1. CS 301 Fall 2002 Assembly Instructions
Slide Set 4
9/20/2018

2. Symbolic Instructions 1 Arithmetic
ADD: Add
ADC: Add with carry
SUB: Subtract
SBB: Subtract with borrow
NEG: Negate
XADD: Exchange and add
INC: Increment by 1
DEC: Decrement by 1
MUL: Unsigned multiply
DIV: Unsigned divide
IMUL: Signed multiply
IDIV: Signed divide
9/20/2018

3. Symbolic Instructions 2 ASCII-BCD conversion
AAA: ASCII Adjust After Addition
AAS: ASCII Adjust After Subtraction
AAM: ASCII Adjust After Multiplication
AAD: ASCII Adjust Before Division
DAA: Decimal Adjust After Addition
DAS: Decimal Adjust After Subtraction
9/20/2018

4. Symbolic Instructions 3 Bit Shifting
RCL: Rotate Left Through Carry
RCR: Rotate Right Through Carry
ROL: Rotate Left
ROR: Rotate Right
SAL: Shift Algebraic Left (=SHL)
SAR: Shift Algebraic Right
SHL: Shift Logical Left (=SAL)
SHR: Shift Logical Right
SHLD: Shift Left Double
SHRD: Shift Right Double
9/20/2018

5. Symbolic Instructions 4 Comparison
BSF/BSR: Bit Scan
BT/BTC/BTR/BTS: Bit Test
CMP: Compare
CMPSn: Compare String
CMPXCHG: Compare and Exchange
CMPXCHG8B: Compare and Exchange
TEST: Test bits
9/20/2018

6. Symbolic Instructions 5 Data Transfer
LDS: Load DS register
LEA: Load Effective Address
LnS: Load nS register
LODS: Load String
MOV: Move Data
MOVSn: Move String
MOVSX: Move with Sign-Extend
MOVZX: Move with Zero-Extend
STOS: Store String
XCHG: Exchange
XLAT: Translate
9/20/2018

7. Symbolic Instructions 6 Flag Operations
CLC/STC: Clear/Set CF
CLD/STD: Clear/Set DF
CLI/STI: Clear/Set IF
CMC: Complement CF
LAHF: Load AH from Flags
SAHF: Store AH in Flags
POPF: Pop Flags Off Stack
PUSH: Push Flags On Stack
9/20/2018

8. Symbolic Instructions 7 Input/Output
IN: Input Byte or Word
OUT: Output Byte or Word
INSn: Input String
OUTSn: Output String
9/20/2018

9. Symbolic Instructions 8 Logical Operations
AND: Logical And
OR: Logical Or
NOT: Logical Not
XOR: Logical XOR
9/20/2018

10. Symbolic Instructions 9 Looping
LOOP: Loop Until Complete
LOOPE: Loop While Equal
LOOPZ: Loop While Zero
LOOPNE: Loop While Not Equal
LOOPNZ: Loop While Not Zero
9/20/2018

11. Symbolic Instructions 10 Stack Operations
ENTER: Make Stack Frame
LEAVE: Terminate Stack Frame
POP: Pop Word Off Stack
PUSH: Push Word On Stack
POPF: Pop Flags Off Stack
PUSHF: Push Flags On Stack
POPA: Pop All General Registers
PUSHA: Push All General Registers
9/20/2018

12. Symbolic Instructions 11 String Operators
CMPS: Compare String
LODS: Load String
MOVS: Move String
REP: Repeat String
REPE: Repeat While Equal
REPZ: Repeat While Zero
REPNE: Repeat While Not Equal
REPNZ: Repeat While Not Zero
SCAS: Scan String
STOS: Store String
9/20/2018

13. Symbolic Instructions 12 Transfer (Conditional) 1
INTO: Interrupt On Overflow
JA: Jump if Above
JAE: Jump if Above/Equal
JB: Jump if Below
JBE: Jump if Below/Equal
JC: Jump if Carry
JCXZ: Jump if CX is Zero
JE: Jump if Equal
JG: Jump if Greater
JGE: Jump if Greater/Equal
JL: Jump if Less
9/20/2018

14. Symbolic Instructions 13 Transfer (Conditional) 2
JLE: Jump if Less/Equal
JNA: Jump if Not Above
JNAE: Jump if Not Above/Equal
JNB: Jump if Not Below
JNBE: Jump if Not Below/Equal
JNC: Jump if No Carry
JNE: Jump if Not Equal
JNG: Jump if Not Greater
JNGE: Jump if Not Greater/Equal
JNL: Jump if Not Less
9/20/2018

15. Symbolic Instructions 14 Transfer (Conditional) 3
JNLE: Jump if Not Less/Equal
JNO: Jump if No Overflow
JNP: Jump if No Parity
JNS: Jump if No Sign
JNZ: Jump if Not Zero
JO: Jump if Overflow
JP: Jump if Parity
JPE: Jump if Parity Is Even
JPO: Jump if Parity Is Odd
JS: Jump if Sign
JZ: Jump if Zero
9/20/2018

16. Symbolic Instructions 15 Transfer (Unconditional)
CALL: Call a Procedure
INT: Interrupt
IRET: Interrupt Return
JMP: Jump
RET: Return
RETN/RETF: Return Near/Far
9/20/2018

17. Symbolic Instructions 16 Type Conversion
CBW: Convert Byte To Word
CDQ: Convert Doubleword to Quadword
CWD: Convert Word to DoubleWord
CWDE: Convert Word to Extended DoubleWord
9/20/2018

18. MOV – Move Data Flags: Affects no flags MOV reg/mem,reg/mem/imm
9/20/2018

19. ADD (and ADC/SUB/SBB)
Add, Add with Carry, Subtract, Subtract with borrow.
Flags: All affect AF,CF,OF,PF,SF, and ZF
ADD reg/mem, reg/mem/imm
ADC reg/mem, reg/mem/imm
SBB reg/mem, reg/mem/imm
SUB reg/mem, reg/mem/imm
9/20/2018

20. MUL - Multiply Unsigned Integers
Flags: Affects CF and OF. (AF,PF,SF, and ZF are undefined)
MUL reg/mem
Size of operand
Effect
8-bit
AX = AL * 8-bit operand
16-bit
DX:AX = AX * 16-bit operand
32-bit
EDX:EAX = EAX * 32-bit operand
9/20/2018

21. DIV - Divide Unsigned Integers IDIV – Divide Signed Integers
Flags: Affect AF,CF,OF,PF,SF, and ZF (all undefined)
DIV reg/mem
IDIV reg/mem
Size of operand
Operation
Quotient
Remainder
8-bit
AX/operand AL AH
16-bit
(DX:AX)/operand AX DX
32-bit
(EDX:EAX)/operand
EAX
EDX
9/20/2018

22. IMUL – Multiply Signed Integers
Flags: Affects CF and OF. (AF,PF,SF, and ZF are undefined)
Format
Effect
dest
source1
source2
IMUL
reg/mem8
AX = AL * source1
reg/mem16
DX:AX = AX * source1
reg/mem32
EDX:EAX = EAX * source1
reg
reg/mem/imm
dest *= source1
reg/mem
imm
dest = source1 * source2
9/20/2018

23. Some Examples
Assembled ADD instructions
math.asm
prime.asm
9/20/2018