Repository: pytorch
Issue: build libtorch problem: Configuring incomplete, errors occurred!  _mm256_abs_epi16
Labels: module: build,triaged

I'm trying to build libtorch to use libtorch(c++) with cuda 9.0 , just follow the doc:
```
mkdir build_libtorch && cd build_libtorch
python ../tools/build_libtorch.py
```

 but always meet this problem:
```
-- Configuring incomplete, errors occurred!
See also "/root/pytorch/build_libtorch/build/CMakeFiles/CMakeOutput.log".
See also "/root/pytorch/build_libtorch/build/CMakeFiles/CMakeError.log".
Traceback (most recent call last):
  File "../tools/build_libtorch.py", line 23, in <module>
    rerun_cmake=True, cmake_only=False, cmake=CMake())
  File "/root/pytorch/tools/build_pytorch_libs.py", line 59, in build_caffe2
    rerun_cmake)
  File "/root/pytorch/tools/setup_helpers/cmake.py", line 323, in generate
    self.run(args, env=my_env)
  File "/root/pytorch/tools/setup_helpers/cmake.py", line 141, in run
    check_call(command, cwd=self.build_dir, env=env)
  File "/root/anaconda3/lib/python3.7/subprocess.py", line 363, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['cmake', '-DBUILD_PYTHON=False', '-DBUILD_TEST=True', '-DCMAKE_BUILD_TYPE=Release', '-DCMAKE_INSTALL_PREFIX=/root/pytorch/torch', '-DCMAKE_PREFIX_PATH=/root/anaconda3/lib/python3.7/site-packages', '-DNUMPY_INCLUDE_DIR=/root/anaconda3/lib/python3.7/site-packages/numpy/core/include', '-DPYTHON_EXECUTABLE=/root/anaconda3/bin/python', '-DPYTHON_INCLUDE_DIR=/root/anaconda3/include/python3.7m', '-DUSE_NUMPY=True', '/root/pytorch']' returned non-zero exit status 1.
```
here is my env:
```
(base) root@53081c1ffdbf:~/pytorch/build_libtorch# python -m torch.utils.collect_env
Collecting environment information...

OS: Ubuntu 16.04.6 LTS
GCC version: (Ubuntu 5.4.0-6ubuntu1~16.04.12) 5.4.0 20160609
CMake version: version 3.14.0

Python version: 3.7
Is CUDA available: No
CUDA runtime version: 9.0.176
GPU models and configuration: Could not collect
Nvidia driver version: Could not collect
cuDNN version: /usr/lib/x86_64-linux-gnu/libcudnn.so.7.6.4

Versions of relevant libraries:
[pip] numpy==1.18.1
[pip] numpydoc==0.9.2
[conda] blas                      1.0                         mkl  
[conda] mkl                       2020.0                      166  
[conda] mkl-service               2.3.0            py37he904b0f_0  
[conda] mkl_fft                   1.0.15           py37ha843d7b_0  
[conda] mkl_random                1.1.0            py37hd6b4f25_0  
```



and here is the "/root/pytorch/build_libtorch/build/CMakeFiles/CMakeError.log":

```
Performing C++ SOURCE FILE Test CAFFE2_NEED_TO_TURN_OFF_DEPRECATION_WARNING failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_1c31b/fast 
/usr/bin/make -f CMakeFiles/cmTC_1c31b.dir/build.make CMakeFiles/cmTC_1c31b.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_1c31b.dir/src.cxx.o
/usr/bin/c++    -DCAFFE2_NEED_TO_TURN_OFF_DEPRECATION_WARNING -std=c++14   -o CMakeFiles/cmTC_1c31b.dir/src.cxx.o -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.cxx
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.cxx:1:30: fatal error: glog/stl_logging.h: No such file or directory
compilation terminated.
