Hi Pekka, thanks for your hints and the link. I had one buffer in the kernel call that had a cast from a float type to a vector type. I have fixed this. But the segfault remains. In the next few days I will try to cook up a simple example that produces the segfault. Fortunately, the kernel itself is not too complicated, so should be able to reduce it.
Best wishes Timo On Wed, 6 Mar 2019 at 10:20, Pekka Jääskeläinen (TAU) < [email protected]> wrote: > Yes, now that I look at it more closely, > your stack trace looks _very_ much to the common data alignment > issues people have. I think this might be worth a FAQ item somewhere. > > > https://stackoverflow.com/questions/5983389/how-to-align-stack-at-32-byte-boundary-in-gcc > > On 6.3.2019 8.45, Pekka Jääskeläinen (TAU) wrote: > > Hi Timo, > > > > Shooting in the dark here, but since just yesterday I debugged a similar > > looking issue > > which was caused by an illegal cast in the source code from float* to > > float4*. It trusted > > the alignment is still fine, which it wasn't after vectorization. A very > > target specific programming > > error which many ocl targets can easily hide. > > > > If this is something else, we need a test case, smaller the better, to > > help you here. > > Before opening an issue though, please with the latest master and LLVM 8. > > > > Pekka > > > > ------------------------------------------------------------------------ > > *From:* Timo Betcke <[email protected]> > > *Sent:* Tuesday, March 5, 2019 11:27:12 PM > > *To:* Portable Computing Language development discussion > > *Subject:* [pocl-devel] POCL Crash in vmovaps operation > > Dear Pocl community, > > > > I was just testing the newest Pocl Version (github master branch) with > > our software. During execution of one of our kernels Pocl crashed. > > Disassembling the crash shows the following operations during the crash: > > > > ------------------ > > 0x00007fffb81efdd8 <+664>: vmulpd xmm2,xmm2,xmm6 > > 0x00007fffb81efddc <+668>: vsubpd xmm2,xmm5,xmm2 > > 0x00007fffb81efde0 <+672>: vpermilpd xmm5,xmm4,0x1 > > 0x00007fffb81efde6 <+678>: vmulsd xmm3,xmm3,xmm5 > > 0x00007fffb81efdea <+682>: vmulsd xmm4,xmm15,xmm4 > > 0x00007fffb81efdee <+686>: vsubsd xmm3,xmm3,xmm4 > > 0x00007fffb81efdf2 <+690>: vpermilpd xmm1,xmm1,0x1 > > 0x00007fffb81efdf8 <+696>: vmulpd xmm0,xmm0,xmm1 > > 0x00007fffb81efdfc <+700>: vpermilpd xmm1,xmm0,0x1 > > 0x00007fffb81efe02 <+706>: vsubsd xmm0,xmm0,xmm1 > > 0x00007fffb81efe06 <+710>: lea rsi,[rdx+rdx*2] > > 0x00007fffb81efe0a <+714>: mov rdx,QWORD PTR [rbx+0x38] > > => 0x00007fffb81efe0e <+718>: vmovaps XMMWORD PTR [rdx+rsi*8],xmm12 > > ---Type <return> to continue, or q <return> to quit--- > > 0x00007fffb81efe13 <+723>: mov QWORD PTR [rbx+0x40],rsi > > 0x00007fffb81efe17 <+727>: mov QWORD PTR [rdx+rsi*8+0x10],0x0 > > 0x00007fffb81efe20 <+736>: vinsertf32x4 ymm1,ymm16,xmm0,0x1 > > ----------------------------- > > This seems to be a similar bug that I discussed a year ago on the > > mailing list. See the thread here: > > > https://www.mail-archive.com/[email protected]/msg01087.html. > > > In summary, the issue was related to us using arrays of arrays within > > our kernels and pocl creating wrong code for it. > > > > During that time a gist was suggested for Pocl, which I tested but did > > not improve things. Afterwards I let it drop for a while as we were in > > early development and had loads of building sites. But our software is > > now close to release ready and it would be great to get it working with > > pocl. > > > > Any help would be greatly appreciated. > > Best wishes > > > > Timo > > > > -- > > Timo Betcke > > Professor of Computational Mathematics > > University College London > > Department of Mathematics > > E-Mail: [email protected] <mailto:[email protected]> > > Tel.: +44 (0) 20-3108-4068 > > > > > > _______________________________________________ > > pocl-devel mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/pocl-devel > > > > -- > Pekka > > > _______________________________________________ > pocl-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/pocl-devel > -- Timo Betcke Professor of Computational Mathematics University College London Department of Mathematics E-Mail: [email protected] Tel.: +44 (0) 20-3108-4068
_______________________________________________ pocl-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/pocl-devel
