ImfDwaCompressorSimd.h:404:34: error: 'vld1q_f32_x2' was not declared in this scope

[dlemstra]

When building this library with aarch64-linux-gnu-gcc 7.5.0 I am getting the following build error:

In file included from /openexr/src/lib/OpenEXR/ImfDwaCompressor.cpp:102:0:
/openexr/src/lib/OpenEXR/ImfDwaCompressorSimd.h: In function 'void Imf_3_2::{anonymous}::convertFloatToHalf64_neon(short unsigned int*, float*)':
/openexr/src/lib/OpenEXR/ImfDwaCompressorSimd.h:404:34: error: 'vld1q_f32_x2' was not declared in this scope
         float32x4x2_t vec_fp32 = vld1q_f32_x2 (src + i);
                                  ^~~~~~~~~~~~
/openexr/src/lib/OpenEXR/ImfDwaCompressorSimd.h:404:34: note: suggested alternative: 'vld1q_f32'
         float32x4x2_t vec_fp32 = vld1q_f32_x2 (src + i);
                                  ^~~~~~~~~~~~
                                  vld1q_f32
make[2]: *** [src/lib/OpenEXR/CMakeFiles/OpenEXR.dir/ImfDwaCompressor.cpp.o] Error 1
src/lib/OpenEXR/CMakeFiles/OpenEXR.dir/build.make:425: recipe for target 'src/lib/OpenEXR/CMakeFiles/OpenEXR.dir/ImfDwaCompressor.cpp.o' failed
make[1]: *** [src/lib/OpenEXR/CMakeFiles/OpenEXR.dir/all] Error 2
CMakeFiles/Makefile2:1509: recipe for target 'src/lib/OpenEXR/CMakeFiles/OpenEXR.dir/all' failed

This issue can be reproduced with the following Dockerfile:

FROM ubuntu:18.04

RUN apt-get update -y && \
    apt-get install -y autoconf clang-format git python3-pip \
      binutils-aarch64-linux-gnu gcc-aarch64-linux-gnu g++-aarch64-linux-gnu

RUN pip3 install --upgrade pip && \
    pip3 install cmake==3.24.1.1

ENV CC=aarch64-linux-gnu-gcc
ENV CXX=aarch64-linux-gnu-g++

RUN git clone https://github.com/AcademySoftwareFoundation/openexr.git && \
    cd openexr && \
    cmake -DBUILD_SHARED_LIBS=off . && \
    make

I am not sure how you want to fix this issue but using the method from the PR pytorch/pytorch#44198 resolves the issue. It might also be a good idea to add an arm64 build to the ci_workflow.yaml file?

[cary-ilm]

This is similar to #1358, sounds like it calls for a similar solution.

[dlemstra]

Sorry for not checking the pull requests. It looks like that PR will solve this issue.

[dlemstra]

That PR did not fix the build. With the Dockerfile from this issue I can still reproduce the build failure.

[dlemstra]

Turns out I need to specify that I was cross compiling with the following cmake option: `-DCMAKE_TOOLCHAIN_FILE=file" where file has the following:

set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR aarch64)
set(CMAKE_CROSSCOMPILING TRUE)