WO2002103633A1

WO2002103633A1 - System, method and computer program product for a programmable pixel processing model with instruction set

Info

Publication number: WO2002103633A1
Application number: PCT/US2002/019504
Authority: WO
Inventors: John Erik Lindholm; Henry P. Moreton; Harold Robert Feldman Zatz
Original assignee: Nvidia Corporation
Priority date: 2001-06-19
Filing date: 2002-06-19
Publication date: 2002-12-27

Abstract

A system, method and computer program product are provided for programmable pixel processing in a computer graphics pipeline (400). Initially, pixel data is received from a source buffer (402). Thereafter, programmable operations (404) are performed on the pixel data in order to generate output. The operations are programmable (404) in that a user may utilize instructions from a predetermined instruction set for generating the same. Such output is stored in a register (406).

Description

SYSTEM, METHOD AND COMPUTER PROGRAM PRODUCT FOR A PROGRAMMABLE PIXEL PROCESSING MODEL WITH INSTRUCTION

SET

RELATED APPLICATIONS

The present application is a continuation-in-part of an application filed 05/31/2000 under serial number 09/586,249, and an application filed 12/06/1999 under serial number 09/454,516, now issued as U.S. Pat. No.: 6,198,488.

FIELD OF THE INVENTION

The present invention relates to computer graphics, and more particularly to providing programmability in a computer graphics processing pipeline.

BACKGROUND OF THE INVENTION Graphics application program interfaces (API's) have been instrumental in allowing applications to be written to a standard interface and to be run on multiple platforms, i.e. operating systems. Examples of such graphics API's include Open Graphics Library (OpenGL^®) and Direct 3D™ (D3D™) pipelines. OpenGL^® is the computer industry's standard graphics API for defining 2-D and 3-D graphic images. With OpenGL^®, an application can create the same effects in any operating system using any OpenGL^®-adhering graphics adapter. OpenGL^® specifies a set of commands or immediately executed functions. Each command directs a drawing action or causes special effects.

Thus, in any computer system which supports this OpenGL^® standard, the operating system(s) and application software programs can make calls according to the standard, without knowing exactly any specifics regarding the hardware configuration of the system. This is accomplished by providing a complete library of low-level graphics manipulation commands, which can be used to implement graphics operations. A significant benefit is afforded by providing a predefined set of commands in graphics API's such as OpenGL^®. By restricting the allowable operations, such commands can be highly optimized in the driver and hardware implementing the graphics API. On the other hand, one major drawback of this approach is that changes to the graphics API are difficult and slow to be implemented. It may take years for a new feature to be broadly adopted across multiple vendors.

With the integration of transform operations into high speed graphics chips and the higher integration levels allowed by semiconductor manufacturing, it is now possible to make part of the pipeline accessible to the application writer. There is thus a need to exploit this trend in order to afford increased flexibility in visual effects. In particular, there is a need to provide a new computer graphics programming model and instruction set that allows convenient implementation of changes to the graphics API, while preserving the driver and hardware optimization afforded by currently established graphics API's.

Disclosure of the Invention

A system, method and computer program product are provided for programmable pixel processing in a computer graphics pipeline. Initially, pixel data is received from a source buffer. Thereafter, programmable operations are performed on the pixel data in order to generate output. The operations are programmable in that a user may utilize instructions from a predetermined instruction set for generating the same. Such output is stored in a register.

In one embodiment of the present invention, the output stored in the register may be used in performing the programmable operations on the data. Further, the pixel data may include a position, a pixel diffuse color, a specular color, a fog value, and/or a plurality of texture coordinates.

In still another embodiment of the present invention, an operation may be performed involving the output. Such operation may include a scissor operation, a color format conversion, an alpha test operation, a z-buffer/stencil operation, a blend operation, a logic operation, a dither operation, and/or a writemask operation.

In yet another embodiment of the present invention, additional standard operations may be performed utilizing a standard graphics application program interface (API). For example, the API may include at least one of OpenGL^® and D3D™

As an option, the pixel data may be negated and/or swizzled prior to performing the programmable operations thereon. Further, the programmable operations may include a texture fetch operation. Such texture fetch operation may involve a slope.

In still yet another embodiment, the programmable operations may support multiple levels of precision. Such levels of precision may include full floating point, half floating point, and fixed point. Further, the programmable operations may be capable of converting the pixel data from a first level of precision to a second level of precision for packing the pixel data into a destination, performing calculations, or any other purpose. Optionally, the programmable operations may be capable of clamping the pixel data for packing the pixel data into a destination. The programmable operations may also be capable of removing, or "killing," the pixel data.

The instruction set of programmable operations may include a no operation, texture fetch, move, derivative, multiply, addition, multiply and addition, reciprocal, reciprocal square root, three component dot product, four component dot product, distance vector, minimum, maximum, pack, unpack, set on less than, set on greater or equal than, floor, fraction, kill pixel, exponential base two (2), logarithm base two (2), and light coefficients.

By this design, the present invention allows a user to program a portion of the graphics pipeline that handles pixel processing. This results in an increased flexibility in generating visual effects. Further, the programmable pixel processing of the present invention allows remaining portions of the graphics pipeline, i.e. primitive processing, to be controlled by a standard graphics application program interface (API) for the purpose of preserving hardware optimizations.

These and other advantages of the present invention will become apparent upon reading the following detailed description and studying the various figures of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects and advantages are better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:

Figure 1 is a schematic diagram illustrating a graphics pipeline in accordance with one embodiment of the present invention;

Figure 2 illustrates the overall operation of the various components of the graphics pipeline of Figure 1;

Figure 3 is a schematic diagram illustrating an exemplary model of the pixel processing module in accordance with one embodiment of the present invention;

Figure 4 is a flowchart illustrating the method by which the programming model of Figure 3 carries out programmable pixel processing in the computer graphics pipeline;

Figure 5 is a detailed table showing various attributes handled by the pixel source buffer; and

Figure 6 illustrates an instruction set of programmable operations that maybe carried out by one embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 is a schematic diagram illustrating a graphics pipeline in accordance with one embodiment of the present invention. As shown, the present embodiment involves a plurality of modules including an attribute buffer 50, a transform module 52, a lighting module 54, a rasterization module 56 with a set-up module 57, and a pixel processing module 58.

As an option, each of the foregoing modules may be situated on a single semiconductor platform. In the present description, the single semiconductor platform may refer to a sole unitary semiconductor-based integrated circuit or chip. It should be noted that the term single semiconductor platform may also refer to multi-chip modules with increased connectivity which simulate on-chip operation, and make substantial improvements over utilizing a conventional CPU and bus implementation. Of course, the present invention may also be implemented on multiple semiconductor platforms and/or utilizing a conventional CPU and bus implementation.

During operation, the buffer 50 is included for gathering and maintaining a plurality of attributes. Completed vertices are processed by the transform module 52 and then sent to the lighting module 54. The transform module 52 generates parameters for the lighting module 54 to light. The output of the lighting module 54 is screen space data suitable for the set-up module which, in turn, sets up primitives. Thereafter, rasterization module 56 carries out rasterization of the primitives. In particular, the rasterization module 56 passes on pixel data including, but not limited to a position, a pixel diffuse color, a specular color, a fog value, a plurality of texture coordinates, and/or any other information relating to the pixels involved with the processing in the graphics pipeline.

