Method and instruction set including register shifts and rotates for data processing
View Patent ↗A method includes identifying a first register with M bits and a second register with N bits. The process also includes shifting K bits, where K<=N, from the second register into the first register. The shifting operation executes a left shift operation including reading bits K . . . N−1 from the first register, writing bits K . . . N−1 into bit positions O . . . N−K−1 of the first register, reading K bits from the second register, and writing K bits from second register into bit positions N−K . . . N−1 of first register, or a right shift operation including reading bits O . . . N−K−1 from the first register, writing bits O . . . N−K−1 into bit position K . . . N−1 of the first register, reading the K bits from the second register, and writing K bits from second register into bit positions O . . . K−1 of first register.
1. A processing method for rotating elements of a pair of registers, comprising:
identifying at least one first register with M bits, the first register being a vector register;
identifying at least one second register with N bits, the second register being a scalar register;
shifting K bits, where K is less than N, from the second register into the first register, wherein the K bits are shifted according to at least one of:
(1) executing a left shift comprising:
reading N−K bits starting at bit position K of the first register, comprising selected contents of the first register,
writing the bits read into bit positions of the first register starting at bit position 0 ,
reading the K bits from the second register, and
writing the K bits read from the second register into bit positions of the first register starting at bit position N−K, or
(2) executing a right shift comprising:
reading N−K bits starting at bit position 0 of the first register, comprising selected contents of the first register,
writing the bits read into bit positions of the first register starting at bit position K,
reading the K bits from the second register, and
writing the K bits read from the second register into bit positions of the first register starting at bit position 0 .
2. The method of claim 1 , wherein the shifting further comprises:
setting the contents of the second register to 0 after writing the K bits from the second register into the first register.
3. The method of claim 1 , wherein the K bits comprise 2 b bits.
4. The method of claim 3 , wherein b is 3, 4, 5, or 6.
5. The method of claim 4 , wherein the K bits are read from different positions in the second register according to a predetermined function.
6. The method of claim 5 , wherein a value of K also is determined by the predetermined function.
7. The method of claim 1 , wherein only one of the left shift or the right shift is executed.
8. The method of claim 1 , wherein the second register is a scalar accumulator register.
9. A processing apparatus, comprising:
a first register with M bits, the first register being a vector register;
a second register with N bits, the second register being a scalar register, wherein the processing apparatus is configured to shift K bits, where K is less than N, from the second register into the first register, wherein the K bits are shifted according to at least one of:
(1) executing a left shift comprising:
reading N−K bits starting at bit position K of the first register, comprising selected contents of the first register,
writing the bits read into bit positions of the first register starting at bit position 0 ,
reading the K bits from the second register, and
writing the K bits read from the second register into bit positions of the first register starting at bit position N−K, or
(2) executing a right shift comprising:
reading N−K bits starting at bit position 0 of the first register, comprising selected contents of the first register,
writing the bits read into bit positions of the first register starting at bit position K,
reading the K bits from the second register, and
writing the K bits read from the second register into bit positions of the first register starting at bit position 0 .
10. The apparatus of claim 9 , wherein the shifting further comprises:
setting the contents of the second register to 0 after writing the K bits from the second register into the first register.
11. The apparatus of claim 9 , wherein the K bits comprise 2 b bits.
12. The apparatus of claim 11 , wherein b is 3, 4, 5, or 6.
13. The apparatus of claim 12 , wherein the K bits are read from different positions in the second register according to a predetermined function.
14. The apparatus of claim 13 , wherein a value of K also is determined by the predetermined function.
15. The apparatus of claim 9 , wherein only one of the left shift or the right shift is executed.
16. The apparatus of claim 9 , wherein the second register is a scalar accumulator register.
17. A processing apparatus, comprising:
means for identifying at least one first register with M bits, the first register being a vector register;
means for identifying at least one second register with N bits, the second register being a scalar register; and
means for shifting K bits, where K is less than N, from the second register into the first register, wherein the K bits are shifted according to at least one of:
(1) executing a left shift comprising:
reading N−K bits starting at bit position K of the first register, comprising selected contents of the first register,
writing the bits read into bit positions of the first register starting at bit position 0 ,
reading the K bits from the second register, and
writing the K bits read from the second register into bit positions of the first register starting at bit position N−K, or
(2) executing a right shift comprising:
reading N−K bits starting at bit position 0 of the first register, comprising selected contents of the first register,
writing the bits read into bit positions of the first register starting at bit position K,
reading the K bits from the second register, and
writing the K bits read from the second register into bit positions of the first register starting at bit position 0 .
18. The apparatus of claim 17 , wherein the means for shifting further comprises:
setting the contents of the second register to 0 after writing the K bits from the second register into the first register.
19. The apparatus of claim 17 , wherein the K bits comprise 2 b bits.
20. The apparatus of claim 19 , wherein b is 3, 4, 5, or 6.
21. The apparatus of claim 20 , wherein the K bits are read from different positions in the second register according to a predetermined function.
22. The apparatus of claim 21 , wherein a value of K also is determined by the predetermined function.
23. The apparatus of claim 22 , wherein only one of the left shift or the right shift is executed.
24. The apparatus of claim 17 , wherein the second register is a scalar accumulator register.