6ae9346cd3
This introduces two new instructions: Jump and JumpIfFalse. Jumps are made to a Bytecode::Label, which is a simple object that represents a location in the bytecode stream. Note that you may not always know the target of a jump when adding the jump instruction itself, but we can just update the instruction later on during codegen once we know where the jump target is. The Bytecode::Interpreter now implements jumping via a jump slot that gets checked after each instruction to see if a jump is pending. If not, we just increment the PC as usual.
52 lines
1.3 KiB
C++
52 lines
1.3 KiB
C++
/*
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* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <LibJS/Bytecode/Block.h>
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#include <LibJS/Bytecode/Instruction.h>
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#include <LibJS/Bytecode/Interpreter.h>
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#include <LibJS/Runtime/GlobalObject.h>
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namespace JS::Bytecode {
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Interpreter::Interpreter(GlobalObject& global_object)
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: m_vm(global_object.vm())
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, m_global_object(global_object)
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{
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}
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Interpreter::~Interpreter()
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{
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}
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void Interpreter::run(Bytecode::Block const& block)
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{
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dbgln("Bytecode::Interpreter will run block {:p}", &block);
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m_registers.resize(block.register_count());
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size_t pc = 0;
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while (pc < block.instructions().size()) {
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auto& instruction = block.instructions()[pc];
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instruction.execute(*this);
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if (m_pending_jump.has_value()) {
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pc = m_pending_jump.release_value();
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continue;
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}
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++pc;
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}
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dbgln("Bytecode::Interpreter did run block {:p}", &block);
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for (size_t i = 0; i < m_registers.size(); ++i) {
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String value_string;
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if (m_registers[i].is_empty())
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value_string = "(empty)";
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else
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value_string = m_registers[i].to_string_without_side_effects();
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dbgln("[{:3}] {}", i, value_string);
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}
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}
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}
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