A pixel processing module 58 is coupled to the rasterization module 56 for processing the pixel data. The pixel processing module 58 begins by reading the pixel data generated by the rasterization module 56. In operation, the pixel processing module 58 outputs a color and a depth value.

Table 1 illustrates operations that may be done after the pixel processing module 58 is finished. A standard application program interface (API) state may be used as appropriate, as will soon become apparent.

Table 1

Scissor

Color Format Conversion Alpha Test Zbuffer/Stencil Blendfunction Logicop

Dither Writemask

Figure 2 illustrates a high level operation 200 of the pixel processing module 58 of Figure 1. As shown, it is constantly determined in decision 202 whether current operation invokes a programmable pixel model of the present invention. If so, a mode is enabled that partially supercedes the pixel processing of the standard graphics API, thus providing increased flexibility in generating visual effects. See operation 204.

When disabled, the present invention allows increased or exclusive control of the graphics pipeline by the standard graphics API, as indicated in operation 206. In one embodiment, states of the standard graphics API may not be overruled by invoking the programmable pixel mode of the present invention. In one embodiment, no graphics API state may be directly accessible by the present invention, with the exception of the bound texture state.

In one embodiment, the standard graphics API may include Open Graphics Library (OpenGL^®) and/or D3D™ APIs. OpenGL^® is the computer industry's standard API for defining 2-D and 3-D graphic images. With OpenGL^®, an application can create the same effects in any operating system using any OpenGL^®-adhering graphics adapter. OpenGL^® specifies a set of commands or immediately executed functions. Each command directs a drawing action or causes special effects. OpenGL^® and D3D™ APIs are commonly known to those of ordinary skill, and more information on the same may be had by reference to the OpenGL^® specification Version 2.1, which is incorporated herein by reference in its entirety.

As is well known, OpenGL^® mandates a certain set of configurable computations defining transformation, texture coordinate generation and transformation, and lighting. Several extensions have been developed to provide further computations to OpenGL^®.

Figure 3 is a schematic diagram illustrating an exemplary model 300 of the pixel processing module 58 in accordance with one embodiment of the present invention. Such programming model 300 may be adapted to work with hardware accelerators of various configuration and/or with central processing unit (CPU) processing.

As shown in Figure 3, the pixel processing module 58 includes a functional module 302 that is capable of carrying out a plurality of different types of operations. The functional module 302 is equipped with three inputs and an output. Associated with each of the three inputs are a swizzling module 304 and a negating module 306 for purposes that will be set forth hereinafter in greater detail. Data swizzling is useful when generating vectors. Such technique allows the efficient generation of a vector cross product and other vectors.

The functional module 302 is capable of carrying out programmable operations and supporting multiple levels of precision. Such levels of precision may include full floating point (i.e. 32-bit), half floating point (i.e. 16-bit), and fixed point. More information regarding the programmable operations and the various levels of precision will be set forth hereinafter in greater detail. Coupled to the output of the functional module 302 is an input of a register file 308 having three outputs. The register file 308 is also equipped with a vector component writemask module 309. The register file 308 has single write and triple read access. The contents of the register file 308 are initialized to (0,0,0,0) at the start of program execution.

Also included are a pixel source buffer 312 and a constant source buffer 314. The pixel source buffer 312 stores data in the form of pixel data, and maybe equipped with write access and/or at least single read access. The constant source buffer 314 stores data in the form of constant data, and may also be equipped with write access and/or at least single read access. It may be read using an absolute address.

In one exemplary embodiment, the pixel source buffer 312 is twelve (12) quad- floats in size (12*128 bits). Operation of the pixel processor module 58 maybe commenced when all pixel attributes are valid. The position contains x and y in integer (D3D™) and +0.5 (OpenGL^®) window coordinates, z is normalized to the range (0,1), and 1/w is in homogeneous clip space. Such attributes may be mandatory in the current exemplary embodiment. The pixel attributes may also be perspective correct. The colors and fog value may be generated at a lower precision, while the texture coordinates may be generated in high precision, i.e. 32-bit floating point. Figure 5 is a detailed table 500 showing various attributes handled by the pixel source buffer 312.

Each of the inputs of the functional module 302 is equipped with a multiplexer 316. This allows the outputs of the register file 308, pixel source buffer 312, and constant source buffer 314 to be fed to the inputs of the functional module 302. This is facilitated by buses 318.

While not shown, the functional module 302 may also be coupled to a texture fetch module (not shown) for fetching texture data. Such texture fetch module may also be coupled to the register file 308. It should be noted that frame buffer contents are only visible to the pixel processing module 58 via texture fetches. There need not necessarily be an explicit connection between texture coordinates and the textures that they may access. It is possible to use the same coordinate, or generated coordinates, to access any of the active textures as many times as desired and in any sequence desired. Programs are allowed access to sixteen (16) active textures. If an accessed texture is not bound, the texture fetch may return (0,0,0,0). The texture fetch instruction specifies the texture identifier desired (i.e. between 0 and 15). In one embodiment, texture components that are in fixed point form may have a bias (0.0,-0.5) and a multiply operation (2x,lx) applied to them before they are returned to the pixel processing module 58. This capability need not necessarily apply to floating point texture components. A texture fetch may return the data at the destination precision.

The pixel processing module 58 of Figure 3 works well with hardware accelerators. In use, pixels are processed independently. Only one pixel is visible to the pixel processing module 58. As an option, there may be one 4-bit condition code register initialized as equal to 0 at program start.

Figure 4 is a flowchart illustrating the method 400 by which the model of Figure 3 carries out programmable pixel processing in the computer graphics pipeline.

Initially, in operation 402, data is received from a pixel source buffer 312. Such data may include any type of information that is involved during the processing of pixels in the computer graphics pipeline. Further, the pixel source buffer 312 may include any type of memory capable of storing data.

Thereafter, in operation 404, programmable operations, i.e. pixel processing 102, are performed on the data in order to generate output. The programmable operations are capable of generating output that maybe stored in the register file 308 in operation 406. During operation 408, the output stored in the register file 308 is used in performing the programmable operations on the data. Thus, the register file 308 may include any type of memory capable of allowing the execution of the programmable operations on the output.

By this design, the present invention allows a user to program a portion of the graphics pipeline that handles pixel processing. This results in an increased flexibility in generating visual effects. Further, the programmable pixel processing of the present invention allows remaining portions of the graphics pipeline to be controlled by the standard API for the purpose of preserving hardware optimizations.

During operation, only one pixel is processed at a time in the functional module

302 that performs the programmable operations. As such, the pixels may be processed independently. Further, the various foregoing operations may be processed for multiple pixels in parallel.

