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EXPECT_EQ(popcount(uint8_t{1}), 1);
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EXPECT_EQ(popcount(static_cast<uint8_t>(-1)), 8);
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EXPECT_EQ(popcount(uint16_t{}), 0);
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EXPECT_EQ(popcount(uint16_t{1}), 1);
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EXPECT_EQ(popcount(static_cast<uint16_t>(-1)), 16);
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EXPECT_EQ(popcount(uint32_t{}), 0);
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EXPECT_EQ(popcount(uint32_t{1}), 1);
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EXPECT_EQ(popcount(~uint32_t{}), 32);
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|
|
EXPECT_EQ(popcount(uint64_t{}), 0);
|
||
|
|
EXPECT_EQ(popcount(uint64_t{1}), 1);
|
||
|
|
EXPECT_EQ(popcount(~uint64_t{}), 64);
|
||
|
|
|
||
|
|
for (int i = 0; i < 8; i++) {
|
||
|
|
EXPECT_EQ(popcount(static_cast<uint8_t>(uint8_t{1} << i)), 1);
|
||
|
|
EXPECT_EQ(popcount(static_cast<uint8_t>(static_cast<uint8_t>(-1) ^
|
||
|
|
(uint8_t{1} << i))),
|
||
|
|
7);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 16; i++) {
|
||
|
|
EXPECT_EQ(popcount(static_cast<uint16_t>(uint16_t{1} << i)), 1);
|
||
|
|
EXPECT_EQ(popcount(static_cast<uint16_t>(static_cast<uint16_t>(-1) ^
|
||
|
|
(uint16_t{1} << i))),
|
||
|
|
15);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 32; i++) {
|
||
|
|
EXPECT_EQ(popcount(uint32_t{1} << i), 1);
|
||
|
|
EXPECT_EQ(popcount(static_cast<uint32_t>(-1) ^ (uint32_t{1} << i)), 31);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 64; i++) {
|
||
|
|
EXPECT_EQ(popcount(uint64_t{1} << i), 1);
|
||
|
|
EXPECT_EQ(popcount(static_cast<uint64_t>(-1) ^ (uint64_t{1} << i)), 63);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename T>
|
||
|
|
struct PopcountInput {
|
||
|
|
T value = 0;
|
||
|
|
int expected = 0;
|
||
|
|
};
|
||
|
|
|
||
|
|
template <typename T>
|
||
|
|
PopcountInput<T> GeneratePopcountInput(absl::BitGen& gen) {
|
||
|
|
PopcountInput<T> ret;
|
||
|
|
for (int i = 0; i < std::numeric_limits<T>::digits; i++) {
|
||
|
|
bool coin = absl::Bernoulli(gen, 0.2);
|
||
|
|
if (coin) {
|
||
|
|
ret.value |= T{1} << i;
|
||
|
|
ret.expected++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(Counting, PopcountFuzz) {
|
||
|
|
absl::BitGen rng;
|
||
|
|
constexpr int kTrials = 100;
|
||
|
|
|
||
|
|
for (int i = 0; i < kTrials; ++i) {
|
||
|
|
auto input = GeneratePopcountInput<uint8_t>(rng);
|
||
|
|
EXPECT_EQ(popcount(input.value), input.expected);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < kTrials; ++i) {
|
||
|
|
auto input = GeneratePopcountInput<uint16_t>(rng);
|
||
|
|
EXPECT_EQ(popcount(input.value), input.expected);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < kTrials; ++i) {
|
||
|
|
auto input = GeneratePopcountInput<uint32_t>(rng);
|
||
|
|
EXPECT_EQ(popcount(input.value), input.expected);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < kTrials; ++i) {
|
||
|
|
auto input = GeneratePopcountInput<uint64_t>(rng);
|
||
|
|
