[cfe-dev] How to increment a Global Variable in a LLVM module?

Kolmogorov e-link at msn.com
Wed May 13 21:23:46 PDT 2015

I want to add an instruction at the end of a basic block to increment a
GlobalVariable (using the LLVM C++ library). I am pretty new to to the LLVM,
can I do this directly or does this require loading the global variable,
incrementing it by the desired value and writing back to the global variable

Even if I load the variable (with LoadInst constructor), How will the "Add"
instruction know where is the variable ?

For example, look at this IR ocde : %cell_index = load i32* %cell_index_ptr 
%new_cell_index = add i32 1, %cell_index

the add instruction knows on which variable to operate (cell_index). But
since I will create the load instruction from the C++ I don't know where the
variable will be created. (I do not operate the IR code directly but using
the C++ it was just for the example

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