In one embodiment of the present invention, a constant may be received, and the programmable operations may be performed based on the constant. During operation, the constant may be stored in and received from the constant source buffer 314. Further, the constant may be accessed in the constant source buffer 314 using an absolute or relative address. As an option, there may be one or more address registers for use during reads from the constant source buffer 314. It may be imtialized to "0" at the start of program execution in operation 204 of Figure 2. Further, the constant source buffer 314 may be written with a program which may or may not be exposed to users.

The register file 308 may be equipped with single write and triple read access.

Register contents may be initialized to (0,0,0,0) at the start of program execution in operation 204 of Figure 2.

Figure 6 illustrates an instruction set of programmable operations 600 that may be carried out by the present invention, in accordance with one embodiment. As shown in Figure 6, such programmable operations 600 include a no operation, texture fetch, move, derivative, multiply, addition, multiply and addition, reciprocal, reciprocal square root, three component dot product, four component dot product, distance vector, minimum, maximum, pack, unpack, set on less than, set on greater or equal than, floor, fraction, kill pixel, exponential base two (2), logarithm base two (2), and light coefficients.

An exemplary assembly language will now be set forth in the context of which the foregoing operations may be executed. Such language refers to a plurality of resources delineated in Table 2. Note the correspondence with the various components of the model 300 of Figure 3.

Table 2

Pixel Source - pf*] of size 12 vectors (192B)

Constant Memory - c [*] of size 32 vectors

(512B)

Data Registers/Output - R0-R7 , H0-H15 , 10 -17 of size 8 , 16 , 8 vectors

( 128B) Condition Codes - RC, HC, IC of size 4 bits

Instruction Storage of size 128 instructions

The data registers and memory locations include four component floating point precision. Further, the registers maybe accessed as full floating point precision (fp32:R0-R7), half floating point precision (φl 6:H0-H15), or signed 12-bit fixed point precision (sl2:I0-I7). These overlap as follows: R0/H0-H1/I0-I1, R1/H2-H3/I2-I3, R2/H4-H5/I4-I5, etc.

Vector components maybe swizzled before use via four subscripts (xyzw). An arbitrary component re-mapping may be done. Some examples are shown in Table 3.

Table 3

.xyzw means source (x,y, z,w) -> input (x,y, z,w) .zzxy means source (x,y, z,w) -> input (z, z,x,y)

.xxxx means source (x,y, z,w) -> input (x,x,x,x) Shortcuts : no subscripts refers to . xyzw ( same as writemask)

. x is the same as .xxxx . y is the same as .yyyy . z is the same as . zzzz . w is the same as . www

All source operands (except condition codes) may be negated by putting a '-' sign in front. The condition codes can be changed whenever data is written (by adding a 'c' to the op-code) and sharing the writemask with the destination. If there is no other destination, RC or HC or IC may be used as a dummy write register. When data is written, each component may compared to 0.0 and its status recorded if the writemask for that component is enabled.

The condition codes are sourced as EQ(equal), NE(not equal), LT(less), GE(greater or equal), LE(less or equal), GT(greater), FL(false), and TR(true), which generates four (4) bits of condition code by applying the specified comparison. As a source (for KTL and writemask modification), the condition codes may be swizzled.

Writes to the register, condition codes, and RC are maskable. Each component is written only if it appears as a destination subscript (from xyzw). Specifying no writemask is the same as a writemask of xyzw. No swizzling may be possible for writemask, and subscripts may be ordered (x before y before z before w). It is also possible to modify the write mask by the condition codes (at the beginning of the instruction) by an 'AND' operation as set forth in Table 4. It should be noted that condition codes here have swizzle control.

Table 4

destination (GT.x) //writemask [4] = 1111 & GT.xxxx destination.xw(EQ.yyzz) //writemask [4] = xOOw & EQ.yyzz

An exemplary assembler format is set forth in Table 5.

Table 5 OPCODE DESTINATION, SOURCE (S)

Valid sources are the pixel source, constants, and registers. Valid destinations are registers, RC, HC, and IC. Output data is taken from the register file 308. It should be noted that vertex programs use the functional module 302 for output. A particular API mode allows selection of an output format for the color and depth values, and whether the program will generate a new depth value.

A blend function and alpha testing may or may not be available based on the color output format. For example, a blend function and alpha testing may be available if the selected color format is four (4) unsigned bytes. The final color is taken from register RO, HO, or 10. The final color vector, regardless of the precision format, may be stored into a frame buffer assuming a similarly sized color buffer.

If a depth value is to be generated, the final value of Rl .x, HI .x, or II .x holds the new depth value. If depth is not to be generated, the standard pipeline depth is used. Depth is normalized to a (0,1) range which is clamped and scaled by hardware to fit the final depth buffer test format. The depth writemask may apply.

As mentioned earlier, three formats are supported for vector components. More information regarding precision will now be set forth in the context of an exemplary embodiment. Table 6 illustrates each of the various formats.

Table 6

Floating point: fp32 (s.e8.m23) Floating point: fpl6 (s.e5.ml0)

Signed fixed point: sl2 (2.10 in 2' s complement, range of -2 to +2047/1024) , where fp32 refers to a 32-bit floating point precision fpl6 refers to a 16-bit floating point precision sl2 refers to fixed point precision It may not necessarily be possible to mix formats inside a vector. Further, in one embodiment, no floating point exceptions or interrupts may be supported. Denorms may be flushed to zero, and NaN may be treated as infinity. Negative 0.0 may also be treated as positive 0.0 in comparisons.

In 32-bit floating point mode, the RCP and RSQ instructions may deliver mantissa results accurate to 1.0/(2**22). Moreover, the approximate output (.z) in the EXP and LOG instructions only have to be accurate to 1.0/(2** 11). The LIT instruction output (.z) allows error equivalent to the combination of the EXP and LOG combination implementing a power function.

In 16-bit floating point mode, the RCP, RSQ, LOG, and EXP instructions deliver results accurate to within one least significant bit of the correct answer. LIT has at least the accuracy of a LOG, multiply, and EXP sequence in 16-bit floating point mode. In fixed point mode, all calculations are performed and then clamped into the valid range.

Since distance is calculated as (d*d)*(l/sqrt(d*d)), 0.0 multiplied by infinity may be 0.0. Since if/then else evaluation is done by multiplying by 1.0/0.0 and adding the values set forth in Table 7.

Table 7

0. 0 * x = 0 . 0 for all x (including infinity and NaN) 1 . 0 * x = x for all x (including infinity and NaN)

0 . 0 + x = x for all x (including infinity and NaN)

In one embodiment, the registers maybe grouped into 128-bit chunks, each of which may be used as a single 4*φ32 quad-float, two 4*φl6 quad-floats, or two 4*sl2 quad-fixed point. There are eight (8) such chunks allowing a maximum of eight (8) registers in φ32 mode and sixteen (16) registers in φl6. It should be noted that there are only eight (8) si 2 registers. The present invention is allowed to use mixed precision registers as sources and destination to an instruction. In this case, conversion to destination precision is done before the instruction is executed. The instruction itself is performed at the destination precision.

If a 128-bit chunk is read in a different format from which it was last written, 0.0 is returned. Pixel source and constants maybe in 32-bit floating point precision, but may be reduced to lower precision by the destination.

