|
发表于 2009-1-23 16:34:00
|
显示全部楼层
Re:求教一个十进制数字转成十六制并写入内存的问题
procedure Move(const Source; var Dest; count : Integer);
{$IFDEF PUREPASCAL}
var
S, D: PChar;
I: Integer;
begin
S := PChar(@Source);
D := PChar(@Dest);
if S = D then Exit;
if Cardinal(D) > Cardinal(S) then
for I := count-1 downto 0 do
D[I] := S[I]
else
for I := 0 to count-1 do
D[I] := S[I];
end;
{$ELSE}
asm
cmp eax, edx
je @@Exit {Source = Dest}
cmp ecx, 32
ja @@LargeMove {Count > 32 or Count < 0}
sub ecx, 8
jg @@SmallMove
@@TinyMove: {0..8 Byte Move}
jmp dword ptr [@@JumpTable+32+ecx*4]
@@SmallMove: {9..32 Byte Move}
fild qword ptr [eax+ecx] {Load Last 8}
fild qword ptr [eax] {Load First 8}
cmp ecx, 8
jle @@Small16
fild qword ptr [eax+8] {Load Second 8}
cmp ecx, 16
jle @@Small24
fild qword ptr [eax+16] {Load Third 8}
fistp qword ptr [edx+16] {Save Third 8}
@@Small24:
fistp qword ptr [edx+8] {Save Second 8}
@@Small16:
fistp qword ptr [edx] {Save First 8}
fistp qword ptr [edx+ecx] {Save Last 8}
@@Exit:
ret
nop {4-Byte Align JumpTable}
nop
@@JumpTable: {4-Byte Aligned}
dd @@Exit, @@M01, @@M02, @@M03, @@M04, @@M05, @@M06, @@M07, @@M08
@@LargeForwardMove: {4-Byte Aligned}
push edx
fild qword ptr [eax] {First 8}
lea eax, [eax+ecx-8]
lea ecx, [ecx+edx-8]
fild qword ptr [eax] {Last 8}
push ecx
neg ecx
and edx, -8 {8-Byte Align Writes}
lea ecx, [ecx+edx+8]
pop edx
@FwdLoop:
fild qword ptr [eax+ecx]
fistp qword ptr [edx+ecx]
add ecx, 8
jl @FwdLoop
fistp qword ptr [edx] {Last 8}
pop edx
fistp qword ptr [edx] {First 8}
ret
@@LargeMove:
jng @@LargeDone {Count < 0}
cmp eax, edx
ja @@LargeForwardMove
sub edx, ecx
cmp eax, edx
lea edx, [edx+ecx]
jna @@LargeForwardMove
sub ecx, 8 {Backward Move}
push ecx
fild qword ptr [eax+ecx] {Last 8}
fild qword ptr [eax] {First 8}
add ecx, edx
and ecx, -8 {8-Byte Align Writes}
sub ecx, edx
@BwdLoop:
fild qword ptr [eax+ecx]
fistp qword ptr [edx+ecx]
sub ecx, 8
jg @BwdLoop
pop ecx
fistp qword ptr [edx] {First 8}
fistp qword ptr [edx+ecx] {Last 8}
@@LargeDone:
ret
@@M01:
movzx ecx, [eax]
mov [edx], cl
ret
@@M02:
movzx ecx, word ptr [eax]
mov [edx], cx
ret
@@M03:
mov cx, [eax]
mov al, [eax+2]
mov [edx], cx
mov [edx+2], al
ret
@@M04:
mov ecx, [eax]
mov [edx], ecx
ret
@@M05:
mov ecx, [eax]
mov al, [eax+4]
mov [edx], ecx
mov [edx+4], al
ret
@@M06:
mov ecx, [eax]
mov ax, [eax+4]
mov [edx], ecx
mov [edx+4], ax
ret
@@M07:
mov ecx, [eax]
mov eax, [eax+3]
mov [edx], ecx
mov [edx+3], eax
ret
@@M08:
fild qword ptr [eax]
fistp qword ptr [edx]
end;
{$ENDIF}
var
Source:AnsiString;
Buffer:AnsiString;
DestinationMemory ointer;
begin
Buffer:=IntToHex(StrToInt(Source),8);
//herecode!copy to dest
Move(DestinationMemory^, @Buffer[1], Length);
end;
|
|