Dual function system and method for shuffling packed data elements

Abstract

An apparatus and method for performing a shuffle operation on packed data using computer-implemented steps is described. In one embodiment, a first packed data operand having at least two data elements is accessed. A second packed data operand having at least two data elements is accessed. One of the data elements in the first packed data operand is shuffled into a lower destination field of a destination register, and one of the data elements in the second packed data operand is shuffled into an upper destination field of the destination register.

Description

|X3|X2|X1X|X0|

The process S500 then proceeds to process step S520, where numbers Y0, Y1, Y2 and Y3 are stored as data elements in a packed data item 525. For present discussion purposes, each data element is 16-bits wide and is contained in register X1, in the following order:
|Y3|Y2|Y1|Y0|

The process S500 then advances to process step S530, where a shuffle instruction is performed on the contents of register X0 (data item 515) and register X1 (data item 525) to shuffle any one of the four data elements from the first data item 515 to the lower two fields of a destination register 535, and to shuffle any one of the four data elements from the second data item 525 to the upper two fields of the destination register 535. The resulting data item 535 is as follows:
|{Y3, Y2, Y1, Y0}|{Y3, Y2, Y1, Y0}|{X3, X2, X1, X0}|{X3, X2, X1, X0}|

Accordingly, a shuffle operation is performed. Although FIG. 5 illustrates an example of the shuffle operation with data operands having four data elements, the principles of the invention may also be implemented in data operands having at least two elements.

An 8-bit immediate value is used as a control word to indicate how data elements should be shuffled. Bits 0,1 of the control word indicate which of the four data elements in the first operand are shuffled into the first or lowest data element of the destination register. Bits 2,3 of the control word indicate which of the four data elements in the first operand are shuffled into the second data element of the destination register. Bits 4,5 of the control word indicate which of the four data elements in the second operand are shuffled into the third data element of the destination register. Bits 6,7 of the control word indicate which of the four data elements in the second operand are shuffled into the fourth data element of the destination register. For example, given a first data operand with four data elements contained in the following order:
|D|C|B|A|
and also given a second data operand with four data elements contained in the following order:
|H|G|F|E|
and also given a shuffle control word of 10001111, the result of the shuffle is as follows:
|G|E|D|D|

It will be recognized by one of ordinary skill in the art that the size of the shuffle control word may vary depending without loss of compatibility with the present invention, depending on the number of data elements in the source data operand and the number of fields in the destination register.

FIG. 6a illustrates a schematic for performing a shuffle operation on two numbers according to one embodiment of the invention. The device 600 reads the contents of a first source packed data operand 605 and a second source packed data operand 610. A four to one data multiplexer 615 shuffles any one of data elements {D,C,B,A} from either data operands 605, 610 into the lower field of destination data item 625. A four to one data multiplexer 620 shuffles any one of data elements {D,C,B,A} from either data operands 605, 610 into the upper field of destination data item 625.

FIG. 6b illustrates a diagram for performing a shuffle operation on two numbers according to one embodiment of the invention. The device 630 reads the contents of a first source packed data operand 635. Any one of data elements {D,C,B,A} from the data operand 635 are shuffled into the lower two fields of destination data item 645. The device 630 then reads the contents of a second source packed data operand 640. Any one of data elements {H,G,F,E} from the data operand 640 are shuffled into the upper two fields of destination data item 645. The first source data operand 635 may be the same as the second source data operand 640. This method of shuffling may be performed with only an 8-bit control word.

Accordingly, a shuffle operation is performed. Although FIGS. 6a and 6b illustrate an example of the shuffle operation with data operands having two data elements, the principles of the invention may also be implemented in data operands having more than two elements.

The shuffle instruction of the present invention may be used as part of many different applications. For example, FIG. 7 is a general block diagram illustrating the use of a digital filter which utilizes a shuffle operation for filtering a TV broadcast signal according to one embodiment of the invention. FIG. 7 shows TV broadcast signals 703 representing a television broadcast being received by a receiving unit 706 of a computer system 700. The receiving unit 706 receives the TV broadcast signals 703 and transforms them into digital data 709. A digital filter unit 715 performs a digital filter (e.g., FIR, IIR, etc.) on the digital data 709 using a set of coefficients 712. As a result, the digital filter unit 715 generates filtered data 718 (also termed as “filtered data items”) representing the filtered analog TV broadcast signals. In performing the filtering operation, shuffle operations are implemented. The filtered data 718 are received by a video decoder 721 for conversion into and audio & video data 724. The techniques performed by video decoder 721 are well known (see Jack, Smith, Keith, “NTSC/PAL Digital Decoder”, Video Demystified, High Text Publications, Inc., 1993) The audio and video data can be used for any purpose (e.g., display on a screen).

