Spatial memory streaming confidence mechanism

A method for a spatial memory streaming (SMS) prefetch engine, comprising:

• maintaining a pattern history table (PHT) comprising at least one table in which each entry has an offset list field comprising sub-fields for offset values from a base offset value within a region and a per-offset confidence field comprising sub-fields for per-offset confidence levels corresponding to each offset value;
• activating a PHT entry;
• updating the per-offset confidence levels corresponding to each offset value in the activated PHT entry by matching current accesses to the stored offset values in the activated PHT entry;
• and
• eliminating one or more offset values from the offset list field of a PHT entry according to their respective per-offset confidence levels,
• wherein continuous learning is provided to the SMS engine at least by the per-offset confidence levels.

An apparatus, comprising:

• one or more non-transitory computer-readable media;
• and
• at least one processor which, when executing instructions stored on one or more non-transitory computer readable media, comprises at least a part of a spatial memory streaming (SMS) prefetch engine which performs the steps of:
• maintaining a pattern history table (PHT) comprising at least one table in which each entry has an offset list field comprising sub-fields for offset values from a base offset value within a region and a per-offset confidence field comprising sub-fields for per-offset confidence levels corresponding to each offset value;
• activating a PHT entry;
• updating the per-offset confidence levels corresponding to each offset value in the activated PHT entry by matching current accesses to the stored offset values in the activated PHT entry;
• and
• eliminating one or more offset values from the offset list field of a PHT entry according to their respective per-offset confidence levels.

A method, comprising:

• manufacturing a chipset comprising:
• at least one processor which, when executing instructions stored on one or more non-transitory computer readable media, performs the steps of:
• maintaining a pattern history table (PHT) for a spatial memory streaming (SMS) prefetch engine, the PHT table comprising at least one table in which each entry has an offset list field comprising sub-fields for offset values from a base offset value within a region and a per-offset confidence field comprising sub-fields for per-offset confidence levels corresponding to each offset value;
• activating a PHT entry;
• updating the per-offset confidence levels corresponding to each offset value in the activated PHT entry by matching current accesses to the stored offset values in the activated PHT entry;
• and
• eliminating one or more offset values from the offset list field of a PHT entry according to their respective per-offset confidence levels;
• and
• the one or more non-transitory computer-readable media which store the instructions.

A method of testing an apparatus, comprising:

• testing whether the apparatus has at least one processor which, when executing instructions stored on one or more non-transitory computer readable media, performs the steps of:
• maintaining a pattern history table (PHT) for a spatial memory streaming (SMS) prefetch engine, the PHT table comprising at least one table in which each entry has an offset list field comprising sub-fields for offset values from a base offset value within a region and a per-offset confidence field comprising sub-fields for per-offset confidence levels corresponding to each offset value;
• activating a PHT entry;
• updating the per-offset confidence levels corresponding to each offset value in the activated PHT entry by matching current accesses to the stored offset values in the activated PHT entry;
• and
• eliminating one or more offset values from the offset list field of a PHT entry according to their respective per-offset confidence levels;
• and
• testing whether the apparatus has the one or more non-transitory computer-readable media which store the instructions.