Intel Itanium 9150M, Manual, Page: 303 / 420

3:294 Volume 3: Instruction Formats
4.1 Format Summary
All instructions in the instruction set are 41 bits in length. The leftmost 4 bits (40:37) of
each instruction are the major opcode.
Table 4-3 shows the major opcode assignments
for each of the 5 instruction types — ALU (A), Integer (I), Memory (M), Floating-point
(F), and Branch (B). Bundle template bits are used to distinguish among the 4 columns,
so the same major op values can be reused in each column.
Unused major ops (appearing as blank entries in Table 4-3 ) behave in one of four ways:
• Ignored major ops (white entries in Table 4-3 ) execute as
nop
instructions.
Table 4-2. Template Field Encoding and Instruction Slot Mapping
Template Slot 0 Slot 1 Slot 2
00 M-unit I-unit I-unit
01 M-unit I-unit I-unit
02 M-unit I-unit I-unit
03 M-unit I-unit I-unit
04 M-unit L-unit X-unit
a
05 M-unit L-unit X-unit
a
06
07
08
M-unit M-unit I-unit
09 M-unit M-unit I-unit
0A M-unit M-unit I-unit
0B M-unit M-unit I-unit
0C M-unit F-unit I-unit
0D M-unit F-unit I-unit
0E M-unit M-unit F-unit
0F M-unit M-unit F-unit
10 M-unit I-unit B-unit
11 M-unit I-unit B-unit
12 M-unit B-unit B-unit
13 M-unit B-unit B-unit
14
15
16
B-unit B-unit B-unit
17 B-unit B-unit B-unit
18 M-unit M-unit B-unit
19 M-unit M-unit B-unit
1A
1B
1C
M-unit F-unit B-unit
1D M-unit F-unit B-unit
1E
1F
a. The MLX template was formerly called MLI, and for compatibility, the X slot may encode break.i and nop.i in
addition to any X-unit instruction.