Basic blocks, jump targets and locals

[Dibyendu Majumdar <mobile@majumdar.org.uk>]

Hi,

In LLVM the IRBuilder has the concept of a current block where
instructions are inserted. Reading the libgccjit docs I think that
there is no notion of current block - i.e. this needs to be maintained
by the caller - is that correct?

Can one create several blocks in advance - and set a block that is not
yet inserted into the function as the target for a jump? The scenario
is this: when compiling Lua bytecode I already know all the jump
targets. So I pre-create all the basic blocks that relate to the jump
targets up front - and as each jump is encountered I can easily set
the jump target to the right block. As and when I cross the bytecode
that is a jump target the block gets added to the function.

I hope above is clear - if not I can explain by an example.

Can I do something similar with libgccjit?

Finally - how are local variable related to blocks. In LLVM one has to
create the local vars in the entry block of the function. Is it the
same with libgccjit?

Thanks and Regards
Dibyendu