Fetch queue population

A method of operating an apparatus comprising a fetch queue configured to identify a sequence of instructions to be fetched for execution, the method comprising:

• storing a plurality of prediction entries comprising a multi-taken entry, the multi-taken entry identifying:
• a first branch instruction comprised in a first instruction block and configured to divert control flow to a first target address identifying a second instruction block;
• and
• a second branch instruction comprised in the second instruction block and configured to divert control flow to a second target address;
• and
• in response to a prediction associated with the multi-taken entry and identifying an outcome of both of the first branch instruction and the second branch instruction in which the first branch instruction is predicted to be taken,
• populating the fetch queue based on the prediction;
• and
• in response to a subsequent identification of a change in an outcome of the second branch instruction, flushing instruction addresses subsequent to a second branch instruction address of the second branch instruction and retaining instruction addresses up to and including the second branch instruction address in the fetch queue.

A non-transitory computer-readable medium storing computer-readable code for fabrication of an apparatus comprising:

• a fetch queue configured to identify a sequence of instructions to be fetched for execution;
• prediction entry storage configured to store a plurality of prediction entries comprising a multi-taken entry, the multi-taken entry identifying:
• a first branch instruction comprised in a first instruction block and configured to divert control flow to a first target address identifying a second instruction block;
• and
• a second branch instruction comprised in the second instruction block and configured to divert control flow to a second target address;
• and
• control circuitry responsive to a prediction associated with the multi-taken entry and identifying an outcome of both of the first branch instruction and the second branch instruction in which the first branch instruction is predicted to be taken,
• to populate the fetch queue based on the prediction;
• and
• in response to a subsequent identification of a change in an outcome of the second branch instruction, to flush instruction addresses subsequent to a second branch instruction address of the second branch instruction and to retain instruction addresses up to and including the second branch instruction address in the fetch queue.