MIPS: Lucas Sequence Returns P every other number when P is 1 - mips

I am implementing a mips program for a lucas sequence. The user enters a number, n, P, and Q and choose 1 for the V sequence and 0 for the U sequence. I am having issues with choosing the V sequence returning P every other number only when P is 1. I know it is something little that I am missing, but I have been trying to find it for hours. Any help would be greatly appreciated.
addi $t1, $s0, 0 # load n into $t1
addi $t3, $zero, 0 # i = 0
jal lucasSequence # go to lucasSequence
end_loop:
la $a0, newline # print a newline \n
jal printString
j main # loop to main menu again
#############################################
# Procedure: lucasSequence #
#############################################
# - produces the Lucas sequence of the #
# first (U) or second (V) order for #
# given constants P and Q. #
# #
# The procedure produces all numbers #
# in the sequence U or V from n=0 #
# up to n=N. #
# #
# - inputs : $a0-integer N #
# $a1-constant P #
# $a2-constant Q #
# $a3-function U (0) or V (1) #
# - outputs: none #
# #
#############################################
lucasSequence:
loop:
move $a0, $t3 # n = i
beq $t3, $t1, end_loop # if i == n, quit.
jal lucasSequenceNumber # print the lucas sequence for N, P, and Q
addi $t3, $t3, 1 # i++
move $a0, $v0 # load int to print
li $v0, 1 # print int
syscall # print call
beq $t3, $t1, end_loop # don't print last comma
li $a0, ',' # load comma
li $v0, 11 # add to print
syscall # print comma
li $a0, ' ' # load space
li $v0, 11 # print space
syscall # print call
j loop # repeat until i = n
lucasSequenceNumber:
addi $sp, $sp, -8 # room for $ra and one temporary
sw $ra, 4($sp) # save $ra
move $v0, $a0 # pre-load return value as n
addi $t4, $zero, 1 # t4 =1
blt $a0, 2, rt # if(n < 2) return
sw $a0, 0($sp) # save a copy of n
addi $a0, $a0, -1 # n - 1
jal lucasSequenceNumber # lucas(n - 1)
lw $a0, 0($sp) # retrieve n
mul $v0, $v0, $a1 # P*lucas(n-1)
sw $v0, 0($sp) # save result of P*lucas(n - 1)
addi $a0, $a0, -2 # n - 2
jal lucasSequenceNumber # lucas(n - 2)
mul $v0, $v0, $a2 # Q*lucas(n-2)
lw $v1, 0($sp) # retrieve P*lucas(n - 1)
sub $v0, $v1, $v0 # P*lucas(n - 1) + Q*lucas(n - 2)
rt:
addi $t4, $zero, 1 # t4 = 1
beq $a3, $t4, return_V # user chose option 2
lucas_rt:
lw $ra, 4($sp) # restore $ra
addi $sp, $sp, 8 # restore $sp
jr $ra # back to caller
return_V:
bgt $a0, $t4, lucas_rt # if choice V and n > 1, got to return
beq $a0, $t4, one_v # if n = 1, go to one_v
li $a0, 2 # if n = 0, return 2
move $v0, $a0
j lucas_rt # back to caller
one_v:
addi $a0, $a1, 0 # return P
move $v0, $a0
j lucas_rt # go to return P call

The function one_v needs to be adjusted so it reads:
one_v:
move $a0, $a1
move $a0, $v0
j lucas_rt

Related

Trying to print ints in MIPS, coming out as ASCII?

Here is some relevant code. I extracted these ints from a .txt file into buffer, and then use extractInts to format them into an array (intArray). Then I use printArray to loop through it and print. The ints in intArray are stored in a .space of 80 bytes, each in their own word.
