Intel Itanium 9150M, Manual

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3:310 Volume 3: Instruction Formats
4.3 I-Unit Instruction Encodings
4.3.1 Multimedia and Variable Shifts
All multimedia multiply/shift/max/min/mix/mux/pack/unpack and variable shift
instructions are encoded within major opcode 7 using two 1-bit opcode extension fields
in bits 36 (z
a
) and 33 (z
b
) and a 1-bit reserved opcode extension in bit 32 (v
e
) as
shown in Table 4-16 . They also have a 2-bit opcode extension field in bits 35:34 (x
2a
)
and a 2-bit field in bits 29:28 (x
2b
) and most have a 2-bit field in bits 31:30 (x
2c
) as
shown in Table 4-17 .
Table 4-16. Multimedia and Variable Shift 1-bit Opcode Extensions
Opcode
Bits
40:37
z
a
Bit
36
z
b
Bit
33
v
e
Bit 32
0 1
7
0
0 Multimedia Size 1 ( Table 4-17 )
1 Multimedia Size 2 ( Table 4-18 )
1
0 Multimedia Size 4 ( Table 4-19 )
1 Variable Shift ( Table 4-20 )
Table 4-17. Multimedia Opcode 7 Size 1 2-bit Opcode Extensions
Opcode
Bits
40:37
z
a
Bit
36
z
b
Bit
33
v
e
Bit
32
x
2a
Bits
35:34
x
2b
Bits
29:28
x
2c
Bits 31:30
0 1 2 3
7 0 0 0
0
0
1
2
3
1
0
1
2
3
2
0 unpack1.h I2 mix1.r I2
1 pmin1.u I2 pmax1.u I2
2 unpack1.l I2 mix1.l I2
3 psad1 I2
3
0
1
2
mux1 I3
3