More information will now be set forth regarding each of the programmable operations 600 of Figure 6.

No Operation (NOP)

Format:

NOP

Description:

No Operation.

Examples:

NOP

Texture Fetch (TEX,TXP,TXD)

Format:

TEX [c] D[.xyzw][(RC[.xyzw])],[-]S0[.xyzw],#tid TXP [c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],#tid TXD [c] D[.xyzw][(RC[.xyzw]]],[-]SO[.xyzw],[-]Sl[.xyzw], [-]S2[.xyzw],#tid

Description:

The contents of the source vector are used as a texture coordinate indexing into the specified (via tid:0-15) texture map. The filtered vector resulting is placed into the destination as a quad-float. TEX generates a texture fetch of (x,y,z) while TXP generates a texture fetch of (x/w,y/w,z/w). TXD allows specification of the derivative in x (SI) and y (S2). These may be used for LOD/anisotropic calculations. TXD generates a texture fetch of (x,y,z).

Operation:

Table 8 sets forth an example of operation associated with the TEX, TXP, and TXD instructions.

Table 8

t .x = sourceO . c*** /* c is x or y or z or w */ t .y = sourceO . *c** t . z = source0 . **c* t .w = source0 . ***c if ( -sourceO) t = -t; q = TextureFetch (t, texid) ; if (destination x) R X = q X if (destination y⁾ R y = q Y if (destination z) R z = q z if (destination w) R w = q w

Examples:

TEX R2,R3,3 //Fetch from texture 3 using R3 as coords. Derivative X (DDX)

Format:

DDX[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw]

Description:

DDX operates to ensure that the rate of change of the components of the source with respect to the horizontal axis 'X' are placed into the destination.

Operation:

Table 9 sets forth an example of operation associated with the DDX instruction.

Table 9

t.x = sourceO.c*** /* c is x or y or z or w */ t.y = source0.*c** t.z = source0.**c* t.w = source0.***c if (-sourceO) t = -t; q.x = d(t.x)/dx; q.y = d(t .y) /dx; q.z = d(t.z) /dx; q.w = d(t .w) /dx; if (destination. ) R.x = q X if (destination.y) R.y = q y if (destination. z) R.Z = q z if (destination. ) R. = q w

Examples:

DDX R2,R1 //Fetch x derivatives of Rl

Derivative Y (DDY) Format:

DDY[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw]

Description:

DDY operates to ensure that the rate of change of the components of the source with respect to the vertical axis 'Y' is placed into the destination.

Operation:

Table 10 sets forth an example of operation associated with the DDY instruction.

Table 10

t.x = sourceO . c***; /* c is x or y or z or w */ t.y = sourceθ.*c** t.z = sourceθ.**c* t.w = sourceθ.***c if (-sourceO) t = -t; q.x = d(t.x) /dy; q.y = d(t.y)/dy; q.z = d(t.z)/dy; q.w = d (t . ) /dy; if (destination. x) R.x = q.x if (destination. y) R.y = q.y if (destination. z) R.z = q.z if (destination. w) R.w = q.w

Examples:

DDY R2,R0 //Fetch y derivatives of R0

Move (MOV) Format:

MOV[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw]

Description:

MOV operates to move the contents of the source into a destination.

Operation:

Table 11 sets forth an example of operation associated with the MOV instruction.

Table 11

t.x = sourceO Q - * * . /* c is x or y or z or w */ t.y = sourceO *_C** • t.z = sourceO **c* . t.w = sourceO ***_c . if (-sourceO) t = -t; q.x = t.x; q.y = t.y; q.z = t . z; q.w = t.w; if (destination. x) R.x = q.x; if (destination. y) R.y = q.y; if (destination. z) R. z = q. z ; if (destination. w) R.w = q.w;

Examples:

MOV RC,-R3 //Compare negative R3 to 0.0 and save

MOV R2,p[POS].w //Move w component of v[POS] into xyzw components ofR2 MOV Rl .xyw,R2.x //Move x component of R2 into x,y,w components of Rl

Multiply (MUL)

Format:

MUL[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],[-]Sl [.xyzw]

Description:

MUL operates to multiply sources into a destination. It should be noted that 0.0 times anything is 0.0.

Operation:

Table 12 sets forth an example of operation associated with the MUL instruction.

Table 12

t .x = sourceO . c*** /* c is x or y or z or w */ t .y = sourceO . *c** t . z = sourceO . **c* t .w = sourceO . ***c if ( -sourceO) t = -t ; u.x = sourcel. _£**•* . /* c is x or y or z or w */ u.y = sourcel. * ** • u.z = sourcel. ** * . u.w = sourcel. * * * . if (-sourcel) u = -u; q.x = t.x*u.x; q. y = t.y*u.y_; q.z = t.z*u.z; q.w = t.w*u.w; if (destination.x) R.x = q.x; if (destination.y) R.y = q-y; if (destination. z) R.z = q.z; if (destination.w) R.w = q.w;

Examples:

MUL H6,H5,c[CON5] //Hβ.xyzw = H5.xyzw * c[CON5].xyzw MUL H6.x,H5.w,-H7 //H6.x = H5.w*-H7.x

Add (ADD)

Format:

ADD[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],[-]Sl[.xyzw]

Description:

ADD serves to add sources into a destination.

Operation:

Table 13 sets forth an example of operation associated with the ADD instruction.

Table 13

t.x = sourceo.c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** /* c is x or y or z or w */ u.y = sourcel. *c** u.z = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u;

q.y = t.y+u.y; q.z = t.z+u.z; q.w = t .w+u.w; if (destination x) R X = q X if (destination y⁾ R y = q y if (destination z) R z = q z if (destination w) R w = q w

Examples:

ADD HC.x,H5.x,c[CON5] //Compare H5.x+c[CON5].x to 0.0 and set RC.x

ADD H6.x,H5,-H7 //H6.x = H5.x - H7.x

ADD H6,-H5,c[CON5] //Hό.xyzw = -H5. xyzw + c[CON5]. xyzw

Multiply And Add (MAD)

Format:

MAD[c] D[.xyzw][(RC[.xyzw])],[-]S0[.xyzw],[-]Sl [.xyzw],

[-]S2[.xyzw]

Description:

MAD serves to multiply and add sources into a destination. It should be noted that 0.0 times anything is 0.0.

Operation:

Table 14 sets forth an example of operation associated with the MAD instruction.

Table 14

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t w = sourceO ^•k i -k . if (-sourceO) t = -t; u X = sourcel ς. je -k -k . I* c is x or y or z or w */ u y = sourcel *C* * « u z = sourcel ie -k Q -k • u w = sourcel * ** • if (-sourcel) u = -u;

V X = source2 * * * . /* c is x or y or z or w */

V y = source2 #C* * .

V z = source2 * *C* .

