-use-intel-optimized-headers not recognized ("argument unused during compilation") for compilation, only for linking?

Question

Trying to follow this (Intel64/Linux):

https://www.intel.com/content/www/us/en/develop/documentation/oneapi-dpcpp-cpp-compiler-dev-guide-and-reference/top/compiler-reference/libraries/intel-c-class-libraries/intel-s-valarray-implementation.html

But it doesn't seem to recognize -use-intel-optimized-headers for compilation, only for linking?

icpx -use-intel-optimized-headers -c valarray.C

icpx: warning: argument unused during compilation: '-u se-intel-optimized-headers' [-Wunused-command-line-argument]

icpx -use-intel-optimized-headers valarray.o

(no error/warning)

icpx -use-intel-optimized-headers valarray.C

(no error/warning)

(FWIW, icpc doesn't seem to produce the same error message)

Answer 1

Yes, you are correct. With the transition from icc/icpc to llvm-based icx/icpx, we improved compiler diagnostics which are now inline with clang.

Given the option "-use-intel-optimized-headers" is only used at link time and not compile time, icpx producing the warning of it being unused in a compile-only step is expected.

Thanks, Varsha