CMakeFiles/cmTC_1c31b.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_1c31b.dir/src.cxx.o' failed
make[1]: *** [CMakeFiles/cmTC_1c31b.dir/src.cxx.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_1c31b/fast' failed
make: *** [cmTC_1c31b/fast] Error 2

Source file was:
#include <glog/stl_logging.h>
    int main(int argc, char** argv) {
      return 0;
    }
Determining if the pthread_create exist failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_f27de/fast 
/usr/bin/make -f CMakeFiles/cmTC_f27de.dir/build.make CMakeFiles/cmTC_f27de.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_f27de.dir/CheckSymbolExists.c.o
/usr/bin/cc   -fPIE   -o CMakeFiles/cmTC_f27de.dir/CheckSymbolExists.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTC_f27de
/root/anaconda3/bin/cmake -E cmake_link_script CMakeFiles/cmTC_f27de.dir/link.txt --verbose=1
/usr/bin/cc     -rdynamic  CMakeFiles/cmTC_f27de.dir/CheckSymbolExists.c.o  -o cmTC_f27de 
CMakeFiles/cmTC_f27de.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text+0x1b): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_f27de.dir/build.make:86: recipe for target 'cmTC_f27de' failed
make[1]: *** [cmTC_f27de] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_f27de/fast' failed
make: *** [cmTC_f27de/fast] Error 2

File /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <pthread.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef pthread_create
  return ((int*)(&pthread_create))[argc];
#else
  (void)argc;
  return 0;
#endif
}

Determining if the function pthread_create exists in the pthreads failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_42684/fast 
/usr/bin/make -f CMakeFiles/cmTC_42684.dir/build.make CMakeFiles/cmTC_42684.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_42684.dir/CheckFunctionExists.c.o
/usr/bin/cc   -DCHECK_FUNCTION_EXISTS=pthread_create -fPIE   -o CMakeFiles/cmTC_42684.dir/CheckFunctionExists.c.o   -c /root/anaconda3/share/cmake-3.14/Modules/CheckFunctionExists.c
Linking C executable cmTC_42684
/root/anaconda3/bin/cmake -E cmake_link_script CMakeFiles/cmTC_42684.dir/link.txt --verbose=1
/usr/bin/cc  -DCHECK_FUNCTION_EXISTS=pthread_create   -rdynamic  CMakeFiles/cmTC_42684.dir/CheckFunctionExists.c.o  -o cmTC_42684 -lpthreads 
/usr/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_42684.dir/build.make:86: recipe for target 'cmTC_42684' failed
make[1]: *** [cmTC_42684] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_42684/fast' failed
make: *** [cmTC_42684/fast] Error 2


Performing C SOURCE FILE Test C_HAS_AVX_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_bedc0/fast 
/usr/bin/make -f CMakeFiles/cmTC_bedc0.dir/build.make CMakeFiles/cmTC_bedc0.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_bedc0.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DC_HAS_AVX_1 -fPIE   -o CMakeFiles/cmTC_bedc0.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_set1_ps(0);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:41:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avxintrin.h:1285:1: error: inlining failed in call to always_inline ‘_mm256_set1_ps’: target specific option mismatch
 _mm256_set1_ps (float __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_set1_ps(0);
       ^
CMakeFiles/cmTC_bedc0.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_bedc0.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_bedc0.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_bedc0/fast' failed
make: *** [cmTC_bedc0/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256 a;
    a = _mm256_set1_ps(0);
    return 0;
  }

Performing C SOURCE FILE Test C_HAS_AVX2_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_cd591/fast 
/usr/bin/make -f CMakeFiles/cmTC_cd591.dir/build.make CMakeFiles/cmTC_cd591.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_cd591.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DC_HAS_AVX2_1 -fPIE   -o CMakeFiles/cmTC_cd591.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_abs_epi16(a);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:43:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avx2intrin.h:63:1: error: inlining failed in call to always_inline ‘_mm256_abs_epi16’: target specific option mismatch
 _mm256_abs_epi16 (__m256i __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_abs_epi16(a);
       ^
CMakeFiles/cmTC_cd591.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_cd591.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_cd591.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_cd591/fast' failed
make: *** [cmTC_cd591/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256i a = {0};
    a = _mm256_abs_epi16(a);
    __m256i x;
    _mm256_extract_epi64(x, 0); // we rely on this in our AVX2 code
    return 0;
  }

Performing C SOURCE FILE Test CXX_HAS_AVX_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_e3a60/fast 
