
4:484
Volume 4: IA-32 SSE Instruction Reference
4.11
Reserved Behavior and Software Compatibility
In many register and memory layout descriptions, certain bits are marked as
reserved
.
When bits are marked as reserved, it is essential for compatibility with future
processors that software treat these bits as having a future, though unknown, effect.
The behavior of reserved bits should be regarded as not only reserved, but
unpredictable. In general, reserved behavior may also be applied in other areas.
Software should follow these guidelines in dealing with reserved behavior:
• Do not depend on the states of any reserved fields when testing the values of
registers which contain such bits. Mask out the reserved fields before testing.
• Do not depend on the states of any reserved fields when storing to memory or to a
register.
• Do not depend on the ability to retain information written into any reserved fields.
• When loading a register, always load the reserved fields with the values indicated in
the documentation, if any, or reload them with values previously read from the
same register.
Note:
Avoid any software dependency upon the reserved state/behavior. Depending
upon reserved behavior will make the software dependent upon the unspecified
manner in which the processor handles this behavior and risks incompatibility
with future processors.
4.12
Notations
Besides opcodes, two kinds of notations are found which both describe information
found in the ModR/M byte:
1.
/digit:
(digit between 0 and 7) indicates that the instruction uses only the r/m
(register and memory) operand. The reg field contains the digit that provides an
extension to the instruction's opcode.
2.
/r
: indicates that the ModR/M byte of an instruction contains both a register
operand and an r/m operand.
In addition, the following abbreviations are used:
•
r32
:
Intel architecture 32-bit integer register.
•
xmm/m128
:Indicates a 128-bit multimedia register or a 128-bit memory location.
•
xmm/m64
: Indicates a 128-bit multimedia register or a 64-bit memory location.
•
xmm/m32:
Indicates a 128-bit multimedia register or a 32-bit memory location.
•
mm/m64
:
Indicates a 64-bit multimedia register or a 64-bit memory location.
Segment Override
(2EH,36H,3EH,26H,64H,65H)
Affects cacheability control instructions with mem. operand
Ignored by cacheability control instruction without mem operand
Repeat Prefix(F3H)
Reserved and may result in unpredictable behavior.
Repeat NE Prefix(F2H)
Reserved and may result in unpredictable behavior.
Lock Prefix (0F0H)
Generates an invalid opcode exception for all cacheability
instructions.
Table 4-8.
Cacheability Control Instruction Behavior with Prefixes
Prefix Type
Effect on SSE Instructions
Содержание ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
Страница 1: ......
Страница 11: ...x Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 12: ...1 1 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Part I Application Architecture Guide ...
Страница 13: ...1 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
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 ...
Страница 230: ......
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 ...