Add compiler flag for SSE4 where available

Change-Id: Iae7800a32f5af3903c330882cdf6f292d885f266

Revert special handling of Windows xNRM2 and enable C+intrinsics kern…

As the new MMA instructions need the inputs in 4x2 order for bfloat16,
changing the format in copy/packing code.  This avoids permute instructions
in the gemm kernel inner loop.

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

Rename "HALF" precision functions (sh prefix) to "BFLOAT16" with "sb" prefix

add fninit to reset fpu registers before assembler routines

Use generic C for (D/Z)NRM2 on Windows x86_64

Support building only a subset of variable types

Optimize the performance of dot by using universal intrinsics in X86/ARM

This patch makes use of new POWER10 vector pair instructions for
loads and stores. Tested in simulator and no new failures.

The implementation of complex scalar * vector multiplication for Z14
makes some LAPACK tests fail because the numerical differences to the
reference implementation exceed the threshold (as can be seen by running
make lapack-test and replacing kernel/zarch/cscal.c with a generic
implementation for comparison).

The complex multiplication uses terms of the form a * b + c * d for both
real and imaginary parts. The assembly code (and compiler-emitted code
as well) uses fused multiply add operations for the second product and
sum. The results can be "surprising", for example when both terms in the
imaginary part nearly cancel each other out. In that case, the second
product contributes more digits to the sum than the first product that
has been rounded before.

One option is to use separate multiplications (which then round the same
way) and a distinct add. Change the code to pursue that path, by (1)
requesting the compiler not to contract the operations into FMAs and (2)
replacing the assembly kernel with corresponding vectorized C code
(where change 1 also applies).

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

... to facilitate reuse beyond gemm_vec.c and avoid code duplication.

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

This patch makes use of new POWER10 vector pair instructions for
loads and stores. Tested in simulator and no new failures.

Add bfloat16 based dot and conversion with single/double

Implementaion of dasum, sasum with AVX2 & AVX512 intrinsic