Reducing issue-to-issue latency by reversing processing order in half-pumped simd execution units

A method comprising:

• receiving a plurality of instructions, wherein
• said plurality of instructions comprises a first vector instruction and a second vector instruction, and
• execution of said second vector instruction depends on an execution result of said first vector instruction,
• executing said first vector instruction utilizing a processor functional unit, wherein said processor functional unit comprises a pipelined execution unit;
• determining a forwarding order of a first portion of said execution result and a second portion of said execution result in dependence on a parity of a clock signal applied to said processor functional unit upon receipt of said first vector instruction;
• and
• forwarding said first portion of said execution result and said second portion of said execution result from an output coupled to said pipelined execution unit to an input coupled to said pipelined execution unit according to said forwarding order.

A data handling system comprising:

• a memory unit;
• a bus coupled to said memory unit;
• and
• processor functional unit coupled to said bus, said processor functional unit comprising:
• a frontend unit coupled to a register file, said register file comprising a plurality of registers to store one or more operands associated with a first vector instruction and a second vector instruction, wherein execution of said second vector instruction depends on an execution result of said first vector instruction;
• an execution core unit coupled to said frontend unit, said execution core unit comprising a pipelined execution unit to execute instructions including said first vector instruction and said second vector instruction;
• a backend unit coupled to said execution core unit, said backend unit comprising a result register to store said execution result;
• an execution order control signal unit to generate a forwarding order control signal in dependence on a parity of a clock signal applied to said processor functional unit;
• a first interconnect coupled between an output of said execution core unit and an input of said execution core unit to selectively forward at least one of a first portion of said execution result and a second portion of said execution result to said input of said execution core unit based on said forwarding order control signal;
• and
• a second interconnect coupled between an output of said backend unit and an input of said frontend unit to selectively forward at least one of said first portion of said execution result and said second portion of said execution result to said input of said frontend unit based on said forwarding order control signal.