Combining instructions when the target of a first instruction is the source of the second

摘要

Two instructions are identified. The target operand of the first instruction is a source operand of the second instruction. If this operand is not used again, then the two instructions are combined into a single instruction. The instructions may apply an immediate operand to a register operand. One instruction may apply an immediate operand to the most significant bits and the other instruction may apply another immediate operand to the least significant bits. If the immediate operand applied to the least significant bits is a negative sign extended value, then a one is subtracted from the immediate operand applied to the most significant bits. The first instruction may be retained and executed out of order.