Data processing systems

A method of operating a data processor in which execution threads may execute program instructions to perform data processing operations and in which execution threads may be grouped together into thread groups in which the plural threads of a thread group can each execute a set of instructions in lockstep, one instruction at a time;

• the data processor comprising:
• execution processing circuitry operable to execute instructions to perform processing operations for execution threads executing a program to perform data processing operations and comprising a set of at least one functional unit operable to perform data processing operations for an instruction being executed by an execution thread;
• wherein:
• the execution processing circuitry is operable as a plurality of execution lanes, each lane being operable to perform processing operations for a respective execution thread of a thread group;
• the method comprising:
• maintaining a pool of thread groups available to be issued to the execution lanes, and storing for each available thread group:
• an indication of a set of at least one next instruction to be executed by the thread group, and an indication of the active threads of the thread group;
• selecting a set of at least one thread group to issue to the execution lanes for execution from the pool of available thread groups based on the indications of the active threads for the thread groups in the thread group pool;
• and
• issuing the selected set of at least one thread group from the pool of available thread groups to the execution lanes for execution.

A computer readable storage medium storing computer software code which when executing on a processor performs a method of operating a data processor in which execution threads may execute program instructions to perform data processing operations and in which execution threads may be grouped together into thread groups in which the plural threads of a thread group can each execute a set of instructions in lockstep, one instruction at a time;

• the data processor comprising:
• execution processing circuitry operable to execute instructions to perform processing operations for execution threads executing a program to perform data processing operations and comprising a set of at least one functional unit operable to perform data processing operations for an instruction being executed by an execution thread;
• wherein:
• the execution processing circuitry is operable as a plurality of execution lanes, each lane being operable to perform processing operations for a respective execution thread of a thread group;
• the method comprising:
• maintaining a pool of thread groups available to be issued to the execution lanes, and storing for each available thread group:
• an indication of a set of at least one next instruction to be executed by the thread group, and an indication of the active threads of the thread group;
• selecting a set of at least one thread group to issue to the execution lanes for execution from the pool of available thread groups based on the indications of the active threads for the thread groups in the thread group pool;
• and issuing the selected set of at least one thread group from the pool of available thread groups to the execution lanes for execution.