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kernel/linux-rt-4.4.41/arch/sparc/lib/memmove.S 1.17 KB
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  /* memmove.S: Simple memmove implementation.
   *
   * Copyright (C) 1997, 2004 David S. Miller (davem@redhat.com)
   * Copyright (C) 1996, 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz)
   */
  
  #include <linux/linkage.h>
  
  	.text
  ENTRY(memmove) /* o0=dst o1=src o2=len */
  	brz,pn		%o2, 99f
  	 mov		%o0, %g1
  
  	cmp		%o0, %o1
  	bleu,pt		%xcc, 2f
  	 add		%o1, %o2, %g7
  	cmp		%g7, %o0
  	bleu,pt		%xcc, memcpy
  	 add		%o0, %o2, %o5
  	sub		%g7, 1, %o1
  
  	sub		%o5, 1, %o0
  1:	ldub		[%o1], %g7
  	subcc		%o2, 1, %o2
  	sub		%o1, 1, %o1
  	stb		%g7, [%o0]
  	bne,pt		%icc, 1b
  	 sub		%o0, 1, %o0
  99:
  	retl
  	 mov		%g1, %o0
  
  	/* We can't just call memcpy for these memmove cases.  On some
  	 * chips the memcpy uses cache initializing stores and when dst
  	 * and src are close enough, those can clobber the source data
  	 * before we've loaded it in.
  	 */
  2:	or		%o0, %o1, %g7
  	or		%o2, %g7, %g7
  	andcc		%g7, 0x7, %g0
  	bne,pn		%xcc, 4f
  	 nop
  
  3:	ldx		[%o1], %g7
  	add		%o1, 8, %o1
  	subcc		%o2, 8, %o2
  	add		%o0, 8, %o0
  	bne,pt		%icc, 3b
  	 stx		%g7, [%o0 - 0x8]
  	ba,a,pt		%xcc, 99b
  
  4:	ldub		[%o1], %g7
  	add		%o1, 1, %o1
  	subcc		%o2, 1, %o2
  	add		%o0, 1, %o0
  	bne,pt		%icc, 4b
  	 stb		%g7, [%o0 - 0x1]
  	ba,a,pt		%xcc, 99b
  ENDPROC(memmove)