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-rw-r--r--absl/base/internal/bits.h219
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diff --git a/absl/base/internal/bits.h b/absl/base/internal/bits.h
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--- 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_