cblas_sgemm test fails on Apple M2

[RossComputerGuy]

Trying to build OpenBLAS with nix on an Apple M2 and consistently getting the test to fail.

openblas>  ******* FATAL ERROR - COMPUTED RESULT IS LESS THAN HALF ACCURATE *******
openblas>            EXPECTED RESULT   COMPUTED RESULT
openblas>        1       0.00000          0.266733
openblas>  ******* cblas_sgemm  FAILED ON CALL NUMBER:
openblas>    4540: cblas_sgemm ( CblasRowMajor,  CblasNoTrans,  CblasNoTrans,
openblas>                       1,  1,  0, 1.0, A,  2, B,  1, 0.0, C,  2).
openblas> 
openblas>  ******* FATAL ERROR - TESTS ABANDONED *******
openblas> ERROR STOP
openblas> 
openblas> Error termination. Backtrace:
openblas> #0  0x102fc880f
openblas> #1  0x102fc93b7
openblas> #2  0x102fca597
openblas> #3  0x1020dc8e3
openblas> #4  0x102cd155f
openblas> make[1]: *** [Makefile:197: all3] Error 1
openblas> make[1]: *** Waiting for unfinished jobs....

[martin-frbg]

Which version of OpenBLAS, and which compiler please ?

[RossComputerGuy]

v0.3.30 & clang

[martin-frbg]

I only have M1 and M4 available for testing, but I expect the M1 should be a good stand-in for the M2. So far I cannot reproduce this with clang-19.1.7 on Debian (any newer LLVM I will probably have to build from source, as this is a shared machine in the GCC Compile Farm)

[paulgessinger]

I see this same issue on an M4 with spack.

[Sbozzolo]

I don't know if this is related, but I am seeing similar-looking errors with LLVM 19 on arm64 with spack, with the difference that my arm64 is an AWS graviton3 (c7g.16xlarge instance, ubuntu 24.04).

[sethrj]

Spack builds openblas on my mac (macbook pro M4) built with:

 '/usr/bin/make' '-j10' '-s' 'CC=.../clang' 'FC=.../gfortran' 'MAKE_NB_JOBS=0' 'ARCH=arm64' 'DYNAMIC_ARCH=1' 'DYNAMIC_OLDER=1' 'TARGET=GENERIC' 'DYNAMIC_ARCH=1' 'USE_LOCKING=1' 'USE_OPENMP=0' 'USE_THREAD=0' 'TIMER=INT_CPU_TIME' 'RANLIB=ranlib' 'NO_AVX512=1' 'NO_SVE=1' 'all'

with:

 TESTS OF THE REAL             LEVEL 3 BLAS

 THE FOLLOWING PARAMETER VALUES WILL BE USED:
   FOR N                   0     1     2     3     5     9    35
   FOR ALPHA             0.0   1.0   0.7
   FOR BETA              0.0   1.0   1.3

 ROUTINES PASS COMPUTATIONAL TESTS IF TEST RATIO IS LESS THAN   16.00

 COLUMN-MAJOR AND ROW-MAJOR DATA LAYOUTS ARE TESTED

 RELATIVE MACHINE PRECISION IS TAKEN TO BE  1.2E-07

 cblas_sgemm  PASSED THE TESTS OF ERROR-EXITS

 cblas_sgemm  PASSED THE COLUMN-MAJOR COMPUTATIONAL TESTS ( 27783 CALLS)
 ******* FATAL ERROR - COMPUTED RESULT IS LESS THAN HALF ACCURATE *******
           EXPECTED RESULT   COMPUTED RESULT
       1       0.00000          0.266733    
 ******* cblas_sgemm  FAILED ON CALL NUMBER:
   4540: cblas_sgemm ( CblasRowMajor,  CblasNoTrans,  CblasNoTrans,
                      1,  1,  0, 1.0, A,  2, B,  1, 0.0, C,  2).

 ******* FATAL ERROR - TESTS ABANDONED *******
ERROR STOP 

with compilers:

• GNU Fortran (Homebrew GCC 15.2.0) 15.2.0
• Apple clang version 17.0.0 (clang-1700.6.3.2)

[martin-frbg]

Closing as fixed in 0.3.31 (most likely by #5423)