[LLVMdev] choice between SSAPRE and bitvector aporach

Daniel Berlin
2008-04-04T21:51:26Z

On Fri, Apr 4, 2008 at 2:38 AM, Bill Wendling <isanbard at gmail.com>
wrote:
> On Apr 2, 2008, at 10:11 PM, Xuehai Qian wrote:
>  > Hi LLVMers,
>  >    I am a PHD student in CS dept in UIUC, I am doing a project for
>  > Vikram's course, it is about PRE. I would like to know why you
didn't
>  > choose SSAPRE in LLVM, since it seems to be more suitable for LLVM
(it
>  > can operate directly on SSA form and avoid the conversion between SSA
>  > and bit-vector). Can anyone tell me the reason?
>
>  Hi Xuehai,
>  >
>
>  If I remember correctly, there were several details that the paper
>  assumed that made adapting it to work in LLVM very difficult.

It would at least require side-data structures to store the
occurrences and expression phis.


>
>  -bw
>
>
> _______________________________________________
>  LLVM Developers mailing list
>  LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>  http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>