It turned out that an 256b-mvc instruction which depends on the
result of a previous 256b-mvc instruction is counterproductive.
Therefore this patch adjusts the 256b-loop by storing the
first byte with stc and setting the remaining 255b with mvc.
Now the 255b-mvc instruction depends on the stc instruction.
This patch moves all ifunc variants for memset
to sysdeps/s390/memset-z900.S. The configure-check/preprocessor logic
in sysdeps/s390/ifunc-memset.h decides if ifunc is needed at all
and which ifunc variants should be available.
E.g. if the compiler/assembler already supports z196 by default,
the older ifunc variants are not included.
If we only need the newest ifunc variant,
then we can skip ifunc at all.
Therefore the ifunc-resolvers and __libc_ifunc_impl_list are adjusted
in order to handle only the available ifunc variants.
ChangeLog:
* sysdeps/s390/ifunc-memset.h: New File.
* sysdeps/s390/memset.S: Move to ...
* sysdeps/s390/memset-z900.S ... here.
Move implementations from memset-s390x.s to here.
* sysdeps/s390/multiarch/memset-s390x.S: Delete File.
* sysdeps/s390/multiarch/Makefile (sysdep_routines):
Remove memset variants.
* sysdeps/s390/Makefile (sysdep_routines):
Add memset variants.
* sysdeps/s390/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Adjust ifunc variants for
memset.
* sysdeps/s390/multiarch/memset.c: Move ifunc resolver
to ...
* sysdeps/s390/memset.c: ... here.
Adjust ifunc variants for memset.