My current output:
The array: 14385 57 14130 53 14388 13873 50 13109 13366 14393
My expected output:
The array: 18 9 27 5 48 16 2 53 64 98
# put ints into array
extractInts:
la $s0, buffer # $s0 points to buffer
la $s1, intArray # $s1 points to intArray
li $t0, 0 # i = 0
li $t1, 3 # intLoop max = 3
li $t3, 4 # nextWord max = 4
# loop to place each int within its own word boundary in intArray
intLoop:
beq $t0, $t1, exitLoop # exit loop if i = end of word
lb $t2, ($s0) # $t2 = intArray[]
beq $t2, '\n', nextWord # if $t2 = \n, go to nextWord
beq $t2, '\0', exitLoop # if $t2 = \0, go to exitLoop
sb $t2, ($s1) # save byte in $t2 to intArray[]
addi $t0, $t0, 1 # i++
addi $s0, $s0, 1 # increment buffer
addi $s1, $s1, 1 # increment intArray
j intLoop
# skip to next word
nextWord:
sub $t4, $t3, $t0 # $t4 = 4 - i
add $s1, $s1, $t4 # increment intArray by $t4
li $t0, 0 # restore i to 0
addi $s0, $s0, 1 # increment buffer
j intLoop
printArray:
li $t0, 0 # i = 0
while:
beq $t0, 80, exit # exit if i = end of array
lw $t1, intArray($t0) # $t1 = intArray[$t0]
addi $t0, $t0, 4 # move to next word in intArray
# print current int
li $v0, 1
move $a0, $t1
syscall
# print space
li $v0, 11
li $a0, 32
syscall
j while

Why is MIPS printing memory locations on the second time around

[Solved]
We were tasked with writing a bubble sort in MIPS and printing both the unsorted and sorted arrays
I've written the following code to accomplish this.
But when I go to run it, the original array prints as I would expect
Original Array
[34, 23, -1, -2, 0]
But then it prints this for the sorted array.
Sorted Array
[173496791, 1818324585, 1920090400, 686433, 1919898378]
(the Unicode squares do print)
array: .word 34, 23, -1, -2, 0, 89
length: .word 6
original: .asciiz "Original Array\n"
sorted: .asciiz "\nSorted Array\n"
.text
# main()
main:
la $a2, length
lw $a2, 0($a2) # a2 <= n_element
add $t9, $0, $0 # t9 : counter
la $a1, array # a1 = &array[0]
addi $t0, $0, 0 # for t0=0 to
addi $a2, $a2, -1 # because we do [i+1]
#says prints original array
la $a0, original
li $v0, 4
syscall
#prints array
jal print
#printing the string saying sorted
la $a0, sorted
li $v0, 4
syscall
#after printing original we reset the values?
la $a2, length
lw $a2, 0($a2) # a2 <= n_element
add $t9, $0, $0 # t9 : counter
add $t8, $0, $0 # t10 : counter 2
la $a1, array # a1 = &array[0]
addi $t0, $0, 0 # for t0=0 to
addi $a2, $a2, -1 # because we do [i+1]
#see if that worked it did
li $s0, 1 #boolean swapped = false 0=false 1=true
outerLoop:
beqz $s0, exit #if flag is false exit
li $s0, 0
addi $a1, $a1, 4 # next array offset
addi $t9, $t9, 1 # counter++
move $t8 $0
sub $s2, $a2, $t9
innerLoop:
bge $t8, $s2, exitInner
lw $t7, 0($a1) # t7 = array[i]
lw $t8, 4($a1) # t8 = array[i+1]
ble $t7, $t8, skip #if array[i]<= arr[i+1] skip the swapping
sw $t8, 0($a1) #a[i+1] = a[1]
sw $t7, 4($a1) #a[i] = a[i+1]
li $s0, 1#flag update
skip:
addi $t8, $t8, 1 #count
addi $a1, $a1, 4
j innerLoop
exitInner:
j outerLoop
exit:
la $a2, length
lw $a2, 0($a2) # a2 <= n_element
add $t9, $0, $0 # t9 : counter
addi $a2, $a2, -1 # because we do [i+1]
jal print
j quit#end Program
#print array
print:
lw $t7,0($a1) # t7 = array[i]
lw $t8,4($a1) # t8 = array[i+1]
add $a0, $t7, 0
addi $v0, $0, 1 #print int using system call the value stored in a0
syscall
addi $a0, $0, 0x20 # ascii 0x20 = ' '
addi $v0, $0, 11
syscall
addi $a1, $a1, 4 # next array offset
addi $t9, $t9, 1 # counter++
beq $t9, $a2, return #return to the where we were we were at beforehand
j print
return:
jr $ra
quit:
addi $v0, $0, 10
syscall
I think these are memory locations? I'm not sure why it's printing that as it is because I reset my counter values before trying to print. So the question is. Why am I printing memory locations? if that is what is happening
I was sorting in place so I had to reset the array before the print function.

