Volume 2, Part 2: Instruction Emulation and Other Fault Handlers
2:583
Instruction Emulation and Other Fault
Handlers
7
This chapter introduces several common emulation handlers that an Itanium
architecture-based operating system must support. A general overview is given for:
• Unaligned Reference Handler – emulation of misaligned memory references that
the processor hardware cannot handle, or has been configured to fault on.
• Unsupported Data Reference Handler – emulation of memory operations that the
processor hardware does not support. Examples are semaphore,
ldfe
or
stfe
operations to uncacheable memory.
• Illegal Dependency Fault Handler – this is a fatal condition that operating system
needs to provide error logging functionality for.
• Long Branch Handler – the Itanium processor does not implement the long branch
instruction. When encountered on the Itanium processor, long branches must be
emulated by the operating system.
Floating-point software assist emulation handlers are not discussed here, but are
presented in
Chapter 8, “Floating-point System Software.”
Additionally,
“Efficient Interruption Handling” on page 2:102
discusses more details about emulation
code in the Itanium architecture.
7.1
Unaligned Reference Handler
Misaligned memory references that are not supported by the processor cause Unaligned
Reference Faults. This behavior is implementation specific but typically occurs in cases
where the access crosses a cache line or page boundary. In cases where the operating
system chooses to emulate misaligned operations, some special cases need to be
considered:
• Emulation of control and data speculative loads as well as advanced check and
“regular” loads requires special attention. For details consult
“Unaligned Handler” on page 2:581
• Emulation of unaligned semaphores, especially when interacting with IA-32 code
require special attention. For details consult
Uncacheable and Misaligned Semaphores” on page 2:509
.
IA-32 programs do not use the Itanium architecture-based handler to support
unaligned references. The hardware that supports IA-32 execution provides the
appropriate behavior if alignment checking is disabled through EFLAGS.ac. If an
unaligned reference occurs in IA-32 code when EFLAGS.ac is set to enable alignment
checking, alignment faults are delivered to a different vector from the unaligned
reference handler. Specifically they are delivered to the
IA_32_Exception(AlignmentCheck) vector; see
Chapter 9, “IA-32 Interruption Vector
for details.
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 ...