In one embodiment, the computer system 100 shown in FIG. 1 is used to implement the computer system 700 in FIG. 7. In this embodiment, the TV broadcast signal receiver 131 acts as the receiving unit 706 and may include a TV tuner, an analog to digital converter, and a DMA channel. The TV broadcast signals 703 are received by the TV tuner, converted into digital data by the analog to digital converter, and then sorted in the storage device 110 by the DMA channel. It will be recognized by one of ordinary skill in the art that the digital data sorted by the TV broadcast signal receiver 131 may be stored in any number of formats. For example, the TV broadcast signal receiver 131 may store the data in the main memory in one or more of the formats described herein—storing two representations of each of the components of the data such that it may be read in as packed data item in the described formats. This data may then be accessed as packed data and copied into registers on the processor 105. Since the data is stored in the disclosed formats, the processor 105 can easily and efficiently perform the shuffle operation as described with reference to FIG. 5 and FIG. 6. It will be recognized by one of ordinary skill in the art that the receiving unit 706 may encompass additional hardware, software, and/or firmware in the TV broadcast signal receiver 131 or software executing on the processor 105. For example, additional software may be sorted in the storage device 110 for further processing the data prior to the digital filter being performed.

In this embodiment, the digital filter unit 718 is implemented using the processor 105 and the software 136 to perform the a digital filter. In this embodiment, the processor 105, executing the software 136, performs the digital filter using shuffle operations, and stores the filtered data 718 in storage device 110. In this manner, the digital filter is performed by the host processor of the computer system, rather than the TV broadcast signal receiver 131. As a result, the complexity of the TV broadcast signal receiver 131 is reduced. In this embodiment, the video decoder 721 may be implemented in any number of different combinations of hardware, software, and/or firmware. The audio and video data 724 can then be sorted, and/or displayed on the display 125 and the sound unit 134, respectively.

FIG. 8 is a general block diagram illustrating the use of a shuffle operation for rendering graphical objects in animation according to one embodiment of the invention. FIG. 8 shows a computer system 800 containing digital data 810 representing 3-dimensional (3D) graphics. The digital data 810 may be stored on a CD ROM or other type of storage device for later use. At sometime, the conversion unit 820 performs alteration of data using 3D geometry which includes the use of a shuffle operation to manipulate (e.g., scale, rotate, etc.) a 3D object in providing animation. The resulting graphical object 830 is then displayed on a screen display 840. The resulting graphical object may also be transmitted to a recording device (e.g., magnetic storage, such as tape).

In one embodiment, the computer system 100 shown in FIG. 1 is used to perform the graphics operation 800 from FIG. 8. In this embodiment, the digital data 810 from FIG. 8 is any data stored in the storage device 110 representing 3D graphics. In one embodiment, the conversion unit 820 from FIG. 8 is implemented using the processor 105 and the software 136 to alter data using 3D geometry. An example of such alteration of data includes the performance of a 3D transformation. In this embodiment, the processor 105, executing the software 136, performs the transformation and stores the transformed data 830 in the storage device 110 and/or provide, the transformed data to the graphics unit 135. In this manner, the 3D manipulation performed by the host processor of the computer system is provided at an increased speed. The present invention thus facilitates the performance of a shuffle operation through the use of available instruction sequences.

While several examples uses of shuffle operations have been described, it will be understood by one of ordinary skill in the art that the invention is not limited to these uses. In addition, while the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described. The method and apparatus of the invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting on the invention.

Claims

1. A computer system comprising:

a hardware unit to transmit data representing graphics to another computer or a display;

a processor coupled to the hardware unit; and

a storage device coupled to the processor and having stored therein an instruction, which when executed by the processor, causes the processor to at least,

access a first packed data operand having at least two data elements;

access a second packed data operand having at least two data elements;

select a first set of data elements from the first packed data operand;

copy each of the data elements in the first set to specified data fields located in the tower half of a destination operand;

select a second set of data elements from the second packed data operand; and

copy each of the data elements in the second set to specified data fields located in the upper half of the destination operand.

2. The computer system of claim 1 wherein the storage device further comprises a packing device for packing floating point data into the data elements.