Practice to convert c to Mips

Does anyone know how to convert this into mips 32? Please show the code and explain for me. Thank you so much
int service (int n) {
if (n <= 10)
return n;
else
return n + service(n+1) + service (n+2);
}
Please pay attention on comments and try to understand what is happening instruction by instruction.
service:
lw $t0, $a0 # Load word from memory to $t0. $a0 is the argument of the function (int n).
addi $t1, 10 # $t1 = 10
bne $t0, $t1, cont # If n != 10 , continue
slti $t2, $t1, $t0 # If 10 < n $t2 = 1, else $t2 = 0
bne $t2, $t0, cont # If $t2 != 0 , then $t2 = 1 so 10 < n , so continue
addi $v0, $t0, $0 # Else return n;
jr $ra
cont:
addi $sp, $sp, -4 # Room on stack for 4 bytes
sw $ra, 0($sp) # Save $ra, recursion
addi $a0, $a0, 1 # n+1
jal service # Call service(n+1)
addi $a0, $a0, 1 # (n+1) + 1 = n+2
jal service # Call service(n+2)
lw $ra, 0($sp) # restore $sp
addi $sp, $sp, 4 # Restore room on stack
jr $ra
Here's my try with clarifications
# assuming $a0 is the parameter n
service:
bgt $a0, 10, else # if $a0 > 10 branch to else part
move $v0, $a0 # $v0 = $a0, to return the value
jr $ra # return n;
else:
addiu $sp, $sp, -8 # using stack to store $ra, $a0 each 4 bytes we need 8 bytes
sw $a0, 0($sp) # store the value of a0 in the stack
sw $ra, 4($sp) # store the caller addrs.
addiu $a0, $a0, 1 # parameter of the first function call (n+1)
jal service # service(n+1)
move $s0, $v0 # s0 = result of service(n+1)
lw $a0, 0($sp) # $a0 = n
addiu $a0, $a0, 2 # parameter of the second function call (n+2)
jal service # service(n+1)
move $s1, $v0 # s1 = result of service(n+1)
lw $a0, 0($sp) # $a0 = n
addu $v0, $a0, $s0 # $v0 = n + service(n+1)
addu $v0, $v0, $s1 # $v0 = n + service(n+1) + service(n+2)
lw $ra, 4($sp) # $ra = old caller return addrs.
addiu $sp, $sp, 8 # freeing the stack
jr $ra # return

Binary Search using recursion in Mips assembly

I have a trouble. I tried to make a binary search algorithm using recursion in mips assembly, but I have some errors that I don't understand how to solve them.
I have an array of 10 integers and I assume that the array is sorted.
this is my code, I appreciate any help and thanks in advance..
