Speculative data processing and recovery
Aspects include copying a plurality of input data into a buffer of a processor configured to perform speculatively executing pipelined streaming of the input data. A bit counter maintains a difference in a number of input bits from the input data entering a pipeline of the processor and a number of the input bits consumed in the pipeline. The pipeline is flushed based on detecting an error. A portion of the input data is recirculated from the buffer into the pipeline based on a value of the bit counter.
1. A computer-implemented method comprising:
copying a plurality of input data into a buffer of a processor configured to perform speculatively executing pipelined streaming of the input data;
maintaining, in a bit counter, a difference in a number of input bits from the input data entering a pipeline of the processor and a number of the input bits consumed in the pipeline;
flushing the pipeline based on detecting an error; and
recirculating a portion of the input data from the buffer into the pipeline based on a value of the bit counter.
2. The computer-implemented method of claim 1 , wherein the pipeline comprises a plurality of computation blocks configured to speculatively decode a plurality of symbols having variable symbol lengths.
3. The computer-implemented method of claim 2 , wherein the computation blocks apply coding for a compression or decompression operation.
4. The computer-implemented method of claim 2 , wherein the error is detected based on resolving an end-of-block symbol in a speculation resolving pipeline stage of the pipeline.
5. The computer-implemented method of claim 4 , wherein the error comprises speculatively decoding a next block header as one or more symbols.
6. The computer-implemented method of claim 5 , wherein the next block header is used to adjust an initial symbol alignment of a next block of symbols upon recirculation.
7. The computer-implemented method of claim 4 , wherein the end-of-block symbol is used to adjust an initial symbol alignment of a next block of symbols upon recirculation.
8. The computer-implemented method of claim 1 , wherein the buffer is a shadow first-in-first-out buffer sized with a greater bit capacity than the pipeline.
9. A system of a processor, the system comprising:
a buffer;
a bit counter;
a pipeline configured to perform speculatively executing pipelined streaming of a plurality of input data; and
a controller configured to perform a plurality of operations comprising:
copying the input data into the buffer;
maintaining, in the bit counter, a difference in a number of input bits from the input data entering the pipeline and a number of the input bits consumed in the pipeline;
flushing the pipeline based on detecting an error; and
recirculating a portion of the input data from the buffer into the pipeline based on a value of the bit counter.
10. The system of claim 9 , wherein the pipeline comprises a plurality of computation blocks configured to speculatively decode a plurality of symbols in parallel having variable symbol lengths.
11. The system of claim 10 , wherein the error is detected based on resolving an end-of-block symbol in a speculation resolving pipeline stage of the pipeline.
12. The system of claim 11 , wherein the error comprises speculatively decoding a next block header as one or more symbols.
13. The system of claim 12 , wherein the next block header is used to adjust an initial symbol alignment of a next block of symbols upon recirculation.
14. The system of claim 11 , wherein the end-of-block symbol is used to adjust an initial symbol alignment of a next block of symbols upon recirculation.
15. The system of claim 9 , wherein the buffer is a shadow first-in-first-out buffer sized with a greater bit capacity than the pipeline.
16. A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to perform a plurality of operations comprising:
copying a plurality of input data into a buffer of a processor configured to perform speculatively executing pipelined streaming of the input data;
maintaining, in a bit counter, a difference in a number of input bits from the input data entering a pipeline of the processor and a number of the input bits consumed in the pipeline;
flushing the pipeline based on detecting an error; and
recirculating a portion of the input data from the buffer into the pipeline based on a value of the bit counter.
17. The computer program product of claim 16 , wherein the pipeline comprises a plurality of computation blocks configured to speculatively decode a plurality of symbols in parallel having variable symbol lengths.
18. The computer program product of claim 17 , wherein the error is detected based on resolving an end-of-block symbol in a speculation resolving pipeline stage of the pipeline and the error comprises speculatively decoding a next block header as one or more symbols.
19. The computer program product of claim 17 , wherein the computation blocks apply coding for a compression or decompression operation.
20. The computer program product of claim 16 , wherein the buffer is a shadow first-in-first-out buffer sized with a greater bit capacity than the pipeline.