[LLVMdev] Regression in 3.4's register allocator?

[Jim Grosbach]

Yep, quite right, Evan. Any regalloc differences due to that patch are purely coincidence;

-Jim

> On Jun 16, 2014, at 10:13 AM, Evan Cheng <evan.cheng at apple.com> wrote:
> 
> Hi Niklas,
> 
> The attached patch has nothing to do with register allocation. r206094 changes how cpu auto-detection is done. I believe it's now the responsibility of the tools (e.g. llc) to detect the cpu. My guess is the proper fix is on the RoboVM side to handle the change.
> 
> Jim, can you confirm?
> 
> Evan
> 
> On Jun 1, 2014, at 1:45 PM, Niklas Therning <niklas at therning.org> wrote:
> 
>> I think we have located the revision which fixes this regression: r206094 (or commit 6bb00df in llvm-mirror on GitHub). I have attached a patch which can be applied to the current release_34 branch (tested against the release_34 branch in llvm-mirror). With this patch the attached reg-alloc-test.ll file doesn't fail with the "LLVM ERROR: ran out of registers during register allocation" error any longer. I haven't run any llvm tests to make sure this patch doesn't break anything else but as far as I can see it doesn't at least break anything when used in RoboVM.
>> 
>> Is it too late to get this into 3.4.2? Is there anything else I can do to make it easier for you to include this patch in 3.4.2 or the next possible point release?
>> 
>> 
>> 
>> On Wed, May 14, 2014 at 3:25 PM, Renato Golin <renato.golin at linaro.org> wrote:
>> On 14 May 2014 14:15, Niklas Therning <niklas at therning.org> wrote:
>> > I can confirm that this regression has been fixed in trunk. Should I report
>> > this as a bug in 3.4?
>> 
>> The 3.4.2 release is coming, you might want to consider finding the
>> patches responsible for the fix and proposing it for back-porting.
>> 
>> Please email Tom (cc'd) if you end up with a proposal.
>> 
>> cheers,
>> --renato
>> 
>> <reg-alloc-regression.patch><reg-alloc-test.ll>_______________________________________________
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