[SOLVED] CS prolog ## On my honor:

##On my honor:
##
## I have not discussed the C language code in my program with
##anyone other than my instructor or the teaching assistants
##assigned to this course.
##
## I have not used C language code obtained from another student,
##the Internet, or any other unauthorized source, either modified
##or unmodified.
##
## If any C language code or documentation used in my program
##was obtained from an authorized source, such as a text book or
##course notes, that has been clearly noted with a proper citation
##in the comments of my program.
##
## I have not designed this program in such a way as to defeat or
##interfere with the normal operation of the grading code.
##
##
##

#############################################################
#This data block contains a digits memory allocation
#that you can use to store any strings that you convert
#from integers.Remember to either clear it after use or
#null-terminate the strings that you save here!
#############################################################

.data
digits:.space 10

.text

.globl PROC_COUNT_FORMAT_SPECIFIERS
.globl PROC_CONVERT_INT_TO_STRING
.globl PROC_SPRINTF

.globl PROC_FIND_LENGTH_STRING
.globl PROC_FIND_NUM_DIGITS
.globl PROC_REVERSE_STRING
.globl PROC_CLEAR_DIGITS

#############################################################
#Given the address of a string, count the number of format
#specifiers that appear in that string
#
#Pre:$a0 contains the address of the string to evaluate
#Post: $v0 contains the number of format specifiers that
#were found in the input string
#############################################################

PROC_COUNT_FORMAT_SPECIFIERS:

# add your solution here

# return
jr $ra

#############################################################
#Given an integer, convert it into a string
#
#Pre:$a0 contains the integer that will be converted
#Post: $v0 contains the address of the newly-created string
#############################################################

PROC_CONVERT_INT_TO_STRING:

# add your solution here

# return
jr $ra

#############################################################
#Given the address of a string and a string which may or
#may not include format specifiers, write a formatted
#version of the string into the output register $v0
#
#Pre:$a0 contains the address of the string dest, where
#the final string will be written into
#$a1 contains the address of a format string, which
#may or may not include format specifiers, and which
#details the required final state of the output
#string
#$a2 contains an unsigned integer or the address of
#a string, or it is empty
#$a3 contains an unsigned integer or the address of
#a string, or it is empty
#Post: $a0 contains the address of the formatted dest,
#including null terminator
#$v0 contains the length of the string written into
#dest, not including null terminator
#############################################################

PROC_SPRINTF:

# add your solution here

# return
jr $ra

#############################################################
#This procedure will find the length of a provided string
#by counting characters until the null terminator is
#reached
#
#Pre:$a0 contains the string to evaluate
#Post: $v0 contains the length of the string
#############################################################

PROC_FIND_LENGTH_STRING:

# prologue
subi $sp, $sp, 4
sw $ra, 0($sp)

# function body
move $t2, $a0# $t2 is the current char were pointing to
li $t4, 0# $t4 is my length counter for my_string

# Loop until we find the null terminator
LOOP_FIND_NULL_BYTE_LENGTH:
lb $t1, 0($t2)# $t1 is the character loaded from offset $t2
beq $t1, $zero, FOUND_NULL_BYTE_LENGTH

addi $t4, $t4, 1# increment length counter
addi $t2, $t2, 1# increment character pointer

j LOOP_FIND_NULL_BYTE_LENGTH

FOUND_NULL_BYTE_LENGTH:
# at this point, $t2 is pointed at
move $v0, $t4

# epilogue
lw $ra, 0($sp)
addi $sp, $sp, 4

# return
jr $ra

#############################################################
#This procedure will determine the number of digits in the
#provided integer input via iterative division by 10.
#
#Pre:$a0 contains the integer to evaluate
#Post: $v0 contains the number of digits in that integer
#############################################################

PROC_FIND_NUM_DIGITS:

# prologue
subi $sp, $sp, 4
sw $ra, 0($sp)

# function body
li $t0, 10# load a 10 into $t0 for the division
li $t5, 0 # $t5 will hold the counter for number of digits
move $t6, $a0 # $t6 will hold the result of the iterative division

NUM_DIGITS_LOOP:
divu $t6, $t0 # divide the number by 10
addi $t5, $t5, 1

mflo $t6 # move quotient back into $t6
beq $t6, $zero, FOUND_NUM_DIGITS# if the quotient was 0, $t5 stores the number of digits
j NUM_DIGITS_LOOP

FOUND_NUM_DIGITS:
move $v0, $t5 # copy the number of digits $t5 into $v0 to return

# epilogue
lw $ra, 0($sp)
addi $sp, $sp, 4

# return
jr $ra

#############################################################
#This procedure will reverse the characters in a string in-
#place when given the addresses of the first and last
#characters in the string.
#
#Pre:$a0 contains the address of the first character
#$a1 contains the address of the last character
#Post: $a0 contains the first character of the reversed
#string
#############################################################

PROC_REVERSE_STRING:

# prologue
subi $sp, $sp, 4
sw $ra, 0($sp)

# function body
move $t0, $a0# move the pointer to the first char into $t0
move $t2, $a1 # move the pointer to the last char into $t2

# Loop until the pointers cross
LOOP_REVERSE:
lb $t9, 0($t2)# backing up the $t2 position char into $t9
lb $t8, 0($t0)# load the $t0 position char into $t8

sb $t8, 0($t2)# write the begin char into $t2 position
sb $t9, 0($t0)# write the end char into $t0 position

# increment and decrement the pointers
addi $t0, $t0, 1
subi $t2, $t2, 1

ble $t2, $t0, END_OF_REVERSE_LOOP
j LOOP_REVERSE

END_OF_REVERSE_LOOP:

# epilogue
lw $ra, 0($sp)
addi $sp, $sp, 4

# return
jr $ra

#############################################################
#This procedure will clear the contents of the digits
#memory allocation that is defined in the data block of
#this file.
#
#Pre:None
#Post: The digits section of memory is cleared to all 0s
#############################################################

PROC_CLEAR_DIGITS:

# prologue
subi $sp, $sp, 4
sw $ra, 0($sp)

# function body
la $t0, digits# get the address of the digits space
li $t1, 10# we need to loop 10 times
li $t2, 0 # and the loop counter starts at 0

CLEAR_LOOP:
sb $zero, 0($t0)# write all zeros into #t0
addi $t0, $t0, 1# move to the next char space
addi $t2, $t2, 1# increment loop counter

beq $t2, $t1, END_CLEAR # break out of the loop after 10 writes
j CLEAR_LOOP

END_CLEAR:

# epilogue
lw $ra, 0($sp)
addi $sp, $sp, 4

# Return
jr $ra

#############################################################