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project5.asm
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project5.asm
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.text
.globl main
main:
la $a0, sign_integer # Prompts the user to enter a signed integer
li $v0, 4 # Print the prompt
syscall
li $v0, 5 # Enter the signed integer: ex: -3
syscall
beqz $v0, done # if($v0 == 0): done
move $t0, $v0 # else: x = $v0
li $s1, 0x80000000 # Bitmask to get sign
and $a3, $t0, $s1 # $a3 = $t0 && $s1 = -3 && 0x80000000 = 1 && 1 = 1
jal sign_check # Check the sign in $a3
la $a0, decimal_num # Prompts the user to enter a decimal number in binary
li $v0, 4 # Prints the prompt
syscall
la $a0, dec_bin_string # $a0 = dec_bin_string (stores the binary string)
li $a1, 32 # Size of the bin_string
li $v0, 8 # Reads the users input as a string.
syscall
bltz $t0, make_positive # if($t0 < 0): (i.e. a negative #) make_positive
j print_sign_bit # Print the sign bit
sign_check:
beqz $a3, zero_sign # if($a3 == 0): zero_sign (0 for sign bit)
li $a3, 1 # else: 1 for sign bit
jr $ra # return to main
zero_sign:
li $a3, 0 # $a3 = 0 (0 for sign bit)
jr $ra # return to main
make_positive:
li $s6, -1 # $s6 = -1
mult $t0, $s6 # ex: -3 * -1 = 3
mflo $t0 # ex: x = 3
print_sign_bit:
la $a0, sign_bit # Prompt "sign bit = "
li $v0, 4 # Print the prompt
syscall
beqz $a3, print_zero_sign_bit # if($a3 == 0): print_zero_sign_bit
la $a0, one # ex: $a0 = $a3 = 1 (sign bit)
li $v0, 4 # Print the sign bit
syscall
sll $a3, $a3, 31 # ex: $a3 = 1 << 31 = 1000 0000 0000 0000 0000 0000 0000 0000
j decimal_point # Jump to decimal_point
print_zero_sign_bit:
la $a0, zero # ex: $a0 = $a3 = 0 (sign bit)
li $v0, 4 # Print the sign bit
syscall
sll $a3, $a3, 31 # ex: $a3 = 0 << 31 = 0000 0000 0000 0000 0000 0000 0000 0000
decimal_point:
la $a0, dec_bin_string # $a0 = dec_bin_string
li $a1, 0x2e # hex for decimal point = '.'
lb $t2, 0($a0) # if dec_bin_string has a decimal point $t2 = . = $a0[0]
bne $t2, $a1, conversion # if($t2 != '.'): conversion
li $t1, 0 # i = 0
la $a1, dec_bin_string # $a1 = dec_bin_string with decimal point = .101
addi $a0, $a0, 1 # $a0[1] = dec_bin_string without decimal point = 101
without_decimal_point:
bgt $t1, 32, conversion # if(i > 32): conversion
lb $t2, 0($a0) # ex: $t2 = $a0[1] = 1
sb $t2, 0($a1) # ex: $a1[0] = 1
addi $a0, $a0, 1 # $a0[1 + 1] = $a0[2]
addi $a1, $a1, 1 # $a1[0 + 1] = $a1[1]
addi $t1, $t1, 1 # i++
j without_decimal_point # for(int i = 0; i <= 32; i++): repeat
conversion:
la $a0, dec_bin_string # $a0 = dec_bin_string
la $a1, store_dec_bin_string # $a1 = store_dec_bin_string
li $t1, 0 # i = 0
li $s1, 0x01010101 # Bitmask to find the exponent
exponent:
bgt $t1, 8, exponent_digits # if(i > 8 (# of bits for exponent)): exponent_digits
lw $t2, 0($a0) # $t2 = $a0[0]
and $t2, $t2, $s1 # ex: $t2 = $t2 && $s1 = 1 && 1 = 1
sw $t2, 0($a1) # $a1[0] = $t2
addi $a0, $a0, 4 # $a0[0 + 1] = $a0[1]
addi $a1, $a1, 4 # $a1[0 + 1] = $a1[1]
addi $t1, $t1, 1 # i = i + 1
j exponent # Repeat
exponent_digits:
la $t1, store_dec_bin_string # $t1 = store_dec_bin_string
li $t2, 31 # Total number of bits: 0 -> 31
li $s6, 0 # y = 0
get_exponent_digits:
bltz $t2,fraction # if($t2 < 0): fraction
lb $t3, 0($t1) # $t3 = $t1[0]
sllv $t3, $t3, $t2 # ex: $t3 = $t3 << $t2 = 1 << 31 = 1000...0000 (31 zeros following 1)
or $s6, $s6, $t3 # ex: $s6 = 0 || 1 = 1
add $t1, $t1, 1 # $t1[0+1] = $t1[1]
sub $t2, $t2, 1 # $t2 = $t2 - 1 = 31 - 1
j get_exponent_digits # Repeat
