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3:164
Volume 3: Instruction Reference
lfetch
lfetch — Line Prefetch
Format:
(
qp
) lfetch.
lftype
.
lfhint
[
r
3
]
no_base_update_form
(
qp
) lfetch.
lftype
.
lfhint
[
r
3
],
r
2
reg_base_update_form
(
qp
) lfetch.
lftype
.
lfhint
[
r
3
],
imm
9
imm_base_update_form
(
qp
) lfetch.
lftype
.excl.
lfhint
[
r
3
]
no_base_update_form, exclusive_form
(
qp
) lfetch.
lftype
.excl.
lfhint
[
r
3
],
r
2
reg_base_update_form, exclusive_form
(
qp
) lfetch.
lftype
.excl.
lfhint
[
r
3
],
imm
9
imm_base_update_form, exclusive_form
Description:
The line containing the address specified by the value in GR
r
3
is moved to the highest
level of the data memory hierarchy. The value of the
lfhint
modifier specifies the locality
of the memory access; see
Section 4.4, “Memory Access Instructions” on page 1:57
for
details. The mnemonic values of
lfhint
are given in
.
The behavior of the memory read is also determined by the memory attribute
associated with the accessed page. See
Chapter 4, “Addressing and Protection” in
. Line size is implementation dependent but must be a power of two greater
than or equal to 32 bytes. In the exclusive form, the cache line is allowed to be marked
in an exclusive state. This qualifier is used when the program expects soon to modify a
location in that line. If the memory attribute for the page containing the line is not
cacheable, then no reference is made.
The completer,
lftype
, specifies whether or not the instruction raises faults normally
associated with a regular load.
defines these two options.
In the base update forms, after being used to address memory, the value in GR
r
3
is
incremented by either the sign-extended value in
imm
9
(in the imm_base_update_form)
or the value in GR
r
2
(in the reg_base_update_form). In the reg_base_update_form, if
the NaT bit corresponding to GR
r
2
is set, then the NaT bit corresponding to GR
r
3
is set
– no fault is raised.
In the reg_base_update_form and the imm_base_update_form, if the NaT bit
corresponding to GR
r
3
is clear, then the address specified by the value in GR
r
3
after
the post-increment acts as a hint to implicitly prefetch the indicated cache line. This
implicit prefetch uses the locality hints specified by
lfhint
. The implicit prefetch does not
affect program functionality, does not raise any faults, and may be ignored by the
implementation.
In the no_base_update_form, the value in GR
r
3
is not modified and no implicit prefetch
hint is implied.
If the NaT bit corresponding to GR
r
3
is set then the state of memory is not affected. In
the reg_base_update_form and imm_base_update_form, the post increment of GR
r
3
is
performed and prefetch is hinted as described above.
lfetch
instructions, like hardware prefetches, are not orderable operations, i.e., they
have no order with respect to prior or subsequent memory operations.
Table 2-37.
lftype
Mnemonic Values
lftype
Mnemonic
Interpretation
none
No faults are raised
fault
Raise faults
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Страница 33: ...1 22 Volume 1 Part 1 Introduction to the Intel Itanium Architecture ...
Страница 57: ...1 46 Volume 1 Part 1 Execution Environment ...
Страница 147: ...1 136 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 149: ...1 138 Volume 1 Part 2 About the Optimization Guide ...
Страница 191: ...1 180 Volume 1 Part 2 Predication Control Flow and Instruction Stream ...
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Страница 248: ...236 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 249: ...2 1 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Part I System Architecture Guide ...
Страница 250: ...2 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 264: ...2 16 Volume 2 Part 1 Intel Itanium System Environment ...
Страница 380: ...2 132 Volume 2 Part 1 Interruptions ...
Страница 398: ...2 150 Volume 2 Part 1 Register Stack Engine ...
Страница 486: ...2 238 Volume 2 Part 1 IA 32 Interruption Vector Descriptions ...
Страница 749: ...2 501 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Part II System Programmer s Guide ...
Страница 750: ...2 502 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 754: ...2 506 Volume 2 Part 2 About the System Programmer s Guide ...
Страница 796: ...2 548 Volume 2 Part 2 Interruptions and Serialization ...
Страница 808: ...2 560 Volume 2 Part 2 Context Management ...
Страница 842: ...2 594 Volume 2 Part 2 Floating point System Software ...
Страница 850: ...2 602 Volume 2 Part 2 IA 32 Application Support ...
Страница 862: ...2 614 Volume 2 Part 2 External Interrupt Architecture ...
Страница 870: ...2 622 Volume 2 Part 2 Performance Monitoring Support ...
Страница 891: ......
Страница 941: ...3 42 Volume 3 Instruction Reference cmp illegal_operation_fault PR p1 0 PR p2 0 Interruptions Illegal Operation fault ...
Страница 1099: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault ...
Страница 1191: ...3 292 Volume 3 Pseudo Code Functions Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 1295: ...3 396 Volume 3 Resource and Dependency Semantics ...
Страница 1296: ......
Страница 1302: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 1494: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Страница 1564: ...4 262 Volume 4 Base IA 32 Instruction Reference LES Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1565: ...Volume 4 Base IA 32 Instruction Reference 4 263 LFS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1568: ...4 266 Volume 4 Base IA 32 Instruction Reference LGS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1583: ...Volume 4 Base IA 32 Instruction Reference 4 281 LSS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1647: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Страница 1663: ...Volume 4 Base IA 32 Instruction Reference 4 361 SHL SHR Shift Instructions See entry for SAL SAR SHL SHR ...
Страница 1668: ...4 366 Volume 4 Base IA 32 Instruction Reference SIDT Store Interrupt Descriptor Table Register See entry for SGDT SIDT ...
Страница 1884: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Страница 1885: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Страница 1886: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 1898: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...