[DirectX 8.1 C/C++ Programmer's Reference] nop (100%)

DirectX 8.1 (C++) > DirectX Graphics > Reference > Pixel Shader Reference > Instructions

[DirectX October 2006 Documentation] nop - ps (46.2613636363636%)

DirectX Graphics > Direct3D 9 > Reference > Asm Shader Reference > Pixel Shaders > Pixel Shader Instructions

[DirectX October 2006 Documentation] nop - vs (40.118006993007%)

DirectX Graphics > Direct3D 9 > Reference > Asm Shader Reference > Vertex Shaders > Vertex Shader Instructions