.data
arr: .word 40
arrMsg: .asciiz "Enter the array : \n"
posMsg: .asciiz "This value exist in the array and its position is "
pos: .word 0
newline: .asciiz "\n"
valMsg: .asciiz "Enter the value you search for : \n"
val: .word 0
notfound:.asciiz "the value doesn't exist in the array !! \n"
.text
main:
# print the array message
li $v0, 4
la $a0, arrMsg
syscall
# read the array from the user
# put $s0 = i
add $s0, $zero, $zero # i = 0
for:
beq $s0, 40, end
li $v0, 5
syscall
sw $v0, arr($s0) # input arr[i]
addi $s0, $s0, 4 # i = i + 4
j for
end:
# print value message
li $v0, 4
la $a0, valMsg
syscall
# read the value from the user
li $v0, 5
syscall
# store the value in the val variable
sw $v0, val
################################################
## put $s0 = start , $s1 = middle , $s2 = end ##
################################################
li $s0, 0
li $s2, 9
jal BinarySearch
li $v0, 10
syscall
############################################################################################################
BinarySearch:
# middle = (start + end ) / 2
add $t0, $s0, $s2 # $t0 = start + end
sra $s1, $t0, 1 # $s1 = $t0 / 2
# save $ra in the stack
addi $sp, $sp, -4
sw $ra, 0($sp)
# base case
ble $s2, $s0, returnNegative1 # if (end <= start)
lw $t1, arr($s1) # $t1 = arr[middle]
lw $t2, val # $t2 = val
beq $t1, $t2, returnMiddle # if (arr[middle] == val)
blt $t2, $t1, returnFirstPart # if (val < arr[middle])
bgt $t2, $t1, returnLastPart # if (val > arr[middle])
returnNegative1:
li $v0, -1
j Exit
returnMiddle:
move $v0, $s1 # return middle
j Exit
returnFirstPart:
move $t3, $s1 # temp = middle
addi $t3, $t3, -1 # temp --
move $s2, $t3 # end = temp
jal BinarySearch
j Exit
returnLastPart:
move $t3, $s1 # temp = middle
addi $t3, $t3, 1 # temp++
move $s0, $t3 # start = temp
jal BinarySearch
j Exit
Exit:
lw $ra, 0($sp)
addi $sp, $sp, 4`
jr $ra
lw $t1, arr($s1) # $t1 = arr[middle]
this is the problem as it is not really the right index as integer takes 4 bytes
so the middle you get from
add $t0, $s0, $s2 # $t0 = start + end
sra $s1, $t0, 1 # $s1 = $t0 / 2
is just the logical address not the real one you will need to multiply it with 4
mul $s4, $s1,4
and then use $s4 as an address
lw $t1, arr($s4) # $t1 = arr[middle]
also there is a mistake with the stopping condition it should be
if (end < start) not (<=)
and sorry for my English

MIPS Programs with more than 4 arguments

The following is my code and the final test case. main and printStats are both given, I had to qrite average (which is at the bottom), so look there for problems. This case changes the value of all registers in $f, $t, $a, and $s and adds 2 items to the top of its stack in order to ensure that the average method is preserving properly the values it will need to run its calculations following the $jr from printStats.
The problem I am having is recurring in a few test cases where there are 3 batters. Batter 3 uses arbitrarily large integers.
