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Re: powerpc -mcpu=common equivalent ?


> On 02/09/2017 11:06 AM, Jakub Jelinek wrote:
>> On Thu, Feb 09, 2017 at 01:47:33PM -0500, David Edelsohn wrote:
>>> Freescale did not implement the POWER architecture.  Again, POWER is a
>>> comment about the original IBM POWER architecture (RIOS processors)
>>> and used in RISC System/6000 computers, not the recent POWER
>>> processors called POWER4, POWER5, POWER6, POWER7, POWER8, POWER9.
>>>
>>> lwsync is part of the ISA and Freescale did not fully implement the
>>> architecture.
>>>
>>> Freescale or someone needs to implement a patch to target the
>>> Freescale non-compliant processors.
>> It seems with -mcpu=8540 and -mcpu=8548 you get sync instead of lwsync:
>> /* E500 cores only support plain "sync", not lwsync.  */
>> #define TARGET_NO_LWSYNC (rs6000_cpu == PROCESSOR_PPC8540 \
>>                            || rs6000_cpu == PROCESSOR_PPC8548)
>> The question is if all the CPUs you're using are these 2, or if you use some
>> others that might not be superset of those.
>>
>>     Jakub
> 
> 
> We tried using e500, but on Freescale t1042 there was another instruction,
> evstdd instruction which caused a fault. Andrii did the testing, he can address
> it better than I can.

evstdd is a Freescale SPE[1] instruction. The generation of SPE instructions can
be disabled w/ -mno-spe (and maybe also supplemented with -mabi=no-spe).

[1] http://www.nxp.com/assets/documents/data/en/reference-manuals/SPEPEM.pdf

Arseny


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