| // Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #ifndef RUNTIME_VM_DISPATCH_TABLE_H_ |
| #define RUNTIME_VM_DISPATCH_TABLE_H_ |
| |
| #include <memory> |
| |
| #include "vm/globals.h" |
| |
| namespace dart { |
| |
| class DispatchTable { |
| public: |
| explicit DispatchTable(intptr_t length) |
| : length_(length), array_(new uword[length]()) {} |
| |
| intptr_t length() const { return length_; } |
| |
| // The element of the dispatch table array to which the dispatch table |
| // register points. |
| #if defined(TARGET_ARCH_X64) |
| // Max negative byte offset / 8 |
| static constexpr intptr_t kOriginElement = 16; |
| #elif defined(TARGET_ARCH_ARM) |
| // Max negative load offset / 4 |
| static constexpr intptr_t kOriginElement = 1023; |
| #elif defined(TARGET_ARCH_ARM64) |
| // Max consecutive sub immediate value |
| static constexpr intptr_t kOriginElement = 4096; |
| #elif defined(TARGET_ARCH_RISCV32) |
| // Max consecutive sub immediate value |
| static constexpr intptr_t kOriginElement = 2048 / 4; |
| #elif defined(TARGET_ARCH_RISCV64) |
| // Max consecutive sub immediate value |
| static constexpr intptr_t kOriginElement = 2048 / 8; |
| #else |
| static constexpr intptr_t kOriginElement = 0; |
| #endif |
| |
| #if defined(TARGET_ARCH_X64) |
| // Origin + Max positive byte offset / 8 |
| static constexpr intptr_t kLargestSmallOffset = 31; |
| #elif defined(TARGET_ARCH_ARM) |
| // Origin + Max positive load offset / 4 |
| static constexpr intptr_t kLargestSmallOffset = 2046; |
| #elif defined(TARGET_ARCH_ARM64) |
| // Origin + Max consecutive add immediate value |
| static constexpr intptr_t kLargestSmallOffset = 8192; |
| #elif defined(TARGET_ARCH_RISCV32) |
| // Origin + Max consecutive add immediate value |
| static constexpr intptr_t kLargestSmallOffset = 4096 / 4; |
| #elif defined(TARGET_ARCH_RISCV64) |
| // Origin + Max consecutive add immediate value |
| static constexpr intptr_t kLargestSmallOffset = 4096 / 8; |
| #else |
| // No AOT on IA32 |
| static constexpr intptr_t kLargestSmallOffset = 0; |
| #endif |
| |
| // Dispatch table array pointer to put into the dispatch table register. |
| const uword* ArrayOrigin() const; |
| |
| private: |
| uword* array() { return array_.get(); } |
| |
| intptr_t length_; |
| std::unique_ptr<uword[]> array_; |
| |
| friend class Deserializer; // For non-const array(). |
| DISALLOW_COPY_AND_ASSIGN(DispatchTable); |
| }; |
| |
| } // namespace dart |
| |
| #endif // RUNTIME_VM_DISPATCH_TABLE_H_ |