[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.
> Andrew
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 
<http://cafxx.strayorange.com> Blog 
<http://www.strayorange.com/blog/category/members/cafxx> LinkedIn 
<http://it.linkedin.com/in/cafxx> Facebook 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110401/172f5a85/attachment.html>

More information about the llvm-dev mailing list