[llvm-dev] How is llvm-avr backound integration going?

Dylan McKay via llvm-dev llvm-dev at lists.llvm.org
Sat Feb 6 21:57:06 PST 2016


You can view the current status of the in-tree AVR backend here
<http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AVR/>.

Allen is right when he says that a good amount of the skeleton code has
been added so far. The backend is probably about 40% in tree currently.
There are a few things that will need to be fixed before the merge is
completed however.

   - We have three 16-bit pointer registers: X, Y, and Z. If a function
   allocates on the stack, Z must be used for the stack pointer. Currently
   we have a hack which hooks into the regalloc, undoing all uses of the Z
   register in a function once it allocates. It is messy, and touches some of
   the generic regalloc code.
   - TableGen related modifications

There is a list of ‘upstream-blocking’ issues detailed here
<https://github.com/avr-llvm/llvm/issues?q=is%3Aopen+is%3Aissue+label%3Ablocks-upstreaming>
.
​

On Sun, Feb 7, 2016 at 8:00 AM, Allen Lorenz <allenlorenz at gmail.com> wrote:

> To those interested in AVR backend additions to LLVM, the LLVM review
> tools "Phabricator" ( don't ask me to say that 3 times fast ),  allows easy
> searching.   Go to http://reviews.llvm.org/  and type in AVR in the
> search entry.  This will give you a list of the commits, and resolutions.
> From my understanding ( NO Expert ), a large part of the skeleton code has
> been added.  The leave the rest of the skeleton,and all the fleshy bits.
> Good progress Dylan!.
>
> On Mon, Dec 21, 2015 at 3:28 AM, Dylan McKay <dylanmckay34 at gmail.com>
> wrote:
>
>> Hey Allen,
>>
>> Progress is slow but it is happening. It will take a number of more
>> releases until it is ready.
>>
>> Currently the backend is marked as an 'experimental' target, which means
>> the only way it can be used is by compiling LLVM from source and passing
>> '-DLLVM_EXPERIMENTAL_TARGETS=AVR' to CMake.
>>
>> At the moment almost no AVR-specific code has been merged, including
>> clang support, which should come after the backend is functional.
>> How is the llvm-avr backend integration going ? Will it be functional (
>> experimental ) in the 3.8 release ?  Will Clang recognize options for avr ?
>>
>> thanks.
>>    Allen
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160207/2752d268/attachment.html>


More information about the llvm-dev mailing list