Intel 386 User Manual page 646

Table E-1. Instruction Set Summary (Sheet 8 of 19)
Instruction
STRING MANIPULATION INSTRUCTIONS
CMPS = Compare
1 0 1 0 0 1 1 w
byte word
INS = Input byte/word
0 1 1 0 1 1 0 w
from DX port
LODS = Load byte/word
1 0 1 0 1 1 0 w
to AL/AX/EAX
MOVS = Move byte word 1 0 1 0 0 1 0 w
OUTS = Output
0 1 1 0 1 1 1 w
byte/word to DX port
SCAS = Scan byte word 1 0 1 0 1 1 1 w
STOS = Store byte/word
1 0 1 0 1 0 1 w
from AL/AX/EX
XLAT = Translate String 1 1 0 1 0 1 1 1
REPEATED STRING MANIPULATION
Repeated by count in CX or ECX:
REPE CMPS = Compare string
find non-match 1 1 1 1 0 0 1 1
find match
1 1 1 1 0 0 1 0
REP INS = Input string 1 1 1 1 0 0 1 0
REP LODS = Load string 1 1 1 1 0 0 1 0
REP MOVS = Move
1 1 1 1 0 0 1 0
string
REP OUTS = Output
1 1 1 1 0 0 1 0
string
REPE SCAS = Scan
string 1 1 1 1 0 0 1 1
Find non-AL/AX/EAX
REPNE SCAS = Scan
string 1 1 1 1 0 0 1 0
Find AL/AX/EAX
REP STOS = Store
1 1 1 1 0 0 1 0
string
BIT MANIPULATION
BSF = scan bit forward 0 0 0 0 1 1 1 1
BSR = scan bit reverse 0 0 0 0 1 1 1 1
BT = test bit
register/memory,
0 0 0 0 1 1 1 1
immediate
Format
1 0 1 0 0 1 1 w
1 0 1 0 0 1 1 w
0 1 1 0 1 1 0 w
1 0 1 0 1 1 0 w
1 0 1 0 0 1 0 w
0 1 1 0 1 1 1 w
1 0 1 0 1 1 1 w
1 0 1 0 1 1 1 w
1 0 1 0 1 0 1 w
1 0 1 1 1 1 0 0 mod reg r/m
1 0 1 1 1 1 0 1 mod reg r/m
1 0 1 1 1 0 1 0 mod 1 0 0 r/m
INSTRUCTION SET SUMMARY
Clock Count
Real Pro-
Ad- tected
dress Virtual
Mode Ad-
or dress
Virtual Mode
8086
Mode
Clk Count
Virtual
10* 10*
8086 Mode
†30 17 10*/32**
5 5*
7 7**
†31 18 11*/33*
7* 7*
4* 4*
5* 5*
Clk Count 5 + 9n** 5 + 9n**
Virtual
5 + 9n** 5 + 9n**
8086 Mode
†31+6n 17 + 7n* 11 + 7n*/
32+ 6n*
5 + 6n* 5 + 6n*
7 + 4n* 7 + 4n**
†30+8n 16 + 8n* 10 + 8n*/
31+ 8n*
5 + 8n* 5 + 8n*
5 + 8n* 5 + 8n*
5 + 5n* 5 + 5n*
10 + 3n* 10 + 3n*
10 + 3n* 10 + 3n*
immed 3/6* 3/6*
8-bit data
Notes
Real Pro-
Ad- tected
dress Virtual
Mode Ad-
or dress
Virtual Mode
8086
Mode
b h
b s/t, h, m
b h
b h
b s/t, h, m
b h
b h
h
b h
b h
b s/t, h, m
b h
b h
b s/t, h, m
b h
b h
b h
b h
b h
b h
E-9