Intel 64 and IA-32 Architectures Software Developers Manual Volume 2B, Instruction Set Reference, N-Z

A-26 Vol. 2B

OPCODE MAP

A.5.2.4 Escape Opcodes with DB as First Byte

Table A-13 and A-14 contain maps for escape instruction opcodes that begin with

DBH. Table A-13 shows the map if the ModR/M byte is in the range of 00H-BFH. Here,

the value of bits 3-5 (the nnn field in Figure A-1) selects the instruction.

Table A-14 shows the map if the ModR/M byte is outside the range of 00H-BFH. Here,

the first digit of the ModR/M byte selects the table row and the second digit selects

the column.

Table A-13. DB Opcode Map When ModR/M Byte is Within 00H to BFH *

nnn Field of ModR/M Byte

000B 001B 010B 011B 100B 101B 110B 111B

FILD

dword-integer

FISTTP dword-

integer

FIST

dword-integer

FISTP

dword-integer

FLD

extended-real

FSTP

extended-real

NOTES:

All blanks in all opcode maps are reserved and must not be used. Do not depend on the operation of unde-

fined or reserved locations.

Table A-14. DB Opcode Map When ModR/M Byte is Outside 00H to BFH *

0 123456 7

C FCMOVNB