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authorGravatar Abseil Team <absl-team@google.com>2020-12-16 11:07:40 -0800
committerGravatar Mark Barolak <mbar@google.com>2020-12-16 15:10:12 -0500
commit1bae23e32ba1f1af7c7d1488a69a351ec96dc98d (patch)
tree273585b193d627065da87b748ccd7f03b38889a7 /absl/base
parent6df644c56f31b100bf731e27c3825069745651e3 (diff)
Export of internal Abseil changes
-- dab5caab05d89d03066ef92584660688595a3aaf by Mark Barolak <mbar@google.com>: Add absl::Status and absl::StatusOr to absl/README.md Import of https://github.com/abseil/abseil-cpp/pull/863 PiperOrigin-RevId: 347857368 -- 1ca3c7a96417cd6e6d62f4dc36fd5ddaa61cfa20 by Chris Kennelly <ckennelly@google.com>: Leverage integer power-of-2 functions and bit counting library in Abseil. PiperOrigin-RevId: 347816486 -- e5cbe05879fd65dce7875e2e0105331a1615d89b by Chris Kennelly <ckennelly@google.com>: Mitigate narrowing warning on MSVC. If sizeof(x) <= sizeof(uint32_t), no truncation occurs when casting to uint32_t, but the compiler cannot always determine this. PiperOrigin-RevId: 347696526 -- 079dff64cb175d282d9e22dfb4a522199ffdae2e by Benjamin Barenblat <bbaren@google.com>: Avoid libgcc -NaN narrowing bug When testing -NaN parsing, avoid narrowing -NaN from double to float. This avoids a bug in libgcc (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98251). PiperOrigin-RevId: 347654751 -- 2e78a7634865aeef6765e1f447e96cf8d9985059 by Chris Kennelly <ckennelly@google.com>: Mark popcount helpers as inline. These are conditionally constexpr, so we need to add inline to cover the non-constexpr builds to avoid ODR violations. PiperOrigin-RevId: 347620138 -- 437fbb363aea1654179f102dcdd607ec33c1af1e by Chris Kennelly <ckennelly@google.com>: Use explicit narrowing cast. This is never invoked in practice, but compilers with -Wimplicit-int-conversion may trigger when sizeof(T) > sizeof(uint16_t) prior to determining this never runs. PiperOrigin-RevId: 347609857 GitOrigin-RevId: dab5caab05d89d03066ef92584660688595a3aaf Change-Id: I6296ddffe7ec646f8ce121138f21e1e85a2cff4b
Diffstat (limited to 'absl/base')
-rw-r--r--absl/base/BUILD.bazel25
-rw-r--r--absl/base/CMakeLists.txt24
-rw-r--r--absl/base/internal/bits.h219
-rw-r--r--absl/base/internal/bits_test.cc97
4 files changed, 0 insertions, 365 deletions
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel
index 9d96abeb..244aa8cc 100644
--- a/absl/base/BUILD.bazel
+++ b/absl/base/BUILD.bazel
@@ -587,31 +587,6 @@ cc_test(
)
cc_library(
- name = "bits",
- hdrs = ["internal/bits.h"],
- linkopts = ABSL_DEFAULT_LINKOPTS,
- visibility = [
- "//absl:__subpackages__",
- ],
- deps = [
- ":config",
- ":core_headers",
- ],
-)
-
-cc_test(
- name = "bits_test",
- size = "small",
- srcs = ["internal/bits_test.cc"],
- copts = ABSL_TEST_COPTS,
- linkopts = ABSL_DEFAULT_LINKOPTS,
- deps = [
- ":bits",
- "@com_google_googletest//:gtest_main",
- ],
-)
-
-cc_library(
name = "exponential_biased",
srcs = ["internal/exponential_biased.cc"],
hdrs = ["internal/exponential_biased.h"],
diff --git a/absl/base/CMakeLists.txt b/absl/base/CMakeLists.txt
index 515d7b4e..3d930b85 100644
--- a/absl/base/CMakeLists.txt
+++ b/absl/base/CMakeLists.txt
@@ -520,30 +520,6 @@ absl_cc_test(
absl_cc_library(
NAME
- internal_bits
- HDRS
- "internal/bits.h"
- COPTS
- ${ABSL_DEFAULT_COPTS}
- DEPS
- absl::config
- absl::core_headers
-)
-
-absl_cc_test(
- NAME
- internal_bits_test
- SRCS
- "internal/bits_test.cc"
- COPTS
- ${ABSL_TEST_COPTS}
- DEPS
- absl::internal_bits
- gtest_main
-)
-
-absl_cc_library(
- NAME
exponential_biased
SRCS
"internal/exponential_biased.cc"
diff --git a/absl/base/internal/bits.h b/absl/base/internal/bits.h
deleted file mode 100644
index 81648e2c..00000000
--- a/absl/base/internal/bits.h
+++ /dev/null
@@ -1,219 +0,0 @@
-// Copyright 2018 The Abseil Authors.
