During the last iteration of some RVV operations, accumulators can get overwritten when VL < VLMAX and tail policy is agnostic.
Commit changes intrinsics tail policy to undistrubed.
* fix multiple numerical stability and corner case issues
* add a script to generate arbitrary gemm kernel shapes
* add a generic zvl256b target to demonstrate large gemm kernel unrolls
This adds an SVE implementation to sdot/ddot when available, falling back to the previous Advanced SIMD kernel where there's no SVE implementation for the kernel.
All the targets were essentially treating `dot_thunderx2t99.c` as the Advanced SIMD implementation so I've renamed it to better fit with the feature detection.
The existing kernel was issuing extra instructions to organise the arguments into the same registers they would usually be in and similarly to put the result into the appropriate register.
This has an impact on smaller sized dots and seemed like a quick fix
These are as similar to dscal_microk_skylakex-2.c as possible
for consistency.
Note that before this change SKYLAKEX+ uses generic C functions for
cscal/zscal via commit 2271c350 from #2610 (which is masked by
commit 086d87a30). However now #3799 disables FMAs (in turn enabled
by `-march=skylake-avx512`) in the plain C code which fixes excessive
LAPACK test failures more nicely.
If e.g. -march=haswell is set in CFLAGS, GCC generates FMAs by default, which
is inconsistent with the microkernels, none of which use FMAs. These
inconsistencies cause a few failures in the LAPACK testcases, where
eigenvalue results with/without eigenvectors are compared.
Moreover using FMAs for multiplication of complex numbers can give surprising
results, see 22aa81f for more information.
This uses the same syntax as used in 22aa81f for zarch (s390x).
There are some test failures in complex dot functions when compiling with gcc12.
The machine constraints used now do not update all the four elements in the
expected result array. Fixing this with a reduced level of optimization.
This is not changing any performance numbers but will be converted to C code in future.
Octavian Maghiar
ZhengSh
Heller Zheng
Zhang Xianyi
Sergei Lewis
Xianyi Zhang
Chris Sidebottom
HellerZheng
Martin Kroeker
Bart Oldeman
Honglin Zhu
Bart Oldeman
gxw
Jiaxun Yang
Ivan Pribec
Rajalakshmi Srinivasaraghavan