Re: [PATCH v2] rs6000: Rework option -mpowerpc64 handling [PR106680]

[Iain Sandoe <iain@sandoe.co.uk>]

> On 12 Oct 2022, at 09:57, Iain Sandoe <iain@sandoe.co.uk> wrote:
>> On 12 Oct 2022, at 09:12, Kewen.Lin <linkw@linux.ibm.com> wrote:
> 
>> PR106680 shows that -m32 -mpowerpc64 is different from
>> -mpowerpc64 -m32, this is determined by the way how we
>> handle option powerpc64 in rs6000_handle_option.
>> 
>> Segher pointed out this difference should be taken as
>> a bug and we should ensure that option powerpc64 is
>> independent of -m32/-m64.  So this patch removes the
>> handlings in rs6000_handle_option and add some necessary
>> supports in rs6000_option_override_internal instead.
>> 
>> With this patch, if users specify -m{no-,}powerpc64, the
>> specified value is honoured, otherwise, for 64bit it
>> always enables OPTION_MASK_POWERPC64; while for 32bit
>> and TARGET_POWERPC64 and OS_MISSING_POWERPC64, it disables
>> OPTION_MASK_POWERPC64.
>> 
>> btw, following Segher's suggestion, I did some tries to warn
>> when OPTION_MASK_POWERPC64 is set for OS_MISSING_POWERPC64.
>> If warn for the case that powerpc64 is specified explicitly,
>> there are some TCs using -m32 -mpowerpc64 on ppc64-linux,
>> they need some updates, meanwhile the artificial run
>> with "--target_board=unix'{-m32/-mpowerpc64}'" will have
>> noisy warnings on ppc64-linux.  If warn for the case that
>> it's specified implicitly, they can just be initialized by
>> TARGET_DEFAULT (like -m32 on ppc64-linux) or set from the 
>> given cpu mask, we have to special case them and not to warn.
>> As Segher's latest comment, I decide not to warn them and
>> keep it consistent with before.
>> 
>> Bootstrapped and regress-tested on:
>> - powerpc64-linux-gnu P7 and P8 {-m64,-m32}
>> - powerpc64le-linux-gnu P9 and P10
>> - powerpc-ibm-aix7.2.0.0 {-maix64,-maix32}
>> 
>> Hi Iain, could you help to test this new patch on darwin
>> again?  Thanks in advance!
> 
> I kicked off a bootstrap - and 'check-gcc-c' .. if all goes well, there will be an 
> answer in ≈ 7hours.  If something fails, the answer will be sooner ;)

bootstrapped and tested on powerpc-darwin9, with default CPU configuration.
I have not yet tried tuning or cpu configure options.

testresults compare “nominal" against a recent set (another day elapsed time
would be needed for a proper regtest).

thanks
Iain