[LLVMdev] Pass Manager Question

[Devang Patel]

On Mar 19, 2009, at 11:43 AM, John Criswell wrote:

> Dear All,
>
> 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.

Normally the pass manager runs pass only when necessary, but in this  
special case you mentioned the pass manager will always re-run the  
function pass.

-
Devang