-//
-// 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
-//
-// https://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.
-
-#ifndef ABSL_BASE_INTERNAL_BITS_H_
-#define ABSL_BASE_INTERNAL_BITS_H_
-
-// This file contains bitwise ops which are implementation details of various
-// absl libraries.
-
-#include <cstdint>
-
-#include "absl/base/config.h"
-
-// Clang on Windows has __builtin_clzll; otherwise we need to use the
-// windows intrinsic functions.
-#if defined(_MSC_VER) && !defined(__clang__)
-#include <intrin.h>
-#if defined(_M_X64)
-#pragma intrinsic(_BitScanReverse64)
-#pragma intrinsic(_BitScanForward64)
-#endif
-#pragma intrinsic(_BitScanReverse)
-#pragma intrinsic(_BitScanForward)
-#endif
-
-#include "absl/base/attributes.h"
-
-#if defined(_MSC_VER) && !defined(__clang__)
-// We can achieve something similar to attribute((always_inline)) with MSVC by
-// using the __forceinline keyword, however this is not perfect. MSVC is
-// much less aggressive about inlining, and even with the __forceinline keyword.
-#define ABSL_BASE_INTERNAL_FORCEINLINE __forceinline
-#else
-// Use default attribute inline.
-#define ABSL_BASE_INTERNAL_FORCEINLINE inline ABSL_ATTRIBUTE_ALWAYS_INLINE
-#endif
-
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace base_internal {
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros64Slow(uint64_t n) {
- int zeroes = 60;
- if (n >> 32) {
- zeroes -= 32;
- n >>= 32;
- }
- if (n >> 16) {
- zeroes -= 16;
- n >>= 16;
- }
- if (n >> 8) {
- zeroes -= 8;
- n >>= 8;
- }
- if (n >> 4) {
- zeroes -= 4;
- n >>= 4;
- }
- return "\4\3\2\2\1\1\1\1\0\0\0\0\0\0\0"[n] + zeroes;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros64(uint64_t n) {
-#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_X64)
- // MSVC does not have __buitin_clzll. Use _BitScanReverse64.
- unsigned long result = 0; // NOLINT(runtime/int)
- if (_BitScanReverse64(&result, n)) {
- return 63 - result;
- }
- return 64;
-#elif defined(_MSC_VER) && !defined(__clang__)
- // MSVC does not have __buitin_clzll. Compose two calls to _BitScanReverse
- unsigned long result = 0; // NOLINT(runtime/int)
- if ((n >> 32) &&
- _BitScanReverse(&result, static_cast<unsigned long>(n >> 32))) {
- return 31 - result;
- }
- if (_BitScanReverse(&result, static_cast<unsigned long>(n))) {
- return 63 - result;
- }
- return 64;
-#elif defined(__GNUC__) || defined(__clang__)
- // Use __builtin_clzll, which uses the following instructions:
- // x86: bsr
- // ARM64: clz
- // PPC: cntlzd
- static_assert(sizeof(unsigned long long) == sizeof(n), // NOLINT(runtime/int)
- "__builtin_clzll does not take 64-bit arg");
-
- // Handle 0 as a special case because __builtin_clzll(0) is undefined.