# printStats puts two values at the top two spots in its stack. This is where
# the number of homeruns and outs were placed when printStats
# is called. A function is allowed to change its own stack.
# Changes the $s registers used by main. The average function should be
# getting arguments from the $a registers and the stack, and not relying
# on what is in the $s registers.
# From test12:
# Tests if $t registers are preserved (if needed) by average.
# printStats puts values into every $t register.
# From test13:
# Tests if $a registers used correctly when average calls printStats.
# printStats changes the contents of $a1, $a2, and $a3 before returning
# test with three batters, both average and slugging percentage
# First batter has no hits, but does have outs
# Second batter has hits and outs, with realistic values
# Third hitter has large values for some of the hits and for the
# outs. This means the hits and outs *have* to be converted from int's
# to float's in order to get the right answer.
.data
mainNumBatters:
.word 3
mainBatter1:
.word 27 # walks
.word 0 # singles
.word 0 # doubles
.word 0 # triples
.word 0 # home runs
.word 423 # outs
mainBatter2:
.word 27 # walks
.word 101 # singles
.word 22 # doubles
.word 4 # triples
.word 10 # home runs
.word 423 # outs
mainBatter3:
.word 102322 # walks
.word 8000000 # singles
.word 22 # doubles
.word 500000 # triples
.word 10 # home runs
.word 23000000 # outs
.data
mainNewline:
.asciiz "\n"
mainBatterNumber:
.asciiz "Batter number: "
mainBattingAverage:
.asciiz "Batting average: "
mainSluggingPercentage:
.asciiz "Slugging percentage: "
mainOnbasePercentage:
.asciiz "On-base percentage: "
.text
main:
# Function prologue -- even main has one
addiu $sp, $sp, -24 # allocate stack space -- default of 24 here
sw $fp, 0($sp) # save frame pointer of caller
sw $ra, 4($sp) # save return address
addiu $fp, $sp, 20 # setup frame pointer of main
# for (i = 0; i < mainNumBatters; i++)
# compute batting average
# compute slugging average
la $s1, mainNumBatters
lw $s6, 0($s1) # $s6 = number of batters
addi $s0, $zero, 0 # $s0 = i = 0
la $s1, mainBatter1 # $s1 = addr of current batter's stats
mainLoopBegin:
slt $t0, $s0, $s6 # $t0 = i < number of batters
beq $t0, $zero, mainDone
la $a0, mainBatterNumber
addi $v0, $zero, 4
syscall
addi $a0, $s0, 1
addi $v0, $zero, 1
syscall
la $a0, mainNewline
addi $v0, $zero, 4
syscall
# Compute the batting average
addi $a0, $zero, 1 # $a0 = 1 = compute batting average
lw $a1, 0($s1) # $a1 = walks
lw $a2, 4($s1) # $a2 = singles
lw $a3, 8($s1) # $a3 = doubles
lw $s2, 12($s1) # $s2 = triples
lw $s3, 16($s1) # $s3 = home runs
lw $s4, 20($s1) # $s4 = outs
sw $s4, -4($sp) # put outs at top of average's stack
sw $s3, -8($sp) # put homeruns 2nd fm top of average's stack
sw $s2, -12($sp) # put triples 3rd fm top of average's stack
jal average
# Print the batting average
mtc1 $v0, $f12 # get result fm $v0 before we print string
la $a0, mainBattingAverage
addi $v0, $zero, 4
syscall
addi $v0, $zero, 2 # print the average
syscall
la $a0, mainNewline
addi $v0, $zero, 4
syscall
syscall
# do it for the slugging percentage
addi $a0, $zero, 2 # $a0 = 2 = compute slugging average
lw $a1, 0($s1) # $a1 = walks
lw $a2, 4($s1) # $a2 = singles
lw $a3, 8($s1) # $a3 = doubles
lw $s2, 12($s1) # $s2 = triples
lw $s3, 16($s1) # $s3 = home runs
lw $s4, 20($s1) # $s4 = outs
sw $s4, -4($sp) # put outs at top of average's stack
sw $s3, -8($sp) # put homeruns 2nd fm top of average's stack
sw $s2, -12($sp) # put triples 3rd fm top of average's stack
jal average
# Print the slugging percentage
mtc1 $v0, $f12 # get result fm $v0 before we print string
la $a0, mainSluggingPercentage
addi $v0, $zero, 4
syscall
addi $v0, $zero, 2 # print the percentage
syscall
la $a0, mainNewline
addi $v0, $zero, 4
syscall
syscall
# do it again for the on-base percentage
addi $a0, $zero, 3 # $a0 = 3 = compute slugging average
lw $a1, 0($s1) # $a1 = walks
lw $a2, 4($s1) # $a2 = singles
lw $a3, 8($s1) # $a3 = doubles
lw $s2, 12($s1) # $s2 = triples
lw $s3, 16($s1) # $s3 = home runs
lw $s4, 20($s1) # $s4 = outs
sw $s4, -4($sp) # put outs at top of average's stack
sw $s3, -8($sp) # put homeruns 2nd fm top of average's stack
sw $s2, -12($sp) # put triples 3rd fm top of average's stack
jal average
# Print the slugging percentage
mtc1 $v0, $f12 # get result fm $v0 before we print string
la $a0, mainOnbasePercentage
addi $v0, $zero, 4
syscall
addi $v0, $zero, 2 # print the percentage
syscall
la $a0, mainNewline
addi $v0, $zero, 4
syscall
syscall
addi $s0, $s0, 1 # i++
addi $s1, $s1, 24 # $s1 = addr of next batter's stats
j mainLoopBegin
mainDone:
# Epilogue for main -- restore stack & frame pointers and return
lw $ra, 4($sp) # get return address from stack
lw $fp, 0($sp) # restore frame pointer for caller
addiu $sp, $sp, 24 # restore frame pointer for caller
jr $ra # return to caller
.data
printStatsOuts:
.asciiz "Outs: "
printStatsWalks:
.asciiz "Walks: "
printStatsSingles:
.asciiz "Singles: "
printStatsDoubles:
.asciiz "Doubles: "
printStatsTriples:
.asciiz "Triples: "
printStatsHomeruns:
.asciiz "Home runs: "
printStatsNewline:
.asciiz "\n"
.text
printStats:
# Function prologue
addiu $sp, $sp, -32 # allocate stack space
sw $a3, 20($sp) # save $a0 thru $a3
sw $a2, 16($sp)
sw $a1, 12($sp)
sw $a0, 8($sp)
