Efficient extraction of execution sets from fetch sets
View Patent ↗An apparatus having a buffer and a circuit is disclosed. The buffer may be configured to store a plurality of fetch sets. Each fetch set generally includes a prefix word and a plurality of instruction words. Each prefix word may include a plurality of symbols. Each symbol generally corresponds to a respective one of the instruction words. The circuit may be configured to (i) identify each of the symbols in each of the fetch sets having a predetermined value and (ii) parse the fetch sets into a plurality of execution sets in response to the symbols having the predetermined value.
1. An apparatus comprising:
a buffer configured to store a plurality of fetch sets as received in a fetch set order from an instruction memory, wherein (i) each of said fetch sets comprises a prefix word and a plurality of instruction words, (ii) each of said prefix words comprises a plurality of symbols and (iii) each of said symbols corresponds to a respective one of said instruction words; and
a circuit configured to (i) identify each of said symbols in each of said fetch sets having a predetermined value and (ii) parse said fetch sets into a plurality of execution sets in response to said symbols having said predetermined value, wherein each of said symbols has (a) said predetermined value to identify an initial one of said instruction words in a respective one of said execution sets and (b) another value to identify a subsequent one of said instruction words after said initial instruction in said respective execution sets.
2. The apparatus according to claim 1 , wherein each of said execution sets comprises a variable length execution set.
3. The apparatus according to claim 1 , further comprising a single decoder, wherein said circuit is further configured to route said execution sets to said decoder in response to said prefix words.
4. The apparatus according to claim 1 , further comprising a single decoder configured to generate one or more decoded instructions by decoding said execution sets.
5. The apparatus according to claim 4 , wherein said decoded instructions are dispatched from said decoder to a plurality of execution units.
6. The apparatus according to claim 5 , wherein said decoded instructions generated from each of said execution sets are dispatched to different ones of said execution units.
7. The apparatus according to claim 1 , wherein each of said symbols having said predetermined value corresponds to a respective one of said execution sets.
8. The apparatus according to claim 1 , wherein each of said symbols is a single bit, one of said bits per said instruction words respectively.
9. The apparatus according to claim 1 , wherein said apparatus is implemented in a pipeline of a digital signal processor.
10. The apparatus according to claim 1 , wherein said apparatus is implemented as one or more integrated circuits.
11. A method for an efficient extraction of a plurality of execution sets from a plurality of fetch sets, comprising the steps of:
(A) storing said fetch sets in a buffer as received in a fetch set order from an instruction memory, wherein (i) each of said fetch sets comprises a prefix word and a plurality of instruction words, (ii) each of said prefix words comprises a plurality of symbols and (iii) each of said symbols corresponds to a respective one of said instruction words;
(B) identifying each of said symbols in each of said fetch sets having a predetermined value; and
(C) parsing said fetch sets into said execution sets in response to said symbols having said predetermined value, wherein each of said symbols has (i) said predetermined value to identify an initial one of said instruction words in a respective one of said execution sets and (ii) another value to identify a subsequent one of said instruction words after said initial instruction in said respective execution sets.
12. The method according to claim 11 , wherein each of said execution sets comprises a variable length execution set.
13. The method according to claim 11 , further comprising the step of:
routing said execution sets to a single decoder in response to said prefix words.
14. The method according to claim 11 , further comprising the step of:
generating one or more decoded instructions by decoding said execution sets using a single decoder.
15. The method according to claim 14 , further comprising the step of:
dispatching said decoded instructions from said decoder to a plurality of execution units.
16. The method according to claim 15 , wherein said decoded instructions generated from each of said execution sets are dispatched to different ones of said execution units.
17. The method according to claim 11 , wherein each of said symbols having said predetermined value corresponds to a respective one of said execution sets.
18. The method according to claim 11 , wherein each of said symbols is a single bit, one of said bits per said instruction words respectively.
19. The method according to claim 11 , wherein said method is implemented in a pipeline of a digital signal processor.
20. An apparatus comprising:
means for storing a plurality of fetch sets as received in a fetch set order from an instruction memory, wherein (i) each of said fetch sets comprises a prefix word and a plurality of instruction words, (ii) each of said prefix words comprises a plurality of symbols and (iii) each of said symbols corresponds to a respective one of said instruction words;
means for identifying each of said symbols in each of said fetch sets having a predetermined value; and
means for parsing said fetch sets into a plurality of execution sets in response to said symbols having said predetermined value, wherein each of said symbols has (i) said predetermined value to identify an initial one of said instruction words in a respective one of said execution sets and (ii) another value to identify a subsequent one of said instruction words after said initial instruction in said respective execution sets.