[LLVMdev] Pass Manager Question

[me22]

On Thu, Mar 19, 2009 at 14:43, John Criswell <criswell at cs.uiuc.edu> wrote:
>
> If I have a ModulePass that requires a FunctionPass, and I include a
> line like the following:
>
> <variable> = &getAnalysis<TheFunctionPass>(*Function);
>
> ... will the PassManager blindly re-run the FunctionPass each time the
> ModulePass requests it, or does it use the Pass dependency information
> to re-run the FunctionPass only when necessary.
>

Apparently it should use the dependency and preservation information
to schedule them efficiently.  See
http://llvm.org/docs/WritingAnLLVMPass.html#passmanager

~ Scott