Instructions

Instructions

Pixel shaders contain the following types of instructions.

• A Version instruction defines the shader version. There is only one version instruction in a shader and it is the first instruction in a shader.
• Constant instructions define constants. These instructions must be after the version instruction and before any arithmetic or texture address instructions.
• A Phase instruction splits a shader into two sections: phase 1 and phase 2. Each phase has separate arithmetic and texture address instruction limits. Version 1.4 is the only version that supports the phase instruction.
• Arithmetic instructions include common mathematical operations such as add and subtract, multiply, and taking a dot product.
• Texture Address instructions manipulate texture coordinate data that is associated with texture stages.

The instructions are listed below.