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

Vol. 2B A-27

OPCODE MAP

A.5.2.5 Escape Opcodes with DC as First Byte

Table A-15 and A-16 contain maps for escape instruction opcodes that begin with

DCH. Table A-15 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-16 shows the map if the ModR/M byte is outside the range of 00H-BFH. In

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

selects the column.

Table A-15. DC Opcode Map When ModR/M Byte is Within 00H to BFH *

nnn Field of ModR/M Byte (refer to Figure A-1)

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

FADD double-

real

FMUL double-

real

FCOM

double-real

FCOMP

double-real

FSUB double-

real

FSUBR

double-real

FDIV double-

real

FDIVR

double-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-16. DC Opcode Map When ModR/M Byte is Outside 00H to BFH *

0 123456 7

CFADD