Can someone please help I stuck since few day on this problem. I want to count numbers of 1's in binary value of 2 decimal/hexa. But I am getting incorrect results. Here a code below:
.386 //32-bit processor
.model small, stdcall
ExitProcess PROTO, deExitCode:DWORD
.data
var1 dw 2
.code
main PROC
LEA ESI,var1
MOV EBX, 4 //SIZE OF ARRAY AS 2 binary will be 0010
MOV ECX,0
L1:CMP EBX,0
JE L3
MOV EAX,[ESI]
CMP EAX,0
JE L2
INC ECX
L2:DEC EBX
ADD SI,2
JMP L1
L3: INVOKE ExitProcess,0
main ENDP
END main
CodePudding user response:
If I understand your weird terminology to count numbers of 1's in binary value, you want to count how many bits is set to 1 in a 16bit memory variable var1
. A straightforward solution is to load the variable to a register (MOVZX EAX,[var1]
) and then 16 times shift the lowest bit to CF (SHR EAX,1
) and add the CF to a counter register (ADC ECX,0
) each time.
However, your code seems to count how many of four words in memory has a nonzero value. There are some bugs in it:
SIZE OF ARRAY which you have statically defined as
var1
is not 4. It would have to be defined asvar1 DW 2,3,4,5 ; Array of four words.
MOV EAX,[ESI]
correctly loadsAX
fromvar1
but it also loads whatever garbage followsvar1
to upper 16 bits ofEAX
.ADD SI,2
should beADD ESI,2
.