Hey everyone I know this might not be a difficult problem but I have been having a hard time with assembly language and keep doing this wrong. All I have to do is Implement the following C++ code in assembly language. Substitute calls to WriteString for the printf() function calls.
I then will run the program several times with different ranges of values for x and y to test the programs logic. But first I need to get it to work right.
If anyone can help I would really appreciate it! Thank you!!
C code:
double X;
double Y;
if( X < Y )
printf("X is lower\n");
else
printf("X is not lower\n")
This is what I have in assembly:
;C code origional:
; double X
; double Y
; if(X < Y)
; printf("X is lower\n")
; else
; printf("X is not lower\n")
;
INCLUDE Irvine32.inc
.data
mssg1 BYTE "X is lower",0dh,0ah,0
mssg2 BYTE "X is not lower",0dh,0ah,0
X = 10
Y = 12
.code
main PROC
compare:
mov eax, X
cmp eax, Y
jl xlower
mov eax, Y
cmp eax, X
jmp xhigher
xlower:
mov edx, OFFSET mssg1
Call WriteString
jmp compare
xhigher:
mov edx, OFFSET mssg2
Call WriteString
exit
main ENDP
END main
mov eax,10
mov ebx,12
.if( eax < ebx )
invoke printf,chr$ ("X is lower",CR,LF)
.else
invoke printf,chr$ ("X is not lower",CR,LF)
.endif
or
mov eax,10
mov ebx,12
CMP EAX,EBX
JNB @notlower
PUSH chr$ ("X is lower",CR,LF)
CALL printf
JMP @out
@notlower:
PUSH chr$ ("X is not lower",CR,LF)
CALL printf
@out:
Thank you for your reply ragdog!! but I need to use calls such as WriteString but your code does help and I am working on it!
Thank you so much! I got it working the way I think it should!
;C code origional:
; double X
; double Y
; if(X < Y)
; printf("X is lower\n")
; else
; printf("X is not lower\n")
;
INCLUDE Irvine32.inc
.data
mssg1 BYTE "X is lower",0dh,0ah,0
mssg2 BYTE "X is not lower",0dh,0ah,0
X = 9
Y = 12
.code
main PROC
compare:
mov eax, X
mov ebx, Y
cmp eax, ebx
jnb xhigher
mov edx, OFFSET mssg1
call WriteString
jmp finished
xlower:
mov edx, OFFSET mssg1
Call WriteString
jmp finished
xhigher:
mov edx, OFFSET mssg2
Call WriteString
finished:
exit
main ENDP
END main
more like from this.//C code original:
#include <stdio.h>
#define X 9
#define Y 12
int main(void) {
if(X < Y)
printf("X is lower\n");
else
printf("X is not lower\n");
return 0;
}
C's double is REAL8 is asm.
That xlower block is useless ?
The compiler is not going to compare floating-point values (doubles in this case) with integer instructions (even though there is a way to do it). At least for the Microsoft Visual C++ Toolkit 2003 compiler, it will use FPU instructions (primarily fcomp), or SSE2 instructions (primarily comisd) with /arch:SSE2.
Quote from: infoMASM on March 14, 2014, 06:20:31 AM
double X;
double Y;
if( X < Y )
printf("X is lower\n");
else
printf("X is not lower\n")
In your C code, you would have to initialise x and y. If you want to stay close to the C version, and work with doubles, here is one option in Assembler (it needs the MasmBasic library (http://masm32.com/board/index.php?topic=94.0)):
include \masm32\MasmBasic\MasmBasic.inc
double equ <REAL8> ; make it look like C ;-)
.data
x double 12.34
y double 56.78
Init
Fcmp x, y ; more (http://www.webalice.it/jj2006/MasmBasicQuickReference.htm#Mb1201)
.if Sign?
inkey "x is less than y"
.elseif Zero?
inkey "x and y are equal"
.else
inkey "x is greater than y"
.endif
Exit
end start
Note the real fun starts (in both C and Assembler) when x and y are
almost equal - see this thread (http://www.masmforum.com/board/index.php?topic=18529.msg156635#msg156635) in the old Forum.
Thank you everyone for you input! Thank you for showing me how to use the MasmBasic library and getting it to work in that sense. I need to stick with the Irvine32.inc unfortunately but I will remember this for future reference.