LTO & aarch64

[Richard Earnshaw (lists)]

On 31/05/17 14:33, John Pullen wrote:
> On 31/05/2017 3:32 PM, Richard Earnshaw (lists) wrote:
>> On 27/05/17 14:39, John Pullen wrote:
>>> Hi all,
>>>
>>> I'm using the latest GCC 7.1 source which I've built locally for
>>> aarch64. Everything works fine, but I'm running into issuses using LTO.
>>>
>>> Normally I compile our dynamic library with -ffixed-x18 and it works
>>> fine, but with LTO enabled, register x18 is used in the output
>>> assembler.
>>>
>>> Is there anyway to stop LTO from using certain registers?
>>>
>>
>> Are you passing -ffixed-x18 to the link/lto step?
>>
>> R.
>>> Cheers,
>>> John.
>>>
>>
>>
> 
> Yea I tried that.
> 
> It does create a different binary, as the size is different, but the x18
> register is still used.
> 

Hmm, not sure then.  Would need a test case to investigate.  What about
the library code?  Was that also built with -ffixed-x18?

Please file something in bugzilla if you think there's a problem.

R.