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LibJS/JIT: Bail in UnsignedRightShift fast path if result is negative
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@ -849,27 +849,47 @@ void Compiler::compile_unsigned_right_shift(Bytecode::Op::UnsignedRightShift con
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load_accumulator(ARG2);
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Assembler::Label end {};
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Assembler::Label slow_case {};
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branch_if_both_int32(ARG1, ARG2, [&] {
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// GPR0 = ARG1
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m_assembler.mov(
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Assembler::Operand::Register(GPR0),
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Assembler::Operand::Register(ARG1));
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// RCX = ARG2
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m_assembler.mov(
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Assembler::Operand::Register(Assembler::Reg::RCX),
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Assembler::Operand::Register(ARG2));
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// ARG1 >>>= CL (32-bit)
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m_assembler.shift_right32(Assembler::Operand::Register(ARG1), {});
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// GPR0 >>>= CL (32-bit)
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m_assembler.shift_right32(Assembler::Operand::Register(GPR0), {});
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// accumulator = ARG1 | SHIFTED_INT32_TAG;
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m_assembler.mov(
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// GPR1 = sign_extended(GPR0)
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m_assembler.mov32(
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Assembler::Operand::Register(GPR1),
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Assembler::Operand::Register(GPR0),
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Assembler::Extension::SignExtend);
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// if (GPR1 < 0) goto slow_case;
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m_assembler.jump_if(
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Assembler::Operand::Register(GPR1),
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Assembler::Condition::SignedLessThan,
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Assembler::Operand::Imm(0),
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slow_case);
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// accumulator = GPR0 | SHIFTED_INT32_TAG;
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m_assembler.mov(
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Assembler::Operand::Register(GPR1),
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Assembler::Operand::Imm(SHIFTED_INT32_TAG));
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m_assembler.bitwise_or(
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Assembler::Operand::Register(ARG1),
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Assembler::Operand::Register(GPR0));
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store_accumulator(ARG1);
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Assembler::Operand::Register(GPR0),
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Assembler::Operand::Register(GPR1));
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store_accumulator(GPR0);
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m_assembler.jump(end);
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});
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slow_case.link(m_assembler);
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native_call((void*)cxx_unsigned_right_shift);
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store_accumulator(RET);
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check_exception();
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