webrev for register decoupling changes

[Venkatachalam, Vasanth]

Please attribute the changes to Vasanth Venkatachalam.

The message can be:

These changes allow the HSAIL register configuration to be used by the register allocator.
The main change was to override Backend.newFrameMap() in HSAILBackend to use the HSAIL register configuration.

Thanks,

Vasanth

-----Original Message-----
From: Doug Simon [mailto:doug.simon at oracle.com] 
Sent: Friday, September 20, 2013 2:34 PM
To: Venkatachalam, Vasanth
Subject: Re: webrev for register decoupling changes

BTW, I'll push through these changes once you let me know who to attribute in the commit message as well as the message itself.

On Sep 20, 2013, at 9:12 PM, "Venkatachalam, Vasanth" <Vasanth.Venkatachalam at amd.com> wrote:

> Hi,
> 
> We never received feedback on this webrev. I'd like to remind people to please review this and provide your feedback.
> These changes are along the lines of what Thomas Wuerthinger recommended to allow the HSAIL register configuration to be used, namely by overriding Backend.newFrameMap( ) in HSAILBackend..
> 
> Vasanth
> 
> From: Venkatachalam, Vasanth
> Sent: Tuesday, September 10, 2013 1:38 PM
> To: graal-dev at openjdk.java.net
> Subject: webrev for register decoupling changes
> 
> Hi,
> 
> Graal's register allocator was previously calling into the x86 runtime to get register numbers to be used for generating HSAIL code.
> The x86 register numbers were getting translated into the corresponding HSAIL register mnemonics in the assembler.
> 
> This small webrev allows  the register allocator to work with the HSAIL register configuration for getting register numbers to be used for generating HSAIL code.
> 
> http://cr.openjdk.java.net/~tdeneau/graal-webrevs/webrev-registerdecoupling/webrev/
> 
> Note: HSAIL uses a special calling convention where function params are passed in an arg segment in memory. Currently Graal only supports a choice between a register-based or stack-based calling convention. We have yet to add support for an arg-segment based calling convention. This will be forthcoming in a later patch.  However, the current patch makes the code generation more accurate from the point of view of the HSAIL register configuration.
> 
> Please review and provide your feedback.
> 
> Vasanth
> 
>