using Graal for a dual-ISA prototype

[Christian Thalinger]

On Feb 12, 2013, at 1:35 PM, "Venkatachalam, Vasanth" <Vasanth.Venkatachalam at amd.com> wrote:

> Christian,
> 
> Thanks for the update. I've started to explore the Graal source. Can you tell me what files I should start looking at so that I can better identify the changes I will have to make (to support other architectures) once your work gets checked in?

Here is the first cut of my PTX changes:

http://cr.openjdk.java.net/~twisti/0000000/

This should give you an idea of what is required.  Note:  it includes the PTXAssembler.java but this one is generated from the ISA description:

http://cr.openjdk.java.net/~twisti/0000000/ptx.isad

-- Chris

> 
> Vasanth 
> 
> -----Original Message-----
> From: Christian Thalinger [mailto:christian.thalinger at oracle.com] 
> Sent: Monday, February 11, 2013 8:24 PM
> To: Venkatachalam, Vasanth
> Cc: sumatra-dev at openjdk.java.net
> Subject: Re: using Graal for a dual-ISA prototype
> 
> 
> On Feb 11, 2013, at 3:30 PM, "Venkatachalam, Vasanth" <Vasanth.Venkatachalam at amd.com> wrote:
> 
>> Hi,
>> 
>> We're thinking of leveraging the Graal OpenJDK project to develop a prototype dual-ISA code generation framework for Sumatra.
>> 
>> http://openjdk.java.net/projects/graal/
>> 
>> Our main idea is that the Hotspot Server JVM will compile the routines that are meant to execute on the CPU, while Graal will intercept and generate GPU-specific code for the few routines that need to execute on the GPU. We thought this approach would lead to a faster prototype and allow us to retain most of Hotspot's existing functionality, as opposed to the riskier approach of writing an entire C2 backend  from scratch.
>> 
>> We have built Graal and run a few test cases using SPECjbb2005. All the runs completed successfully.
>> We are digging deeper into Graal to understand what hooks we need to modify so that Graal intercepts the compilation of routines that need to execute on the GPU.
>> 
>> We'll keep you informed and ask questions as this work progresses. If anyone has feedback, let us know.
> 
> I'm also working on getting Graal to emit code for GPUs.  As a first prototype I took the PTX architecture and implemented initial support in Graal.  The prototype is now able to compile specially annotated methods to PTX code and dump in on the screen (no execution).
> 
> My plan is to push what I have into the Graal repository this week so that other people can pick up the work and implement other architectures, like HSAIL.
> 
> -- Chris
> 
>> 
>> Vasanth
> 
> 
>