topic Everything looks correct. How in Intel® oneAPI Math Kernel Library

cblas_ddot access violation

Di_Luca__Daniele — Sat, 02 Mar 2019 23:27:09 GMT

Hi,

I was just trying to learn how to use the 64 bit platform on Parallel Studio XE, when running a very simple example (using cblas_ddot() - as shown below) I've got the following exception:

Exception thrown at 0x00007FF7AA60EB36 in mkl64bit.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.

Then I tried the Intel Inspector tool and it says there was an invalid memory access: 0x1eb36 vmovsd xmm4, qword ptr [r9+rax*8]

The code is:

int main() {
   double v1[3], v2[3];
   for (size_t i = 0; i != 3; ++i)
       v1 = v2 = 1.5;

double result;
result = cblas_ddot(3, v1, 1, v2, 1);

return 0;}

I'm using Intel Parallel Studio XE Cluster Edition 2019 for Windows on Visual Studio 2017.

May you please help me to understand what's wrong and how could I fix the problem?

Thanks in advance,

Daniele

Everything looks correct. How

Gennady_F_Intel — Sun, 03 Mar 2019 04:18:09 GMT

Everything looks correct. How did you build this example? You may take a look at the existing ddot examples into <mkltoot>\examples\cblas\source\

I figured it out I was

Di_Luca__Daniele — Tue, 05 Mar 2019 20:49:06 GMT

I figured it out I was linking mkl_intel_ilp64.lib without the /DMKL_ILP64 option for the compiler and when I switched to the automatic linking through the Intel Performance Libraries option, I kept linking mkl_intel_ilp64.lib, instead of mkl_intel_lp64, but I forgot to turn on the “Use ILP64 interfaces” flag too. I've screwed it up a little bit, but now it seems to work fine,

thanks for the support,

Daniele

Gennady F. (Intel) wrote:
Everything looks correct. How did you build this example? You may take a look at the existing ddot examples into <mkltoot>\examples\cblas\source\

Daniele, thanks for keeping

Gennady_F_Intel — Wed, 06 Mar 2019 05:00:27 GMT

Daniele, thanks for keeping us inform. We always recommend to see mkl examples which will greatly help to mitigate such problems as well.