🚀 go-pugleaf

Yaqub Ali Sheikh wrote:

> The program will run in a loop which will prompt the user to enter an
> integer (a simple prompt will do). If the value entered is less than or
> equal to 0 the loop will terminate. Otherwise the program will add up all
> values from one to the user's chosen value and display the sum. (Please
> compute this sum using a loop, not a formula.) i am using xspim to compile
> it.and the language is RISC assembly language

This looks like MIPS assembly for me. I'm not familiar with that, so
anything I say can be wrong.

> here is what i have so far, but my logic on the loop doesnt work right, im
> sortta confused on how for loops work in assmebly language or if i even
> need a for loop for this
> any suggestions on how to fix this?
> 
> .text
> .globl main
> main:
> la $a0, prompt # print prompt on screen
> li $v0, 4 # system call to print
> syscall
> next:
> li $v0, 5 # syscall 5 reads an integer
> syscall

You probably know what you're doing, but I wonder what operating system has
a syscall to read an integer like this?

> move $t3, $v0
> add $t0, $t0, $v0 # adds the number to t0

You seem to rely on the fact that t0 contains the value 0 at the start of
the program.

> move $a0, $t0 # print result
> li $v0, 1
> syscall

You seem to rely on the fact that t0 will still hold the same value after
the system call.

> la $a0, endl # system call to print
> li $v0, 4 # out a new line
> syscall
> blez $t3, done
> li $t3, 0
> bgez $t3, next # loop while user doesnt enter in 0

I suppose bgez means "branch if greater or equal to zero". You just zeroed
t3, so this test will always be true.

> done:
> li $v0, 10 # system call to exit
> syscall

Btw: I think a group on MIPS assembler is better suited for this question
:-).

-- 
Nicolas Barbier
Protecting innovation against patent inflation <url:http://swpat.ffii.org/>