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Replace RtlMoveMemory x86 asm code with the code from CRT's memmove, which is better. Now we can close bug #1941

svn path=/trunk/; revision=50116
This commit is contained in:
Timo Kreuzer 2010-12-23 19:11:19 +00:00
parent c884962fb3
commit e7f8fba710
1 changed files with 102 additions and 48 deletions
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150
reactos/lib/rtl/i386/rtlmem.s
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@ -210,70 +210,124 @@ ByteZero:
_RtlMoveMemory@12:
push ebp
mov ebp, esp
/* Save volatiles */
/* Save non-volatiles */
push esi
push edi
/* Get pointers and size */
mov esi, [esp+16]
mov edi, [esp+12]
mov ecx, [esp+20]
cld
mov edi, [ebp + 8]
mov esi, [ebp + 12]
mov ecx, [ebp + 16]
/* Check if the destination is higher (or equal) */
cmp esi, edi
jbe Overlap
/* Use downward copy if source < dest and overlapping */
cmp edi, esi
jbe .CopyUp
mov eax, ecx
add eax, esi
cmp edi, eax
jb .CopyDown
/* Set ULONG size and UCHAR remainder */
DoMove:
mov edx, ecx
and edx, 3
shr ecx, 2
.CopyUp:
cld
/* Do the move */
rep movsd
or ecx, edx
jnz ByteMove
/* Check for small moves */
cmp ecx, 16
jb .CopyUpBytes
/* Return */
pop edi
pop esi
ret 12
/* Check if its already aligned */
mov edx, ecx
test edi, 3
je .CopyUpDwords
ByteMove:
/* Move what's left */
rep movsb
/* Make the destination dword aligned */
mov ecx, edi
and ecx, 3
sub ecx, 5
not ecx
sub edx, ecx
rep movsb
mov ecx, edx
DoneMove:
/* Restore volatiles */
pop edi
pop esi
ret 12
.CopyUpDwords:
shr ecx, 2
rep movsd
mov ecx, edx
and ecx, 3
Overlap:
/* Don't copy if they're equal */
jz DoneMove
.CopyUpBytes:
test ecx, ecx
je .CopyUpEnd
rep movsb
/* Compare pointer distance with given length and check for overlap */
mov eax, edi
sub eax, esi
cmp ecx, eax
jbe DoMove
.CopyUpEnd:
mov eax, [ebp + 8]
pop edi
pop esi
pop ebp
ret 12
/* Set direction flag for backward move */
std
.CopyDown:
std
/* Copy byte-by-byte the non-overlapping distance */
add esi, ecx
add edi, ecx
dec esi
dec edi
/* Go to the end of the region */
add edi, ecx
add esi, ecx
/* Check for small moves */
cmp ecx, 16
jb .CopyDownSmall
/* Check if its already aligned */
mov edx, ecx
test edi, 3
je .CopyDownAligned
/* Make the destination dword aligned */
mov ecx, edi
and ecx, 3
sub edx, ecx
dec esi
dec edi
rep movsb
mov ecx, edx
sub esi, 3
sub edi, 3
.CopyDownDwords:
shr ecx, 2
rep movsd
mov ecx, edx
and ecx, 3
je .CopyDownEnd
add esi, 3
add edi, 3
.CopyDownBytes:
rep movsb
.CopyDownEnd:
cld
mov eax, [ebp + 8]
pop edi
pop esi
pop ebp
ret 12
.CopyDownAligned:
sub edi, 4
sub esi, 4
jmp .CopyDownDwords
.CopyDownSmall:
test ecx, ecx
je .CopyDownEnd
dec esi
dec edi
jmp .CopyDownBytes
/* Do the move, reset flag and return */
rep movsb
cld
jmp DoneMove
@RtlPrefetchMemoryNonTemporal@8: