Commit graph

6 commits

Author SHA1 Message Date
Mateusz Guzik
8291e88748 amd64: sync up libc memcmp with the kernel version (r357309) 2020-01-30 19:57:05 +00:00
Mateusz Guzik
4846152a08 amd64: sync up libc memcmp with the kernel version (r357208) 2020-01-29 01:57:07 +00:00
Mateusz Guzik
5bbde333cd amd64: reimplement libc memcmp and bcmp with kernel memcmp
Both are significantly slower than hand-coded loops. See r338963 for
kernel commit.

bcmp differs from memcmp by always returning 1 when a difference is
found, as opposed to going for a value bigger or lower than 0
depending on what it is. This means it can do less work. For now the
code is duplicated and modified. This will get deduplicated after
another round of optimization when memcmp will get a longer-term form.

Both tested with the glibc suite. While the suite does not have a test
for bcmp, I created a wrapper routine which verified that values match
(0 vs 0, 1 vs non-zero).

Reviewed by:	kib
Approved by:	re (gjb)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D17336
2018-09-27 17:08:29 +00:00
Konstantin Belousov
93ab758670 Add section .note.GNU-stack for assembly files used by 386 and amd64. 2011-01-07 16:08:40 +00:00
Peter Wemm
5d053f461c We've been lax about matching END() macros in asm code for some time. This
is used to set the ELF size attribute for functions.  It isn't normally
critical but some things can make use of it (gdb for stack traces).
Valgrind needs it so I'm adding it in.  The problem is present on all
branches and on both i386 and amd64.
2008-11-02 01:10:54 +00:00
Alan Cox
26f6218be9 Add machine-specific, optimized implementations of bcmp and memcmp.
PR: 73111
Submitted by: Ville-Pertti Keinonen <will@iki.fi> (taken from NetBSD)
MFC after: 3 weeks
2005-04-08 05:15:55 +00:00