/usr/bin/make -f CMakeFiles/cmTC_e3a60.dir/build.make CMakeFiles/cmTC_e3a60.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_e3a60.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DCXX_HAS_AVX_1 -fPIE   -o CMakeFiles/cmTC_e3a60.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_set1_ps(0);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:41:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avxintrin.h:1285:1: error: inlining failed in call to always_inline ‘_mm256_set1_ps’: target specific option mismatch
 _mm256_set1_ps (float __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_set1_ps(0);
       ^
CMakeFiles/cmTC_e3a60.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_e3a60.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_e3a60.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_e3a60/fast' failed
make: *** [cmTC_e3a60/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256 a;
    a = _mm256_set1_ps(0);
    return 0;
  }

Performing C SOURCE FILE Test CXX_HAS_AVX2_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_7f99a/fast 
/usr/bin/make -f CMakeFiles/cmTC_7f99a.dir/build.make CMakeFiles/cmTC_7f99a.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_7f99a.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DCXX_HAS_AVX2_1 -fPIE   -o CMakeFiles/cmTC_7f99a.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_abs_epi16(a);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:43:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avx2intrin.h:63:1: error: inlining failed in call to always_inline ‘_mm256_abs_epi16’: target specific option mismatch
 _mm256_abs_epi16 (__m256i __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_abs_epi16(a);
       ^
CMakeFiles/cmTC_7f99a.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_7f99a.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_7f99a.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_7f99a/fast' failed
make: *** [cmTC_7f99a/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256i a = {0};
    a = _mm256_abs_epi16(a);
    __m256i x;
    _mm256_extract_epi64(x, 0); // we rely on this in our AVX2 code
    return 0;
  }

Performing C++ SOURCE FILE Test CAFFE2_NEED_TO_TURN_OFF_DEPRECATION_WARNING failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_caaf1/fast 
/usr/bin/make -f CMakeFiles/cmTC_caaf1.dir/build.make CMakeFiles/cmTC_caaf1.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_caaf1.dir/src.cxx.o
/usr/bin/c++    -DCAFFE2_NEED_TO_TURN_OFF_DEPRECATION_WARNING -std=c++14   -o CMakeFiles/cmTC_caaf1.dir/src.cxx.o -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.cxx
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.cxx:1:30: fatal error: glog/stl_logging.h: No such file or directory
compilation terminated.
CMakeFiles/cmTC_caaf1.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_caaf1.dir/src.cxx.o' failed
make[1]: *** [CMakeFiles/cmTC_caaf1.dir/src.cxx.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_caaf1/fast' failed
make: *** [cmTC_caaf1/fast] Error 2

Source file was:
#include <glog/stl_logging.h>
    int main(int argc, char** argv) {
      return 0;
    }
Determining if the pthread_create exist failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_7fbd2/fast 
/usr/bin/make -f CMakeFiles/cmTC_7fbd2.dir/build.make CMakeFiles/cmTC_7fbd2.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_7fbd2.dir/CheckSymbolExists.c.o
/usr/bin/cc   -fPIE   -o CMakeFiles/cmTC_7fbd2.dir/CheckSymbolExists.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTC_7fbd2
/root/anaconda3/bin/cmake -E cmake_link_script CMakeFiles/cmTC_7fbd2.dir/link.txt --verbose=1
/usr/bin/cc     -rdynamic  CMakeFiles/cmTC_7fbd2.dir/CheckSymbolExists.c.o  -o cmTC_7fbd2 
CMakeFiles/cmTC_7fbd2.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text+0x1b): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_7fbd2.dir/build.make:86: recipe for target 'cmTC_7fbd2' failed
make[1]: *** [cmTC_7fbd2] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_7fbd2/fast' failed
make: *** [cmTC_7fbd2/fast] Error 2

File /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <pthread.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef pthread_create
  return ((int*)(&pthread_create))[argc];
#else
  (void)argc;
  return 0;
#endif
}

Determining if the function pthread_create exists in the pthreads failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_574f5/fast 
/usr/bin/make -f CMakeFiles/cmTC_574f5.dir/build.make CMakeFiles/cmTC_574f5.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_574f5.dir/CheckFunctionExists.c.o
/usr/bin/cc   -DCHECK_FUNCTION_EXISTS=pthread_create -fPIE   -o CMakeFiles/cmTC_574f5.dir/CheckFunctionExists.c.o   -c /root/anaconda3/share/cmake-3.14/Modules/CheckFunctionExists.c
Linking C executable cmTC_574f5
/root/anaconda3/bin/cmake -E cmake_link_script CMakeFiles/cmTC_574f5.dir/link.txt --verbose=1
/usr/bin/cc  -DCHECK_FUNCTION_EXISTS=pthread_create   -rdynamic  CMakeFiles/cmTC_574f5.dir/CheckFunctionExists.c.o  -o cmTC_574f5 -lpthreads 
/usr/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_574f5.dir/build.make:86: recipe for target 'cmTC_574f5' failed
make[1]: *** [cmTC_574f5] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_574f5/fast' failed
make: *** [cmTC_574f5/fast] Error 2


