Segmentation fault with cpu_selector, works with default and gpu.

[Dmitry_Savin]

An application https://gitlab.com/miptitep/syclbrot adapted from https://gitlab.com/VileLasagna/toyBrot compiles with the dpcpp and runs if the default selector is used (2de42a2009e3833e0631d2eb8e11266548ad7813) but fails with the cpu_selector (236bbf18ce65e9708ce1811fe25b55c2a6838b44). Reproduced in the DevCloud. Also works with the gpu_selector (now commit SHA, see the diff between the two and substitute accordingly). The error message emerges at the start of the compiled application: Running on Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz > Stack dump: > 0. Running pass 'Function Pass Manager' on module 'main'. > 1. Running pass 'VPlan Vectorization Driver' on function '' > Segmentation fault (core dumped) The stack trace obtained under Valgrind: Process terminating with default action of signal 11 (SIGSEGV) General Protection Fault at 0x2066129B: llvm::Constant::getAllOnesValue(llvm::Type*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x206612B9: llvm::Constant::getAllOnesValue(llvm::Type*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x206612B9: llvm::Constant::getAllOnesValue(llvm::Type*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20664BCB: llvm::ConstantExpr::getNot(llvm::Constant*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20B22E34: llvm::vpo::VPOCodeGen::vectorizeInstruction(llvm::vpo::VPInstruction*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20B43E54: llvm::vpo::VPInstruction::execute(llvm::vpo::VPTransformState&) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20B4839D: llvm::vpo::VPBasicBlock::execute(llvm::vpo::VPTransformState*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20B49A18: llvm::vpo::VPRegionBlock::execute(llvm::vpo::VPTransformState*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20B49A18: llvm::vpo::VPRegionBlock::execute(llvm::vpo::VPTransformState*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20B47AAF: llvm::vpo::VPlan::execute(llvm::vpo::VPTransformState*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20B3A639: llvm::vpo::LoopVectorizationPlanner::executeBestPlan(llvm::vpo::VPOCodeGen&) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) by 0x20A69725: bool llvm::vpo::VPlanDriver::processLoop(llvm::Loop*, llvm::Function&, llvm::vpo::WRNVecLoopNode*) (in /opt/intel/inteloneapi/compiler/2021.1-beta03/linux/lib/x64/libOclCpuBackEnd.so.2019.9.11.0) The full output is attached.

[AnubhavJ_intel]

Hi Savin,

Thanks for reaching out to us. We are working on this issue and we'll get back to you soon.

Anubhav

[AnubhavJ_intel]

Hi Savin,

We are able to reproduce this Issue with cpu_selector as you mentioned. We are working on it. 

Anubhav

[Dmitry_Savin]

Hi Anubhav, The issue is fixed in the beta04, checked on a local machine. As of the time of this comment (February 11th 2020) beta03 is used in the DevCloud. Can anybody explain what the issue was or point to the commit in the GitHub repo that fixed it? Dima

[AnubhavJ_intel]

Hi Savin,

Issue is fixed by Engineering team. We don't have much details on it.

Anubhav

[Subarnarek_G_Intel]

Hi Anubhav,

Please go ahead and close the ticket.

Regards,

Subarna

[AnubhavJ_intel]

Hi Savin,

Since Issue is fixed in the beta04 version, we are closing this thread. Please raise new threads for further Issues.

Anubhav