3. The computer system of claim 1 wherein the storage device further comprises a packing device for packing integer data into the data elements.

4. A system as claimed in claim 1 wherein the first and second packed data operands are the same operand.

5. A method comprising the computer-implemented steps of:

decoding a single instruction;

in response to the step of decoding the single instruction,

accessing a first packed data operand having at least two data elements;

accessing a second packed data operand having at least two data elements;

selecting a first set of data elements from the first packed data operand;

copying each of the data elements in the first set to specified data fields located in the lower half of a destination operand;

selecting a second set of data elements from the second packed data operand; and

copying each of the data elements in the second set to specified data fields located in the upper half of the destination operand.

6. The method of claim 5 further comprising the step of packing floating point data into the data elements.

7. The method of claim 5 further comprising the step of packing integer data into the data elements.

8. A method as claimed in claim 5 wherein the first and second packed data operands are the same operand.

9. A method comprising the computer implemented steps of:

accessing data representative of a first three-dimensional image;

altering the data using three-dimensional geometry to generate a second

three-dimensional image, the step of altering at least including,

accessing a first packed data operand having at least two data elements;

accessing a second packed data operand having at least two data elements;

selecting a first set of data elements from the first packed data operand;

copying each of the data elements in the first set to specified data fields located in the lower half of a destination operand;

selecting a second set of data elements from the second packed data operand;

copying each of the data elements in the second set to specified data fields located in the upper half of the destination operand; and

displaying the second three-dimensional image.

10. The method of claim 9 wherein the step of altering includes the performance of a three-dimensional transformation.

11. The method of claim 9 wherein the step of altering includes the step of packing floating point data into the data elements.

12. The method of claim 9 wherein the step of altering includes the step of packing integer data into the data elements.

13. A method as claimed in claim 9 wherein the first and second packed data operands are the same operand.

14. A method comprising the computer implemented steps of:

accessing data representative of a first three-dimensional image;

altering the data using three-dimensional geometry to generate a second three-dimensional image, the step of altering at least including,

accessing a first packed data operand having at least two data elements;

accessing a second packed data operand having at least two data elements;

selecting a first set of data elements from the first packed data operand;

copying each of the data elements in the first set to specified data fields located in the lower half of a destination operand;

selecting a second set of data elements from the second packed data operand;

copying each of the data elements in the second set to specified data fields located in the upper half of the destination operand; and

displaying the second three-dimensional image.

15. The method of claim 14 wherein the step of altering includes the performance of a three-dimensional transformation.

16. The method of claim 14 wherein the step of altering includes the step of packing floating point data into the data elements.

17. The method of claim 14 wherein the step of altering includes the step of packing integer data into the data elements.

18. A method as claimed in claim 14 wherein the first and second packed data operands are the same operand.

19. A processor-implemented method for reducing the number of control hits required to shuffle packed data elements from first and second source operands, comprising the steps of:

decoding a single instruction specifying first and second source operands and a field of control bits; and

responsive to the field of control bits, generating a resultant packed data operand comprised of packed data elements from the first and second source operands,

wherein the control bits are limited to specifying for the upper and lower halves of the resultant packed data operand, data elements from the first and second source operands, respectively.

20. The method as claimed in claim 19 wherein the first and second packed data source operands and the resultant packed data operand are comprised of four packed data elements, and the field of control bits is an 8-bit field.

21. The method as claimed in claim 19 wherein the first and second packed data source operands are the same operand.

22. The method as claimed in claim 19 wherein the first and second packed data source operands are packed with floating point data.

23. A processor for performing a shuffle operation in response to a shuffle instruction comprising:

a decoder which decodes a single instruction specifying first and second source operands and a field of control bits; and

an execution unit which, responsive to the field of control bits, generates a resultant packed data operand comprised of packed data elements from the first and second source operands,

wherein the control bits are limited to specifying for the upper and lower halves of the resultant packed data operand, data elements from the first and second source operands, respectively.

24. The processor as claimed in claim 23 wherein the first and second source operands are the same operand.

25. The method as claimed in claim 19 wherein the first and second packed data source operands and the resultant packed data operand are each comprised of at least two packed data elements.

26. The method as claimed in claim 19 wherein the field of control bits is an 8-bit field.

27. The method as claimed in claim 26 wherein an 8-bit immediate to fill the field of control bits is decoded with the single instruction.

28. The processor of claim 23 wherein said field of control bits comprises of an 8-bit immediate value.

29. The processor of claim 23 wherein said field of control bits comprises of an 8-bits.

30. The processor of claim 29 wherein said first and second source operands comprise of double-precision floating-point values.

