| 1 | //===-- Portable optimization macros ----------------------------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // This header file defines portable macros for performance optimization. |
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| 9 | |
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| 10 | #ifndef LLVM_LIBC_SRC___SUPPORT_MACROS_OPTIMIZATION_H |
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| 11 | #define LLVM_LIBC_SRC___SUPPORT_MACROS_OPTIMIZATION_H |
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| 12 | |
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| 13 | #include "src/__support/macros/attributes.h" // LIBC_INLINE |
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| 14 | #include "src/__support/macros/properties/compiler.h" // LIBC_COMPILER_IS_CLANG |
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| 15 | |
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| 16 | // We use a template to implement likely/unlikely to make sure that we don't |
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| 17 | // accidentally pass an integer. |
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| 18 | namespace LIBC_NAMESPACE::details { |
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| 19 | template <typename T> |
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| 20 | LIBC_INLINE constexpr bool expects_bool_condition(T value, T expected) { |
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| 21 | return __builtin_expect(value, expected); |
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| 22 | } |
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| 23 | } // namespace LIBC_NAMESPACE::details |
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| 24 | #define LIBC_LIKELY(x) LIBC_NAMESPACE::details::expects_bool_condition(x, true) |
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| 25 | #define LIBC_UNLIKELY(x) \ |
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| 26 | LIBC_NAMESPACE::details::expects_bool_condition(x, false) |
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| 27 | |
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| 28 | #if defined(LIBC_COMPILER_IS_CLANG) |
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| 29 | #define LIBC_LOOP_NOUNROLL _Pragma("nounroll") |
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| 30 | #elif defined(LIBC_COMPILER_IS_GCC) |
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| 31 | #define LIBC_LOOP_NOUNROLL _Pragma("GCC unroll 0") |
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| 32 | #else |
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| 33 | #error "Unhandled compiler" |
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| 34 | #endif |
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| 35 | |
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| 36 | #endif // LLVM_LIBC_SRC___SUPPORT_MACROS_OPTIMIZATION_H |
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| 37 | |
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