The following code is meant to find the highest value from a list of integers, but when (using cygwin) but after assembly and linkin, "echo $?" only returns 127 and not the 222 as expected. I dont think it is an error but i'm also not sure how to go about it.
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#PURPOSE: This program finds the maximum number of
# a set of data items
#VARIABLES: The registers have the following uses:
#
# %edi - Holds the index of the data item being examined
# %ebx - Largest data item found
# %eax - Current data item
#
# The following memory locations are used:
# data_items - contains the item data. A 0 is used to terminate data
#
#
.section .data
data_items: #These are the data items
.long 3, 67, 34, 222, 45, 75, 54, 34, 44, 33, 22, 11, 66, 0
.section .text
.globl _start
_start:
movl $0, %edi # move 0 into the index register
movl data_items (,%edi,4), %eax # load the first byte of data
movl %eax, %ebx #since this is the first item, %eax is the biggest
start_loop: #start loop
cmpl $0, %eax #check to see if we've hit the end
je loop_exit
incl %edi #load the next value
movl data_items(,%edi,4), %eax
cmpl %ebx, %eax #compare values
jle start_loop #jump to loop beginning if the new
#one isnt bigger
movl %eax, %ebx #move the value as the largest
jmp start_loop #jump to loop beginning
loop_exit:
#%ebx is the status code for the exit system call
#and it already has the maximum number
movl $1, %eax #1 is the exit() sys call
int $0x80
