[cfe-dev] [OpenCL] Question about pre-linking passes required to build OpenCL program

Anastasia Stulova via cfe-dev cfe-dev at lists.llvm.org
Wed May 11 09:50:48 PDT 2016


Hi Brian,

> For example, we transform printf calls into a form that interacts with our library.  We also transform calls to pipe functions, kernel enqueue related functions, and transform calls to the atomic functions to corresponding LLVM atomic instructions (and keep track of the memory scope elsewhere currently).

Sounds like most of the transformation are affecting OpenCL 2.0. It would be nice to see progress with the latest standards on LLVM side too.

> You may have noticed that we have a proposal out to enable the atomic instructions to directly carry a memory scope.

Yes, but probably need to look more into this.

Thanks,
Anastasia

From: Liu, Yaxun (Sam) [mailto:Yaxun.Liu at amd.com]
Sent: 10 May 2016 22:17
To: Sumner, Brian; Anastasia Stulova; cfe-dev (cfe-dev at lists.llvm.org); Pan, Xiuli; Bader, Alexey (alexey.bader at intel.com); llvm-dev at lists.llvm.org
Cc: Stellard, Thomas; Mekhanoshin, Stanislav; nd
Subject: RE: [OpenCL] Question about pre-linking passes required to build OpenCL program

+ llvm-dev

From: Sumner, Brian
Sent: Tuesday, May 10, 2016 3:11 PM
To: Anastasia Stulova <Anastasia.Stulova at arm.com<mailto:Anastasia.Stulova at arm.com>>; Liu, Yaxun (Sam) <Yaxun.Liu at amd.com<mailto:Yaxun.Liu at amd.com>>; cfe-dev (cfe-dev at lists.llvm.org<mailto:cfe-dev at lists.llvm.org>) <cfe-dev at lists.llvm.org<mailto:cfe-dev at lists.llvm.org>>; Pan, Xiuli <xiuli.pan at intel.com<mailto:xiuli.pan at intel.com>>; Bader, Alexey (alexey.bader at intel.com<mailto:alexey.bader at intel.com>) <alexey.bader at intel.com<mailto:alexey.bader at intel.com>>
Cc: Stellard, Thomas <Tom.Stellard at amd.com<mailto:Tom.Stellard at amd.com>>; Mekhanoshin, Stanislav <Stanislav.Mekhanoshin at amd.com<mailto:Stanislav.Mekhanoshin at amd.com>>; nd <nd at arm.com<mailto:nd at arm.com>>
Subject: RE: [OpenCL] Question about pre-linking passes required to build OpenCL program

Hi Anastasia,

I'm glad to hear there could be some support for such a mechanism.  On our side, we use such pre-link passes to interface with the specifics of our built-in function library.  For example, we transform printf calls into a form that interacts with our library.  We also transform calls to pipe functions, kernel enqueue related functions, and transform calls to the atomic functions to corresponding LLVM atomic instructions (and keep track of the memory scope elsewhere currently).  You may have noticed that we have a proposal out to enable the atomic instructions to directly carry a memory scope.

Thanks,
Brian

From: Anastasia Stulova [mailto:Anastasia.Stulova at arm.com]
Sent: Tuesday, May 10, 2016 11:45 AM
To: Liu, Yaxun (Sam); cfe-dev (cfe-dev at lists.llvm.org<mailto:cfe-dev at lists.llvm.org>); Pan, Xiuli; Bader, Alexey (alexey.bader at intel.com<mailto:alexey.bader at intel.com>)
Cc: Stellard, Thomas; Sumner, Brian; Mekhanoshin, Stanislav; nd
Subject: RE: [OpenCL] Question about pre-linking passes required to build OpenCL program

Hi Sam,

It seems to be generally useful to the community. Could you give some examples of those transformations that can be shared?

Also I am guessing this will be a part of LLVM code base. Do you intend it to be publically available on the master branch?  If yes, perhaps llvm-dev should be added to the discussion too.

Cheers,
Anastasia

From: Liu, Yaxun (Sam) [mailto:Yaxun.Liu at amd.com]
Sent: 09 May 2016 21:14
To: cfe-dev (cfe-dev at lists.llvm.org<mailto:cfe-dev at lists.llvm.org>); Anastasia Stulova; Pan, Xiuli; Bader, Alexey (alexey.bader at intel.com<mailto:alexey.bader at intel.com>)
Cc: Stellard, Thomas; Sumner, Brian; Mekhanoshin, Stanislav
Subject: [OpenCL] Question about pre-linking passes required to build OpenCL program

Hi,

We typically need to apply some transformations to the IR between clang and the standard linker. I am wondering if other OpenCL platforms require the same as well?

I'm wondering if we all need such transformations (likely target specific). Is there any way to collaborate on a common infrastructure for pre-linking transformation that would reduce the size of the additions we have to make?

Thanks.

Sam
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