A-20
OPCODE MAP
Table A-17. DD Opcode Map When ModR/M Byte is Within 00H to BFH
1
NOTE:
1.All blanks in the opcode map are reserved and should not be used. Do not depend on the operation of
these undefined opcodes.
Table A-18 shows the opcode map if the accompanying ModR/M byte is outside the range of
00H to BFH. In this case the first digit of the ModR/M byte selects the row in the table and the
second digit selects the column.
Table A-18. DD Opcode Map When ModR/M Byte is Outside 00H to BFH
1
NOTE:
1.All blanks in the opcode map are reserved and should not be used. Do not depend on the operation of
these undefined opcodes.
nnn Field of ModR/M Byte (refer to Figure A-1)
000
001
010011100101110
111
FLD
double-real
FST
double-real
FSTP
double-real
FRSTOR
98/108bytes
FSAVE
98/108bytes
FSTSW
2 bytes
0
1
2
3
4
5
7
C
FFREE
ST(0)ST(1)ST(2)ST(3)ST(4)ST(5)ST(6)ST(7)
D
FST
ST(0)ST(1)ST(2)ST(3)ST(4)ST(5)ST(6)ST(7)
E
FUCOM
ST(0),ST(0)ST(1),ST(0)ST(2),ST(0)ST(3),ST(0)ST(4),ST(0)ST(5),ST(0)ST(6),ST(0)ST(7),ST(0)
F
8
9
A
B
C
D
E
F
C
D
FSTP
ST(0)ST(1)ST(2)ST(3)ST(4)ST(5)ST(6)ST(7)
E
FUCOMP
ST(0)ST(1)ST(2)ST(3)ST(4)ST(5)ST(6)ST(7)
F
