System and method for repairing a speculative global history record

In a microprocessor system using pipelined instruction processing, a method for repairing a speculative global history prediction record, the method comprising:

• accepting a first microprocessor instruction of consecutive operations, including a first conditional branch operation with an associated first branch address, at a first stage in a pipelined microprocessor execution process;
• making a first branch prediction in response to using a speculative global history record (SGHR) of conditional branch resolutions and predictions, and a branch history table (BHT) of pervious first conditional branch resolutions;
• resolving the first conditional branch operation;
• and,
• in response to the first branch prediction being incorrect, correcting the SGHR using the non-speculative global history record.

A pipelined instruction microprocessor system with a repairable speculative global history prediction record, the system comprising:

• a pipeline including a plurality of sequential stages for parallel processing microprocessor instructions, each microprocessor instruction including a plurality of consecutive operations, the pipeline including a first stage for processing a first conditional branch operation from a first microprocessor instruction;
• a sequencer with an interface for accessing the pipelined stages and processing the operations;
• a first address register containing a first branch address associated with the first conditional branch operation;
• a speculative global history record (SGHR) to provide a first vector representing a combination of resolved branch decisions and predicted branch decisions executed immediately before the first conditional branch operation;
• and,
• a non-speculative global history record (NSGHR) of branch resolutions having an input to accept a first branch resolution and an output for updating the SGHR in response to a first branch prediction being incorrect.