Thank you for your follow-up. One other thing related to cl_amd_vec3 I just noticed is that the usertype.dat file included in AMD APP SDK 2.7 does not include syntax highlighting for those types (and some convert_* functions seem to be missing). I've attached an updated file that I think fills in the blanks.
I have created another bug report.
http://www.amd.com/report will redirect you to a form with a URL like:
I think this is the official bug reporting mechanism.
You can also contact AMD support either by email (http://emailcustomercare.amd.com/) or by phone (http://support.amd.com/us/contacts/Pages/global-technical-support.aspx) to report bugs.
The email form is nice in that it lets you send attachments.
Just a quick follow-up about the original issue with cl_amd_vec3 not being recognized. If you query a device using clGetDeviceInfo for CL_DEVICE_OPENCL_C_VERSION and it returns OpenCL C 1.1 or 1.2 (and probably anything thereafter), then vec3's are already supported as per those specifications, so no extensions required. So maybe the cl_amd_vec3 extension is only an issue for OpenCL C 1.0 devices.
A fix has been checked into the development branch for the vec3 & fp64 problems.
I cannot say for sure when users will see the fix, but the process usually takes several months.