V w = source2 ^•k -k it_Q • if (-source2)

V = -V; q X = t .x*u.x+v.x; q y = t.y*u.y+v.y; q z = t . z*u.z+v.z; q w = t .w*u.w+v.w; if (destination.x) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w

Examples:

MAD H6,-H5,p[POS],-H3 //H6 = -H5 * p[POS] - H3

MAD H6.z,H5.w,p[POS],H5 //H6.z = H5.w * p[POS].z + H5.z

Reciprocal (RCP)

Format:

RCP[c] D[.xyzw][(RC[.xyzw])],[-]S0.[xyzw]

Description:

RCP inverts source scalar into a destination. The source may have one subscript. Output maybe exactly 1.0 if the input is exactly 1.0.

RCP(-Inf) gives (-0.0,-0.0,-0.0,-0.0) RCP(-O.O) gives (-Inf,-Inf,-Inf,-Inf) RCP(+0.0) gives (+mf,+ f,+Lιf,+Inf) RCP(+Inf) gives (0.0,0.0,0.0,0.0)

Operation:

Table 15 sets forth an example of operation associated with the RCP instruction.

Table 15

t.x = sourceO. c*** is x or y or z or w t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; if (t.x == 1.0) q.x = q.y = q.z = q.w = 1.0; else q.x = q.y = q.z = q.w = 1.0/t.x; where |q.x IEEE(1.0/t.x) I < 1/(2**22) for all 1.0<=t.X<2.0 if (destination.x) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination. w) R.w = q.w

Examples:

RCP R2,c[14].x //R2.xyzw = l/c[14].x RCP R2.w,R3.z //R2.w = l/R3.z

Reciprocal Square Root (RSQ)

Format:

RSQ[c] D[.xyzw][(RC[.xyzw])],[-]S0.[xyzw]

Description: RSQ performs an inverse square root of absolute value of source scalar into a destination. The source may have one subscript. Output may be exactly 1.0 if the input is exactly 1.0.

RSQ(O.O) gives (+hιf,+Inf,+Inf,+Inf) RSQ(Inf) gives (0.0,0.0,0.0,0.0)

Operation:

Table 16 sets forth an example of operation associated with the RSQ instruction.

Table 16

t.x = sourceO ,c***; /* c is x or y or z or w */ t.y = sourceO .*c**; t.z = sourceO . **cⁱ t.w = sourceO . ***c; if (-sourceO) t = -t; if (t.x == 1.0) q.x = q.y = q.z = q.w = 1.0; else q.x=q.y=q.z=q.w=l.0/sqrt (abs (t.x) ) ; with |q.x -

IEEE (1.0/sqrt (t.x) ) | < 1/(2**22) for 1.0<=t.x<4.0 if (destination.x) R.x = q.x; if (destination.y) R.y = q.y; if (destination. z) R.z = q.z; if (destination.w) R.w = q.w;

Examples:

RSQ R3,R3.y //R3 = l/sqrt(abs(R3.y))

RSQ R2.w,p[9].x //R2.w = l/sqrt(abs(p[9].x))

Three Component Dot Product (DP3)

Format: DP3[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],[-]Sl[.xyzw]

Description:

DP3 performs a three component dot product of the sources into a destination. It should be noted that 0.0 times anything is 0.0.

Operation:

Table 17 sets forth an example of operation associated with the DP3 instruction.

Table 17

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** /* c is x or y or z or w */ u.y = sourcel. *c** u.tz = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u; q.x = q.y = q.z = q.w = t.x*u.x + t.y*u.y + t.z*u.z; if (destination.x) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination. ) R.w = q.w

Examples:

DP3 H6,H3,H4 //H6.xyzw = H3.x*H4.x + H3.y*H4.y + H3.z*H4.z DP3 H6.w,H3,H4 //H6.w = H3.x*H4.x + H3.y*H4.y + H3.z*H4.z

Four Component Dot Product (DP4) Format:

DP4[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],[-]Sl [.xyzw]

Description:

DP4 performs a four component dot product of the sources into a destination. It should be noted that 0.0 times anything is 0.0.

Operation:

Table 18 sets forth an example of operation associated with the DP4 instruction.

Table 18

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** is x or y or z or w */ u.y = sourcel. *c** u.z = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u; q.x = q.y = q z = q.w = t.x*u.x + t.y*u.y + t.z*u.z + t.W*U.W; if (destination. ) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w

Examples:

DP4 H6,p[POS],c[MV0] //H6.xyzw = p.x*c.x + p.y*c.y + p.z*c.z + p.w*c.w DP4 H6.xw,p[POS].w,H3 //H6.xw = ρ.w*H3.x + p.w*H3.y + p.w*H3.z + p.w*H3.w Distance Vector (DST)

Format:

DST[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],[-]Sl[.xyzw]

Description:

DST calculates a distance vector. A first source vector is assumed to be

(NA,d*d,d*d,NA) and second source vector is assumed to be (NA,l/d,NA,l/d). A destination vector is then (l,d,d*d,l/d). It should be noted that 0.0 times anything is 0.0.

Operation:

Table 19 sets forth an example of operation associated with the DST instruction.

Table 19

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** is x or y or z or w */ u.y = sourcel. *c** u.z = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u; q.x = 1.0; q.y = t.y*u.y; q.z = . z; q.w = u.w; if (destination. ) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w Examples:

DST R2,R3,H4 //R2.xyzw = (1.0,R3.y*H4.y,R3.z,H4.w)

Minimum (MIN)

Format:

MF [c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],[-]Sl[.xyzw]

Description:

MIN serves to move a minimum of sources into a destination.

Operation:

Table 20 sets forth an example of operation associated with the MIN instruction.

Table 20

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** /* c is y or z or w */ u.y = sourcel. *c** u.z = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u; q.x = (t.x < u.x) ' ' t X : u.x; q.y = (t.y < u.y) ' ' t y : u.y; q.z = (t .z < u. z) ' ' t z : U . z ; q.w = (t.w < u.w) ' ' t w : U.w; if (destination.x) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination. ) R.w = q.w Examples:

MIN R2,R3,H0 //R2 = component min(R3,H0)

MIN R2.x,R3.z,H0 //R2.x = min(R3.z,H0.x)

MIN CH,R3.z,H0 //Compare min(R3.z,H0.xyzw) to 0.0 and set RC

Maximum (MAX)

Format:

MAX[c] D[.xyzw][(RC[.xyzw])],[-]S0[.xyzw],[-]Sl [.xyzw]

Description:

MAX moves a maximum of sources into a destination.

Operation:

Table 21 sets forth an example of operation associated with the MAX instruction.

Table 21

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** /* c is x or y or z or w */ u.y = sourcel. *c** u.z = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u; q.x = (t.x u.x) ? t.x U.X; q- • y = (t.y >= u. ^■ y) ? t.y : : U.y; q- . z = (t.z >= u. .z) ? t.z : : U . Z ; . . w = (t. >= u. , w) ? t.W : : U.W; if (destination.x) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination. ) R.w = q.w

Examples:

MAX R2,R3,H0 //R2 = component max(R3,H0) MAX R2.w,R3.x,H0 //R2.w = max(R3.x,H0.w)

Pack2 (PK2)

Format:

PK2[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw]

Description:

PK2 packs two source components (.xy after swizzle) into a destination. The destination may be a φ32 "R" register. The source components are converted into φl6 format and packed into a destination.

