132 строки
2.0 KiB
ArmAsm
132 строки
2.0 KiB
ArmAsm
/* Copyright 2002 Andi Kleen */
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/dwarf2.h>
|
|
#include <asm/cpufeature.h>
|
|
|
|
/*
|
|
* memcpy - Copy a memory block.
|
|
*
|
|
* Input:
|
|
* rdi destination
|
|
* rsi source
|
|
* rdx count
|
|
*
|
|
* Output:
|
|
* rax original destination
|
|
*/
|
|
|
|
ALIGN
|
|
memcpy_c:
|
|
CFI_STARTPROC
|
|
movq %rdi,%rax
|
|
movl %edx,%ecx
|
|
shrl $3,%ecx
|
|
andl $7,%edx
|
|
rep movsq
|
|
movl %edx,%ecx
|
|
rep movsb
|
|
ret
|
|
CFI_ENDPROC
|
|
ENDPROC(memcpy_c)
|
|
|
|
ENTRY(__memcpy)
|
|
ENTRY(memcpy)
|
|
CFI_STARTPROC
|
|
pushq %rbx
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
CFI_REL_OFFSET rbx, 0
|
|
movq %rdi,%rax
|
|
|
|
movl %edx,%ecx
|
|
shrl $6,%ecx
|
|
jz .Lhandle_tail
|
|
|
|
.p2align 4
|
|
.Lloop_64:
|
|
decl %ecx
|
|
|
|
movq (%rsi),%r11
|
|
movq 8(%rsi),%r8
|
|
|
|
movq %r11,(%rdi)
|
|
movq %r8,1*8(%rdi)
|
|
|
|
movq 2*8(%rsi),%r9
|
|
movq 3*8(%rsi),%r10
|
|
|
|
movq %r9,2*8(%rdi)
|
|
movq %r10,3*8(%rdi)
|
|
|
|
movq 4*8(%rsi),%r11
|
|
movq 5*8(%rsi),%r8
|
|
|
|
movq %r11,4*8(%rdi)
|
|
movq %r8,5*8(%rdi)
|
|
|
|
movq 6*8(%rsi),%r9
|
|
movq 7*8(%rsi),%r10
|
|
|
|
movq %r9,6*8(%rdi)
|
|
movq %r10,7*8(%rdi)
|
|
|
|
leaq 64(%rsi),%rsi
|
|
leaq 64(%rdi),%rdi
|
|
jnz .Lloop_64
|
|
|
|
.Lhandle_tail:
|
|
movl %edx,%ecx
|
|
andl $63,%ecx
|
|
shrl $3,%ecx
|
|
jz .Lhandle_7
|
|
.p2align 4
|
|
.Lloop_8:
|
|
decl %ecx
|
|
movq (%rsi),%r8
|
|
movq %r8,(%rdi)
|
|
leaq 8(%rdi),%rdi
|
|
leaq 8(%rsi),%rsi
|
|
jnz .Lloop_8
|
|
|
|
.Lhandle_7:
|
|
movl %edx,%ecx
|
|
andl $7,%ecx
|
|
jz .Lende
|
|
.p2align 4
|
|
.Lloop_1:
|
|
movb (%rsi),%r8b
|
|
movb %r8b,(%rdi)
|
|
incq %rdi
|
|
incq %rsi
|
|
decl %ecx
|
|
jnz .Lloop_1
|
|
|
|
.Lende:
|
|
popq %rbx
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
CFI_RESTORE rbx
|
|
ret
|
|
.Lfinal:
|
|
CFI_ENDPROC
|
|
ENDPROC(memcpy)
|
|
ENDPROC(__memcpy)
|
|
|
|
/* Some CPUs run faster using the string copy instructions.
|
|
It is also a lot simpler. Use this when possible */
|
|
|
|
.section .altinstr_replacement,"ax"
|
|
1: .byte 0xeb /* jmp <disp8> */
|
|
.byte (memcpy_c - memcpy) - (2f - 1b) /* offset */
|
|
2:
|
|
.previous
|
|
.section .altinstructions,"a"
|
|
.align 8
|
|
.quad memcpy
|
|
.quad 1b
|
|
.byte X86_FEATURE_REP_GOOD
|
|
/* Replace only beginning, memcpy is used to apply alternatives, so it
|
|
* is silly to overwrite itself with nops - reboot is only outcome... */
|
|
.byte 2b - 1b
|
|
.byte 2b - 1b
|
|
.previous
|