[LLVMdev] How to add LiveVariables pass (original) (raw)

e e hasnoadditives at gmail.com
Thu Oct 2 09:15:49 PDT 2014

Hi,

In LLVM 3.4 using C++ API I would like to track which physical registers are live. Therefore I want to add a LiveVariables pass to FunctionPassManager. However I get this failed assertion:

Pass 'Remove unreachable machine basic blocks' is not initialized. Verify if there is a pass dependency cycle. Required Passes: ~/llvm-3.4/lib/IR/LegacyPassManager.cpp:645: void llvm::PMTopLevelManager::schedulePass(llvm::Pass*): Assertion `PI && "Expected required passes to be initialized"' failed.

Looking into CodeGen/UnreachableBlockElim.cpp I find that 'Remove unreachable machine basic blocks' is the name of UnreachableMachineBlockElim, for which exists a function prototype 'void initializeUnreachableMachineBlockElimPass(PassRegistry&);' in InitializePasses.h. Calling that function (for which I don't see any implementation...) with llvm::PassRegistry::getPassRegistry() before adding LiveVariables to the pass manager still results in the same failed assertion. Creating an instance of UnreachableMachineBlockElim is not possible because the class is not declared in a header file and therefore not visible to the compiler.

How can I add LiveVariables to my FunctionPassManager?

Best regards, Christoph -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20141002/e39e71f7/attachment.html>

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