I'm a long time user of icc (dating back to the first version for OS X) and I've never gotten precompiled headers to work with icc and Xcode. What exactly are we supposed to do?
When using the default compiler in Xcode, all I have to do is enable precompiled headers and set the filename of the prefix header. In the prefix header, I include my commonly used headers. This works just fine whenever I build with clang (and in the past, gcc).
However, when I enable Precompile Prefix Header in the Intel C++ Compiler XE 14.0 settings and set the compiler to icc in my project, prefix.h is compiled with every file in my project which more than doubles my compile time.
So what are we supposed to do in the project settings in Xcode to get precompiled headers working when compiling with icc?