[llvm-commits] [llvm] r117709 - /llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp

[Eli Friedman]

On Fri, Oct 29, 2010 at 2:05 PM, Owen Anderson <resistor at mac.com> wrote:
> Author: resistor
> Date: Fri Oct 29 16:05:17 2010
> New Revision: 117709
>
> URL: http://llvm.org/viewvc/llvm-project?rev=117709&view=rev
> Log:
> Give up on doing in-line instruction simplification during correlated value propagation.  Instruction simplification
> needs to be guaranteed never to be run on an unreachable block.  However, earlier block simplifications may have
> changed the CFG to make block that were reachable when we began our iteration unreachable by the time we try to
> simplify them. (Note that this also means that our depth-first iterators were potentially being invalidated).

It isn't obvious to me how value propagation actually modifies the CFG...

-Eli