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-//
-// Copyright 2017 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.
-//
-// -----------------------------------------------------------------------------
-// File: optimization.h
-// -----------------------------------------------------------------------------
-//
-// This header file defines portable macros for performance optimization.
-
-#ifndef ABSL_BASE_OPTIMIZATION_H_
-#define ABSL_BASE_OPTIMIZATION_H_
-
-#include "absl/base/config.h"
-
-// ABSL_BLOCK_TAIL_CALL_OPTIMIZATION
-//
-// Instructs the compiler to avoid optimizing tail-call recursion. Use of this
-// macro is useful when you wish to preserve the existing function order within
-// a stack trace for logging, debugging, or profiling purposes.
-//
-// Example:
-//
-//   int f() {
-//     int result = g();
-//     ABSL_BLOCK_TAIL_CALL_OPTIMIZATION();
-//     return result;
-//   }
-#if defined(__pnacl__)
-#define ABSL_BLOCK_TAIL_CALL_OPTIMIZATION() if (volatile int x = 0) { (void)x; }
-#elif defined(__clang__)
-// Clang will not tail call given inline volatile assembly.
-#define ABSL_BLOCK_TAIL_CALL_OPTIMIZATION() __asm__ __volatile__("")
-#elif defined(__GNUC__)
-// GCC will not tail call given inline volatile assembly.
-#define ABSL_BLOCK_TAIL_CALL_OPTIMIZATION() __asm__ __volatile__("")
-#elif defined(_MSC_VER)
-#include <intrin.h>
-// The __nop() intrinsic blocks the optimisation.
-#define ABSL_BLOCK_TAIL_CALL_OPTIMIZATION() __nop()
-#else
-#define ABSL_BLOCK_TAIL_CALL_OPTIMIZATION() if (volatile int x = 0) { (void)x; }
-#endif
-
-// ABSL_CACHELINE_SIZE
-//
-// Explicitly defines the size of the L1 cache for purposes of alignment.
-// Setting the cacheline size allows you to specify that certain objects be
-// aligned on a cacheline boundary with `ABSL_CACHELINE_ALIGNED` declarations.
-// (See below.)
-//
-// NOTE: this macro should be replaced with the following C++17 features, when
-// those are generally available:
-//
-//   * `std::hardware_constructive_interference_size`
-//   * `std::hardware_destructive_interference_size`
-//
-// See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0154r1.html
-// for more information.
-#if defined(__GNUC__)
-// Cache line alignment
-#if defined(__i386__) || defined(__x86_64__)
-#define ABSL_CACHELINE_SIZE 64
-#elif defined(__powerpc64__)
-#define ABSL_CACHELINE_SIZE 128
-#elif defined(__aarch64__)
-// We would need to read special register ctr_el0 to find out L1 dcache size.
-// This value is a good estimate based on a real aarch64 machine.
-#define ABSL_CACHELINE_SIZE 64
-#elif defined(__arm__)
-// Cache line sizes for ARM: These values are not strictly correct since
-// cache line sizes depend on implementations, not architectures.  There
-// are even implementations with cache line sizes configurable at boot
-// time.
-#if defined(__ARM_ARCH_5T__)
-#define ABSL_CACHELINE_SIZE 32
-#elif defined(__ARM_ARCH_7A__)
-#define ABSL_CACHELINE_SIZE 64
-#endif
-#endif
-
-#ifndef ABSL_CACHELINE_SIZE
-// A reasonable default guess.  Note that overestimates tend to waste more
-// space, while underestimates tend to waste more time.
-#define ABSL_CACHELINE_SIZE 64
-#endif
-
-// ABSL_CACHELINE_ALIGNED
-//
-// Indicates that the declared object be cache aligned using
-// `ABSL_CACHELINE_SIZE` (see above). Cacheline aligning objects allows you to
-// load a set of related objects in the L1 cache for performance improvements.
-// Cacheline aligning objects properly allows constructive memory sharing and
-// prevents destructive (or "false") memory sharing.
-//
-// NOTE: this macro should be replaced with usage of `alignas()` using
-// `std::hardware_constructive_interference_size` and/or
-// `std::hardware_destructive_interference_size` when available within C++17.
-//
-// See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0154r1.html
-// for more information.
-//
-// On some compilers, `ABSL_CACHELINE_ALIGNED` expands to an `__attribute__`
-// or `__declspec` attribute. For compilers where this is not known to work,
-// the macro expands to nothing.
-//
-// No further guarantees are made here. The result of applying the macro
-// to variables and types is always implementation-defined.
-//
-// WARNING: It is easy to use this attribute incorrectly, even to the point
-// of causing bugs that are difficult to diagnose, crash, etc. It does not
-// of itself guarantee that objects are aligned to a cache line.
-//
-// NOTE: Some compilers are picky about the locations of annotations such as
-// this attribute, so prefer to put it at the beginning of your declaration.
-// For example,
-//
-//   ABSL_CACHELINE_ALIGNED static Foo* foo = ...
-//
-//   class ABSL_CACHELINE_ALIGNED Bar { ...
