C ++ embedded assembly and speed Testing

By the way, Consortium compiled a strcpy. Let's take an example and test the speed ..

Char * strcpy (char * des, const char * SRC, unsigned _ int32 count)
{
If (des = NULL)
{
Return 0;
}

If (src = NULL)
{
Des [0] = 0;
Return des;
}

_ ASM
{
MoV EDI, des
MoV ESI, SRC
MoV ECx, count
Dec ECx

_ Loop:
CMP byte PTR [esi], 0
JZ _ break
Movsb
Loop _ Loop

_ Break:
MoV byte PTR [EDI], 0
MoV eax, des
}
}

Int main ()
{
Byte bytype = 2;
Char des [10] = {0 };
Char * src = "masefee ";

Large_integer itemp;
Longlong lltime1, lltime2;
Double dtime;
Queryperformancefrequency (& itemp );
Queryperformancecounter (& itemp );
Lltime1 = itemp. quadpart;

Strcpy (DES, SRC, 8 );

Queryperformancecounter (& itemp );
Lltime2 = itemp. quadpart;
Dtime = (double) (lltime2-lltime1 );

Printf ("% F/N", dtime );

Return 0;
}

 

Output: 1210.000000