[x265] MinGW/GCC: Unsupported intrinsics in Win32/8bit compilation?

[Mario *LigH* Rohkrämer]

I tried to build a multilib encoder for Win32 in MSYS2/MinGW32 with GCC 
9.2.0. The librraries for 10 and 12 bit precision passed (without any 
Assembler optimization). The linking for the 8 bit precision library failed:

+----
[ 82%] Built target common
Scanning dependencies of target x265-shared
[ 83%] Building RC object CMakeFiles/x265-shared.dir/x265.rc.obj
[ 84%] Linking CXX shared library libx265.dll
E:/MABS/msys64/mingw32/bin/../lib/gcc/i686-w64-mingw32/9.2.0/../../../../i686-w64-mingw32/bin/ld.exe: 
CMakeFiles/x265-shared.dir/objects.a(vec-primitives.cpp.obj):vec-primitives.cpp:(.text+0x2c): 
undefined reference to 
`x265::setupIntrinsicDCT_sse3(x265::EncoderPrimitives&)'
E:/MABS/msys64/mingw32/bin/../lib/gcc/i686-w64-mingw32/9.2.0/../../../../i686-w64-mingw32/bin/ld.exe: 
CMakeFiles/x265-shared.dir/objects.a(vec-primitives.cpp.obj):vec-primitives.cpp:(.text+0x39): 
undefined reference to 
`x265::setupIntrinsicDCT_ssse3(x265::EncoderPrimitives&)'
E:/MABS/msys64/mingw32/bin/../lib/gcc/i686-w64-mingw32/9.2.0/../../../../i686-w64-mingw32/bin/ld.exe: 
CMakeFiles/x265-shared.dir/objects.a(vec-primitives.cpp.obj):vec-primitives.cpp:(.text+0x4f): 
undefined reference to 
`x265::setupIntrinsicDCT_sse41(x265::EncoderPrimitives&)'
+----

Please note that it compiled despite some ccache warnings. I don't know 
if ccache has any impact here. I read in the patch notes when 
media-autobuild suite introduced experimental ccache support that it 
"needs to run at least once to have any effect", but that may only be 
related to speed-up effects in subsequent compilations?

-- 

Fun and success!

Mario *LigH* Rohkrämer
maito:contact at ligh.de