EXPECT_EQ(popcount(input.value), input.expected);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(IntegralPowersOfTwo, SingleBit) {
|
||
|
|
EXPECT_FALSE(has_single_bit(uint8_t{}));
|
||
|
|
EXPECT_FALSE(has_single_bit(static_cast<uint8_t>(-1)));
|
||
|
|
EXPECT_FALSE(has_single_bit(uint16_t{}));
|
||
|
|
EXPECT_FALSE(has_single_bit(static_cast<uint16_t>(-1)));
|
||
|
|
EXPECT_FALSE(has_single_bit(uint32_t{}));
|
||
|
|
EXPECT_FALSE(has_single_bit(~uint32_t{}));
|
||
|
|
EXPECT_FALSE(has_single_bit(uint64_t{}));
|
||
|
|
EXPECT_FALSE(has_single_bit(~uint64_t{}));
|
||
|
|
|
||
|
|
static_assert(!has_single_bit(0u), "");
|
||
|
|
static_assert(has_single_bit(1u), "");
|
||
|
|
static_assert(has_single_bit(2u), "");
|
||
|
|
static_assert(!has_single_bit(3u), "");
|
||
|
|
static_assert(has_single_bit(4u), "");
|
||
|
|
static_assert(!has_single_bit(1337u), "");
|
||
|
|
static_assert(has_single_bit(65536u), "");
|
||
|
|
static_assert(has_single_bit(uint32_t{1} << 30), "");
|
||
|
|
static_assert(has_single_bit(uint64_t{1} << 42), "");
|
||
|
|
|
||
|
|
EXPECT_FALSE(has_single_bit(0u));
|
||
|
|
EXPECT_TRUE(has_single_bit(1u));
|
||
|
|
EXPECT_TRUE(has_single_bit(2u));
|
||
|
|
EXPECT_FALSE(has_single_bit(3u));
|
||
|
|
EXPECT_TRUE(has_single_bit(4u));
|
||
|
|
EXPECT_FALSE(has_single_bit(1337u));
|
||
|
|
EXPECT_TRUE(has_single_bit(65536u));
|
||
|
|
EXPECT_TRUE(has_single_bit(uint32_t{1} << 30));
|
||
|
|
EXPECT_TRUE(has_single_bit(uint64_t{1} << 42));
|
||
|
|
|
||
|
|
EXPECT_TRUE(has_single_bit(
|
||
|
|
static_cast<uint8_t>(std::numeric_limits<uint8_t>::max() / 2 + 1)));
|
||
|
|
EXPECT_TRUE(has_single_bit(
|
||
|
|
static_cast<uint16_t>(std::numeric_limits<uint16_t>::max() / 2 + 1)));
|
||
|
|
EXPECT_TRUE(has_single_bit(
|
||
|
|
static_cast<uint32_t>(std::numeric_limits<uint32_t>::max() / 2 + 1)));
|
||
|
|
EXPECT_TRUE(has_single_bit(
|
||
|
|
static_cast<uint64_t>(std::numeric_limits<uint64_t>::max() / 2 + 1)));
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename T, T arg, T = bit_ceil(arg)>
|
||
|
|
bool IsBitCeilConstantExpression(int) {
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
template <typename T, T arg>
|
||
|
|
bool IsBitCeilConstantExpression(char) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(IntegralPowersOfTwo, Ceiling) {
|
||
|
|
#if ABSL_INTERNAL_HAS_CONSTEXPR_CLZ
|
||
|
|
static_assert(bit_ceil(0u) == 1, "");
|
||
|
|
static_assert(bit_ceil(1u) == 1, "");
|
||
|
|
static_assert(bit_ceil(2u) == 2, "");
|
||
|
|
static_assert(bit_ceil(3u) == 4, "");
|
||
|
|
static_assert(bit_ceil(4u) == 4, "");
|
||
|
|
static_assert(bit_ceil(1337u) == 2048, "");
|
||
|
|
static_assert(bit_ceil(65536u) == 65536, "");
|
||
|
|
static_assert(bit_ceil(65536u - 1337u) == 65536, "");
|
||
|
|
static_assert(bit_ceil(uint32_t{0x80000000}) == uint32_t{0x80000000}, "");
|
||
|
|
static_assert(bit_ceil(uint64_t{0x40000000000}) == uint64_t{0x40000000000},
|
||
|
|
"");
|
||
|
|
static_assert(
|
||
|
|
bit_ceil(uint64_t{0x8000000000000000}) == uint64_t{0x8000000000000000},
|
||
|
|
"");
|
||
|
|
|
||
|
|
EXPECT_TRUE((IsBitCeilConstantExpression<uint8_t, uint8_t{0x0}>(0)));
|
