1 files changed, 145 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/string/memmove.asm b/src/VBox/Runtime/common/string/memmove.asm
new file mode 100644
index 00000000..c8e53416
--- /dev/null
+++ b/src/VBox/Runtime/common/string/memmove.asm
@@ -0,0 +1,145 @@
+; $Id: memmove.asm $
+;; @file
+; IPRT - No-CRT memmove - AMD64 & X86.
+;
+
+;
+; Copyright (C) 2006-2019 Oracle Corporation
+;
+; This file is part of VirtualBox Open Source Edition (OSE), as
+; available from http://www.virtualbox.org. This file is free software;
+; you can redistribute it and/or modify it under the terms of the GNU
+; General Public License (GPL) as published by the Free Software
+; Foundation, in version 2 as it comes in the "COPYING" file of the
+; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+;
+; The contents of this file may alternatively be used under the terms
+; of the Common Development and Distribution License Version 1.0
+; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+; VirtualBox OSE distribution, in which case the provisions of the
+; CDDL are applicable instead of those of the GPL.
+;
+; You may elect to license modified versions of this file under the
+; terms and conditions of either the GPL or the CDDL or both.
+;
+
+%include "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; @param    pvDst   gcc: rdi  msc: rcx  x86:[esp+4]    wcall: eax
+; @param    pvSrc   gcc: rsi  msc: rdx  x86:[esp+8]    wcall: edx
+; @param    cb      gcc: rdx  msc: r8   x86:[esp+0ch]  wcall: ebx
+RT_NOCRT_BEGINPROC memmove
+        ; Prolog.
+%ifdef RT_ARCH_AMD64
+ %ifdef ASM_CALL64_MSC
+        mov     r10, rdi                ; save
+        mov     r11, rsi                ; save
+        mov     rdi, rcx
+        mov     rsi, rdx
+        mov     rcx, r8
+        mov     rdx, r8
+ %else
+        mov     rcx, rdx
+ %endif
+        mov     rax, rdi                ; save the return value
+%else
+        push    edi
+        push    esi
+ %ifdef ASM_CALL32_WATCOM
+        mov     edi, eax
+        mov     esi, edx
+        mov     ecx, ebx
+        mov     edx, ebx
+ %else
+        mov     edi, [esp + 04h + 8]
+        mov     esi, [esp + 08h + 8]
+        mov     ecx, [esp + 0ch + 8]
+        mov     edx, ecx
+        mov     eax, edi                ; save the return value
+ %endif
+%endif
+
+        ;
+        ; Decide which direction to perform the copy in.
+        ;
+%if 1 ; keep it simple for now.
+        cmp     xDI, xSI
+        jnb     .backward
+
+        ;
+        ; Slow/simple forward copy.
+        ;
+        cld
+        rep movsb
+        jmp .epilog
+
+%else ; disabled - it seems to work, but play safe for now.
+        ;sub     xAX, xSI
+        ;jnb     .backward
+        cmp     xDI, xSI
+        jnb     .backward
+
+        ;
+        ; Fast forward copy.
+        ;
+.fast_forward:
+        cld
+%ifdef RT_ARCH_AMD64
+        shr     rcx, 3
+        rep movsq
+%else
+        shr     ecx, 2
+        rep movsd
+%endif
+
+        ; The remaining bytes.
+%ifdef RT_ARCH_AMD64
+        test    dl, 4
+        jz      .forward_dont_move_dword
+        movsd
+%endif
+.forward_dont_move_dword:
+        test    dl, 2
+        jz      .forward_dont_move_word
+        movsw
+.forward_dont_move_word:
+        test    dl, 1
+        jz      .forward_dont_move_byte
+        movsb
+.forward_dont_move_byte:
+
+%endif ; disabled
+
+        ;
+        ; The epilog.
+        ;
+.epilog:
+%ifdef RT_ARCH_AMD64
+ %ifdef ASM_CALL64_MSC
+        mov     rdi, r10
+        mov     rsi, r11
+ %endif
+%else
+        pop     esi
+        pop     edi
+%endif
+        ret
+
+        ;
+        ; Slow/simple backward copy.
+        ;
+ALIGNCODE(16)
+.backward:
+        ;; @todo check if they overlap.
+        lea     xDI, [xDI + xCX - 1]
+        lea     xSI, [xSI + xCX - 1]
+        std
+        rep movsb
+        cld
+        jmp .epilog
+ENDPROC RT_NOCRT(memmove)
+