sw $ra, 4($sp) # save return address
sw $fp, 0($sp) # save frame pointer of caller
addiu $fp, $sp, 28 # setup frame pointer of average
# printStats expects to find the following:
# $a0 = walks
# $a1 = singles
# $a2 = doubles
# $a3 = triples
# 5th argument = homeruns
# 6th argument = outs
# print the outs
la $a0, printStatsOuts
syscall
lw $a0, 0($fp) # the outs are at the top of our stack
addi $v0, $zero, 1
syscall
la $a0, printStatsNewline
addi $v0, $zero, 4
syscall
# print the walks
la $a0, printStatsWalks
addi $v0, $zero, 4
syscall
lw $a0, 8($sp) # the walks were passed in $a0
addi $v0, $zero, 1
syscall
la $a0, printStatsNewline
addi $v0, $zero, 4
syscall
# print the singles
la $a0, printStatsSingles
addi $v0, $zero, 4
syscall
addi $a0, $a1, 0 # the singles were passed in $a1
addi $v0, $zero, 1
syscall
la $a0, printStatsNewline
addi $v0, $zero, 4
syscall
# print the doubles
la $a0, printStatsDoubles
addi $v0, $zero, 4
syscall
addi $a0, $a2, 0 # the doubles were passed in $a2
addi $v0, $zero, 1
syscall
la $a0, printStatsNewline
addi $v0, $zero, 4
syscall
# print the triples
la $a0, printStatsTriples
addi $v0, $zero, 4
syscall
addi $a0, $a3, 0 # the doubles were passed in $a3
addi $v0, $zero, 1
syscall
la $a0, printStatsNewline
addi $v0, $zero, 4
syscall
# print the homeruns
la $a0, printStatsHomeruns
addi $v0, $zero, 4
syscall
lw $a0, -4($fp) # the homeruns are 4 bytes below the top of our stack
addi $v0, $zero, 1
syscall
la $a0, printStatsNewline
addi $v0, $zero, 4
syscall
# Put -1 in $t0, then copy that value to each of the $f registers
addi $t0, $zero, -1
mtc1 $t0, $f0
mtc1 $t0, $f1
mtc1 $t0, $f2
mtc1 $t0, $f3
mtc1 $t0, $f4
mtc1 $t0, $f5
mtc1 $t0, $f6
mtc1 $t0, $f7
mtc1 $t0, $f8
mtc1 $t0, $f9
mtc1 $t0, $f10
mtc1 $t0, $f11
mtc1 $t0, $f12
mtc1 $t0, $f13
mtc1 $t0, $f14
mtc1 $t0, $f15
mtc1 $t0, $f16
mtc1 $t0, $f17
mtc1 $t0, $f18
mtc1 $t0, $f19
mtc1 $t0, $f20
mtc1 $t0, $f21
mtc1 $t0, $f22
mtc1 $t0, $f23
mtc1 $t0, $f24
mtc1 $t0, $f25
mtc1 $t0, $f26
mtc1 $t0, $f27
mtc1 $t0, $f28
mtc1 $t0, $f29
mtc1 $t0, $f30
mtc1 $t0, $f31
# Put various values in the $t registers
addi $t0, $zero, -1111
addi $t1, $zero, -2222
addi $t2, $zero, -3333
addi $t3, $zero, -4444
addi $t4, $zero, -5555
addi $t5, $zero, -6666
addi $t6, $zero, -7777
addi $t7, $zero, -8888
addi $t8, $zero, -9999
addi $t9, $zero, -1111
# Put various values in the $a registers.
addi $a0, $zero, -1111
addi $a1, $zero, -1111
addi $a2, $zero, -2222
addi $a3, $zero, -3333
# Put two values at the top two spots in our stack. This is where
# the number of homeruns and outs were placed when printStats
# is called. A function is allowed to change its own stack.
addi $t7, $zero, -1234
sw $t7, 0($fp)
sw $t7, -4($fp)
printStatsDone:
# Epilogue for printStats -- restore stack & frame pointers and return
lw $ra, 4($sp) # get return address from stack
lw $fp, 0($sp) # restore frame pointer for caller
addiu $sp, $sp, 32 # restore frame pointer for caller
jr $ra # return to caller
# Your code goes below this line
average:
#takes 7 arguments
#Arguments $a0-$a3 are put on the Caller's stack
#arguments 5-7 are put on the Callee's stack and called
