opnsense-src/lib/libc/amd64/string/memset.S
Mateusz Guzik 7e02ad0769 amd64: reimplement libc memset and bzero with kernel memset
This is a depessimization, see r334537 for an explanation. Routines
remain significantly slower than they have to be.

bzero was removed from the kernel but remains in libc. Macroify to
accommodate differences to memset (no return value, always setting to 0).

The bzero.S file is left in place due to libc build magic which pulls in
a C variant if a matching .S file is missing.

Reviewed by:	kib
Approved by:	re (gjb)
Differential Revision:	https://reviews.freebsd.org/D17355
2018-10-01 20:39:17 +00:00

77 lines
2 KiB
ArmAsm

/*-
* Copyright (c) 2018 The FreeBSD Foundation
*
* This software was developed by Mateusz Guzik <mjg@FreeBSD.org>
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
.macro MEMSET bzero
.if \bzero == 1
movq %rsi,%rcx
movq %rsi,%rdx
xorl %eax,%eax
.else
movq %rdi,%r9
movq %rdx,%rcx
movzbq %sil,%r8
movabs $0x0101010101010101,%rax
imulq %r8,%rax
.endif
cmpq $15,%rcx
jbe 1f
shrq $3,%rcx
rep
stosq
movq %rdx,%rcx
andq $7,%rcx
jne 1f
.if \bzero == 0
movq %r9,%rax
.endif
ret
1:
rep
stosb
.if \bzero == 0
movq %r9,%rax
.endif
ret
.endm
#ifndef BZERO
ENTRY(memset)
MEMSET bzero=0
END(memset)
#else
ENTRY(bzero)
MEMSET bzero=1
END(bzero)
#endif
.section .note.GNU-stack,"",%progbits