[PATCH] Disable passes on optnone functions

[Robinson, Paul]

> -----Original Message-----
> From: Nick Lewycky [mailto:nicholas at mxc.ca]
> Sent: Saturday, March 01, 2014 1:17 AM
> To: Robinson, Paul
> Cc: llvm-commits at cs.uiuc.edu
> Subject: Re: [PATCH] Disable passes on optnone functions
> 
> Robinson, Paul wrote:
> > This patch disables a number of Machine Function Passes for functions
> > with the 'optnone' attribute.
> >
> > To come up with the list of passes, I looked at CodeGen/Passes.cpp,
> > and disabled whatever would be excluded under CodeGenOpt::None.
> > Except, I did not disable anything listed in addOptimizedRegAlloc(),
> > as I can't see how to substitute one RA pass sequence for another on
> > a per-function basis.  Maybe there's a way to deal with that safely,
> > but for now it seemed prudent (and not horribly harmful to the goals
> > of 'optnone') to leave well enough alone.
> > If anybody has an idea, we're open to it.
> 
> I note that I'm on the 'to' line, but I am certainly not the right
> person to review this. I know some high-level design of the codegen
> parts, but that's about it.

Ah, sorry.  You were there for me on the {Function|BasicBlock|Loop}Pass
part, I shouldn't have presumed about MachineFunctionPass.

> 
> Would someone else please take a look?
> 
> Nick

--paulr