trying to redeclare the built-in gl_LastFragData to change its precision in PVRShaderEditor 2.6 (SDK build 3.5@3523712) using the G6x00 compiler causes a compilation error.
#extension GL_EXT_shader_framebuffer_fetch: require
lowp vec4 gl_LastFragData[gl_MaxDrawBuffers];
This gives the error [blockquote]0:123: ‘gl_LastFragData’ : cannot redeclare this built-in[/blockquote]
However the description of GL_EXT_shader_framebuffer_fetch explicitly allows the redeclaration of gl_LastFragData. See question 3 “What is the precision of gl_LastFragData in practice?” with the resolution “Allow redeclaration of gl_LastFragData in order to change its precision.”.