llvm dev - Apr 2015 - [LLVMdev] Machine Level IR text-based serialization

Hi,

I'm Alex, and last summer I was working on the code coverage support
for pgo for LLVM and clang at Apple.

I'm currently interning at Apple again, and I'm planning to work on a
project that was suggested to me by Bob Wilson.


I plan on developing a text-based, human readable format that allows LLVM to

serialize the machine level IR (The data structures like
MachineFunction, etc. from CodeGen).

The motivation for this project is that it will enable easier testing
of the CodeGen passes,

and will allow developers to run tests that invoke just a single CodeGen pass,

or that start from a specific pass (llc's -start-after option).


I would be interested in hearing from other people who might be
working on a similar

project or have ideas in which direction this project should go. I
will be posting

an initial proposal for the format in a couple of days.

Thanks,

Alex
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----- Original Message -----
> From: "Alex L" <arphaman at gmail.com>
> To: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>
> Sent: Tuesday, April 21, 2015 12:12:40 PM
> Subject: [LLVMdev] Machine Level IR text-based serialization
> 
> 
> 
> Hi, I'm Alex, and last summer I was working on the code coverage
> support for pgo for LLVM and clang at Apple. I'm currently interning
> at Apple again, and I'm planning to work on a project that was
> suggested to me by Bob Wilson.
> I plan on developing a text-based, human readable format that allows
> LLVM to serialize the machine level IR (The data structures like
> MachineFunction, etc. from CodeGen). The motivation for this project
> is that it will enable easier testing of the CodeGen passes, and
> will allow developers to run tests that invoke just a single CodeGen
> pass, or that start from a specific pass (llc's -start-after
> option).
Great! This is very badly needed.
> I would be interested in hearing from other people who might be
> working on a similar project or have ideas in which direction this
> project should go. I will be posting an initial proposal for the
> format in a couple of days. Thanks, Alex
My one requirement is that it support references to the IR (we still need
IR-level aliasing analysis during CodeGen, and so the MachineMemOperand data
structures need to be available and point to the right things).

Thanks again,
Hal
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> 
-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory

On 04/21/2015 10:12 AM, Alex L wrote:
> Hi,
> I'm  Alex,  and  last  summer  I  was  working  on  the  code  coverage
support  for  pgo  for  LLVM  and  clang  at  Apple.
> I'm  currently  interning  at  Apple  again,  and  I'm  planning 
to  work  on  a  project  that  was  suggested  to  me  by  Bob  Wilson.
> I  plan  on  developing  a  text-based,  human  readable  format  that 
allows  LLVM  to
> serialize  the  machine  level  IR  (The  data  structures  like 
MachineFunction,  etc.  from  CodeGen).
> The  motivation  for  this  project  is  that  it  will  enable  easier 
testing  of  the  CodeGen  passes,
> and  will  allow  developers  to  run  tests  that  invoke  just  a  single
CodeGen  pass,
> or  that  start  from  a  specific  pass  (llc's  -start-after 
option).
This is very needed.  Thank you for working on this.
> I  would  be  interested  in  hearing  from  other  people  who  might  be 
working  on  a  similar
> project  or  have  ideas  in  which  direction  this  project  should  go. 
I  will  be  posting
> an  initial  proposal  for  the  format  in  a  couple  of  days.

Philip

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+1, I'd love this to happen!
On Tue, 21 Apr 2015 at 22:17, Philip Reames <listmail at philipreames.com>
wrote:
>
> On 04/21/2015 10:12 AM, Alex L wrote:
>
>  Hi,
>
> I'm Alex, and last summer I was working on the code coverage support
for pgo for LLVM and clang at Apple.
>
> I'm currently interning at Apple again, and I'm planning to work on
a project that was suggested to me by Bob Wilson.
>
> I plan on developing a text-based, human readable format that allows LLVM
to
>
> serialize the machine level IR (The data structures like MachineFunction,
etc. from CodeGen).
>
> The motivation for this project is that it will enable easier testing of
the CodeGen passes,
>
> and will allow developers to run tests that invoke just a single CodeGen
pass,
>
> or that start from a specific pass (llc's -start-after option).
>
>  This is very needed.  Thank you for working on this.
>
>  I would be interested in hearing from other people who might be working on
a similar
>
> project or have ide
> as in which direction this project should go. I will be posting
>
> an initial proposal for the format in a couple of days.
>
>
>
> Philip
>
>  _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
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Hi Alex,
> I plan on developing a text-based, human readable format that allows 
> LLVM to
> serialize the machine level IR (The data structures like
> MachineFunction, etc. from CodeGen).
> 
> The motivation for this project is that it will enable easier testing
> of the CodeGen passes,
> and will allow developers to run tests that invoke just a single 
> CodeGen pass,
> or that start from a specific pass (llc's -start-after option).
> 
> I would be interested in hearing from other people who might be
> working on a similar
> project or have ideas in which direction this project should go. I
> will be posting
> an initial proposal for the format in a couple of days.
I have been working on a textual Machine IR for the past few months to
facilitate both testing and use of the internal Machine IR in external
tools related to code generation.

The solution we've employed isn't nearly feature complete and it's 
missing
a lot of data, including type data and globals/metadata from the IR, 
but it's
capable of performing the task you describe using -start-after, as well 
as
printing the Machine IR after a given pass with -stop-after.

Unfortunately I can't share any code as this is (currently) a closed
project, but I'd be very interested in hearing about/discussing the 
approach
to this problem and will be looking forward to hearing more about this 
in
the future!

On 4/21/2015 12:12 PM, Alex L wrote:
>
> I plan on developing a text-based, human readable format that allows LLVM
to
> serialize the machine level IR (The data structures like MachineFunction,
etc.
 > from CodeGen).

That is fantastic!

-Krzysztof

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, 
hosted by The Linux Foundation

2015-04-27 1:37 GMT-07:00 <bevinh at sics.se>:
> Hi Alex,
>
>  I plan on developing a text-based, human readable format that allows LLVM
>> to
>> serialize the machine level IR (The data structures like
>> MachineFunction, etc. from CodeGen).
>>
>> The motivation for this project is that it will enable easier testing
>> of the CodeGen passes,
>> and will allow developers to run tests that invoke just a single
CodeGen
>> pass,
>> or that start from a specific pass (llc's -start-after option).
>>
>> I would be interested in hearing from other people who might be
>> working on a similar
>> project or have ideas in which direction this project should go. I
>> will be posting
>> an initial proposal for the format in a couple of days.
>>
>
> I have been working on a textual Machine IR for the past few months to
> facilitate both testing and use of the internal Machine IR in external
> tools related to code generation.
>
> The solution we've employed isn't nearly feature complete and
it's missing
> a lot of data, including type data and globals/metadata from the IR, but
> it's
> capable of performing the task you describe using -start-after, as well as
> printing the Machine IR after a given pass with -stop-after.
>
> Unfortunately I can't share any code as this is (currently) a closed
> project, but I'd be very interested in hearing about/discussing the
> approach
> to this problem and will be looking forward to hearing more about this in
> the future!
>
That's great that you've got it working! I would be interested in
hearing
more details
about the format and the approach that you chose.

Btw, my proposal is now up:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-April/084932.html.
It's quite high level right now, but I would be interested in hearing your
thoughts on the
proposed format.

Cheers,
Alex.
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