# Prologue: set up stack and frame pointers for average
addiu $sp, $sp, -36 # allocate stack space -- 36 needed here
sw $fp, 0($sp) # save caller's frame pointer
sw $ra, 4($sp) # save return address
# save parameter values $a0-$a3 on the stack
sw $a0, 8($sp) # designates which calculation to do
sw $a1, 12($sp) # walks
sw $a2, 16($sp) # singles
sw $a3, 20($sp) # doubles
addiu $fp, $sp, 32 # setup average frame pointer
#Allocate proper locations of arguments for printStats
#arguments 5 and 6 (home runs and outs will be placed on stack)
addi $t5, $a0, 0 #$t5 designates which calculation to run
addi $a0, $a1, 0 #walks of printStats
addi $a1, $a2, 0 #singles of printStats
addi $a2, $a3, 0 #doubles of printStats
lw $a3, 24($sp) #triples of printStats
lw $t1, 28($sp) #home runs of printStat
sw $t1, -8($sp) #home runs now 2nd from top of stack
lw $t2, 32($sp) #outs of printStats
sw $t2, -4($sp) #out now top of stack
jal printStats
#restore registers used in average
lw $t2, 32($sp) #outs
lw $t1, 28($sp) #homeruns
lw $a3, 24($sp) #triples
lw $a2, 20($sp) #doubles
lw $a1, 16($sp) #singles
lw $a0, 12($sp) #walks
lw $t5, 8($sp) #compare which calculation to run
#convert outs to float
mtc1 $t2, $f4 #outs = $f4
#hits
#hits = singles + doubles + triples + home runs
add $t3, $a1, $a2 # hits = singles + doubles
add $t3, $t3, $a3 # hits = $t3 + triples
add $t3, $t3, $t1 # hits = $t3 + home runs
mtc1 $t3, $f1 #convert hits to float $f1
#atBats
#atBats = hits + outs
add.s $f2, $f1, $f4 # atBats = hits + outs
mfc1 $t4, $f2 #convert atBats to int for compare
#Compare $t5
#if $t5 == 1, computer batting average
#if $t5 == 2, compute slugging percentage
#if $t5 == 3, compute on-base percentage
addi $t0, $zero, 1 #$t0 = 1
beq $t5, $t0, averageBattingAverage
addi $t0, $zero, 2 #$t0 = 2
beq $t5, $t0, averageSluggingPercentage
addi $t0, $zero, 3 #$t0 = 3
beq $t5, $t0, averageOnBasePercentage
averageBattingAverage:
#batting average
#batting average = hits/atBats
#if atBats == 0, average = 0
#compare atBats
beq $t4, $zero, averageBattingSluggingZero
#batting
div.s $f3, $f1, $f2 #batting average = hits/atBats
#Set to print
mfc1 $v0, $f3 #return $v0 the batting average
j averageDone #done
averageSluggingPercentage:
#Slugging percentage
#slugging percentage = (singles + doubles*2 + triples*3
# + home runs*4)/atBats
#if atBats == 0, percentage = 0
#compare atBats
beq $t4, $zero, averageBattingSluggingZero
#slugging
add $t5, $a2, $a2 #doubles*2
add $t6, $a3, $a3 #$t6 = triples * 2
add $t6, $t6, $a3 #$t6 = triples * 3
add $t7, $t1, $t1 #$t7 = home runs * 2
add $t7, $t7, $t7 #$t7 = home runs * 4
add $t8, $a1, $t5 #$t8 = singles + doubles*2
add $t8, $t8, $t6 #$t8 = $t8 + triples*3
add $t8, $t8, $t7 #$t8 = $t8 + home runs*4
mtc1 $t8, $f1 #convert $t8 to float $f1
div.s $f3, $f1, $f2 #slugging percentage = $f1/atBats
#set to print
mfc1 $v0, $f3 #return $v0 the slugging percentage
j averageDone #done
averageOnBasePercentage:
#On-base percentages
#on-base percentages = (hits + walks)/(atBats + walks)
#if atBats + walks is zero, percentage is zero
add $t6, $t3, $a0 #$t6 = hits + walks
add $t7, $t4, $a0 #$t7 = atBats + walks
#compare atBats + walks
beq $t7, $zero, averageOnBaseZero
#on-base
