Strange behavior - kernel works fine with this:
__constant sampler_t imageSampler = CLK_NORMALIZED_COORDS_FALSE | CLK_ADDRESS_NONE | CLK_FILTER_NEAREST, using this - read_imagef(image, imageSampler, coords);
without sampler and with "read_imagef(image, coords)" (should work the same way as above) - data goes randomly crippled.
An image is a 3D-image, referenced from OpenGL, rendered there slice by slice through FBO.
Seems like a bug?
P.S. Other regular 2D-image works fine with or without sampler.