-//
-// Recommendations:
-//
-// 1) Consult compiler documentation; this comment is not kept in sync as
-//    toolchains evolve.
-// 2) Verify your use has the intended effect. This often requires inspecting
-//    the generated machine code.
-// 3) Prefer applying this attribute to individual variables. Avoid
-//    applying it to types. This tends to localize the effect.
-#define ABSL_CACHELINE_ALIGNED __attribute__((aligned(ABSL_CACHELINE_SIZE)))
-#elif defined(_MSC_VER)
-#define ABSL_CACHELINE_SIZE 64
-#define ABSL_CACHELINE_ALIGNED __declspec(align(ABSL_CACHELINE_SIZE))
-#else
-#define ABSL_CACHELINE_SIZE 64
-#define ABSL_CACHELINE_ALIGNED
-#endif
-
-// ABSL_PREDICT_TRUE, ABSL_PREDICT_FALSE
-//
-// Enables the compiler to prioritize compilation using static analysis for
-// likely paths within a boolean branch.
-//
-// Example:
-//
-//   if (ABSL_PREDICT_TRUE(expression)) {
-//     return result;                        // Faster if more likely
-//   } else {
-//     return 0;
-//   }
-//
-// Compilers can use the information that a certain branch is not likely to be
-// taken (for instance, a CHECK failure) to optimize for the common case in
-// the absence of better information (ie. compiling gcc with `-fprofile-arcs`).
-//
-// Recommendation: Modern CPUs dynamically predict branch execution paths,
-// typically with accuracy greater than 97%. As a result, annotating every
-// branch in a codebase is likely counterproductive; however, annotating
-// specific branches that are both hot and consistently mispredicted is likely
-// to yield performance improvements.
-#if ABSL_HAVE_BUILTIN(__builtin_expect) || \
-    (defined(__GNUC__) && !defined(__clang__))
-#define ABSL_PREDICT_FALSE(x) (__builtin_expect(false || (x), false))
-#define ABSL_PREDICT_TRUE(x) (__builtin_expect(false || (x), true))
-#else
-#define ABSL_PREDICT_FALSE(x) (x)
-#define ABSL_PREDICT_TRUE(x) (x)
-#endif
-
-// ABSL_INTERNAL_ASSUME(cond)
-// Informs the compiler that a condition is always true and that it can assume
-// it to be true for optimization purposes. The call has undefined behavior if
-// the condition is false.
-// In !NDEBUG mode, the condition is checked with an assert().
-// NOTE: The expression must not have side effects, as it will only be evaluated
-// in some compilation modes and not others.
-//
-// Example:
-//
-//   int x = ...;
-//   ABSL_INTERNAL_ASSUME(x >= 0);
-//   // The compiler can optimize the division to a simple right shift using the
-//   // assumption specified above.
-//   int y = x / 16;
-//
-#if !defined(NDEBUG)
-#define ABSL_INTERNAL_ASSUME(cond) assert(cond)
-#elif ABSL_HAVE_BUILTIN(__builtin_assume)
-#define ABSL_INTERNAL_ASSUME(cond) __builtin_assume(cond)
-#elif defined(__GNUC__) || ABSL_HAVE_BUILTIN(__builtin_unreachable)
-#define ABSL_INTERNAL_ASSUME(cond)        \
-  do {                                    \
-    if (!(cond)) __builtin_unreachable(); \
-  } while (0)
-#elif defined(_MSC_VER)
-#define ABSL_INTERNAL_ASSUME(cond) __assume(cond)
-#else
-#define ABSL_INTERNAL_ASSUME(cond)      \
-  do {                                  \
-    static_cast<void>(false && (cond)); \
-  } while (0)
-#endif
-
-// ABSL_INTERNAL_UNIQUE_SMALL_NAME(cond)
-// This macro forces small unique name on a static file level symbols like
-// static local variables or static functions. This is intended to be used in
-// macro definitions to optimize the cost of generated code. Do NOT use it on
-// symbols exported from translation unit since it may casue a link time
-// conflict.
-//
-// Example:
-//
-// #define MY_MACRO(txt)
-// namespace {
-//  char VeryVeryLongVarName[] ABSL_INTERNAL_UNIQUE_SMALL_NAME() = txt;
-//  const char* VeryVeryLongFuncName() ABSL_INTERNAL_UNIQUE_SMALL_NAME();
-//  const char* VeryVeryLongFuncName() { return txt; }
-// }
-//
-
-#if defined(__GNUC__)
-#define ABSL_INTERNAL_UNIQUE_SMALL_NAME2(x) #x
-#define ABSL_INTERNAL_UNIQUE_SMALL_NAME1(x) ABSL_INTERNAL_UNIQUE_SMALL_NAME2(x)
-#define ABSL_INTERNAL_UNIQUE_SMALL_NAME() \
-  asm(ABSL_INTERNAL_UNIQUE_SMALL_NAME1(.absl.__COUNTER__))
-#else
-#define ABSL_INTERNAL_UNIQUE_SMALL_NAME()
-#endif
-
-#endif  // ABSL_BASE_OPTIMIZATION_H_