History log of /freebsd/lib/libc/amd64/string/strcmp.S (Results 1 – 9 of 9)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: release/14.0.0
# bca25680 16-Sep-2023 Robert Clausecker <fuz@FreeBSD.org>

lib/libc/amd64/string/strcmp.S: add baseline implementation

This is the most complicated one so far. The basic idea is to process
the bulk of the string in aligned blocks of 16 bytes such that one

lib/libc/amd64/string/strcmp.S: add baseline implementation

This is the most complicated one so far. The basic idea is to process
the bulk of the string in aligned blocks of 16 bytes such that one
string runs ahead and the other runs behind. The string that runs ahead
is checked for NUL bytes, the one that runs behind is compared with the
corresponding chunk of the string that runs ahead. This trades an extra
load per iteration for the very complicated block-reassembly needed in
the other implementations (bionic, glibc). On the flip side, we need
two code paths depending on the relative alignment of the two buffers.

The initial part of the string is compared directly if it is known not
to cross a page boundary. Otherwise, a complex slow path to avoid
crossing into unmapped memory commences.

Performance-wise we beat bionic for misaligned strings (i.e. the strings
do not share an alignment offset) and reach comparable performance for
aligned strings. glibc is a bit better as it has a special kernel for
AVX-512, where this stuff is a bit easier to do.

Sponsored by: The FreeBSD Foundation
Tested by: developers@, exp-run
Approved by: mjg
MFC after: 1 month
MFC to: stable/14
PR: 275785
Differential Revision: https://reviews.freebsd.org/D41971

show more ...


# 1d386b48 16-Aug-2023 Warner Losh <imp@FreeBSD.org>

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/


Revision tags: release/13.2.0, release/12.4.0, release/13.1.0, release/12.3.0, release/13.0.0, release/12.2.0, release/11.4.0, release/12.1.0, release/11.3.0, release/12.0.0, release/11.2.0, release/10.4.0, release/11.1.0, release/11.0.1, release/11.0.0
# 32223c1b 30-Apr-2016 Pedro F. Giffuni <pfg@FreeBSD.org>

libc: spelling fixes.

Mostly on comments.


Revision tags: release/10.3.0, release/10.2.0, release/10.1.0, release/9.3.0, release/10.0.0, release/9.2.0, release/8.4.0, release/9.1.0, release/8.3.0_cvs, release/8.3.0, release/9.0.0, release/7.4.0_cvs, release/8.2.0_cvs, release/7.4.0, release/8.2.0
# 93ab7586 07-Jan-2011 Konstantin Belousov <kib@FreeBSD.org>

Add section .note.GNU-stack for assembly files used by 386 and amd64.


Revision tags: release/8.1.0_cvs, release/8.1.0, release/7.3.0_cvs, release/7.3.0, release/8.0.0_cvs, release/8.0.0, release/7.2.0_cvs, release/7.2.0, release/7.1.0_cvs, release/7.1.0
# e57c2b13 04-Dec-2008 Dag-Erling Smørgrav <des@FreeBSD.org>

integrate from head@185615


Revision tags: release/6.4.0_cvs, release/6.4.0
# 5d053f46 02-Nov-2008 Peter Wemm <peter@FreeBSD.org>

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 fo

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.

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Revision tags: release/7.0.0_cvs, release/7.0.0, release/6.3.0_cvs, release/6.3.0, release/6.2.0_cvs, release/6.2.0, release/5.5.0_cvs, release/5.5.0, release/6.1.0_cvs, release/6.1.0, release/6.0.0_cvs, release/6.0.0, release/5.4.0_cvs, release/5.4.0
# e5dd4df8 09-Apr-2005 Alan Cox <alc@FreeBSD.org>

Add a machine-specific, optimized implementation of strcmp.

PR: 73111
Submitted by: Ville-Pertti Keinonen <will@iki.fi> (taken from NetBSD)
MFC after: 3 weeks


Revision tags: release/6.4.0_cvs, release/6.4.0
# 5d053f46 02-Nov-2008 Peter Wemm <peter@FreeBSD.org>

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 fo

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.

show more ...


Revision tags: release/7.0.0_cvs, release/7.0.0, release/6.3.0_cvs, release/6.3.0, release/6.2.0_cvs, release/6.2.0, release/5.5.0_cvs, release/5.5.0, release/6.1.0_cvs, release/6.1.0, release/6.0.0_cvs, release/6.0.0, release/5.4.0_cvs, release/5.4.0
# e5dd4df8 09-Apr-2005 Alan Cox <alc@FreeBSD.org>

Add a machine-specific, optimized implementation of strcmp.

PR: 73111
Submitted by: Ville-Pertti Keinonen <will@iki.fi> (taken from NetBSD)
MFC after: 3 weeks