assembly - MIPS: multiplying two 32 bit numbers, getting a 64 bit -
i attempting multiply 2 32 bit numbers in mips. have code here uses mult operation. use mfhi , mflo operations 2 parts mult, not sure how put these together. have them print out operations separately example.
the input numbers have been using are: 1143330295 , 999999223
the output program (obviously needs work) is: 266202121 -1483441327
the correct output 1143329406632360785 or can in binary if easier.
this code larger project working on have multiply 2 32 bit numbers using shift , add algorithm without using mult function. trying wrap head around representing 64 bit number first. advice/input.
.data geta: .asciiz "please enter first number(multiplicand): " getb: .asciiz "please enter second number(multiplier): " space: .asciiz " " promptstart: .asciiz "this program multiplies 2 numbers. " mipmult: .asciiz "the product, using mips mult is: " endline: .asciiz "\n" .text main: li $v0,4 la $a0,promptstart syscall li $v0,4 la $a0,endline syscall #prompt multiplicand li $v0,4 la $a0,geta syscall #acquire multiplicand li $v0,5 syscall move $s0,$v0 move $s5,$s0 #prompt multiplier li $v0,4 la $a0,getb syscall #acquire multiplier li $v0,5 syscall move $s1,$v0 move $s6,$s1 # copy mult $s5, $s6 mfhi $t0 mflo $t1 li $v0,4 la $a0,mipmult syscall # print out result (this not correct, need help) li $v0,1 move $a0,$t0 syscall li $v0,4 la $a0,space syscall # print out result li $v0,1 move $a0,$t1 syscall # print line feed li $v0,4 la $a0,endline syscall li $v0,10 syscall # exit program
i guess dealing unsigned integers, should use multu instead of mult.
to print 64-bit number in decimal think can implement algorithm takes modulus 10 of 64 bit number, stores somewhere in memory, , repeat quotient until quotient zero. traverse string in reverse order print number digit-by-digit.
in question said ok print number in binary. easier can print value of each bit left right both registers (hi order first, low order).
to that, besides using multu instead of mult change call
# print out result (this not correct, need help) li $v0,1 move $a0,$t0 syscall li $v0,4 la $a0,space syscall # print out result li $v0,1 move $a0,$t1 syscall with
move $t2, $t0 jal print_binary move $t2, $t1 jal print_binary and add subroutine:
# $t2 should hold number print in binary print_binary: li $t3, 32 li $v0, 1 print_bit: subiu $t3, $t3, 1 srlv $a0, $t2, $t3 andi $a0, $a0, 1 syscall bgtz $t3, print_bit jr $ra