Operation:

Table 22 sets forth an example of operation associated with the PK2 instruction.

Table 22

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; t.x = fpl6 (t.x) ; t.y = fpl6(t.y); q.x = q.y = q.z = q.w = ( (t.x) I (t.y«16)) ; /* raw bit packing */ if (destination. ) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w

Examples:

PK2 R0.z,R3 // pack x,y components of R3 into R0.5

Pack4 (PK4)

Format:

PK4[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw]

Description:

PK4 packs four source components into a destination. The destination may be a φ32 "R" register. The source components are clamped to the range (-1.008,1.0) before being packed into a destination as unsigned 8bit bytes.

Operation:

Table 23 sets forth an example of operation associated with the PK4 instruction.

Table 23

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; q.x = t.x; if (q.x > 1.0) q.x 1.0; else if (q.x <

1.008) q.x = -1.008; q.y = t.y; if (q.y > 1.0) q.y 1.0; else if (q.y <

1.008) q.y = -1.008; q.z = t.z; if (q.z > 1.0) q.z 1.0; else if (q.z <

1.008) q.z = -1.008; q.w = t.w; if (q.w > 1.0) q.w 1.0; else if (q.w <

1.008) q.w = -1.008; ub.x = 127.0*q.x + 128 /* ub is unsigned byte vector */ ub.y = 127.0*q.y + 128 ub.z = 127.0*q.z + 128 ub.w = 127.0*q.w + 128 q.x = q.y = q.z = q.w = ((ub.x) | (ub.y<<8) | (ub.z<<16) (ub.w<<24)); /* raw bit packing */ if (destination. ) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w

Examples:

PK4 R0.z,R3 // pack 4 components of R3 into RO.z

Unpack2 (UP2)

Format:

UP2[c] D[.xyzw][(RC[.xyzw])],[-]S0.[xyzw]

Description:

UP2 unpacks source component into a destination. The source may be a φ32

"R" register scalar. The source component is assumed to be a packed φl6 pair.

Operation:

Table 24 sets forth an example of operation associated with the UP2 instruction.

Table 24 t.x = sourceO .c***; /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; q.x = q.z = (t.x>> 0) & Oxffff ; /* use raw bits of t.x */ q.y = q.w = (t.x»16) & Oxffff; /* use raw bits of t.x */ if (destination.x) R.x = q.x; if (destination.y) R.y = q.y; if (destination. z) R.z = q.z; if (destination.w) R.w = q.w;

Examples:

UP2 R0.xy,R3.y // unpack two components of R3.y into RO.xy

Unpack4 (UP4)

Format:

UP4[c] D[.xyzw] [(RC[.xyzw])],[-]S0.[xyzw]

Description:

UP4 unpacks source component into a destination. The source may be a φ32 "R" register scalar. The source component is assumed to be a packed unsigned 8-bit quartet and all are biased and scaled back into the range (-1.008,1.0) before assignment to destination.

Operation:

Table 25 sets forth an example of operation associated with the UP4 instruction. Table 25

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; . (t.X» 0) & Oxff /* use raw bits of t.x */ q^ (t.X>> 8) & Oxff /* use raw bits of t.x */ q> (t.X>>16) & Oxff /* use raw bits of t.x */ q> (t.X>>24) & Oxff /* use raw bits of t.x */ q. (q.x 128)/127.0 q- (q-y 128)/127.0 q> (q.z 128)/127.0 q.w (q.w 128)/127.0 if (destination. ) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w

Examples:

UP4 R0,R3.x // unpack four components of R3.x into RO.xyzw

Set On Less Than (SLT)

Format:

SLT[c] D[.xyzw][(RC[.xyzw])],[-]S0[.xyzw],[-]Sl[.xyzw]

Description:

SLT sets the destination to 1.0/0.0 if sourceO is less_than/greater_or_equal to sourcel . The following relationships should be noted:

SetEQ R0,R1 = (SGE R0,R1) * (SGE -R0.-R1) SetNE R0,R1 = (SLT R0,R1) + (SLT -R0,-R1) SetLE R0,R1 = SGE -R0,-R1 SetGT R0,R1 = SLT -R0.-R1

Operation:

Table 26 sets forth an example of operation associated with the SLT instruction.

Table 26

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** /* c is x or y or z or w */ u.y = sourcel. *c** u.s = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u; q.x = (t.x < u.x) ? 1.0 0 . 0 q.y = (t.y < u.y) ? 1.0 0. 0 q.z = (t.z < u.z) ? 1.0 0 . 0 q.w = (t.w < u.w) ? 1.0 0 . 0 if (destination. ) R.x = q - if (destination.y) R.y = q - if (destination. z) R.z = q - if (destination.w) R.w = q. w

Examples:

SLT H4,H3,H7 //H4.xyzw = (H3.xyzw < H7.xyzw ? 1.0 : 0.0) SLT H3.xz,H6.w,H4 //H3.xz = (H6.w < H4.xyzw ? 1.0 : 0.0)

Set On Greater Or Equal Than (SGE)

Format:

SGE[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw],[-]Sl[.xyzw] Description:

SGE sets the destination to 1.0/0.0 if sourceO is greater_or_equal/less_than sourcel.

Operation:

Table 27 sets forth an example of operation associated with the SGE instruction.

Table 27

t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; u.x = sourcel. c*** /* c is x or y or z or w */ u.y = sourcel. *c** u.z = sourcel. **c* u.w = sourcel. ***c if (-sourcel) u = -u; q.x = (t.x >= u.x) 7 1. 0 0 o q.y = (t.y >= u.y) •> 1 0 0 0 q.z = (t.z >= u.z) ? 1 0 0 o q.w = (t.w >= u.w) ^■p 1 0 0 0 if (destination.x) R X = cj.x if (destination.y) R y = ci-y if (destination. z) R z = cϊ-z if (destination.w) R w = c [.W

Examples:

SGE H4,H3,H7 //H4.xyzw = (H3.xyzw >= H7.xyzw ? 1.0 : 0.0) SGE H3.xz,H6.w,H4 //H3.xz = (H6.w >= H4.xyzw ? 1.0 : 0.0)

Floor (FLR)

Format: FLR[c] D[.xyzw][(RC[.xyzw])],[-]SO[.xyzw]

Description:

FLR set the destination to floor of source.

Operation:

Table 28 sets forth an example of operation associated with the FLR instruction.

Table 28

t. .X = sourceO , /* c is x or y or z or w */ t. ^■ y = sourceO . *C** t. .z = sourceO . **c* t. .w = sourceO . ***n if (-!sourceO) t = = -t; . .X = floor (t. .x); q- ^■ y = floor (t.y) ; q- . z = floor (t. • z); q- .w = floor (t. ,w) ; if (destination . x) R .x = q . x if (destination. y) R.y = q.y if (destination. z) R . z = q . z if (destination . ) R. w = q. w

Examples:

FLR H4.z,R3 //H4.z = floor(R3.z)

Fraction (FRC)

Format:

FRC[c] D[.xyzw][(RC[.xyzw])],[-]S0[.xyzw] Description:

FRC sets a destination to a fractional part of a source. The fraction is 0.0 <= fraction < 1.0.

