Multi-threading techniques for a processor utilizing a replay queue

A processor comprising:

• an execution unit to execute instructions;
• a replay system coupled to the execution unit to replay instructions which have not executed properly, the replay system comprising:
• a checker to determine whether each instruction has executed properly;
• and
• a replay queue coupled to the checker to temporarily store one or more instructions of a plurality of threads for replay, the replay queue partitioned into a plurality of sections, each section provided for storing instructions of a corresponding thread.

A processor comprising:

• a multiplexer having an output;
• a scheduler coupled to a first input of the multiplexer;
• an execution unit coupled to an output of the multiplexer;
• a checker coupled to the output of the multiplexer to determine whether an instruction has executed properly;
• a plurality of thread-specific replay queue sections to temporarily store instructions for each of a plurality of threads, an output of each of the replay queue sections coupled to additional inputs of the multiplexer;
• and
• a controller coupled to the checker to determine when to load an instruction into one of the replay queue sections and to determine when to unload the replay queue sections.

A method of processing instructions comprising:

• dispatching an instruction where the instruction to an execution unit and to a replay system;
• determining whether the instruction executed properly;
• if the instruction did not execute properly, then:
• determining whether the instruction should be routed back for re-execution or whether the instruction should be temporarily stored based on a thread of the instruction.

A method of processing instructions comprising:

• dispatching an instruction where the instruction is received by an execution unit and a replay system;
• determining whether the instruction executed properly;
• if the instruction did not execute properly, then:
• routing the instruction to the execution unit for re-execution if the instruction is a first type of instruction;
• otherwise, loading the instruction into one of a plurality of thread-specific replay queue sections based on a thread of the instruction if the instruction is a second type of instruction.

A method of processing instructions comprising:

• initially allocating execution resources for multiple threads;
• determining that a first thread has stalled;
• temporarily storing one or more instructions of the first thread in a queue;
• and
• continuing to allocate execution resources to other threads which have not stalled