Hi Ranjan im not sure what you mean when you say load in a branch/jump delay slot. im guessing thats whats causing the irregular behavior, the way i see it is that my 'bne' jump is never being executed, where this should be the default behavior in the majority of inputs. thanks for your help, its really appreicated :) michael ----- Original Message ----- From: "Ranjan Parthasarathy" <ranjanp@efi.com> To: "'Michael'" <trott@bigpond.net.au>; <linux-mips@linux-mips.org> Sent: Thursday, August 07, 2003 5:08 AM Subject: RE: debuging problems > You seem to be having branches in jump delay slots. Also there are some > loads in delay slots which I think might not be intentional. You might want > to check these. > > e.g. > load in a branch/jump delay slot ( intentional ? ) > j r1 > > cr: li $13,0 # clear line number > > e.g. > branch in an jump delay slot (?) > j r2 > > r3: bne $19,$10,exit # branch if line total != magic number > > Thanks > > Ranjan > > -----Original Message----- > From: Michael [mailto:trott@bigpond.net.au] > Sent: Tuesday, August 05, 2003 9:10 PM > To: linux-mips@linux-mips.org > Subject: debuging problems > > > i have written a mips program to verify if a given input is a magic square, > > a magic square is a n*n matrix whose values are from 1..n^2, and each > row/column diagonal gives the same sum, this sum is know as the magic > number. > > All my program does is go through and sum each of the rows then each of the > columns, at every stage the sum of the row or column in question is > compared to the magic number, if not equal then not valid magic square. the > formula is given in my doco. > > im having problems working out what the actual problem is. I've completely > coded it and spent alot of time steping through it but i cant see any > problems. regardless of the input, the result is always negative. > > just wondering has anyone got any suggestions, any help would be greatly > appreicated :) > > ive pasted my program at the bottom of this, > > thanks everyone > > michael > > _______________________________________________________________ > > > > # Program Name: Magic Square Verifier > # > # Author: Michael > # > # The purpose of this program is to determine whether > or not > # a given input is a valid magic square. > # > # The start address for the matrix is to be given in > $8, with > # the size of the matrix supplied in $9. Major row > # representation must be used to store the matrix > values. > # > # At completeion of the program, $11 will store the > # result of the program. if $11 == 1, then input was a > # valid magic square, if $11 == 0, the input was not a > valid > # magic square. > # > # for more details, plese consult the attached program > # description file > > > > > .text > > main: li $11,0 # is magic square = 0 > li $12,2 # temporary > li $13,0 # Line number > li $14,0 # temporary > li $16,0 # Line position > li $17,0 # start address + offset > li $18,4 # constant 4 > li $19,0 # Line total > > > # Calculation of magic number for > specified n > mul $10,$9,$9 # n^2 > addi $10,$10,1 # (n^2)+1 > mul $10,$10,$9 # ((n^2)+1)n > divu $10,$10,$12 # (((n^2)+1)n)/2 == magic_number > addi $15,$9,1 # n+1 > > r1: beq $13,$9,cr # branch if line# == n > > r2: beq $16,$9,r3 # branch when line_pos == n > > > mul $12,$13,$9 # line# . n > add $12,$12,$16 # (line # . n)+ line_pos > mul $12,$12,$18 # ((line # . n)+ line_pos)4 > add $17,$8,$12 # start address + offset > lw $23, 0($17) # load word, viz[i], into $17 > add $19,$19,$23 # line_total = line_total + viz[i] > addi $16,$16,1 # line_position ++ > j r2 > > r3: bne $19,$10,exit # branch if line total != magic number > addi $13,$13,1 # line# ++ > li $16,0 # set line_pos > j r1 > > cr: li $13,0 # clear line number > li $16,0 # clear line position > li $19,0 # clear line total > > c1: beq $13,$9,sum # branch if line# == n > > c2: beq $16,$9,c3 # branch if line# == n > > > mul $12,$9,$18 # n . 4 > mul $12,$12,$16 # (n . 4) . line_position > mul $14,$13,$18 # line# . 4 > add $12,$12,$14 # ((n . 4) . line_position)+( line# . 4) > add $17,$12,$8 # start address + offset > lw $23,0($17) # load word, viz[i], into $17 > add $19,$19,$23 # start address + offset > addi $16,$16,1 # line_total = line_total + viz[i] > j c2 > > c3: bne $19,$10,exit # branch if line_total != magic_number > addi $13,$13,1 # line# ++ > li $16,0 # clear line _pos > j c1 > > sum: li $12,0 > li $14,0 > add $17,$8,$0 > > s1: beq $12,$9,s2 # branch if counter == n > lw $23,0($17) # load word, viz[i], into $17 > add $14,$14,$23 # seq_total = seq_total + viz[i] > addi $17,$17,4 # viz[i] = viz[i + 1] > addi $12,$12,1 # counter ++ > j s1 > > s2: li $16,0 # total > li $19,1 # i of n > > > s3: beq $19,$15,s4 # branch if (i of n ) == (n + 1) > add $16,$16,$19 # total = total + (i of n ) > addi $19,$19,1 # (i of n ) ++ > > s4: bne $16,$14,exit > > dc: li $12,0 > li $13,0 > li $16,0 > li $19,0 > > mul $14,$15,$18 # (n + 1) 4 > add $17,$8,$0 # copy start addr to $17 > > d1: beq $13,$9,d2 # branch if line# == n > > lw $23,0($17) # load word, viz[i], into $17 > add $19,$19,$23 # diag_total = diag_total + viz[i] > add $17,$17,$14 # viz[i] = viz[i+1] > addi $13,$13,1 # line# ++ > j d1 > > d2: bne $19,$10,exit # branch if diagonal_total != > magic_number > j complete # else complete, therefore input is > magic square > > > complete: li $11,1 > > exit: > > > >
