B-21
INSTRUCTION FORMATS AND ENCODINGS
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Table B-14. MMX Instruction Formats and Encodings
Instruction and Format
Encoding
BWDQ
EMMS - Empty MMX state0000 1111:01110111
n/an/an/an/a
MOVD - Move doubleword
NNY N
reg to mmreg
0000 1111:01101110: 11 mmxreg reg
reg from mmxreg
0000 1111:01111110: 11 mmxreg reg
mem to mmxreg
0000 1111:01101110: mod mmxreg r/m
mem from mmxreg
0000 1111:01111110: mod mmxreg r/m
MOVQ - Move quadword
NNN Y
mmxreg2 to mmxreg1
0000 1111:01101111: 11 mmxreg1 mmxreg2
mmxreg2 from mmxreg10000 1111:01111111: 11 mmxreg1 mmxreg2
mem to mmxreg
0000 1111:01101111: mod mmxreg r/m
mem from mmxreg
0000 1111:01111111: mod mmxreg r/m
PACKSSDW
1
- Pack dword to
word data (signed with
saturation)
n/a OIn/a
mmxreg2 to mmxreg1
0000 1111:01101011: 11 mmxreg1 mmxreg2
memory to mmxreg
0000 1111:01101011: mod mmxreg r/m
PACKSSWB
1
- Pack word to
byte data (signed with
saturation)
O In/an/a
mmxreg2 to mmxreg1
0000 1111:01100011: 11 mmxreg1 mmxreg2
memory to mmxreg
0000 1111:01100011: mod mmxreg r/m
PACKUSWB
1
- Pack word to
byte data (unsigned with
saturation)
O In/an/a
mmxreg2 to mmxreg1
0000 1111:01100111: 11 mmxreg1 mmxreg2
memory to mmxreg
0000 1111:01100111: mod mmxreg r/m
PADD - Add with wrap-around
YYY N
mmxreg2 to mmxreg1
0000 1111: 111111gg: 11 mmxreg1 mmxreg2
memory to mmxreg
0000 1111: 111111gg: mod mmxreg r/m
PADDS - Add signed with
saturation
YYN N
mmxreg2 to mmxreg1
0000 1111: 111011gg: 11 mmxreg1 mmxreg2
memory to mmxreg
0000 1111: 111011gg: mod mmxreg r/m
