US 12,373,219 B2
Reduced power consumption prediction using prediction tables
Thibaut Elie Lanois, Peymeinade (FR); Guillaume Bolbenes, Vallauris (FR); and Jonatan Christoffer Lövgren, Nice (FR)
Assigned to Arm Limited, Cambridge (GB)
Filed by Arm Limited, Cambridge (GB)
Filed on Dec. 19, 2023, as Appl. No. 18/544,901.
Prior Publication US 2025/0199815 A1, Jun. 19, 2025
Int. Cl. G06F 9/38 (2018.01); G06F 1/3287 (2019.01)
CPC G06F 9/3844 (2013.01) [G06F 1/3287 (2013.01); G06F 9/3806 (2013.01); G06F 9/3848 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
history storage circuitry configured to store history information comprising a series of values corresponding to a series of processing events to represent a path through program execution;
a predictor configured to provide a prediction, the predictor comprising:
a plurality of prediction tables to store prediction entries providing prediction information;
lookup circuitry configured to perform table lookups in the plurality of prediction tables using table lookup information;
lookup information generation circuitry configured to generate the table lookup information for the plurality of prediction tables based on different lengths of input history information, wherein the input history information is based on the history information stored in the history storage circuitry; and
prediction generating circuitry configured to generate the prediction based on the prediction information in prediction entries identified by the lookup circuitry; and
input history selection circuitry configured to prevent a given portion of the input history information input into the lookup information generation circuitry for generating the table lookup information for a given prediction from differing with respect to a corresponding portion of the input history information input into the lookup information generation circuitry for generating the table lookup information for a preceding prediction; wherein
the table lookup information for looking up an active subset of the plurality of prediction tables is independent from the given portion of the input history information, and the table lookup information for looking up an inactive subset of the plurality of prediction tables is dependent on the given portion of the input history information, and
the table lookup information for looking up the inactive subset of the plurality of prediction tables is based on a longer length of input history information than the table lookup information for looking up the active subset of the plurality of prediction tables.