It seems that the new Crimson driver has introduced an issue with CodeXL (versions 1.8 and 1.9 tested, both on Windows) - when GLSL code contains a call to texture() or similar, several lines of the ISA code are overwritten with V_NOP.
You can test the issue with any short shader that contains a texture() call - the only output will be lots of V_NOP. With longer shaders that have a lot of non-texture commands, only the first chunk of instructions are overwritten.
I noticed in the CodeXL 1.9 changelog that a fix for an issue that sounds exactly like this was made for Ubuntu. I think the same fix is needed on Windows.