- if (n == 0) {
- return 64;
- }
- return __builtin_clzll(n);
-#else
- return CountLeadingZeros64Slow(n);
-#endif
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros32Slow(uint64_t n) {
- int zeroes = 28;
- if (n >> 16) {
- zeroes -= 16;
- n >>= 16;
- }
- if (n >> 8) {
- zeroes -= 8;
- n >>= 8;
- }
- if (n >> 4) {
- zeroes -= 4;
- n >>= 4;
- }
- return "\4\3\2\2\1\1\1\1\0\0\0\0\0\0\0"[n] + zeroes;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountLeadingZeros32(uint32_t n) {
-#if defined(_MSC_VER) && !defined(__clang__)
- unsigned long result = 0; // NOLINT(runtime/int)
- if (_BitScanReverse(&result, n)) {
- return 31 - result;
- }
- return 32;
-#elif defined(__GNUC__) || defined(__clang__)
- // Use __builtin_clz, which uses the following instructions:
- // x86: bsr
- // ARM64: clz
- // PPC: cntlzd
- static_assert(sizeof(int) == sizeof(n),
- "__builtin_clz does not take 32-bit arg");
-
- // Handle 0 as a special case because __builtin_clz(0) is undefined.
- if (n == 0) {
- return 32;
- }
- return __builtin_clz(n);
-#else
- return CountLeadingZeros32Slow(n);
-#endif
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero64Slow(uint64_t n) {
- int c = 63;
- n &= ~n + 1;
- if (n & 0x00000000FFFFFFFF) c -= 32;
- if (n & 0x0000FFFF0000FFFF) c -= 16;
- if (n & 0x00FF00FF00FF00FF) c -= 8;
- if (n & 0x0F0F0F0F0F0F0F0F) c -= 4;
- if (n & 0x3333333333333333) c -= 2;
- if (n & 0x5555555555555555) c -= 1;
- return c;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero64(uint64_t n) {
-#if defined(_MSC_VER) && !defined(__clang__) && defined(_M_X64)
- unsigned long result = 0; // NOLINT(runtime/int)
- _BitScanForward64(&result, n);
- return result;
-#elif defined(_MSC_VER) && !defined(__clang__)
- unsigned long result = 0; // NOLINT(runtime/int)
- if (static_cast<uint32_t>(n) == 0) {
- _BitScanForward(&result, static_cast<unsigned long>(n >> 32));
- return result + 32;
- }
- _BitScanForward(&result, static_cast<unsigned long>(n));
- return result;
-#elif defined(__GNUC__) || defined(__clang__)
- static_assert(sizeof(unsigned long long) == sizeof(n), // NOLINT(runtime/int)
- "__builtin_ctzll does not take 64-bit arg");
- return __builtin_ctzll(n);
-#else
- return CountTrailingZerosNonZero64Slow(n);
-#endif
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero32Slow(uint32_t n) {
- int c = 31;
- n &= ~n + 1;
- if (n & 0x0000FFFF) c -= 16;
- if (n & 0x00FF00FF) c -= 8;
- if (n & 0x0F0F0F0F) c -= 4;
- if (n & 0x33333333) c -= 2;
- if (n & 0x55555555) c -= 1;
- return c;
-}
-
-ABSL_BASE_INTERNAL_FORCEINLINE int CountTrailingZerosNonZero32(uint32_t n) {
-#if defined(_MSC_VER) && !defined(__clang__)
- unsigned long result = 0; // NOLINT(runtime/int)
- _BitScanForward(&result, n);
- return result;
-#elif defined(__GNUC__) || defined(__clang__)
- static_assert(sizeof(int) == sizeof(n),
- "__builtin_ctz does not take 32-bit arg");
- return __builtin_ctz(n);
-#else
- return CountTrailingZerosNonZero32Slow(n);
-#endif
-}
-
-#undef ABSL_BASE_INTERNAL_FORCEINLINE
-
-} // namespace base_internal
-ABSL_NAMESPACE_END
-} // namespace absl
-
-#endif // ABSL_BASE_INTERNAL_BITS_H_
diff --git a/absl/base/internal/bits_test.cc b/absl/base/internal/bits_test.cc
deleted file mode 100644
index 7855fa62..00000000
--- a/absl/base/internal/bits_test.cc
+++ /dev/null
@@ -1,97 +0,0 @@
-// Copyright 2018 The Abseil Authors.
