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