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/*-
* 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.
*/
#include <machine/asm.h>
/*
* Note: this routine was written with kernel use in mind (read: no simd),
* it is only present in userspace as a temporary measure until something
* better gets imported.
*/
#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
/*
* memmove(dst, src, cnt)
* rdi, rsi, rdx
*/
/*
* Register state at entry is supposed to be as follows:
* rdi - destination
* rsi - source
* rdx - count
*
* The macro possibly clobbers the above and: rcx, r8, r9, 10
* It does not clobber rax nor r11.
*/
.macro MEMMOVE erms overlap begin end
\begin
/*
* For sizes 0..32 all data is read before it is written, so there
* is no correctness issue with direction of copying.
*/
cmpq $32,%rcx
jbe 101632f
.if \overlap == 1
movq %rdi,%r8
subq %rsi,%r8
cmpq %rcx,%r8 /* overlapping && src < dst? */
jb 2f
.endif
cmpq $256,%rcx
ja 1256f
ALIGN_TEXT
103200:
movq (%rsi),%rdx
movq %rdx,(%rdi)
movq 8(%rsi),%rdx
movq %rdx,8(%rdi)
movq 16(%rsi),%rdx
movq %rdx,16(%rdi)
movq 24(%rsi),%rdx
movq %rdx,24(%rdi)
leaq 32(%rsi),%rsi
leaq 32(%rdi),%rdi
subq $32,%rcx
cmpq $32,%rcx
jae 103200b
cmpb $0,%cl
jne 101632f
\end
ret
ALIGN_TEXT
101632:
cmpb $16,%cl
jl 100816f
movq (%rsi),%rdx
movq 8(%rsi),%r8
movq -16(%rsi,%rcx),%r9
movq -8(%rsi,%rcx),%r10
movq %rdx,(%rdi)
movq %r8,8(%rdi)
movq %r9,-16(%rdi,%rcx)
movq %r10,-8(%rdi,%rcx)
\end
ret
ALIGN_TEXT
100816:
cmpb $8,%cl
jl 100408f
movq (%rsi),%rdx
movq -8(%rsi,%rcx),%r8
movq %rdx,(%rdi)
movq %r8,-8(%rdi,%rcx,)
\end
ret
ALIGN_TEXT
100408:
cmpb $4,%cl
jl 100204f
movl (%rsi),%edx
movl -4(%rsi,%rcx),%r8d
movl %edx,(%rdi)
movl %r8d,-4(%rdi,%rcx)
\end
ret
ALIGN_TEXT
100204:
cmpb $2,%cl
jl 100001f
movzwl (%rsi),%edx
movzwl -2(%rsi,%rcx),%r8d
movw %dx,(%rdi)
movw %r8w,-2(%rdi,%rcx)
\end
ret
ALIGN_TEXT
100001:
cmpb $1,%cl
jl 100000f
movb (%rsi),%dl
movb %dl,(%rdi)
100000:
\end
ret
ALIGN_TEXT
1256:
testb $15,%dil
jnz 100f
.if \erms == 1
rep
movsb
.else
shrq $3,%rcx /* copy by 64-bit words */
rep
movsq
movq %rdx,%rcx
andl $7,%ecx /* any bytes left? */
jne 100408b
.endif
\end
ret
100:
movq (%rsi),%r8
movq 8(%rsi),%r9
movq %rdi,%r10
movq %rdi,%rcx
andq $15,%rcx
leaq -16(%rdx,%rcx),%rdx
neg %rcx
leaq 16(%rdi,%rcx),%rdi
leaq 16(%rsi,%rcx),%rsi
movq %rdx,%rcx
.if \erms == 1
rep
movsb
movq %r8,(%r10)
movq %r9,8(%r10)
.else
shrq $3,%rcx /* copy by 64-bit words */
rep
movsq
movq %r8,(%r10)
movq %r9,8(%r10)
movq %rdx,%rcx
andl $7,%ecx /* any bytes left? */
jne 100408b
.endif
\end
ret
.if \overlap == 1
/*
* Copy backwards.
*/
ALIGN_TEXT
2:
cmpq $256,%rcx
ja 2256f
leaq -8(%rdi,%rcx),%rdi
leaq -8(%rsi,%rcx),%rsi
cmpq $32,%rcx
jb 2016f
ALIGN_TEXT
2032:
movq (%rsi),%rdx
movq %rdx,(%rdi)
movq -8(%rsi),%rdx
movq %rdx,-8(%rdi)
movq -16(%rsi),%rdx
movq %rdx,-16(%rdi)
movq -24(%rsi),%rdx
movq %rdx,-24(%rdi)
leaq -32(%rsi),%rsi
leaq -32(%rdi),%rdi
subq $32,%rcx
cmpq $32,%rcx
jae 2032b
cmpb $0,%cl
jne 2016f
\end
ret
ALIGN_TEXT
2016:
cmpb $16,%cl
jl 2008f
movq (%rsi),%rdx
movq %rdx,(%rdi)
movq -8(%rsi),%rdx
movq %rdx,-8(%rdi)
subb $16,%cl
jz 2000f
leaq -16(%rsi),%rsi
leaq -16(%rdi),%rdi
2008:
cmpb $8,%cl
jl 2004f
movq (%rsi),%rdx
movq %rdx,(%rdi)
subb $8,%cl
jz 2000f
leaq -8(%rsi),%rsi
leaq -8(%rdi),%rdi
2004:
cmpb $4,%cl
jl 2002f
movl 4(%rsi),%edx
movl %edx,4(%rdi)
subb $4,%cl
jz 2000f
leaq -4(%rsi),%rsi
leaq -4(%rdi),%rdi
2002:
cmpb $2,%cl
jl 2001f
movw 6(%rsi),%dx
movw %dx,6(%rdi)
subb $2,%cl
jz 2000f
leaq -2(%rsi),%rsi
leaq -2(%rdi),%rdi
2001:
cmpb $1,%cl
jl 2000f
movb 7(%rsi),%dl
movb %dl,7(%rdi)
2000:
\end
ret
ALIGN_TEXT
2256:
std
leaq -8(%rdi,%rcx),%rdi
leaq -8(%rsi,%rcx),%rsi
shrq $3,%rcx
rep
movsq
cld
movq %rdx,%rcx
andb $7,%cl
jne 2004b
\end
ret
.endif
.endm
.macro MEMMOVE_BEGIN
movq %rdi,%rax
movq %rdx,%rcx
.endm
.macro MEMMOVE_END
.endm
#ifndef MEMCPY
ENTRY(memmove)
MEMMOVE erms=0 overlap=1 begin=MEMMOVE_BEGIN end=MEMMOVE_END
END(memmove)
#else
ENTRY(memcpy)
MEMMOVE erms=0 overlap=1 begin=MEMMOVE_BEGIN end=MEMMOVE_END
END(memcpy)
#endif
.section .note.GNU-stack,"",%progbits
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