Conditional shader for graphics

A conditional shader apparatus, comprising:

• a conditional pixel shader to,
• wherein the conditional pixel shader is to be split into two invocations to:
• determine, in the first invocation of the conditional pixel shader, if one or more pixels meet a shader condition associated with an execution unit instruction set that includes single instruction multiple data (SIMD) instructions, wherein the SIMD instructions support parallel execution of a plurality of threads in an absence of multiple independent instruction units, and wherein the shader condition is whether any of the one or more pixels survives or not, and wherein the condition comprises a visibility-type shader condition;
• and
• process, in the second invocation of the conditional pixel shader, the surviving pixels based on whether the one or more processing elements are determined to meet the shader condition, and wherein the surviving pixels are passed to parallel execution via the SIMD instructions only when a given pixel survives;
• and
• a pixel regrouper communicatively coupled to the conditional pixel shader to regroup the surviving pixels for parallel execution via the SIMD instructions, wherein the regroup operation is based on whether the one or more pixels are determined to meet the shader condition.

A method of conditional shading, comprising:

• determining if one or more pixels meet a shader condition, via a conditional pixel shader that is split into two invocations, wherein the determining if one or more pixels meet the shader condition comprises:
• determining, in the first invocation of the conditional pixel shader, if one or more pixels meet a shader condition associated with an execution unit instruction set that includes single instruction multiple data (SIMD) instructions, wherein the SIMD instructions support parallel execution of a plurality of threads in an absence of multiple independent instruction units, and wherein the shader condition is whether any of the one or more pixels survives or not and wherein the condition comprises a visibility-type shader condition;
• and
• processing, in the second invocation of the conditional pixel shader, the surviving pixels based on whether the one or more processing elements are determined to meet the shader condition, and wherein the surviving pixels are passed to parallel execution via the SIMD instructions only when a given pixel survives;
• and
• regrouping the surviving pixels for parallel execution via the SIMD instructions, wherein the regroup operation is based on whether the one or more pixels are determined to meet the shader condition.