67 lines
989 B
ArmAsm
67 lines
989 B
ArmAsm
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! This programs checks if a number n>1 is prime
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! it checks for divisors from 2 to n-1, but does not terminate if n=1
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_EXIT = 1
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_WRITE = 4
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_STDOUT = 1
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.SECT .TEXT
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start:
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MOV BX,37 ! hardcoded number to check
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CALL check_prime
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PUSH 2
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PUSH _EXIT
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SYS
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! n is loaded from BX
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check_prime:
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MOV CX,2 ! number to start at for primality check
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l: CMP CX,BX
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JE end_is_prime ! if CX=BX, exit, n is prime
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! operate division (DX/CX) <=> (num/current)
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XOR DX,DX ! will store remainder
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MOV AX,BX
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DIV CX
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CMP DX,0 ! check if CX divides BX
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JE end_is_not_prime
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INC CX ! continue loop
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JMP l
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end_is_prime:
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PUSH 6
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PUSH is_prime
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PUSH _STDOUT
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PUSH _WRITE
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SYS
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SUB SP,8
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PUSH 0
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PUSH _EXIT
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SYS
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end_is_not_prime:
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PUSH 10
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PUSH not_prime
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PUSH _STDOUT
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PUSH _WRITE
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SYS
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SUB SP,8
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PUSH 1
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PUSH _EXIT
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SYS
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.SECT .DATA
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is_prime:
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.ASCII "prime\n"
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not_prime:
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.ASCII "not prime\n"
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.SECT .BSS
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