Performing C SOURCE FILE Test C_HAS_AVX_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_d3ffb/fast 
/usr/bin/make -f CMakeFiles/cmTC_d3ffb.dir/build.make CMakeFiles/cmTC_d3ffb.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_d3ffb.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DC_HAS_AVX_1 -fPIE   -o CMakeFiles/cmTC_d3ffb.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_set1_ps(0);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:41:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avxintrin.h:1285:1: error: inlining failed in call to always_inline ‘_mm256_set1_ps’: target specific option mismatch
 _mm256_set1_ps (float __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_set1_ps(0);
       ^
CMakeFiles/cmTC_d3ffb.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_d3ffb.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_d3ffb.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_d3ffb/fast' failed
make: *** [cmTC_d3ffb/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256 a;
    a = _mm256_set1_ps(0);
    return 0;
  }

Performing C SOURCE FILE Test C_HAS_AVX2_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_fd2c4/fast 
/usr/bin/make -f CMakeFiles/cmTC_fd2c4.dir/build.make CMakeFiles/cmTC_fd2c4.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_fd2c4.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DC_HAS_AVX2_1 -fPIE   -o CMakeFiles/cmTC_fd2c4.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_abs_epi16(a);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:43:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avx2intrin.h:63:1: error: inlining failed in call to always_inline ‘_mm256_abs_epi16’: target specific option mismatch
 _mm256_abs_epi16 (__m256i __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_abs_epi16(a);
       ^
CMakeFiles/cmTC_fd2c4.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_fd2c4.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_fd2c4.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_fd2c4/fast' failed
make: *** [cmTC_fd2c4/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256i a = {0};
    a = _mm256_abs_epi16(a);
    __m256i x;
    _mm256_extract_epi64(x, 0); // we rely on this in our AVX2 code
    return 0;
  }

Performing C SOURCE FILE Test CXX_HAS_AVX_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_3eba8/fast 
/usr/bin/make -f CMakeFiles/cmTC_3eba8.dir/build.make CMakeFiles/cmTC_3eba8.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_3eba8.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DCXX_HAS_AVX_1 -fPIE   -o CMakeFiles/cmTC_3eba8.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_set1_ps(0);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:41:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avxintrin.h:1285:1: error: inlining failed in call to always_inline ‘_mm256_set1_ps’: target specific option mismatch
 _mm256_set1_ps (float __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_set1_ps(0);
       ^
CMakeFiles/cmTC_3eba8.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_3eba8.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_3eba8.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_3eba8/fast' failed
make: *** [cmTC_3eba8/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256 a;
    a = _mm256_set1_ps(0);
    return 0;
  }

Performing C SOURCE FILE Test CXX_HAS_AVX2_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_3b3d2/fast 
/usr/bin/make -f CMakeFiles/cmTC_3b3d2.dir/build.make CMakeFiles/cmTC_3b3d2.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_3b3d2.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DCXX_HAS_AVX2_1 -fPIE   -o CMakeFiles/cmTC_3b3d2.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_abs_epi16(a);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:43:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avx2intrin.h:63:1: error: inlining failed in call to always_inline ‘_mm256_abs_epi16’: target specific option mismatch
 _mm256_abs_epi16 (__m256i __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_abs_epi16(a);
       ^
CMakeFiles/cmTC_3b3d2.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_3b3d2.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_3b3d2.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_3b3d2/fast' failed
make: *** [cmTC_3b3d2/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256i a = {0};
    a = _mm256_abs_epi16(a);
    __m256i x;
    _mm256_extract_epi64(x, 0); // we rely on this in our AVX2 code
    return 0;
  }

Performing C++ SOURCE FILE Test CAFFE2_NEED_TO_TURN_OFF_DEPRECATION_WARNING failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_992ee/fast 
/usr/bin/make -f CMakeFiles/cmTC_992ee.dir/build.make CMakeFiles/cmTC_992ee.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_992ee.dir/src.cxx.o
/usr/bin/c++    -DCAFFE2_NEED_TO_TURN_OFF_DEPRECATION_WARNING -std=c++14   -o CMakeFiles/cmTC_992ee.dir/src.cxx.o -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.cxx
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.cxx:1:30: fatal error: glog/stl_logging.h: No such file or directory
compilation terminated.