31. The processor of claim 29 wherein said first and second source operands comprise single-precision floating-point values.

32. The processor of claim 29 wherein said packed data elements comprise of packed double words.

33. The processor of claim 29 wherein said packed data elements comprise of packed words.

34. The processor of claim 29 wherein said packed data elements comprise of packed bytes.

35. The processor of claim 29 wherein said first and said second operands comprise of 128-bits of packed data.

36. An apparatus comprising:

a decode unit to decode a shuffle instruction into control signals, said shuffle instruction to include a first operand, a second operand, and a third operand wherein said third operand comprises of an 8-bit immediate value;

said first operand to identify a first register to hold at least two packed data elements;

said second operand to identify a memory location to hold at least two packed data elements;

said third operand is to provide selection bits to indicate which of said packed data elements in said first operand and said second operand to select and copy to a resultant register; and

an execution unit coupled to said decode unit, said execution unit responsive to said control signals and said selection bits to select a first set of data elements from said first register and to copy said first set of data elements to one or more lower destination fields of said resultant register, said execution unit further responsive to said control signals and said selection bits to select a second set of data elements from said memory location and to copy said second set of data elements to one or more upper destination fields of said resultant register.

37. The apparatus of claim 36 wherein said data elements of said first register and said second register comprise double-precision floating-point values.

38. The apparatus of claim 36 wherein said data elements of said first register and said second register comprise of single-precision floating-point values.

39. The apparatus of claim 36 wherein said packed data elements comprise of packed double words.

40. The apparatus of claim 36 wherein said packed data elements comprise of packed words.

41. The apparatus of claim 36 wherein said packed data elements comprise of packed bytes.

42. The apparatus of claim 36 wherein said first register is also said resultant register.

43. An apparatus comprising:

an instruction decoder to receive and decode a shuffle instruction, said shuffle instruction to include an immediate operand comprising two or more sets of control bits;

a first source register to hold a first packed data, said first packed data comprising of a first data element and a second data element;

a second source register to hold a second packed data, said second packed data comprising of a third data element and a fourth data element;

a destination register to hold a third packed data;

an execution unit coupled to said first source resister to receive said first packed data, and to said second source register to receive said second packed data; and

wherein said execution unit is further coupled to said instruction decoder to receive said two or more sets of control bits, said execution unit to select from said first source register at least one of said first and second data elements in response to a first one of said two or more sets of control bits and to copy said selected data element from said first source register to a first data field in a lower half of said destination register, and said execution unit to select from said second source register at least one of said third and fourth data elements in response to a second one of said two or more sets of control bits and to copy said selected data element from said second source register to a second data field in an upper half of said destination register.

44. The apparatus of claim 43 wherein said immediate operand is an 8-bit immediate operand.

45. The apparatus of claim 43 wherein said data elements of said first source register and said second source register comprise of double-precision floating-point values.

46. The apparatus of claim 43 wherein said data elements of said first source register and said second source register comprise of single-precision floating-point values.

47. The apparatus of claim 43 wherein said packed data comprise of packed double words.

48. The apparatus of claim 43 wherein said packed data comprise of packed words.

49. The apparatus of claim 43 wherein said packed data comprise of packed bytes.

50. The apparatus of claim 43 wherein said apparatus is defined by machine readable data on a machine readable medium.

51. The apparatus of claim 43 wherein said first source register is also said destination register.

52. The apparatus of claim 43 wherein said first source register is the same as said second source register.

53. The apparatus of claim 43 wherein said two or more sets of control bits comprise bits 0 and 1 of the immediate operand.

54. The apparatus of claim 44 wherein said 8-bit immediate operand comprises bits 0 and 1 to select from said first source register which data element is copied into the lowest data field in the lower half of the destination register, and bits 4 and 5 to select from said second source register which data element is copied into the lowest data field in the upper half of the destination register.

55. The apparatus of claim 44 wherein said 8-bit immediate operand comprises bits 0 through 3 to select from said first source register which data elements are copied into the lower half of the destination register, and bits 4 through 7 to select from said second source register which data elements are copied into the upper half of the destination register.

56. The apparatus of claim 55 wherein said 8-bit immediate operand comprises bits 2 and 3 to select from said first source register which data element is copied into the highest data field in the lower half of the destination register, and bits 6 and 7 to select from said second source register which data element is copied into the highest data field in the upper half of the destination register.