[LLVMdev] LiveValues removal
Carlo Alberto Ferraris
cafxx at strayorange.com
Fri Apr 1 04:56:56 PDT 2011
Il 31/03/2011 18:50, Andrew Clinton ha scritto:
> LiveVariables is the optimized and tested way to get variable liveness
> information (it's used by register allocation). Unfortunately it
> requires a MachineFunction to work - so you'll either need to lower to
> one of the built-in targets or add your own target to acquire access
> to this pass.
I just realized that I actually need something looser than LiveValues. I
just need to know, at the begining of a BB, the list of values defined
in the predecessor(s). If there are multiple predecessors it's easy (I
just iterate over the PHIs and get all I need to know there), but I'm
kind of stuck on how to do it when there's a single predecessor, i.e.
there are no PHIs.
How is this problem dealt with internally by LLVM?
Carlo Alberto Ferraris <cafxx at strayorange.com
<mailto:cafxx at strayorange.com>>
+39 333 7643 235 XMPP <xmpp:cafxx at strayorange.com> Website
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