[llvm-dev] OptBisect implementation for new pass manager

[David Greene via llvm-dev]

I'm concerned about codegen.  If Codegen is not yet ready for the new
PM, should the new PM really become default?  I would at least like to
see a plan of how Codegen is going to migrate before the new PM becomes
default.  Codegen pass pipelines have been wonky ever since I started
working with LLVM and it would be nice to get that cleaned up.

                            -David

Philip Pfaffe <philip.pfaffe at gmail.com> writes:

> Well, I think we don't have a clear idea about new-PM codegen should
> work in general. Is this really something that concerns us right now?
>
> Philip
>
> On Wed, Sep 26, 2018 at 7:54 PM Friedman, Eli
> <efriedma at codeaurora.org> wrote:
>
>     On 9/26/2018 10:47 AM, Philip Pfaffe via llvm-dev wrote:
>     > Hi Fedor,
>     >
>     > can you make an example where a pass actually needs to opt-out? 
>     > Because IMO, bisect should quite literally to DebugCounter-style
>     skip 
>     > every step in every ::run method's loop. Passes should not even
>     be 
>     > concerned with this.
>     
>     This isn't so much an issue for the optimization pipeline, but
>     code 
>     generation involves some passes which are mandatory (e.g. isel).
>     
>     -Eli
>     
>     -- 
>     Employee of Qualcomm Innovation Center, Inc.
>     Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>     a Linux Foundation Collaborative Project
>