Method and apparatus for parallel pixel shading

A method implemented in a graphics processing unit (GPU) to perform hashing of pixel blocks among sub-groups of the GPU's processing resources, the method comprising:

• determining X and Y coordinates for a pixel block to be processed;
• and
• performing a hashing operation using the X and Y coordinates to assign each pixel block to a particular sub-group of processing resources,
• wherein performing the hashing operation comprises checking for divisibility by N where N is the number of sub-groups of processing resources, performing one or more additional operations to assign the pixel block to one of the N−1 sub-groups of processing resources if the divisibility by N operation is determined to be FALSE, the one or more additional operations comprising performing an XOR operation on a bit from the X coordinate and a bit from the Y coordinate to generate a result and adding one to the result;
• and
• using the result to select a specified one of the sub-groups of processing resources for processing the pixel block.

A processor comprising:

• N sub-groups of processing resources to perform parallel processing of graphics instructions;
• a dispatcher circuitry to dispatch graphics instructions to each of the processing resources within each of the N sub-groups;
• and
• sub-group selection circuitry to:
• determine X and Y coordinates for a pixel block to be processed;
• perform a first set of one or more modulus operations using even bits from the X and Y coordinates to generate a first intermediate result;
• perform a second set of one or more modulus operations using odd bits from the X and Y coordinates to generate a second intermediate result;
• compare the first intermediate result and the second intermediate result to generate a final result;
• and
• use the final result to select a first sub-group of processing resources from the set of N processing resources for processing the pixel block.