# Intrin\_avx.hpp compile error **URL:** \ **Category:** C++\ **Tags:** build, core\ **Created:** [December 12, 2021, 12:59pm UTC](https://forum.opencv.org/t/intrin-avx-hpp-compile-error/6677 "2021-12-12T12:59:11Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Zhijie\_Zhang](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/zhijie_zhang/32/3995_2.png) [@Zhijie\_Zhang](https://forum.opencv.org/u/Zhijie_Zhang)\ **Post date:** [December 12, 2021, 12:59pm UTC](https://forum.opencv.org/t/intrin-avx-hpp-compile-error/6677/1 "2021-12-12T12:59:11Z")
Hi, guys, can you give me some advice for the problem. ##### System information (version) - OpenCV =\> 4.2.0 - Operating System / Platform =\> ubuntu 16.04 64 Bit - Compiler =\> g++ 7.5.0 ##### Detailed description Compiling the single intrin\_avx.hpp fails when using avx/avx2 supported device. ```auto [50%] Building CXX object CMakeFiles/test.dir/test.cpp.o In file included from /home/workspace/Test/test.cpp:2:0: /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:17:1: error: ‘CV_CPU_OPTIMIZATION_HAL_NAMESPACE_BEGIN’ does not name a type CV_CPU_OPTIMIZATION_HAL_NAMESPACE_BEGIN ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:24:8: error: ‘__m256’ does not name a type inline __m256 _v256_combine(const__m128& lo, const __m128& hi) ^ ~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:27:8: error: ‘__m256d’ does not name a type inline __m256d _v256_combine(const__m128d& lo, const __m128d& hi) ^ ~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:30:35: error: ‘__m256i’ does not name a type inline int _v_cvtsi256_si32(const __m256i& a) ^ ~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp: In function ‘int cv::_v_cvtsi256_si32(const int&)’: /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:31:28: error: ‘_mm256_castsi256_si128’ was not declared in this scope { return _mm_cvtsi128_si32(_mm256_castsi256_si128(a)); } ^ ~~~~~~~~~~~~~~~~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:31:28: note: suggested alternative: ‘_v_cvtsi256_si32’ { return _mm_cvtsi128_si32(_mm256_castsi256_si128(a)); } ^ ~~~~~~~~~~~~~~~~~~~~~ _v_cvtsi256_si32 /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:31:10: error: ‘_mm_cvtsi128_si32’ was not declared in this scope { return _mm_cvtsi128_si32(_mm256_castsi256_si128(a)); } ^ ~~~~~~~~~~~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:31:10: note: suggested alternative: ‘_v_cvtsi256_si32’ { return _mm_cvtsi128_si32(_mm256_castsi256_si128(a)); } ^ ~~~~~~~~~~~~~~~~ _v_cvtsi256_si32 /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp: At global scope: /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:33:8: error: ‘__m256i’ does not name a type inline __m256i _v256_shuffle_odd_64(const__m256i& v) ^ ~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:36:8: error: ‘__m256d’ does not name a type inline __m256d _v256_shuffle_odd_64(const__m256d& v) ^ ~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:40:8: error: ‘__m256i’ does not name a type inline __m256i _v256_permute2x128(const__m256i& a, const __m256i& b) ^ ~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:44:8: error: ‘__m256’ does not name a type inline __m256 _v256_permute2x128(const__m256& a, const __m256& b) ^ ~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:48:8: error: ‘__m256d’ does not name a type inline __m256d _v256_permute2x128(const__m256d& a, const __m256d& b) ^ ~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp: In function ‘_Tpvec cv::v256_permute2x128(const _Tpvec&, const _Tpvec&)’: /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:53:17: error: ‘_v256_permute2x128’ was not declared in this scope { return _Tpvec(_v256_permute2x128(a.val, b.val)); } ^ ~~~~~~~~~~~~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:53:17: note: suggested alternative: ‘v256_permute2x128’ { return _Tpvec(_v256_permute2x128(a.val, b.val)); } ^ ~~~~~~~~~~~~~~~~~ v256_permute2x128 /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp: At global scope: /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:56:8: error: ‘__m256i’ does not name a type inline __m256i _v256_permute4x64(const__m256i& a) ^ ~~~~~~ /usr/local/include/opencv4/opencv2/core/hal/intrin_avx.hpp:60:8: error: ‘__m256d’ does not name a type ``` ##### Steps to reproduce - test.cpp ```auto #include #include "opencv2/core/hal/intrin_avx.hpp" int main() { printf("test\n"); return 0; } ``` - CMakeLists.txt ```auto CMAKE_MINIMUM_REQUIRED(VERSION 3.15) PROJECT(test) SET(CMAKE_CXX_STANDARD 11) # avx SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mavx2") # opencv MESSAGE(STATUS "FIND OpenCV on LINUX.") FIND_PACKAGE(OpenCV REQUIRED) ADD_EXECUTABLE(test test.cpp) TARGET_LINK_LIBRARIES( test ${OpenCV_LIBS} ) ``` ---
**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\ **Post date:** [December 12, 2021, 1:13pm UTC](https://forum.opencv.org/t/intrin-avx-hpp-compile-error/6677/2 "2021-12-12T13:13:32Z")
> [@Zhijie\_Zhang](#): > > OpenCV =\> 4.2.0 please do not bother with such an outdated (prebuilt ?) version also, the problem can only be mended by building the opencv libs from src. if the problem persists, there’s a CPU\_DISPATCH flag, where you ca remove avx support ---
**Author:** ![Zhijie\_Zhang](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/zhijie_zhang/32/3995_2.png) [@Zhijie\_Zhang](https://forum.opencv.org/u/Zhijie_Zhang)\ **Post date:** [December 13, 2021, 9:33am UTC](https://forum.opencv.org/t/intrin-avx-hpp-compile-error/6677/3 "2021-12-13T09:33:41Z")
Thanks for your advice. [Alexander Alekhin](https://github.com/alalek) told me that the intrin\_avx.hpp could not be directly included. I fix it by including opencv2/core/simd\_intrinsics.hpp and adding -maxv2 compile flag. ---
**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\ **Post date:** [December 13, 2021, 11:22am UTC](https://forum.opencv.org/t/intrin-avx-hpp-compile-error/6677/4 "2021-12-13T11:22:33Z")
related: [How to fix the compile error when include the opencv intrin\_avx.hpp - Stack Overflow](https://stackoverflow.com/questions/70323813/how-to-fix-the-compile-error-when-include-the-opencv-intrin-avx-hpp)