[LLVMdev] sccp pass with opt

[Shuxin Yang]

This compiler does not have mem-SSA,  as far as I know, only few pass 
can propagate value along memory.

You need to promote those local variable into register first before sccp 
is invoked.
  e.g1. opt a.ll -basicaa -gvn -sccp -S
  eg.2. opt a.ll -sroa -sccp -S

On 4/16/13 12:37 PM, Niko Zarzani wrote:
> Hi all,
>
> I am trying to see how single llvm optimizations work by running them 
> one by one with opt and looking how the IR changes.
> Since I was interested in seeing how constant propagation was working 
> I tried to run opt on the Sparse Conditional Constant Propagation, 
> however by passing as argument -S -sccp -die it does not change 
> anything in the output IR code. I attached the file with the source 
> code I used, I think that the x value in that example should be 
> propagated in the mul instruction. What am I missing?
>
> Thank you in advance,
>
> Niko
>
>
>
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