||
|
|
EXPECT_TRUE((IsBitCeilConstantExpression<uint8_t, uint8_t{0x80}>(0)));
|
||
|
|
EXPECT_FALSE((IsBitCeilConstantExpression<uint8_t, uint8_t{0x81}>(0)));
|
||
|
|
EXPECT_FALSE((IsBitCeilConstantExpression<uint8_t, uint8_t{0xff}>(0)));
|
||
|
|
|
||
|
|
EXPECT_TRUE((IsBitCeilConstantExpression<uint16_t, uint16_t{0x0}>(0)));
|
||
|
|
EXPECT_TRUE((IsBitCeilConstantExpression<uint16_t, uint16_t{0x8000}>(0)));
|
||
|
|
EXPECT_FALSE((IsBitCeilConstantExpression<uint16_t, uint16_t{0x8001}>(0)));
|
||
|
|
EXPECT_FALSE((IsBitCeilConstantExpression<uint16_t, uint16_t{0xffff}>(0)));
|
||
|
|
|
||
|
|
EXPECT_TRUE((IsBitCeilConstantExpression<uint32_t, uint32_t{0x0}>(0)));
|
||
|
|
EXPECT_TRUE((IsBitCeilConstantExpression<uint32_t, uint32_t{0x80000000}>(0)));
|
||
|
|
EXPECT_FALSE(
|
||
|
|
(IsBitCeilConstantExpression<uint32_t, uint32_t{0x80000001}>(0)));
|
||
|
|
EXPECT_FALSE(
|
||
|
|
(IsBitCeilConstantExpression<uint32_t, uint32_t{0xffffffff}>(0)));
|
||
|
|
|
||
|
|
EXPECT_TRUE((IsBitCeilConstantExpression<uint64_t, uint64_t{0x0}>(0)));
|
||
|
|
EXPECT_TRUE(
|
||
|
|
(IsBitCeilConstantExpression<uint64_t, uint64_t{0x8000000000000000}>(0)));
|
||
|
|
EXPECT_FALSE(
|
||
|
|
(IsBitCeilConstantExpression<uint64_t, uint64_t{0x8000000000000001}>(0)));
|
||
|
|
EXPECT_FALSE(
|
||
|
|
(IsBitCeilConstantExpression<uint64_t, uint64_t{0xffffffffffffffff}>(0)));
|
||
|
|
#endif
|
||
|
|
|
||
|
|
EXPECT_EQ(bit_ceil(0u), 1);
|
||
|
|
EXPECT_EQ(bit_ceil(1u), 1);
|
||
|
|
EXPECT_EQ(bit_ceil(2u), 2);
|
||
|
|
EXPECT_EQ(bit_ceil(3u), 4);
|
||
|
|
EXPECT_EQ(bit_ceil(4u), 4);
|
||
|
|
EXPECT_EQ(bit_ceil(1337u), 2048);
|
||
|
|
EXPECT_EQ(bit_ceil(65536u), 65536);
|
||
|
|
EXPECT_EQ(bit_ceil(65536u - 1337u), 65536);
|
||
|
|
EXPECT_EQ(bit_ceil(uint64_t{0x40000000000}), uint64_t{0x40000000000});
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(IntegralPowersOfTwo, Floor) {
|
||
|
|
#if ABSL_INTERNAL_HAS_CONSTEXPR_CLZ
|
||
|
|
static_assert(bit_floor(0u) == 0, "");
|
||
|
|
static_assert(bit_floor(1u) == 1, "");
|
||
|
|
static_assert(bit_floor(2u) == 2, "");
|
||
|
|
static_assert(bit_floor(3u) == 2, "");
|
||
|
|
static_assert(bit_floor(4u) == 4, "");
|
||
|
|
static_assert(bit_floor(1337u) == 1024, "");
|
||
|
|
static_assert(bit_floor(65536u) == 65536, "");
|
||
|
|
static_assert(bit_floor(65536u - 1337u) == 32768, "");
|
||
|
|
static_assert(bit_floor(uint64_t{0x40000000000}) == uint64_t{0x40000000000},
|
||
|
|
"");
|
||
|
|
#endif
|
||
|
|
|
||
|
|
EXPECT_EQ(bit_floor(0u), 0);
|
||
|
|
EXPECT_EQ(bit_floor(1u), 1);
|
||
|
|
EXPECT_EQ(bit_floor(2u), 2);
|
||
|
|
EXPECT_EQ(bit_floor(3u), 2);
|
||
|
|
EXPECT_EQ(bit_floor(4u), 4);
|
||
|
|
EXPECT_EQ(bit_floor(1337u), 1024);
|
||
|
|
EXPECT_EQ(bit_floor(65536u), 65536);
|
||
|
|
EXPECT_EQ(bit_floor(65536u - 1337u), 32768);
|
||
|
|
EXPECT_EQ(bit_floor(uint64_t{0x40000000000}), uint64_t{0x40000000000});
|
||
|
|
|
||
|
|
for (int i = 0; i < 8; i++) {
|
||
|
|
uint8_t input = uint8_t{1} << i;
|
||
|
|
EXPECT_EQ(bit_floor(input), input);
|
||
|
|
if (i > 0) {
|
||
|
|
EXPECT_EQ(bit_floor(static_cast<uint8_t>(input + 1)), input);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 16; i++) {
