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Henrik_S_
Beginner
153 Views

Possible AVX compile bug.


How do I report a possible AMD/AVX bug to Intel? Is there an email address or form?

The following will work on a Intel CPU, but crashes at compile time on an Interlagos AMD Opteron Processor 6220 CPU (CentOS 6.2 64bit). The same code compiles fine on same OS, but with Intel i7-2635QM CPU (as an example). Note removing the "-mavx" results in a clean compile.

- henrik

--------

# cat /proc/cpuinfo | grep name | head -1
model name : AMD Opteron Processor 6220

# icc -v
icc version 12.1.3 (gcc version 4.4.6 compatibility)

wget http://cran.r-project.org/src/base/R-2/R-2.14.2.tar.gz
tar zxf R-2.14.2.tar.gz
cd R-2.14.2

export CC="icc -mavx -std=c99 -diag-disable 188"
export CXX=$CC
./configure
make

...
*** caught segfault ***
address 0x3b73000, cause 'memory not mapped'
/bin/sh: line 1: 7971 Done echo "tools:::.install_package_description('.', '"../../../library/tools"')"
7972 Segmentation fault | R_DEFAULT_PACKAGES=NULL ../../../bin/R --vanilla --slave > /dev/null


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5 Replies
Brandon_H_Intel
Employee
153 Views

Henrik,

Let me see if I can reproduce this seg fault.
Henrik_S_
Beginner
153 Views

Where you able to duplicate the problem?

- Henrik
stretcho44
Beginner
153 Views

Henrik,
I have seen several reports of AMD AVX related problems. The Intel group might not be able to easilyreproduce the problem.A number of people are interested in the understanding the solution to this instability. The thing that these all seem to have in common is AMD memory and AVX problems with new CPU. I have not seen any comment from AMD on the AVX ormemory complaints either.


Subject Memory issues with Opteron 6220

https://lkml.org/lkml/2012/2/8/164

AMD FX X8 8120 not working with AVX!

www.primegrid.com/forum_thread.php?id=3933

Brandon_H_Intel
Employee
153 Views

I've been trying to gain access to an AMD* system on my end, but it's been more problematic than it initially looked. I've confirmed that I can't reproduce the problem on an Intel CPU - the make script builds fine. I'm continuing to work to get access to a similar environment to reproduce the problem - as soon as I make any progress I'll update the thread.
Henrik_S_
Beginner
153 Views

It appears the above described crash is gone with Intel compiler 2011 Update 10 (12.1.4). The above compiles cleanly on AMD with the latest compilers. The only AVX related bug notice in the compiler fixes is
DPD200179872FortranLoop distribution Internal Compiler Error with -xAVX -fpic -fp-model precise
which is not match to what I was using, but the crash I reported is no longer present.
- Henrik
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