Use of Register Renaming System for Forwarding Intermediate Results Between Constituent Instructions of an Expanded Instruction

A processor, comprising:

• one or more instruction execution pipelines operative to execute an expanded instruction by generating a first constituent instruction generating intermediate results and a second constituent instruction receiving the intermediate results;
• a pool of physical registers, each having a physical register number;
• a constituent instruction rename table operative to map instruction identifiers to physical register numbers;
• and
• control logic operative to create an entry in the constituent instruction rename table for the first constituent instruction and further operative to perform a constituent instruction rename table lookup for the second constituent instruction;
• whereby intermediate results are passed from the first to the second constituent instructions via physical registers identified by the physical register numbers.