fraction:
move $t2, $t0 # $t2 = signed integer
li $t1, 32 # i = 32
li $s1, 0x80000000 # Bit mask to get the fraction bits
fraction_digits:
and $t3, $t2, $s1 # $t3 = $t2 && $t1 = 1 && 1 = 1
beq $t3, $s1, get_fraction_digits # if($t3 == 8): get_fraction_digits
sll $t2, $t2, 1 # ex: $t2 = $t2 << 1 = 1 << 1 = 10
sub $t1, $t1, 1 # i-- = i - 1 = 32 - 1 = 31
j fraction_digits # Repeat
get_fraction_digits:
move $t2, $s6 # ex: $t2 = 0
sub $t3, $t1, 1 # $t3 = 8 - 1
srlv $t2, $t2, $t3 # ex: $t2 = $t2 >> $t3 = 0 >> 7 = 0000 0000
li $s3, 33 # $s3 = 33
sub $s3, $s3, $t1 # $s3 = 33 - 8
sllv $t3, $t0, $s3 # ex: $t3 = 1 << 25 = 1000 0000 0000 0000 0000 0000 0
or $s3, $t3, $t2 # ex: $s3 = $t3 || $t2 = 1 || 0 = 1
srl $a2, $s3, 9 # ex: $a2 = 1 >> 9 = 00 0000 0001
print_exponent_in_decimal:
# exponent - biased
sub $t1, $t1, 1 # exponent - 1
add $a1,$t1,127 # $a1 = exponent + 127
la $a0, dec_point # Prompt the user: "Exponent in decimal ="
li $v0, 4 # Print the prompt
syscall
move $a0, $a1 # $a0 = $a1 = exponent in decimal
li $v0, 1 # Print the exponent in decimal
syscall
sll $a1, $a1, 23 # ex: $a1 = $a1 << 23 = 1 << 23 = 1000 0000 0000 0000 0000 0000
or $s0, $a3, $a1 # $s0 = $a3(sign bit) || $a1(exponent)
or $s0, $s0, $a2 # $s0 = $s0 || $a2(fraction)
floating_point:
la $a0, bits_float # Prompt the user: "All bits of the floating point number are:"
li $v0, 4 # Print the prompt
syscall
li $t1, 0 # i = 0
move $t2, $s0 # $t2 = floating point number
li $t3, 0x80000000 # bit mask for floating point bits
li $s7, 0 # j = 0
li $t8, 4 # j == 4
print_floating_point_bits:
beq $t1, 32, print_floating_point_num # if(i == 32): print_floating_point_num
beq $s7, $t8, bit_space # if(j == 4): bit_space (print white space after printing four bits = a nibble)
and $a0, $t2, $t3 # ex: $a0 = $t2 && $t3 = 1 && 0 = 0
srl $a0, $a0, 31 # ex: $a0 = 0 >> 31 = 0000 ... 0000 (31 0 bits following 0 ($a0))
beqz $a0, print_zero # if($a0 == 0): print_zero
la $a0, one # else: print "1"
li $v0, 4 # print "1"
syscall
sll $t2, $t2, 1 # ex: $t2 = 1 << 1 = 10
addi $s7, $s7, 1 # j = j + 1
addi $t1, $t1, 1 # i = i + 1
j print_floating_point_bits # Repeat
print_zero:
la $a0, zero # $a0 = "0"
li $v0, 4 # Print "0"
syscall
sll $t2, $t2, 1 # ex: $t2 = 1 << 1 = 10
addi $s7, $s7, 1 # j = j + 1
addi $t1, $t1, 1 # $t1 = $t1 + 1
j print_floating_point_bits # Jump to floating_point_bits
bit_space:
li $s7, 0 # Reset j to 0
la $a0, white_space # $a0 = " "
li $v0, 4 # Print the whitespace
syscall
j print_floating_point_bits # Jump to floating_point_bits
print_floating_point_num:
la $a0, float_point_num # Prompt the user: "The floating point number is: "
li $v0, 4 # Print the prompt
syscall
mtc1 $s0, $f12 # ex: float = $s0 = 1100 0000 0110 1000 0000 0000 0000 0000
li $v0, 2 # System call to print a floating point integer
syscall
done:
la $a0, complete # Prompts the user that the program is complete
li $v0, 4 # Print the prompt
syscall
li $v0, 10 # Exit the program
syscall
.data
sign_integer: .asciiz "Enter signed integer part.\n"
decimal_num: .asciiz "Enter fraction as a binary string.\n"
nl: .asciiz "\n"
sign_bit: .asciiz "\nsign bit = "
dec_point: .asciiz "\nExponent in decimal = "
bits_float: .asciiz "\nAll bits of the floating point number are:\n"
float_point_num: .asciiz "\nThe floating point number is:\n"
.align 2
dec_bin_string: .space 128
store_dec_bin_string: .space 128
one: .asciiz "1"
zero: .asciiz "0"
white_space: .asciiz " "
complete: .asciiz "\n\nProgram Complete"