Commit Graph

4 Commits

Author SHA1 Message Date
Heiko Carstens 551f413434 s390/lib: improve memmove, memset and memcpy
Improve the memmove implementation to save one instruction and use
better label names. Also use better label names for the memset and
memcpy implementations so everything looks consistent.

Suggested-by: Jens Remus <jremus@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-01-16 07:27:51 +01:00
Heiko Carstens b4623d4e5b s390: provide memmove implementation
Provide an s390 specific memmove implementation which is faster than
the generic implementation which copies byte-wise.

For non-destructive (as defined by the mvc instruction) memmove
operations the following table compares the old default implementation
versus the new s390 specific implementation:

size     old   new
   1     1ns   8ns
   2     2ns   8ns
   4     4ns   8ns
   8     7ns   8ns
  16    17ns   8ns
  32    35ns   8ns
  64    65ns   9ns
 128   146ns  10ns
 256   298ns  11ns
 512   537ns  11ns
1024  1193ns  19ns
2048  2405ns  36ns

So only for very small sizes the old implementation is faster. For
overlapping memmoves, where the mvc instruction can't be used, the new
implementation is as slow as the old one.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-12-12 12:11:32 +01:00
Al Viro 711f5df7bf s390: move exports to definitions
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-07 23:47:20 -04:00
Heiko Carstens 304987e365 s390: remove "64" suffix from mem64.S and swsusp_asm64.S
Rename two more files which I forgot. Also remove the "asm" from the
swsusp_asm64.S file, since the ".S" suffix already makes it obvious
that this file contains assembler code.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-03-25 11:49:51 +01:00