Reg: Executing ModulePass before O2/O3 optimizations

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1

Hello Everyone

I have created a custom ModulePass which works fine when no optimization flag is enabled i.e. on -O0 level. I am trying to order the passes such that I run my ModulePass first and then the O2/O3 optimizations. Currently I am doing it in multiple steps, where at each step I getting the transformed IR and providing as input. Is it possible to specify this order in when invoking via clang itself.
Kindly guide me in this.

Thanking you
Sai

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If you’re using the new PassManager you can register your Pass with PassBuilder::registerPipelineStartEPCallback.

-Min

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Thanks Min-Yih. But currently I am using the legacy PassManager. Is there any alternative way to achieve this?