CMakeFiles/cmTC_992ee.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_992ee.dir/src.cxx.o' failed
make[1]: *** [CMakeFiles/cmTC_992ee.dir/src.cxx.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_992ee/fast' failed
make: *** [cmTC_992ee/fast] Error 2

Source file was:
#include <glog/stl_logging.h>
    int main(int argc, char** argv) {
      return 0;
    }
Determining if the pthread_create exist failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_24124/fast 
/usr/bin/make -f CMakeFiles/cmTC_24124.dir/build.make CMakeFiles/cmTC_24124.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_24124.dir/CheckSymbolExists.c.o
/usr/bin/cc   -fPIE   -o CMakeFiles/cmTC_24124.dir/CheckSymbolExists.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
Linking C executable cmTC_24124
/root/anaconda3/bin/cmake -E cmake_link_script CMakeFiles/cmTC_24124.dir/link.txt --verbose=1
/usr/bin/cc     -rdynamic  CMakeFiles/cmTC_24124.dir/CheckSymbolExists.c.o  -o cmTC_24124 
CMakeFiles/cmTC_24124.dir/CheckSymbolExists.c.o: In function `main':
CheckSymbolExists.c:(.text+0x1b): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_24124.dir/build.make:86: recipe for target 'cmTC_24124' failed
make[1]: *** [cmTC_24124] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_24124/fast' failed
make: *** [cmTC_24124/fast] Error 2

File /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <pthread.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef pthread_create
  return ((int*)(&pthread_create))[argc];
#else
  (void)argc;
  return 0;
#endif
}

Determining if the function pthread_create exists in the pthreads failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_20a20/fast 
/usr/bin/make -f CMakeFiles/cmTC_20a20.dir/build.make CMakeFiles/cmTC_20a20.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_20a20.dir/CheckFunctionExists.c.o
/usr/bin/cc   -DCHECK_FUNCTION_EXISTS=pthread_create -fPIE   -o CMakeFiles/cmTC_20a20.dir/CheckFunctionExists.c.o   -c /root/anaconda3/share/cmake-3.14/Modules/CheckFunctionExists.c
Linking C executable cmTC_20a20
/root/anaconda3/bin/cmake -E cmake_link_script CMakeFiles/cmTC_20a20.dir/link.txt --verbose=1
/usr/bin/cc  -DCHECK_FUNCTION_EXISTS=pthread_create   -rdynamic  CMakeFiles/cmTC_20a20.dir/CheckFunctionExists.c.o  -o cmTC_20a20 -lpthreads 
/usr/bin/ld: cannot find -lpthreads
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_20a20.dir/build.make:86: recipe for target 'cmTC_20a20' failed
make[1]: *** [cmTC_20a20] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_20a20/fast' failed
make: *** [cmTC_20a20/fast] Error 2


Performing C SOURCE FILE Test C_HAS_AVX_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_e0f9c/fast 
/usr/bin/make -f CMakeFiles/cmTC_e0f9c.dir/build.make CMakeFiles/cmTC_e0f9c.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_e0f9c.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DC_HAS_AVX_1 -fPIE   -o CMakeFiles/cmTC_e0f9c.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_set1_ps(0);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:41:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avxintrin.h:1285:1: error: inlining failed in call to always_inline ‘_mm256_set1_ps’: target specific option mismatch
 _mm256_set1_ps (float __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_set1_ps(0);
       ^
CMakeFiles/cmTC_e0f9c.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_e0f9c.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_e0f9c.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_e0f9c/fast' failed
make: *** [cmTC_e0f9c/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256 a;
    a = _mm256_set1_ps(0);
    return 0;
  }

Performing C SOURCE FILE Test C_HAS_AVX2_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_31e86/fast 
