Mostly because I didn't know/think of that. But you are right, that would
be better.

Bas Vermeulen

On Tue, Feb 6, 2018 at 5:48 PM, John Paul Adrian Glaubitz <
glaub...@physik.fu-berlin.de> wrote:

>
>
> On Feb 6, 2018, at 5:26 PM, Bas Vermeulen <b...@daedalean.ai> wrote:
>
> I am evaluating the following patch to gcc-7 to fix the problem. It's
> currently building, I'll follow up when I know it works. The patch is added
> to debian/rules.patch to get it included.
>
>
> Why do you want to patch the upstream sources when you could just modify
> debian/rules2 to pass the proper “—with-cpu=powerpc64” to gcc’s configure
> script?
>
> Adrian
>
> Bas Vermeulen
>
> On Tue, Feb 6, 2018 at 5:16 PM, Lennart Sorensen <
> lsore...@csclub.uwaterloo.ca> wrote:
>
>> On Tue, Feb 06, 2018 at 03:40:20PM +0100, Bas Vermeulen wrote:
>> > I am trying to run the ppc64 unstable on a Freescale T2080, which uses
>> the
>> > e6500 CPU. Running python (or any other application using sqrt or sqrtf)
>> > will cause an illegal instruction exception, because the sqrtf opcode is
>> > not supported on the e6500.
>> >
>> > This seems to be caused by gcc compiling for power4 by default
>> > (_ARCH_PWR4=1 and _ARCH_PPCSQ=1 set in gcc -E -mD - < /dev/null),
>> although
>> > jrtc27 on #debian-ports pointed to
>> > https://github.com/gcc-mirror/gcc/blob/da8dff89fa9398f04b107
>> e388cb706517ced9505/gcc/config/rs6000/default64.h#L30
>> > which sets MASK_PPC_GPOPT by default (which includes fp sqrt).
>> >
>> > What would be the best way to solve this problem?
>>
>> Why is the default not powerpc64 instead of power4?  After all that is
>> the setting for generic 64 bit bit endian powerpc as far as I know.
>>
>> It seems the e6500 is missing quite a few floating point instructions
>> from the Power ISA so targeting power4 (which is I believe full Power
>> ISA 2.01) is likely to cause issues.
>>
>> --
>> Len Sorensen
>>
>
> <ppc64-use-powerpc64-by-default.diff>
>
>

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