Re: Backport [PATCH,rs6000] Handle conflicting target options -mno-power9-vector and -mcpu=power9

[Kelvin Nilsen <kdnilsen at linux dot vnet dot ibm dot com>]

I have bootstrapped and tested this patch on
powerpc64le-unkonwn-linux-gnu with no regressions.  Is this ok for
backporting to gcc 6?



On 03/22/2017 10:17 PM, Segher Boessenkool wrote:
> On Wed, Mar 22, 2017 at 05:55:53PM -0600, Kelvin Nilsen wrote:
>>> Or it could do -mpower9-dform-scalar but disable -mpower9-dform-vector?
>>> That seems more reasonable.
>>
>> The internal problem report sent to me said "-mno-power9-vector should
>> override power9-dform unless the latter has been deliberately specified
>> by the user."  I'm just following orders.
> 
> Heh :-)
> 
>> If you think it preferable to
>> only override -mpower-dform-vector, I'll make that modification.
> 
> It is more logical.  Or so I though.  But as it turns out,
> -mpower9-dform-scalar is about vector registers as well.
> 
> So the patch is approved for trunk as-is.  Thanks!
> 
>>>> 	* config/rs6000/rs6000.c (rs6000_option_override_internal): Change
>>>> 	handling of certain combinations of target options, including the
>>>> 	combinations -mpower8-vector vs. -mno-vsx, -mpower8-vector vs.
>>>> 	-mno-power8-vector, and -mpower9_dform vs. -mno-power9-vector.
>>>
>>> Those other changes are independent?
>>
>> Actually, these other changes are not independent.  My initial attempt
>> at a patch only changed the behavior of -mpower9_dform vs.
>> -mno-power9-vector.  But this actually resulted in a regression of an
>> existing test.  To "properly" handle the new case without impacting
>> existing "established" behavior (as represented in the existing dejagnu
>> testsuite), I had to make these other changes as well.
> 
> Too many options :-(
> 
> 
> Segher
> 
> 

-- 
Kelvin Nilsen, Ph.D.  kdnilsen@linux.vnet.ibm.com
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