[llvm-dev] "cannot find libdevice for sm_"

[Jost, Gabriele (ARC-TNC)[Supersmith] via llvm-dev]

Hello,
I have installed clang12 with OpenMP target-offload on a cluster of v100 nodes using cuda 10.1 and gcc 8.2.
When I try to test it:
clang  -c -I../common -O3 -g -fopenmp -fopenmp-targets=nvptx64-nvida-cuda -Xopenmp-target=nvptx64-nvidia-cuda -march=sm_70 -mcmodel=medium -DCRPL_COMP=0 ft.c
clang-12: error: cannot find libdevice for sm_

with a blank architecture.

I have the openmp target bc libraries
lrwxrwxrwx 1 gjost scicon       19 Aug 21 14:39 libRemarks.so -> libRemarks.so.12git
-rw-r--r-- 1 gjost scicon    69656 Aug 21 14:52 libomptarget-nvptx-sm_35.bc
-rw-r--r-- 1 gjost scicon    69196 Aug 21 14:52 libomptarget-nvptx-sm_70.bc
-rw-r--r-- 1 gjost scicon    69608 Aug 21 14:52 libomptarget-nvptx-sm_60.bc
lrwxrwxrwx 1 gjost scicon        9 Aug 21 15:07 libgomp.so -> libomp.so
lrwxrwxrwx 1 gjost scicon        9 Aug 21 15:07 libiomp5.so -> libomp.so

The only place in the llvm code where I see a message like this is here:

grep "cannot find libdevice for sm_" llvm-project/clang/test/Driver/cuda-detect.cu
// MISSINGLIBDEVICE: error: cannot find libdevice for sm_20.
pfe25.gjost 69> grep MISSINGLIBDEVICE llvm-project/clang/test/Driver/cuda-detect.cu
// RUN:   | FileCheck %s -check-prefix COMMON -check-prefix MISSINGLIBDEVICE
// RUN:   | FileCheck %s -check-prefix COMMON -check-prefix MISSINGLIBDEVICE
// MISSINGLIBDEVICE: error: cannot find libdevice for sm_20.


Have you seen this behavior before? Maybe clang12/cuda/10.1 and gcc8.2 is a bad combo?
Thanks in advance and greetings,


Gabriele Jost

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Gabriele Jost       NASA Ames Research Center
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