freebsd stable - Dec 2014 - CPUTYPEs includig avx are suspicious with clang in stable/10

On 19 Dec 2014, at 17:06, Harry Schmalzbauer <freebsd at omnilan.de>
wrote:
> 
> I'm seeing sporadic problems (core dumps) with binaries compiled with
> CPUTYPE=core-i-avx.
> They run fine on IvyBridge, but fail on Haswells.
> Stripping avx from MACHINE_CPU (by defining CPUTYPE=corei7 instead of
> core-i-avx) solved all crashes on the haswell system.
Can you provide a concrete test case?  E.g. binaries with both
optimizations, of which one exhibits the crash?


> I have no idea if applications like pkg(8) make use of AVX, I'd bet
they
> don't do.
If you put CPUTYPE?=core-i-avx in /etc/make.conf, and recompile ports
with that configuration, they can certainly use AVX, if there are parts
in the code that can be vectorized (e.g. certain loops).

> So I guess it's something wrong with clang.
> Unfortuantely I currently don't have a development installation on any
> haswell system to provide some useful backtraces, but perhaps somebody
> with compiler knowledge can have a look at this problem?
It is hard to say anything without more concrete information. :)

-Dimitry

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Bez?glich Dimitry Andric's Nachricht vom 22.12.2014 21:49
(localtime):
> On 19 Dec 2014, at 17:06, Harry Schmalzbauer <freebsd at omnilan.de>
wrote:
>>
>> I'm seeing sporadic problems (core dumps) with binaries compiled
with
>> CPUTYPE=core-i-avx.
>> They run fine on IvyBridge, but fail on Haswells.
>> Stripping avx from MACHINE_CPU (by defining CPUTYPE=corei7 instead of
>> core-i-avx) solved all crashes on the haswell system.
> 
> Can you provide a concrete test case?  E.g. binaries with both
> optimizations, of which one exhibits the crash?
At least this is something I can do at the momen. Please find them here
(i386 versions):
http://www.omnilan.de/downloads/pkg-static.core-i-avx
http://www.omnilan.de/downloads/pkg-static.core7

The former crashes on Haswell while running fine on IvyBridge, the
latter has been compiled with CPUTYPE=corei7 instead of core-i-avx and
doesn't show problems on any syste,

Thansk for your attention!!!

-Harry