ifx: pass LLVM options through front-end

[foxtran]

Dear,

I have tried to look which optimisation pass of LLVM takes long time with option -ftime-report=per-pass-run. However, ifx said that it does not know such option:

ifx: command line warning #10006: ignoring unknown option '-ftime-report=per-pass-run'

How can I pass options to LLVM via ifx front-end? I'm using ifx (IFX) 2023.2.0 20230721

Best regards,
Igor

[Barbara_P_Intel · Accepted solution]

Not all LLVM compiler options are recognized by ifx. There is an undocumented compiler option -i_tapi that creates <source>.tapi with compiler profile information. It works for both ifx and ifort. 

[foxtran]

Thanks, Barbara!

It helps!

[Barbara_P_Intel]

There is this ifx compiler option: -mllvm <LLVM option>. It passes the option to LLVM. BTW, ftime-report=per-pass-run doesn't work with -mllvm; it's a Clang option.

I was just warned that -i_tapi may get renamed at some point.

[foxtran]

 Ok! Thank you!

I will remember it.

[Eugene_E_Intel]

Note that ifx -c -mllvm -time-passes hello.f90 should work with a recent ifx compiler and should be equivalent to -ftime-report=per-pass-run