Asemmbly help!

Comments

• assassin

  October 2001

  fyi, this is MIPS assembly. dunno how helpful an x86 messageboard will be for you.. i'll fire up SPIM and see where i get, which may be nowhere, given my hatred of quicksort.
  
  l8rz
  
  
  : Basically I am trying to write a quicksort method in one of my programs in Assembly and its turning out to be a real nightmare. Anyone have any suggestions. I think that I am going wrong when I am allocating loading the stacks, although the partition method isn't running smoothly either.
  : most of the .data that I will post will not be relevant to the code, because it pertains to other parts of the program.
  :
  : .data
  : .align 2
  : single: .space 4
  : charactr: .space 104
  : initspce: .space 400 ############################
  : donearry: .space 400 # allocate space for arrays
  : table: .space 104 ############################
  : exitMsg: .asciiz "
  
  Thank you, goodbye!
  "
  : instruct: .asciiz "Enter a sentence less than 100 characters:
  
  "
  : endprob1: .asciiz "
  This is the array without spaces or special characters:
  
  "
  : dash: .asciiz "-"
  : space: .asciiz " "
  : newLn: .asciiz "
  
  "
  : freq: .asciiz "
  
  Frequencies of each letter alphabetically:
  
  "
  :
  : .text
  :
  :
  : part3: la $s0,table #left bound of the array
  : addi $s1,$s0,25 #right bound of the array
  : #quicksort: beq $s0,$s1,printpl
  : # blt $s1,$s0,recurse
  : # j partition
  : #partref: addi $sp,$sp,-8
  : # sw $s1,4($sp)
  : # sw $s3,0($sp)
  : # addi $s1,$s3,-1
  : # jal quicksort
  : #this: addi $s0,$s0,1
  : # j quicksort
  : #recurse: lw $s0,0($sp)
  : # lw $s1,4($sp)
  : # addi $sp,$sp,8
  : # jr $ra
  :
  : partition: addi $s3,$s0,-1 #left bound minus one (i on algorithm)
  : addi $s4,$s1,0 #right bound of the array (j on algorithm)
  : lb $s5,0($s1) #pivot value (v on algorithm)
  :
  : while1: addi $s3,$s3,1 # this is the first while loop. if the
  : lb $t0,0($s3) # leftmost value is less than the pivot
  : blt $t0,$s5,while2 # go to loop 2. if not go to next value
  : beq $s5,$zero,while2 #
  : j while1 # to the right and so forth
  :
  : while2: addi $s4,$s4,-1 # this is the second while loop. if the
  : lb $t1,0($s4) # rightmost value is greater than or equal
  : blt $s5,$t1,point # to the pivot, go to point. also if you
  : beq $s5,$t1,point # get to the beginning of the array go to
  : beq $s4,$s0,point # point. If its not greater, go to next
  : j while2 # value to the left and so forth
  :
  : point: blt $s4,$s3,breakpt # if your indices are equal or they have
  : beq $s4,$s3,breakpt # crossed then go to breakpt
  : sb $t1,0($s3) #
  : sb $t0,0($s4) # else, switch the two indices and go back
  : j partition # to partition (infinite loop until it breaks)
  :
  : breakpt: lb $t2,0($s3) # here the indices are equal or have crossed
  : lb $t3,0($s1) # so switch the pivot with the value that i
  : sb $t2,0($s1) # was on. everything left of the pivot is
  : sb $t3,0($s3) # greater or equal, and everything right is less
  : # j partref
  :
  : printpl: la $a0,newLn
  : li $v0,4
  : syscall
  : la $s2,table
  : addi $t5,$zero,25
  : addi $t6,$zero,0
  : back: lb $a0,0($s2)
  : li $v0,1
  : syscall
  : addi $s2,$s2,1
  : addi $t6,$t6,1
  : beq $t6,$t5,exit
  : j back
  :
  :
  :
  :
  : exit: la $a0,exitMsg ##########################################
  : li $v0,4 # Print out an exit message and then
  : syscall # exit the program
  : li $v0,10 #
  : syscall ##########################################
  :
  :
  : sorry about the aesthetics of the code. The copy and paste method isn't exactly nice. Any help would be greatly appreciated.