/usr/bin/make -f CMakeFiles/cmTC_31e86.dir/build.make CMakeFiles/cmTC_31e86.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_31e86.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DC_HAS_AVX2_1 -fPIE   -o CMakeFiles/cmTC_31e86.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_abs_epi16(a);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:43:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avx2intrin.h:63:1: error: inlining failed in call to always_inline ‘_mm256_abs_epi16’: target specific option mismatch
 _mm256_abs_epi16 (__m256i __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_abs_epi16(a);
       ^
CMakeFiles/cmTC_31e86.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_31e86.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_31e86.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_31e86/fast' failed
make: *** [cmTC_31e86/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256i a = {0};
    a = _mm256_abs_epi16(a);
    __m256i x;
    _mm256_extract_epi64(x, 0); // we rely on this in our AVX2 code
    return 0;
  }

Performing C SOURCE FILE Test CXX_HAS_AVX_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_783c4/fast 
/usr/bin/make -f CMakeFiles/cmTC_783c4.dir/build.make CMakeFiles/cmTC_783c4.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_783c4.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DCXX_HAS_AVX_1 -fPIE   -o CMakeFiles/cmTC_783c4.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_set1_ps(0);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:41:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avxintrin.h:1285:1: error: inlining failed in call to always_inline ‘_mm256_set1_ps’: target specific option mismatch
 _mm256_set1_ps (float __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_set1_ps(0);
       ^
CMakeFiles/cmTC_783c4.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_783c4.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_783c4.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_783c4/fast' failed
make: *** [cmTC_783c4/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256 a;
    a = _mm256_set1_ps(0);
    return 0;
  }

Performing C SOURCE FILE Test CXX_HAS_AVX2_1 failed with the following output:
Change Dir: /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_66b17/fast 
/usr/bin/make -f CMakeFiles/cmTC_66b17.dir/build.make CMakeFiles/cmTC_66b17.dir/build
make[1]: Entering directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_66b17.dir/src.c.o
/usr/bin/cc   -fopenmp -DNDEBUG -DCXX_HAS_AVX2_1 -fPIE   -o CMakeFiles/cmTC_66b17.dir/src.c.o   -c /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c: In function ‘main’:
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: warning: AVX vector return without AVX enabled changes the ABI [-Wpsabi]
     a = _mm256_abs_epi16(a);
       ^
In file included from /usr/lib/gcc/x86_64-linux-gnu/5/include/immintrin.h:43:0,
                 from /root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:2:
/usr/lib/gcc/x86_64-linux-gnu/5/include/avx2intrin.h:63:1: error: inlining failed in call to always_inline ‘_mm256_abs_epi16’: target specific option mismatch
 _mm256_abs_epi16 (__m256i __A)
 ^
/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp/src.c:7:7: error: called from here
     a = _mm256_abs_epi16(a);
       ^
CMakeFiles/cmTC_66b17.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_66b17.dir/src.c.o' failed
make[1]: *** [CMakeFiles/cmTC_66b17.dir/src.c.o] Error 1
make[1]: Leaving directory '/root/pytorch/build_libtorch/build/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_66b17/fast' failed
make: *** [cmTC_66b17/fast] Error 2

Source file was:

  #include <immintrin.h>

  int main()
  {
    __m256i a = {0};
    a = _mm256_abs_epi16(a);
    __m256i x;
    _mm256_extract_epi64(x, 0); // we rely on this in our AVX2 code
    return 0;
  }

```

Anyone could help me about this?????? 
Thank you!

cc @malfet