http://www.programmersheaven.com/ Contains the latest posts from the thread 'Merge Sort MIPS Assembly help with stack pointer' posted on the 'Assembler Developer' forum at Programmer's Heaven. en Copyright 2013 Programmers Heaven Wed, 19 Jun 2013 18:13:06 -0700 Wed, 19 Jun 2013 18:13:06 -0700 Argotic Syndication Framework 2007.3.0.1, http://www.codeplex.com/Argotic http://www.rssboard.org/rss-specification 360 http://www.programmersheaven.com/images/ph.gif http://www.programmersheaven.com/ 88 31 http://www.programmersheaven.com/mb/pharabee/427937/427937/merge-sort-mips-assembly-help-with-stack-pointer/ I am in some need of some desperate help at the moment. I have a merge sort program running in MIPS assembly and I am almost complete. I have a few issues with my pointer, but I cannot seem to find them. If anyone would help that will be much appreciative. <br /> Feel free to ask me if uncertain what is going on in a certain place.<br /> Thanks in advance!<br /> <pre class="sourcecode"> main: li $s0, 0 addi $s1, $s1, 19 # $s1=hi addi $s0, $s0, 0 # $s0=lo la $a0, list addi $s2, $s2, 0 addi $sp, $sp, -20 sw $ra, 16($sp) sw $a0, 12($sp) sw $s2, 8($sp) # m sw $s1, 4($sp) # hi sw $s0, 0($sp) # lo jal merge_sort merge_sort: add $t0, $s0, $s1 # t0 = lo+hi div $s2, $t0, 2 # m=lo+hi/2 slt $t0, $s0, $s1 # $t0=1 if lo&lt;hi bne $t0, $zero, L1 # if lo&lt;hi branch to L1 jr $ra L1: addi $sp, $sp, -20 sw $ra, 16($sp) sw $a0, 12($sp) sw $s2, 8($sp) # m sw $s1, 4($sp) # hi sw $s0, 0($sp) # lo add $s1, $s2, $zero # hi=m jal merge_sort # merge_sort(a(a0), ?, $s0, $ L2: addi $sp, $sp, -20 sw $ra, 16($sp) # sw $a0, 12($sp) # sw $s2, 8($sp) # m # sw $s1, 4($sp) # hi # sw $s0, 0($sp) # lo addi $s0, $s1, 1 jal merge_sort addi $sp, $sp, 20 lw $s0, 0($sp) lw $s1, 4($sp) lw $s2, 8($sp) lw $a0, 12($sp) jal merge lw $s0, 0($sp) ## lw $s1, 4($sp) lw $s2, 8($sp) lw $a0, 12($sp) lw $ra, 16($sp) addi $sp, $sp, 20 jr $ra ######################################### merge: li $t2, 0 # i li $t3, 0 # j li $t4, 0 # k move $t2, $s0 # i=lo ##FOR LOOP FROM MERGE### ######################## for: slt $t1, $s1, $t2 # $t1=1;hi&lt;i bne $t1, $zero, next #if i&gt;hi next loop la $a0, list # array list into $a0 move $t5, $t2 # save iterator sll $t5, $t5, 2 # shift by 4 add $t6, $t5, $a0 # $t6=a[i] lw $t1, 0($t6) la $a0, b_array move $t7, $t2 sll $t7, $t7, 2 # shift 4 add $t7, $t7, $a0 sw $t1, 0($t7) # $b[i]=a[i] addi $t2, $t2, 1 j for ###START OF WHILE LOOP 1#### next: move $t2, $s0 # i=lo addi $t3, $s2, 1 # j=m+1 (Hopefully) move $t4, $s0 # k=lo while1: slt $t1, $s2, $t2 #$t1=1;m&lt;i bne $t1, $zero, while2 #ifm&lt;i branch to while2 slt $t1, $s1, $t3 #$t1=1;hi&lt;j bne $t1, $zero, while2 #if j&gt;hi branch to while2 ##### getting b[i] &amp; storing into $s3 ####### move $t5, $t2 #preserve i into $t5 la $a0, b_array sll $t5, $t5, 2 add $t6, $t5, $a0 #load b[i] into $t6 lw $s3, 0($t6) #load content of b[i] into $s3 ###Getting element b[j] &amp; storing into $s4######## la $a0, b_array move $t7, $t3 #preserve j sll $t7, $t7, 2 #j*4 add $t6 $t7, $a0 #b[j]=$t6 lw $s4, 0($t6) #content of b[j] into $s4 ####Compare value of $s3 &amp; $s4####### if: slt $t1, $s4, $s3 #$t1=1 if b[j]&lt;b[j] bne $t1, $zero, else #if b[i]&gt;b[j] branch to else ####copy b[i++] into a[k++] ##b[i++]## la $a0, b_array move $t5, $t2 # preserve i sll $t5, $t5, 2 # shift address *4 add $t6, $t5, $a0 lw $t0, 0($t6) # load element into $t0 ##a[k++]## la $a0, list move $t5, $t4 #preserve k sll $t5, $t5, 2 #shift by 4 add $t6, $t5, $a0 sw $t0, 0($t6) # a[k++]=b[i++] addi $t2, $t2, 1 #i++ addi $t4, $t4, 1 #k++ j while1 ###else b[j++]---&gt;a[k++]### else: ##b[j++]## la $a0, b_array move $t5, $t3 # preserve j sll $t5, $t5, 2 # shift 4 add $t6, $t5, $a0 # load into $t6 lw $t0, 0($t6) # $t6--&gt;$t0 ##a[k++] la $a0, list move $t5, $t4 #preserve k sll $t5, $t5, 2 #shift 4 add $t6, $t5, $a0 #load into $t6 sw $t0, 0($t6) # $t0--&gt;0($t6) addi $t3, $t3, 1 #j++ addi $t4, $t4, 1 #k++ j while1 while2: slt $t1, $s2, $t2 #$t1=1;m&lt;i bne $t1, $zero, end_merge #ifm&lt;i branch to end_me$ ###a[k++]=b[i++]### la $a0, b_array move $t5, $t2 # preserve i sll $t5, $t5, 2 # shift address *4 add $t6, $t5, $a0 lw $t0, 0($t6) la $a0, list move $t5, $t4 sll $t5, $t5, 2 add $t6, $t5, $a0 sw $t0, 0($t6) # a[k++] addi $t2, $t2, 1 #i++ addi $t4, $t4, 1 j while2 end_merge: j $ra #jump to previous location </pre><br /> http://www.programmersheaven.com/mb/pharabee/427937/427937/merge-sort-mips-assembly-help-with-stack-pointer/ Tue, 20 Mar 2012 21:15:39 -0700 Assembler Developer