|
||
|
|
uint16_t input = uint16_t{1} << i;
|
||
|
|
EXPECT_EQ(bit_floor(input), input);
|
||
|
|
if (i > 0) {
|
||
|
|
EXPECT_EQ(bit_floor(static_cast<uint16_t>(input + 1)), input);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 32; i++) {
|
||
|
|
uint32_t input = uint32_t{1} << i;
|
||
|
|
EXPECT_EQ(bit_floor(input), input);
|
||
|
|
if (i > 0) {
|
||
|
|
EXPECT_EQ(bit_floor(input + 1), input);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 64; i++) {
|
||
|
|
uint64_t input = uint64_t{1} << i;
|
||
|
|
EXPECT_EQ(bit_floor(input), input);
|
||
|
|
if (i > 0) {
|
||
|
|
EXPECT_EQ(bit_floor(input + 1), input);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
TEST(IntegralPowersOfTwo, Width) {
|
||
|
|
#if ABSL_INTERNAL_HAS_CONSTEXPR_CLZ
|
||
|
|
static_assert(bit_width(uint8_t{}) == 0, "");
|
||
|
|
static_assert(bit_width(uint8_t{1}) == 1, "");
|
||
|
|
static_assert(bit_width(uint8_t{3}) == 2, "");
|
||
|
|
static_assert(bit_width(static_cast<uint8_t>(-1)) == 8, "");
|
||
|
|
static_assert(bit_width(uint16_t{}) == 0, "");
|
||
|
|
static_assert(bit_width(uint16_t{1}) == 1, "");
|
||
|
|
static_assert(bit_width(uint16_t{3}) == 2, "");
|
||
|
|
static_assert(bit_width(static_cast<uint16_t>(-1)) == 16, "");
|
||
|
|
static_assert(bit_width(uint32_t{}) == 0, "");
|
||
|
|
static_assert(bit_width(uint32_t{1}) == 1, "");
|
||
|
|
static_assert(bit_width(uint32_t{3}) == 2, "");
|
||
|
|
static_assert(bit_width(~uint32_t{}) == 32, "");
|
||
|
|
static_assert(bit_width(uint64_t{}) == 0, "");
|
||
|
|
static_assert(bit_width(uint64_t{1}) == 1, "");
|
||
|
|
static_assert(bit_width(uint64_t{3}) == 2, "");
|
||
|
|
static_assert(bit_width(~uint64_t{}) == 64, "");
|
||
|
|
#endif
|
||
|
|
|
||
|
|
EXPECT_EQ(bit_width(uint8_t{}), 0);
|
||
|
|
EXPECT_EQ(bit_width(uint8_t{1}), 1);
|
||
|
|
EXPECT_EQ(bit_width(uint8_t{3}), 2);
|
||
|
|
EXPECT_EQ(bit_width(static_cast<uint8_t>(-1)), 8);
|
||
|
|
EXPECT_EQ(bit_width(uint16_t{}), 0);
|
||
|
|
EXPECT_EQ(bit_width(uint16_t{1}), 1);
|
||
|
|
EXPECT_EQ(bit_width(uint16_t{3}), 2);
|
||
|
|
EXPECT_EQ(bit_width(static_cast<uint16_t>(-1)), 16);
|
||
|
|
EXPECT_EQ(bit_width(uint32_t{}), 0);
|
||
|
|
EXPECT_EQ(bit_width(uint32_t{1}), 1);
|
||
|
|
EXPECT_EQ(bit_width(uint32_t{3}), 2);
|
||
|
|
EXPECT_EQ(bit_width(~uint32_t{}), 32);
|
||
|
|
EXPECT_EQ(bit_width(uint64_t{}), 0);
|
||
|
|
EXPECT_EQ(bit_width(uint64_t{1}), 1);
|
||
|
|
EXPECT_EQ(bit_width(uint64_t{3}), 2);
|
||
|
|
EXPECT_EQ(bit_width(~uint64_t{}), 64);
|
||
|
|
|
||
|
|
for (int i = 0; i < 8; i++) {
|
||
|
|
EXPECT_EQ(bit_width(static_cast<uint8_t>(uint8_t{1} << i)), i + 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 16; i++) {
|
||
|
|
EXPECT_EQ(bit_width(static_cast<uint16_t>(uint16_t{1} << i)), i + 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 32; i++) {
|
||
|
|
EXPECT_EQ(bit_width(uint32_t{1} << i), i + 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (int i = 0; i < 64; i++) {
|
||
|
|
EXPECT_EQ(bit_width(uint64_t{1} << i), i + 1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace
|
||
|
|
ABSL_NAMESPACE_END
|
||
|
|
} // namespace absl
|