摘要:
A system and method for predicting a branch target for a current instruction in a microprocessor, the system comprising a cache storing indirect branch instructions and a path register. The path register is updated on certain branches by an XOR operation on the path register and the branch instruction, followed by the addition of one or more bits to the register. The cache is indexed by performing an operation on a portion of the current instruction address and the path register; the entry returned, if any, may be used to predict the target of the current instruction.
摘要:
A system and method for predicting a branch target for a current instruction in a microprocessor, the system comprising a cache storing indirect branch instructions and a path register. The path register is updated on certain branches by an XOR operation on the path register and the branch instruction, followed by the addition of one or more bits to the register. The cache is indexed by performing an operation on a portion of the current instruction address and the path register; the entry returned, if any, may be used to predict the target of the current instruction.
摘要:
A memory cache bank prediction unit is provided for use in a processor having a plurality of memory cache banks. The memory cache bank prediction unit has an input port that receives an instruction. The memory cache bank prediction unit also has an evaluation unit, coupled to the input port, that predicts which of the plurality of memory cache banks is associated with the instruction.
摘要:
A multi-mode predictor for a processor having a plurality of prediction modes is disclosed. The prediction modes are used to predict non-binary values. The predictor is a multi-mode predictor comprising a per-IP (“PIP”) table and a next value table. The PIP table includes a plurality of PIP information fields and the next value table includes a plurality of fields. The multi-mode predictor also includes a plurality of prediction modes. The processor includes a set of instructions that index the PIP table to provide a valid signal. The processor also includes a set of predicted values for the set of instructions. The set of predicted values is stored in the PIP table and the next value table. According to the valid signal a hit/miss condition in the next value table, a predicted value is selected from the PIP table or the next value table.
摘要:
A microprocessor having a correlated address predictor, and methods of performing correlated address prediction. A first table memory can be populated by a plurality of buffer entries. Each buffer entry can include a first buffer field to store a first tag based on an instruction pointer and a second buffer field to store an address history. A second table memory can be populated by a plurality of link entries. Each link entry can include a first link field to store a link tag based on an address history and a second link field to store a predicted address. A first comparator can be in communication with the first table memory and an instruction pointer input. A second comparator can be in communication with the first table memory and the second table memory. An output in communication with the second table memory.
摘要:
A memory cache bank prediction unit is provided for use in a processor having a plurality of memory cache banks. The memory cache bank prediction unit has an input port that receives an instruction. The memory cache bank prediction unit also has an evaluation unit, coupled to the input port, that predicts which of the plurality of memory cache banks is associated with the instruction.
摘要:
A cache bank prediction unit is provided for use in a processor having a plurality of cache memory banks. The cache bank prediction unit has an input port that receives an instruction. The cache bank prediction unit also has an evaluation unit, coupled to the input port, that predicts which of the plurality of cache banks is associated with the instruction.
摘要:
A method for dynamically controlling the population size of confidence assignments to which confidence level predictions are assigned. The method includes comparing a confidence level prediction and a threshold indication to generate a confidence assignment. The confidence assignment is used to generate another threshold indication. The threshold indication is dynamically adjusted so as to control the population size of confidence assignments to which confidence level predictions are assigned.
摘要:
In a front-end system for a processor, a recording scheme for instruction segments stores the instructions in reverse program order. Instruction segments may be traces, extended blocks or basic blocks. By storing the instructions in reverse program order, the instruction segment is easily extended to include additional instructions. The instruction segments may be extended without having to re-index tag arrays, pointers that associate instruction segments with other instruction segments.
摘要:
A memory cache bank prediction unit is provided for use in a processor having a plurality of memory cache banks. The memory cache bank prediction unit has an input port that receives an instruction. The memory cache bank prediction unit also has an evaluation unit, coupled to the input port, that predicts which of the plurality of memory cache banks is associated with the instruction.