LibJS/JIT: Support the GetById bytecode op

We can now do basic property (get) access in jitted code! :^)

Userland/Libraries/LibJS/Bytecode/Op.h

@@ -559,6 +559,9 @@ public:
     ThrowCompletionOr<void> execute_impl(Bytecode::Interpreter&) const;
     DeprecatedString to_deprecated_string_impl(Bytecode::Executable const&) const;
 
+    IdentifierTableIndex property() const { return m_property; }
+    u32 cache_index() const { return m_cache_index; }
+
 private:
     IdentifierTableIndex m_property;
     u32 m_cache_index { 0 };

Userland/Libraries/LibJS/JIT/Compiler.cpp

@@ -5,6 +5,7 @@
  */
 
 #include <AK/OwnPtr.h>
+#include <LibJS/Bytecode/CommonImplementations.h>
 #include <LibJS/Bytecode/Instruction.h>
 #include <LibJS/Bytecode/Interpreter.h>
 #include <LibJS/JIT/Compiler.h>
@@ -366,6 +367,25 @@ void Compiler::compile_new_string(Bytecode::Op::NewString const& op)
     store_vm_register(Bytecode::Register::accumulator(), RET);
 }
 
+static Value cxx_get_by_id(VM& vm, Value base, Bytecode::IdentifierTableIndex property, u32 cache_index)
+{
+    return TRY_OR_SET_EXCEPTION(Bytecode::get_by_id(vm.bytecode_interpreter(), property, base, base, cache_index));
+}
+
+void Compiler::compile_get_by_id(Bytecode::Op::GetById const& op)
+{
+    load_vm_register(ARG1, Bytecode::Register::accumulator());
+    m_assembler.mov(
+        Assembler::Operand::Register(ARG2),
+        Assembler::Operand::Imm64(op.property().value()));
+    m_assembler.mov(
+        Assembler::Operand::Register(ARG3),
+        Assembler::Operand::Imm64(op.cache_index()));
+    m_assembler.native_call((void*)cxx_get_by_id);
+    store_vm_register(Bytecode::Register::accumulator(), RET);
+    check_exception();
+}
+
 OwnPtr<NativeExecutable> Compiler::compile(Bytecode::Executable& bytecode_executable)
 {
     if (getenv("LIBJS_NO_JIT"))
@@ -430,6 +450,9 @@ OwnPtr<NativeExecutable> Compiler::compile(Bytecode::Executable& bytecode_execut
             case Bytecode::Instruction::Type::NewString:
                 compiler.compile_new_string(static_cast<Bytecode::Op::NewString const&>(op));
                 break;
+            case Bytecode::Instruction::Type::GetById:
+                compiler.compile_get_by_id(static_cast<Bytecode::Op::GetById const&>(op));
+                break;
 
 #define DO_COMPILE_COMMON_BINARY_OP(TitleCaseName, snake_case_name)                              \
     case Bytecode::Instruction::Type::TitleCaseName:                                             \

Userland/Libraries/LibJS/JIT/Compiler.h

@@ -23,6 +23,7 @@ private:
     static constexpr auto ARG0 = Assembler::Reg::RDI;
     static constexpr auto ARG1 = Assembler::Reg::RSI;
     static constexpr auto ARG2 = Assembler::Reg::RDX;
+    static constexpr auto ARG3 = Assembler::Reg::RCX;
     static constexpr auto RET = Assembler::Reg::RAX;
     static constexpr auto STACK_POINTER = Assembler::Reg::RSP;
     static constexpr auto REGISTER_ARRAY_BASE = Assembler::Reg::R8;
@@ -49,6 +50,7 @@ private:
 
     void compile_return(Bytecode::Op::Return const&);
     void compile_new_string(Bytecode::Op::NewString const&);
+    void compile_get_by_id(Bytecode::Op::GetById const&);
 
     void store_vm_register(Bytecode::Register, Assembler::Reg);
     void load_vm_register(Assembler::Reg, Bytecode::Register);