Operation:

Table 29 sets forth an example of operation associated with the FRC instruction.

Table 29

t.x = sourceO.c*** /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; q.x = t .x - floor (t.x) ; q.y = t.y - floor (t.y) ; q.z = t.z - floor (t . z) ; q.w = t.w - floor (t.w) ; if (destination. ) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination. ) R.w = q.w

Examples:

FRC H4.z,R3 //H4.z = R3.z- floor(R3.z)

Kill Pixel (KIL)

Format:

KTL RC[.xyzw] Description:

KDL kills the pixel based on any of the RC bits (post swizzle) being TRUE. KIL cannot set the condition codes.

Operation:

Table 30 sets forth an example of operation associated with the KLL instruction.

Table 30

b.x = RC.C*** /* c is x or y or z or w */ b.y = RC.*c** b.z = RC.**c* b.w = RC.***c if (b.x j b.y I b.z | b.w) Kill pixel;

Examples:

KIL EQ //Kill pixel if RC x or y or z or w are = 0.0

KILLT.x //Kill pixel ifRCx bit < 0.0

KXL NE.xxzz //Kill pixel if x or z RC bits != 0.0

Exponential Base 2 (EXP)

Format:

EXP[c] D[.xyzw][(RC[.xyzw])],[-]S0.[xyzw]

Description:

EXP generates an approximate answer in dest.z and allows for a more accurate answer of dest.x*FUNC(dest.y) where FUNC is some user approximation to 2**dest.y (0.0 <= dest.y < 1.0). EXP accepts a scalar sourceO. Reduced precision arithmetic is acceptable in evaluating dest.z.

EXP(-Inf) or underflow gives (0.0,0.0,0.0,1.0) EXP(+Inf) or overflow gives (+Inf,0.0,+Inf,1.0)

Operation:

Table 31 sets forth an example of operation associated with the EXP instruction.

Table 31

t.x = sourceO. c*** is x or y or z or w */ t.y = sourceθ.*c** t.z = sourceO. **c* t.w = sourceθ.***c if (-sourceO) t = -t; q.x = 2**TruncateTo-Infinity ( .x) ; q.y = t.x - TruncateTo-Infinity (t.x) ; q.z = q.x * APPX(q.y); where

|exp(q.y* N2) -APPX(q.y) I < 1/(2**11) for all 0<=q.y<1.0 q.w = 1.0; if (destination.x) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w

Examples:

EXP H4,R3.z

Logarithm Base 2 (LOG)

Format:

LOG[c] D[.xyzw][(RC[.xyzw])],[-]S0.[xyzw] Description:

LOG generates an approximate answer in dest.z and allows for a more accurate answer of dest.x+FUNC(dest.y) where FUNC is some user approximation of log2(dest.y) (1.0 <= dest.y < 2.0). LOG accepts a scalar sourceO of which the sign bit is ignored. LOG provides reduced precision arithmetic is acceptable in evaluating dest.z.

LOG(O.O) gives (-Inf,1.0,-Inf,1.0) LOG(h f) gives (Inf,1.0,Inf,1.0)

Operation:

Table 32 sets forth an example of operation associated with the LOG instruction.

Table 32

t.x = sourceO .c***; /* c is x or y or z or w */ t.y = sourceO. *c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; if (abs(t.x) != 0.0) { q.x = exponent (t.x) (-128.0 <= e < 127) q.y = mantissa (t.x) (1.0 <= m < 2.0) q.z = q.x + APPX(q.y) where | log (q.y) /LN2-

APPX(q.y) I < 1/(2**11) for all 1.0<=q.y<2.0 q.w = 1.0;

} else { q.x = -inf; q.y = 1.0; q.z = -inf; q.w = 1.0 ; } if (destination.x) R.x = q.x if (destination.y) R.y = q.y if (destination. z) R.z = q.z if (destination.w) R.w = q.w

Examples: LOG H4,R3.z

Light Coefficients (LIT)

Format:

LIT[c] D[.xyzw] [(RC[.xyzw])],[-]S0[.xyzw]

Description:

LIT provides lighting partial support. LIT calculates lighting coefficients from two dot products and a power (which gets clamped to — 128.0<power<128.0). Source vector is:

SourceO.x = n*l (unit normal and light vectors)

SourceO.y = n*h (unit normal and halfangle vectors) SourceO.z is unused SourceO .w = power

Reduced precision arithmetic is acceptable in evaluating dest.z. Allowed error is equivalent to a power function combining the LOG and EXP instructions (EXP(w*LOG(y))). An implementation may support at least 8 fraction bits in the power. It should be noted that since 0.0 times anything may be 0.0, taking any base to the power of 0.0 yields 1.0.

Operation:

Table 33 sets forth an example of operation associated with the LIT instruction.

Table 33 t.x = sourceO. c*** /* c is x or y or z or w */ t.y = sourceθ.*c** t.z = sourceO. **c* t.w = sourceO. ***c if (-sourceO) t = -t; if (t.w < -127.9961) t.w = -127.9961; /* assuming power is s8.8 */ else if (t.w > 127.9961) t.w = 127.9961; if (t.x < 0.0) t.x = 0.0; if (t.y < 0.0) t.y = 0.0; q.x = 1.0;

/* ambient */ q.y = t.x;

/* diffuse */ q.z = (t.x > 0.0 ? EXP(t.w* OG(t.y) ) : 0.0)

/* specular */ q.w = 1.0; if (destination.x) R.x = q.x; if (destination.y) R.y = q.y; if (destination. z) R.z = q. z ; if (destination.w) R.w = q.w;

Examples:

LIT R0,R3

Appendix A sets forth a plurality of programming examples.

APPENDIX A

The #define statements are meant for a cpp run.

i )

; Absolute Value H4 = abs (R0)

MAX H4 , 0 , -R0 ;

2)

Cross Product i j k into R2 |R0.x RO.y RO.z J |Rl.x Rl.y Rl.z|

MUL R2 , O . zxyw, Rl .yzxw; MAD R2, RO.yzxw, Rl. zxyw, -R2;

; reduce Rl to fundamental period

#define PERIOD 70; location PERIOD is 1.0/ (2*PI) ,2*PI, 0.0, 0.0

MUL R0,Rl,c [PERIOD] .x; //divide by period FRC R2 , R0 ; MUL R2,R2,c [PERIOD] .y; //multiply by period

; H4 = p->weight.x*H2 + (1. θ-p->weight.x) *H3

#define I GT 8; source weight

ADD H4,H2,-H3; //LERP

MAD H4,p[IWGT] .X,H4,H3;

6)

; R0 = (GT.X I I LT.y) ? Rl : R2 ;

MOV R0 , R2 ;

MOV R0(GT.x),Rl;

MOV RO(LT.y) ,R1;

7)

; RO.y = (EQ.XZW && LT.y) ? Rl . z : R2.W;

MOV R0.y,Rl.z; MOV RO.y (NE.XZWW) ,R2.w; MOV RO.y(GE.y) ,R2.w; While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

CLAIMSWhat is claimed is:

1. A method for programmable pixel processing in a computer graphics pipeline, comprising:

(a) receiving pixel data from a source buffer;

(b) performing programmable operations on the pixel data in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set; and

(c) storing the output in a register.

