Displaying 4 results from an estimated 4 matches for "canjoinphys".
2016 Feb 26
2
Reserved/Unallocatable Registers
...tant registers and other reserved registers but I can’t find it now. We do some register coalescing that is not consistent with your rules here: If a virtual register is defined as a copy of a constant register, we will replace the virtual register with the constant register. See RegisterCoalescer::canJoinPhys(). This can mean the the register is read multiple times. This optimization was added for the ARM64 zero register.
>
> Thanks,
> /jakob
>
>
>> On Feb 25, 2016, at 18:14, Matthias Braun <mbraun at apple.com> wrote:
>>
>> Lately I have had a few discussions...
2016 Feb 26
0
Reserved/Unallocatable Registers
...tant registers and other reserved registers but I can’t find it now. We do some register coalescing that is not consistent with your rules here: If a virtual register is defined as a copy of a constant register, we will replace the virtual register with the constant register. See RegisterCoalescer::canJoinPhys(). This can mean the the register is read multiple times. This optimization was added for the ARM64 zero register.
Thanks,
/jakob
> On Feb 25, 2016, at 18:14, Matthias Braun <mbraun at apple.com> wrote:
>
> Lately I have had a few discussions of what it means for a register to be...
2016 Feb 26
0
Reserved/Unallocatable Registers
...tant registers and other reserved registers but I can’t find it now. We do some register coalescing that is not consistent with your rules here: If a virtual register is defined as a copy of a constant register, we will replace the virtual register with the constant register. See RegisterCoalescer::canJoinPhys(). This can mean the the register is read multiple times. This optimization was added for the ARM64 zero register.
>>
>> Thanks,
>> /jakob
>>
>>
>>> On Feb 25, 2016, at 18:14, Matthias Braun <mbraun at apple.com> wrote:
>>>
>>> Late...
2016 Feb 26
6
Reserved/Unallocatable Registers
Lately I have had a few discussions of what it means for a register to be unallocatable or reserved. As this comes up every now and again and I often struggled answering such questions I decided to write down some definite rules and codify the current usage and assumptions. I plan to put the rules below into the doxygen comments of MachineRegisterInfo etc. And I also hope that people will correct