I-Unit Instruction Encodings; Multimedia And Variable Shifts; Multimedia And Variable Shift 1-Bit Opcode Extensions; Multimedia Opcode 7 Size 1 2-Bit Opcode Extensions - Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 3 REV 2.3 Manual

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
shown in
and a 2-bit field in bits 29:28 (x
shown in
Table 4-16.
Opcode
Bits
40:37
7
Table 4-17.
Opcode
Bits
40:37
7
3:310
) and 33 (z ) and a 1-bit reserved opcode extension in bit 32 (v
a b
Table 4-16. They also have a 2-bit opcode extension field in bits 35:34 (x
Table 4-17.

Multimedia and Variable Shift 1-bit Opcode Extensions

z z
a b
Bit Bit
36 33
0 Multimedia Size 1
0
1 Multimedia Size 2
0 Multimedia Size 4
1
1 Variable Shift

Multimedia Opcode 7 Size 1 2-bit Opcode Extensions

z z v x x
a b e 2a
Bit Bit Bit Bits Bits
36 33 32 35:34 29:28
0
1
0 0 0
2
3
) and most have a 2-bit field in bits 31:30 (x
2b
v
e
Bit 32
0
(Table 4-17)
(Table 4-18)
(Table 4-19)
(Table 4-20)
2b
0
0
1
2
3
0
1
2
3
0 unpack1.h
1 pmin1.u I2 pmax1.u
2 unpack1.l
3
0
1
2
3
e
1
x
2c
Bits 31:30
1 2
I2 mix1.r I2
I2
I2 mix1.l I2
psad1 I2
mux1 I3
Volume 3: Instruction Formats
) as
)
2a
) as
2c
3