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2:146
Volume 2, Part 1: Register Stack Engine
6.7
RSE Behavior on Interruptions
When the processor raises an interruption, the current register stack frame remains
unchanged. If PSR.ic is one, the valid bit in the Interruption Function State register
(IFS.v) is cleared. When the IFS.v bit is clear, the contents of the interruption frame
marker field (IFS.ifm) are undefined.
While an interruption handler is running and the RSE is in store/load intensive or eager
mode, the RSE continues spilling/filling registers to/from the backing store on behalf of
the interrupted context as long as the registers are not part of the current frame as
defined by CFM.
A sequence of mandatory RSE loads or stores (from
alloc
,
br.ret
,
flushrs
,
loadrs
and
rfi
) can be interrupted by an external interrupt.
When PSR.ic is 0, faults taken on mandatory RSE operations may not be recoverable.
6.8
RSE Behavior with an Incomplete Register Frame
The current register frame is considered
incomplete
when one of the mandatory RSE
loads after a br.ret or a rfi faults, leaving BSPSTORE pointing to a location above BSP
(i.e., RSE.ndirty_words is negative). The frame becomes complete when
RSE.ndirty_words becomes non-negative, either by executing a cover instruction, or by
handling the fault and completing the original sequence of mandatory RSE loads.
When the current frame is incomplete the following instructions have undefined
behavior:
alloc
,
br.call
,
brl.call
,
br.ret
,
flushrs
,
loadrs
, and move to
BSPSTORE. Software must guarantee that the current frame is complete before
executing these instructions.
6.9
RSE and ALAT Interaction
The ALAT (see
“Data Speculation” on page 1:63
) uses physical register addresses to
track advanced loads. RSE.BOF may only change as the result of a
br.call
(by
CFM.sol),
cover
(by CFM.sof),
br.ret
(by AR[PFM].sol) or
rfi
(by CR[IFS].ifm.sof
when CR[IFS].v =1). This ensures, for ALAT invalidation purposes, that hardware does
not update virtual to physical register address mapping, unless explicitly instructed to
do so by software.
When software performs backing store switches that could cause program values to be
placed in different physical registers, then the ALAT must be explicitly invalidated with
the
invala
instruction. Typically this happens as part of a process or thread context
switch, longjmp or call stack unwind, when software re-writes AR[BSPSTORE], but
cannot guarantee that RSE.BOF was preserved.
A stacked register is said to be
deallocated
when an
alloc
,
br.ret
, or
rfi
instruction
changes the top of the current frame such that the register is no longer part of the
current frame. Once a stacked register is deallocated, its value, its corresponding NaT
bit, and its ALAT state are undefined. If that register is subsequently made part of the
Содержание ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
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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 ...