diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 03:01:46 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 03:01:46 +0000 |
commit | f8fe689a81f906d1b91bb3220acde2a4ecb14c5b (patch) | |
tree | 26484e9d7e2c67806c2d1760196ff01aaa858e8c /src/VBox/Runtime/common/string/memmove.asm | |
parent | Initial commit. (diff) | |
download | virtualbox-upstream.tar.xz virtualbox-upstream.zip |
Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/VBox/Runtime/common/string/memmove.asm')
-rw-r--r-- | src/VBox/Runtime/common/string/memmove.asm | 145 |
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) + |