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Length: 1024 (0x400)
Types: TextFile
Names: »CMP16.MAC«
└─⟦01b5c9619⟧ Bits:30005906 Microsoft Multiplan v1.05 og HELP
└─ ⟦this⟧ »CMP16.MAC«
; ; ; Title 16-bit compare ; Name: CMP16 ; ; ; Purpose: Compare 2 16-bit signed or unsigned words and ; return the C,Z,S flags set or cleared ; ; Entry: Register HL = Minuend ; Register DE = Subtrahend ; ; Exit: Flags returned based on minuend - subtrahend ; If both the minuend and the subtrahend are 2's ; complement numbers, then use the Z and S ; flags; ; Else use the Z and C flags ; If minuend = subtrahend THEN ; Z=1,S=0,C=0 ; If minuend > subtrahend THEN ; Z=0,S=0,C=0 ; If minuend < subtrahend THEN ; Z=0,S=1,C=1 ; ; Registers used: AF,HL ; ; Time: 30 cycles if no overflow, else 57 cycles ; ; Size: Program 11 bytes ; ; ; CMP16: or a ;Clear carry sbc hl,de ;Subtract subtrahend from minuend ret po ;return if no overflow rra ;save carry in bit 7 xor 01000000b ;Complement bit 6 (sign bit) scf ;Enshure a non-zero result adc a,a ;Restore carry, complemented sign ; Zero flag = 0 for shure ret «eof»