-//
-// 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
-//
-// https://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 "absl/base/internal/bits.h"
-
-#include "gtest/gtest.h"
-
-namespace {
-
-int CLZ64(uint64_t n) {
- int fast = absl::base_internal::CountLeadingZeros64(n);
- int slow = absl::base_internal::CountLeadingZeros64Slow(n);
- EXPECT_EQ(fast, slow) << n;
- return fast;
-}
-
-TEST(BitsTest, CountLeadingZeros64) {
- EXPECT_EQ(64, CLZ64(uint64_t{}));
- EXPECT_EQ(0, CLZ64(~uint64_t{}));
-
- for (int index = 0; index < 64; index++) {
- uint64_t x = static_cast<uint64_t>(1) << index;
- const auto cnt = 63 - index;
- ASSERT_EQ(cnt, CLZ64(x)) << index;
- ASSERT_EQ(cnt, CLZ64(x + x - 1)) << index;
- }
-}
-
-int CLZ32(uint32_t n) {
- int fast = absl::base_internal::CountLeadingZeros32(n);
- int slow = absl::base_internal::CountLeadingZeros32Slow(n);
- EXPECT_EQ(fast, slow) << n;
- return fast;
-}
-
-TEST(BitsTest, CountLeadingZeros32) {
- EXPECT_EQ(32, CLZ32(uint32_t{}));
- EXPECT_EQ(0, CLZ32(~uint32_t{}));
-
- for (int index = 0; index < 32; index++) {
- uint32_t x = static_cast<uint32_t>(1) << index;
- const auto cnt = 31 - index;
- ASSERT_EQ(cnt, CLZ32(x)) << index;
- ASSERT_EQ(cnt, CLZ32(x + x - 1)) << index;
- ASSERT_EQ(CLZ64(x), CLZ32(x) + 32);
- }
-}
-
-int CTZ64(uint64_t n) {
- int fast = absl::base_internal::CountTrailingZerosNonZero64(n);
- int slow = absl::base_internal::CountTrailingZerosNonZero64Slow(n);
- EXPECT_EQ(fast, slow) << n;
- return fast;
-}
-
-TEST(BitsTest, CountTrailingZerosNonZero64) {
- EXPECT_EQ(0, CTZ64(~uint64_t{}));
-
- for (int index = 0; index < 64; index++) {
- uint64_t x = static_cast<uint64_t>(1) << index;
- const auto cnt = index;
- ASSERT_EQ(cnt, CTZ64(x)) << index;
- ASSERT_EQ(cnt, CTZ64(~(x - 1))) << index;
- }
-}
-
-int CTZ32(uint32_t n) {
- int fast = absl::base_internal::CountTrailingZerosNonZero32(n);
- int slow = absl::base_internal::CountTrailingZerosNonZero32Slow(n);
- EXPECT_EQ(fast, slow) << n;
- return fast;
-}
-
-TEST(BitsTest, CountTrailingZerosNonZero32) {
- EXPECT_EQ(0, CTZ32(~uint32_t{}));
-
- for (int index = 0; index < 32; index++) {
- uint32_t x = static_cast<uint32_t>(1) << index;
- const auto cnt = index;
- ASSERT_EQ(cnt, CTZ32(x)) << index;
- ASSERT_EQ(cnt, CTZ32(~(x - 1))) << index;
- }
-}
-
-
-} // namespace