2. The method as recited in claim 1, wherein the output stored in the register is used in performing the programmable operations on the pixel data.

3. The method as recited in claim 1, wherein the pixel data includes a position, a pixel diffuse color, a specular color, a fog value, and a plurality of texture coordinates.

4. The method as recited in claim 1, wherein the pixel data is selected from the group consisting of a position, a pixel diffuse color, a specular color, a fog value, and a plurality of texture coordinates.

5. The method as recited in claim 1, and further comprising performing an operation involving the output, the operation selected from the group consisting of a scissor operation, a color format conversion, an alpha test operation, a z-buffer/stencil operation, a blend operation, a logic operation, a dither operation, and a writemask operation.

6. The method as recited in claim 1 , wherein further standard operations are performed on the pixel data utilizing a standard graphics application program interface (API).

7. The method as recited in 1 , wherein the output includes a color value and a depth value .

8. The method as recited in claim 1, and further comprising negating the pixel data prior to performing the programmable operations thereon.

9. The method as recited in claim 1 , and further comprising swizzling the pixel data prior to performing the programmable operations thereon.

10. The method as recited in claim 1, wherein the programmable operations includes a texture fetch operation.

11. The method as recited in claim 10, wherein the texture fetch operation involves a slope.

12. The method as recited in claim 10, wherein the texture fetch operation is capable of being used in a level of detail (LOD) calculation.

13. The method as recited in claim 1 , wherein the programmable operations support multiple levels of precision.

14. The method as recited in claim 13, wherein the levels of precision include full floating point, half floating point, and fixed point.

15. The method as recited in claim 13 , wherein the programmable operations are capable of converting the pixel data from a first level of precision to a second level of precision.

16. The method as recited in claim 1, wherein the programmable operations are capable of clamping the pixel data for packing the pixel data into a destination.

17. The method as recited in claim 1, wherein condition codes are initialized prior to the programmable operations being performed.

18. The method as recited in claim 1 , wherein the programmable operations are capable of removing the pixel data.

19. The method as recited in claim 1 , wherein the programmable operations are selected from the group consisting of a no operation, texture fetch, move, derivative, multiply, addition, multiply and addition, reciprocal, reciprocal square root, three component dot product, four component dot product, distance vector, minimum, maximum, pack, unpack, set on less than, set on greater or equal than, floor, fraction, kill pixel, exponential base two (2), logarithm base two (2), and light coefficients.

20. A computer program product for programmable pixel processing in a computer graphics pipeline, comprising: (a) computer code for receiving pixel data from a source buffer; (b) computer code for performing programmable operations on the pixel data in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set; and (c) computer code for storing the output in a register.

21. A system for programmable pixel processing, comprising: (a) a source buffer for storing pixel data; (b) a functional module coupled to the source buffer for performing programmable operations on the pixel data received therefrom in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set; and

(c) a register coupled to the functional module for storing the output.

22. A method for programmable pixel processing in a computer graphics pipeline, comprising:

(a) receiving pixel data from a source buffer;

(b) performing programmable operations on the pixel data in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set, and the programmable operations support multiple levels of precision; and

(c) converting the pixel data from a first level of precision to a second level of precision.

23. A method for programmable pixel processing in a computer graphics pipeline, comprising:

(a) receiving pixel data from a source buffer;

(b) performing programmable operations on the pixel data including a texture fetch in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set; and

(c) storing the output in a register.

24. A method for programmable pixel processing in a computer graphics pipeline, comprising:

(a) detennining whether the graphics pipeline is operating in a programmable mode;

G ) performing programmable operations on pixel data in order to generate output if it is determined that the graphics pipeline is operating in the programmable mode; and

(c) performing standard operations on the pixel data in order to generate output in accordance with a standard graphics application program interface if it is determined that the graphics pipeline is not operating in the programmable mode.

25. The method as recited in claim 24, wherein the standard graphics application program interface includes OpenGL^®.

26. A computer program product for programmable pixel processing in a computer graphics pipeline, comprising:

(a) computer code for determining whether the graphics pipeline is operating in a programmable mode;

(b) computer code for performing programmable operations on pixel data in order to generate output if it is determined that the graphics pipeline is operating in the programmable mode; and

(c) computer code for performing standard operations on the pixel data in order to generate output in accordance with a standard graphics application program interface if it is determined that the graphics pipeline is not operating in the programmable mode.

27. The computer program product as recited in claim 26, wherein the standard graphics application program interface includes OpenGL^®.

28. A system for programmable pixel processing in a computer graphics pipeline, comprising:

(a) means for determining whether the graphics pipeline is operating in a programmable mode;

(b) means for performing programmable operations on pixel data in order to generate output if it is determined that the graphics pipeline is operating in the programmable mode; and

(c) means for performing standard operations on the pixel data in order to generate output in accordance with a standard graphics application program interface if it is determined that the graphics pipeline is not operating in the programmable mode.

29. The computer program product as recited in claim 29, wherein the standard graphics application program interface includes OpenGL^®.

30. A method for programmable pixel processing in a computer graphics pipeline, comprising: (a) determining whether the graphics pipeline is operating in a programmable mode; (b) performing programmable operations on pixel data in order to generate output if it is determined that the graphics pipeline is operating in the programmable mode; and (c) performing standard operations on the pixel data in order to generate output in accordance with a standard graphics application program interface if it is determined that the graphics pipeline is not operating in the programmable mode; (d) wherein the programmable operations are selected from the group consisting of a no operation, texture fetch, move, derivative, multiply, addition, multiply and addition, reciprocal, reciprocal square root, three component dot product, four component dot product, distance vector, minimum, maximum, pack, unpack, set on less than, set on greater or equal than, floor, fraction, kill pixel, exponential base two (2), logarithm base two (2), and light coefficients

31. A method for programmable processing in a computer graphics pipeline, comprising: (a) receiving pixel data including texture information; and (b) performing programmable operations on the pixel data in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set; (c) wherein the operations include a mathematical operation for altering the texture information of the pixel data.

A method for programmable processing in a computer graphics pipeline, comprising:

(a) providing pixel data including texture information; and

(b) performing programmable operations on the pixel data in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set; (c) wherein the operations include a mathematical operation for altering the texture information of the pixel data.

33. A method for programmable processing in a computer graphics pipeline, comprising:

(a) receiving pixel data including color information; and

(b) performing programmable operations on the pixel data in order to generate output, wherein the operations are programmable by a user utilizing instructions from a predetermined instruction set; (c) wherein the operations include a mathematical operation for altering the color information of the pixel data.

34. A method for programmable processing in a computer graphics pipeline, comprising: (a) receiving pixel data including texture information and color information; and (b) performing programmable operations on the pixel data in order to generate output, wherein the operations are programmable by a user utilizing instructions from a single instruction set.