Program To Check If A Magic Square Is Valid In ARM Assembly Language Using KEIL Assignment Solution

Instructions

Objective

Write an ARM assignment to check if a magic square is valid in ARM assembly language using KEIL.

Requirements and Specifications

Screenshots of output

Source Code

AREA magicSquares, CODE EXPORT __main ALIGN ENTRY __main PROC ; the code will initialize R1 and use a test matrix to run the code, ; if R1 is set somewhere else and a matrix is set at 0x20000010, ; then uncomment the following line ; B start MOV R1, #4 ; matrix size N ; copy test matrix to matrix space at 0x20000010 LDR R2, =tstmat1 ; start address of test matrix 1 ;LDR R2, =tstmat2 ; start address of test matrix 2 LDR R3, =0x20000010 ; start address of matrix MOV R4, R1 ; number of rows copyrows MOV R5, R1 ; number of cols copycols LDR R0, [R2], #4 ; load value from test matrix STR R0, [R3], #4 ; store value in matrix SUBS R5, R5, #1 ; decrement remaining cols BNE copycols ; repeat while not zero SUBS R4, R4, #1 ; decrement remaining rows BNE copyrows ; repeat while not zero start ; fill rows variable LDR R2, =0x20000010 ; load address of matrix LDR R3, =rows ; point to start of rows array LSL R4, R1, #2 ; size of a row = N*4 MOV R5, #0 ; start in position 0 loopr STR R2, [R3, R5, LSL #2]; save address in rows ADD R2, R2, R4 ; advance to next row ADD R5, R5, #1 ; increment index CMP R5, R1 ; compare index with N BLT loopr ; repeat while i < N ; fill cols variable LDR R2, =0x20000010 ; load address of matrix LDR R3, =cols ; point to start of cols array MOV R4, #0 ; start in position 0 loopc STR R2, [R3, R4, LSL #2]; save address in cols ADD R2, R2, #4 ; advance to next col ADD R4, R4, #1 ; increment index CMP R4, R1 ; compare index with N BLT loopc ; repeat while i < N ; calculate sum number = N*(N^2 + 1)/2 MUL R2, R1, R1 ; N*N ADD R3, R2, #1 ; N*N + 1 MUL R3, R3, R1 ; N*(N*N + 1) LSR R3, R3, #1 ; N*(N*N + 1)/2 MOV R8, #0 ; assume it's not magic at start ; First we test the matrix elements LDR R4, =rows ; load rows MOV R5, #0 ; row index loop1 LDR R6, [R4, R5, LSL #2] ; load row address MOV R7, #0 ; col index loop2 LDR R0, [R6, R7, LSL #2] ; load element from row CMP R0, #1 ; check if >= 1 BLT endTest ; if < 1, it's not a magic square CMP R0, R2 ; check if <= N^2 BGT endTest ; if > N^2, it's not a magic square ADD R7, R7, #1 ; increment col index CMP R7, R1 ; compare index with N BLT loop2 ; repeat while col < N ADD R5, R5, #1 ; increment row index CMP R5, R1 ; compare index with N BLT loop1 ; repeat while row < N ; We now test the row sums LDR R4, =rows ; load rows MOV R5, #0 ; row index sumrows1 LDR R6, [R4, R5, LSL #2] ; load row address MOV R7, #0 ; col index MOV R9, #0 ; start sum in zero sumcols1 LDR R0, [R6, R7, LSL #2] ; load element from row ADD R9, R9, R0 ; add element to sum ADD R7, R7, #1 ; increment col index CMP R7, R1 ; compare index with N BLT sumcols1 ; repeat while col < N CMP R9, R3 ; check if sum = N*(N*N + 1)/2 BNE endTest ; if != N^2, it's not a magic square ADD R5, R5, #1 ; increment row index CMP R5, R1 ; compare index with N BLT sumrows1 ; repeat while row < N ; We now test the column sums LDR R4, =cols ; load cols MOV R5, #0 ; col index sumcols2 LDR R6, [R4, R5, LSL #2] ; load col address MOV R7, #0 ; row index MOV R9, #0 ; start sum in zero sumrows2 MUL R0, R7, R1 ; row * num cols LSL R0, R0, #2 ; address of element = row * num cols * 4 LDR R0, [R6, R0] ; load element from col ADD R9, R9, R0 ; add element to sum ADD R7, R7, #1 ; increment row index CMP R7, R1 ; compare index with N BLT sumrows2 ; repeat while row < N CMP R9, R3 ; check if sum = N*(N*N + 1)/2 BNE endTest ; if != N^2, it's not a magic square ADD R5, R5, #1 ; increment col index CMP R5, R1 ; compare index with N BLT sumcols2 ; repeat while col < N ; We now test the first diagonal sum LDR R4, =rows ; load rows MOV R5, #0 ; row index MOV R6, #0 ; start sum in zero sumdiag1 LDR R7, [R4, R5, LSL #2] ; load row address LDR R0, [R7, R5, LSL #2] ; load element from row at index position (row,row) ADD R6, R6, R0 ; add element to sum ADD R5, R5, #1 ; increment row index CMP R5, R1 ; compare index with N BLT sumdiag1 ; repeat while row < N CMP R6, R3 ; check if sum = N*(N*N + 1)/2 BNE endTest ; if != N^2, it's not a magic square ; Lastly, we test the second diagonal sum LDR R4, =rows ; load rows SUB R5, R1, #1 ; row index = N-1 MOV R6, #0 ; col index = 0 MOV R7, #0 ; start sum in zero sumdiag2 LDR R9, [R4, R5, LSL #2] ; load row address LDR R0, [R9, R6, LSL #2] ; load element from row at index position (row,col) ADD R7, R7, R0 ; add element to sum SUB R5, R5, #1 ; decrement row index ADD R6, R6, #1 ; increment col index CMP R6, R1 ; compare col with N BLT sumdiag2 ; repeat while col < N CMP R7, R3 ; check if sum = N*(N*N + 1)/2 BNE endTest ; if != N^2, it's not a magic square MOV R8, #1 ; if we end all tests, matrix is a magic square endTest ; here, R8 will have 1 if the matrix is magic and 0 otherwise done B done ENDP ALIGN AREA myData1, DATA, READWRITE SPACE 16 ; leave 16 bytes (0x10) matrix SPACE 400 ; start of matrix at 0x20000010, at most 10x10 rows SPACE 40 ; space to save rows (at most 10) cols SPACE 40 ; space to save columns (at most 10) AREA myData2, DATA, READONLY tstmat1 DCD 16, 3, 2, 13 ; magic square matrix DCD 5, 10, 11, 8 DCD 9, 6, 7, 12 DCD 4, 15, 14, 1 tstmat2 DCD 5, 10, 11, 8 ; swapped 2 first rows, not magic DCD 16, 3, 2, 13 DCD 9, 6, 7, 12 DCD 4, 15, 14, 1 END