147 lines
2.0 KiB
ArmAsm
147 lines
2.0 KiB
ArmAsm
/*
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* ====================================================
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* Copyright (C) 1998 by Cygnus Solutions. All rights reserved.
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*
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include "i386mach.h"
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.global SYM (memmove)
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SOTYPE_FUNCTION(memmove)
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SYM (memmove):
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pushl ebp
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movl esp,ebp
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pushl esi
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pushl edi
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pushl ebx
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movl 8(ebp),edi
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movl 16(ebp),ecx
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movl 12(ebp),esi
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/* check for destructive overlap (src < dst && dst < src + length) */
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cld
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cmpl edi,esi
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jae .L2
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leal -1(ecx,esi),ebx
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cmpl ebx,edi
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ja .L2
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/* IF: destructive overlap, must copy backwards */
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addl ecx,esi
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addl ecx,edi
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std
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#ifndef __OPTIMIZE_SIZE__
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cmpl $8,ecx
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jbe .L13
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.L18:
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/* move trailing bytes in reverse until destination address is long word aligned */
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movl edi,edx
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movl ecx,ebx
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andl $3,edx
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jz .L21
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movl edx,ecx
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decl esi
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decl edi
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subl ecx,ebx
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rep
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movsb
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mov ebx,ecx
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incl esi
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incl edi
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.L21:
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/* move bytes in reverse, a long word at a time */
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shrl $2,ecx
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subl $4,esi
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subl $4,edi
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rep
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movsl
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addl $4,esi
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addl $4,edi
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movl ebx,ecx
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andl $3,ecx
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#endif /* !__OPTIMIZE_SIZE__ */
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/* handle any remaining bytes not on a long word boundary */
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.L13:
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decl esi
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decl edi
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.L15:
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rep
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movsb
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jmp .L5
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.p2align 4,,7
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/* ELSE: no destructive overlap so we copy forwards */
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.L2:
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#ifndef __OPTIMIZE_SIZE__
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cmpl $8,ecx
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jbe .L3
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/* move any preceding bytes until destination address is long word aligned */
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movl edi,edx
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movl ecx,ebx
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andl $3,edx
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jz .L11
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movl $4,ecx
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subl edx,ecx
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andl $3,ecx
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subl ecx,ebx
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rep
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movsb
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mov ebx,ecx
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/* move bytes a long word at a time */
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.L11:
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shrl $2,ecx
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.p2align 2
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rep
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movsl
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movl ebx,ecx
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andl $3,ecx
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#endif /* !__OPTIMIZE_SIZE__ */
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/* handle any remaining bytes */
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.L3:
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rep
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movsb
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.L5:
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movl 8(ebp),eax
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cld
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leal -12(ebp),esp
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popl ebx
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popl edi
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popl esi
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leave
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ret
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