Kernel symlinks cause build failure in msys2 #13
Description
Another one for you, following up on #9
When I try to build the Sandy Bridge configuration on Windows in MSYS2 with MinGW compiler (on an i7-2630QM), I get a failure to link the test executable:
Archiving lib/sandybridge/libblis.a
Linking test_libblis.x against './lib/sandybridge/libblis.a -lm'
./lib/sandybridge/libblis.a(bli_gemm_cntl.o):bli_gemm_cntl.c:(.text+0x1bc): undefined reference to `bli_dgemm_opt_8x4_ref_u4_nodupl_avx1'
./lib/sandybridge/libblis.a(bli_gemm_ukernel.o):bli_gemm_ukernel.c:(.text+0x11): undefined reference to `bli_dgemm_opt_8x4_ref_u4_nodupl_avx1'
./lib/sandybridge/libblis.a(bli_gemmtrsm_l_ukr_ref.o):bli_gemmtrsm_l_ukr_ref.c:(.text+0x10d): undefined reference to `bli_dgemm_opt_8x4_ref_u4_nodupl_avx1'
./lib/sandybridge/libblis.a(bli_gemmtrsm_u_ukr_ref.o):bli_gemmtrsm_u_ukr_ref.c:(.text+0x10d): undefined reference to `bli_dgemm_opt_8x4_ref_u4_nodupl_avx1'
./lib/sandybridge/libblis.a(bli_gemm4m_ukr_ref.o):bli_gemm4m_ukr_ref.c:(.text+0xe94): undefined reference to `bli_dgemm_opt_8x4_ref_u4_nodupl_avx1'
./lib/sandybridge/libblis.a(bli_gemm4m_ukr_ref.o):bli_gemm4m_ukr_ref.c:(.text+0xedb): more undefined references to `bli_dgemm_opt_8x4_ref_u4_nodupl_avx1' follow
d:/code/mingw-builds/x64-4.8.1-win32-seh-rev5/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/4.8.1/../../../../x86_64-w64-mingw32/bin/ld.exe: ./lib/sandybridge/libblis.a(bli_gemm4m_ukr_ref.o): bad reloc address 0x0 in section `.pdata'
collect2.exe: error: ld returned 1 exit status
Makefile:531: recipe for target 'test_libblis.x' failed
make: *** [test_libblis.x] Error 1
If I try in Cygwin, setting CC := x86_64-w64-mingw32-gcc and AR := x86_64-w64-mingw32-ar in config/sandybridge/make_defs.mk to use the MinGW cross-compiler, then the executable links correctly but segfaults when running the tests. The backtrace is more interesting if I set BLIS_SIMD_ALIGN_SIZE to 1 in config/sandybridge/config.h, since my patch in #9 didn't completely fix the alignment problems. Backtrace with alignment=1 (also uncommented CDBGFLAGS := -g to get debug info) posted here https://gist.github.com/tkelman/25d290b131c0a1205b27. Everything passes until blis_dgemm_nn_ccc. The same bli_dgemm_opt_8x4_ref_u4_nodupl_avx1 that was an undefined reference in MSYS2 is causing the segfault in Cygwin-to-MinGW cross-compile.