mtc1 $t6, $f1 #convert $t6 to float $f6
mtc1 $t7, $f2 #convert $t7 to float $f7
div.s $f3, $f1, $f2 #on-base percentage = $f6/$f7
#set to print
mfc1 $v0, $f3 #return $v0 the on-base percentage
j averageDone #done
averageBattingSluggingZero:
#if atBats is zero, batting average and slugging
#percentage are both zero
addi $t0, $zero, 0 #$t0 = 0
mtc1 $t0, $f0 #convert 0 to float $f0
#set to print
mfc1 $v0, $f0 #return $v0 = 0
j averageDone #done
averageOnBaseZero:
#if atBats + walks is zero, on-base percentage
# is also zero
addi $t0, $zero, 0 #$t0 = 0
mtc1 $t0, $f0 #convert 0 to float $f0
#set to print
mfc1 $v0, $f0 #return $v0 = 0
j averageDone #done
averageDone: # Epilogue: restore stack and frame pointers and return
lw $ra, 4($sp) # get return address from stack
lw $fp, 0($sp) # restore the caller's frame pointer
addiu $sp, $sp, 36 # restore the caller's stack pointer
jr $ra # return to caller's code
My outputs are not lining up and I don't get why.
The following is the correct output for batter 3.
Batter number: 3
Outs: 23000000
Walks: 102322
Singles: 8000000
Doubles: 22
Triples: 500000
Home runs: 10
Batting average: 0.26984200
Outs: 23000000
Walks: 102322
Singles: 8000000
Doubles: 22
Triples: 500000
Home runs: 10
Slugging percentage: 0.30158967
Outs: 23000000
Walks: 102322
Singles: 8000000
Doubles: 22
Triples: 500000
Home runs: 10
On-base percentage: 0.27220613
And here's my output, with a ! to mark the inconsistencies
Batter number: 3
Outs: 23000000
Walks: 102322
Singles: 8000000
Doubles: 22
Triples: 500000
Home runs: 10
!Batting average: 0.22532867
Outs: 23000000
Walks: 102322
Singles: 8000000
Doubles: 22
Triples: 500000
Home runs: 10
!Slugging percentage: 0.25183919
Outs: 23000000
Walks: 102322
Singles: 8000000
Doubles: 22
Triples: 500000
Home runs: 10
!On-base percentage: 0.22559348
How are my calculations off for this one batter, and what can I do to fix it?
There are multiple calling conventions, you should figure out which one you are supposed to follow. If you have no documentation, you could look at compiler-generated assembly code, or use a debugger.
That said, judging from the fact that only 4 arguments are passed on the stack, you seem to be using the O32 calling convention. This means, the stack upon entry to your function contains 4 argument slots for saving the first 4 arguments which are passed in the registers $a0-$a3. Following them are all the remaining arguments. So, upon entry to your function, the 5th argument (the first one that is not passed via register) will be at address 16($sp) with the 6th at 20($sp) and the 7th at 24($sp). (This is assuming your arguments are 1 word each.) You subtract 36 from $sp to make space for your locals, thus after that all the offsets increase by that amount, i.e. 5th argument at 52($sp) and so on. You can access them using these addresses.
You then set $fp to $sp + 32. I don't think calling convention mandates any particular value for $fp, so that should be fine. If you subsequently wish to access your arguments relative to $fp, you need to adjust the offsets again to compensate, this time by -32. Thus, 5th argument should be at 20($fp), followed by the rest.