Power10 fixes

Revert PR747 - SYRK parameter changes for Haswell and related targets

1. Using core loongson3r3 and loongson3r4 for loongson
2. Add DYNAMIC_ARCH for loongson

Change-Id: I1c6b54dbeca3a0cc31d1222af36a7e9bd6ab54c1

ARM64 DYNAMIC_ARCH build fix for BSD/OSX

After a fork it is possible that blas_thread_buffer has already
allocated memory buffers: goto_set_num_threads does allocate those
already and it may be called by num_cpu_avail in case the OpenBLAS
NUM_THREADS differ from the OMP num threads.
This leads to a memory leak which can cause subsequent execution of BLAS
kernels to fail.

Fixes #2993

If the toolchain is too old, or the mma features isn't set on a POWER10
fall back to the POWER9 loops.

Improve the performance of rot by using AVX512 and AVX2 intrinsic

fix avx2 detection

reword commits to make it clearer

1. Add a new API -- sbgemv to support bfloat16 based gemv
2. Implement a generic kernel for sbgemv
3. Implement an avx512-bf16 based kernel for sbgemv

Signed-off-by: Chen, Guobing <guobing.chen@intel.com>

Try to read cpu ID from /sys/devices/.../cpu0 if HWCAP_CPUID fails

to be able to include a binutils version check

This patch fixes compilation errors due to recent renaming from SH to SB
with BUILD_BFLOAT16.

Avoid out of bounds access on invalid memory free

Lazyly reinit threads after a fork in OMP mode

This initializes the per-thread memory buffers which get
cleared/released on a fork via pthread_at_fork. Not doing so leads to
each thread calling blas_memory_alloc on almost every execution which
slows down the code significantly as the threads race for the memory
allocation using locks to serialize that.

Adding performance patch for trmm, just like trsm (#2836)

Add bfloat16 based dot and conversion with single/double

Enable building DYNAMIC_ARCH support with older versions of glibc that
do not know about the hwcap flag HWCAP_S390_VXE yet.

Signed-off-by: Marius Hillenbrand <mhillen@linux.ibm.com>

... instead of duplicating the (old) mechanism from the Makefile that
aimed to derive supported architecture generations from the gcc
version.

To enable builds with DYNAMIC_ARCH with older compiler releases, the
Makefile and drivers/other/dynamic_arch.c need a common view of the
architecture support built into the library.

We follow the notation from x86 when used with DYNAMIC_LIST, where
defines DYN_<ARCH NAME> denote support for a given generation to be
built in. Since there are far fewer architecture generations in OpenBLAS
for s390x, that does not bloat command lines too much.

Signed-off-by: Marius Hillenbrand <mhillen@linux.ibm.com>

1. Added bfloat16 based dot as new API: shdot
2. Implemented generic kernel and cooperlake-specific (AVX512-BF16) kernel for shdot
3. Added 4 conversion APIs for bfloat16 data type <=> single/double: shstobf16 shdtobf16 sbf16tos dbf16tod
     shstobf16 -- convert single float array to bfloat16 array
     shdtobf16 -- convert double float array to bfloat16 array
     sbf16tos  -- convert bfloat16 array to single float array
     dbf16tod  -- convert bfloat16 array to double float array
4. Implemented generic kernels for all 4 conversion APIs, and cooperlake-specific kernel for shstobf16 and shdtobf16
5. Update level1 thread facilitate functions and macros to support multi-threading for these new APIs
6. Fix Cooperlake platform detection/specify issue when under dynamic-arch building
7. Change the typedef of bfloat16 from unsigned short to more strict uint16_t

Signed-off-by: Chen, Guobing <guobing.chen@intel.com>

In current code, no matter what number of threads specified, all
available CPU count is used when invoking OMP, which leads to very bad
performance if the workload is small while all available CPUs are big.
Lots of time are wasted on inter-thread sync. Fix this issue by really
using the number specified by the variable 'num' from calling API.

Signed-off-by: Chen, Guobing <guobing.chen@intel.com>

Enable new build target platform -- COOPERLAKE. This target platform
supports all the SKYLAKEX supported ISAs + avx512bf16. So all the
SKYLAKEX specific kernels/drivers and related code are now extended
to be also active on COOPERLAKE. Besides, new BF16 related kernels
are active under this target.