Re: The nvptx port [10/11+] Target files

[Jeff Law <law at redhat dot com>]

On 10/28/14 08:56, Bernd Schmidt wrote:
> I have patches that expose all the address spaces to the middle-end
> through a lower-as pass that runs early. The preliminary patches for
> that ran into some resistance and into general brokenness of our address
> space support, so I decided to rip all that out for the moment to get
> the basic port into the next version.
>
> This new version also implements a way of providing realloc that was
> suggested in another thread. Calls to malloc and free are redirected to
> libgcc variants. I'm not a big fan of wasting extra space on every
> allocation (which is why I didn't originally consider this approach
> viable), but it seems we'll have to do it that way. There's a change to
> the libgcc build system: on ptx we need comments in the assembly to
> survive, so we can't use -xassembler-with-cpp. I've not found any files
> named "*.asm", so I've changed that suffix to mean plain assembler.
>
>
> Bernd
>
>
> 010-target.diff
>
>
> 	* configure.ac: Allow configuring lto for nvptx.
> 	* configure: Regenerate.
>
> 	gcc/
> 	* config/nvptx/nvptx.c: New file.
> 	* config/nvptx/nvptx.h: New file.
> 	* config/nvptx/nvptx-protos.h: New file.
> 	* config/nvptx/nvptx.md: New file.
> 	* config/nvptx/t-nvptx: New file.
> 	* config/nvptx/nvptx.opt: New file.
> 	* common/config/nvptx/nvptx-common.c: New file.
> 	* config.gcc: Handle nvptx-*-*.
>
> 	libgcc/
> 	* config.host: Handle nvptx-*-*.
> 	* shared-object.mk (as-flags-$o): Define.
> 	($(base)$(objext), $(base)_s$(objext)): Use it instead of
> 	-xassembler-with-cpp.
> 	* static-object.mk: Identical changes.
> 	* config/nvptx/t-nvptx: New file.
> 	* config/nvptx/crt0.s: New file.
> 	* config/nvptx/free.asm: New file.
> 	* config/nvptx/malloc.asm: New file.
> 	* config/nvptx/realloc.c: New file.
A "nit" -- Richard S. recently removed the need to include the "enum" 
for "enum machine_mode".  I believe he had a script to handle the 
mundane parts of that change.  Please make sure to update the nvptx port 
to conform to that new convention, obviously feel free to use the script 
if you want.

You may need to update with James Greenhalgh's changes to 
MOVE_BY_PIECES_P and friends.

With those two issues addressed as needed, this is OK for the trunk.


FWIW, I'm amazed at how many similarities there are between what needs 
to be done for the PTX tools and what needed to be done to interface 
with the native HPPA tools way-back-when.  Simply amazing.

I notice that you've got some OpenMP bits (write_as_kernel).  Are y'all 
doing any testing with OpenMP or is that an artifact of layering OpenACC 
on top of the OpenMP infrastructure?

Also, I've asked the steering committee to appoint you as the maintainer 
for the nvptx port as well.

jeff