
Volume 1, Part 1: IA-32 Application Execution Model in an Intel
®
Itanium
®
System Environment
1:133
Instruction set transitions do not automatically fence memory data references. To
ensure proper ordering software needs to take into account the following ordering
rules.
Transitions from Itanium instruction set to IA-32 instruction set
• All data dependencies are honored, IA-32 loads see the results of all prior Itanium
stores
• IA-32 stores (
release
) can not pass any prior Itanium load or store
• IA-32 loads (
acquire
) can pass prior Itanium unordered loads or any prior Itanium
store to a different address. Itanium architecture-based software can prevent IA-32
loads from passing prior Itanium loads and stores by issuing an
acquire
operation
(or
mf
) before the instruction set transition.
Transitions from IA-32 instruction set to Itanium instruction set
• All data dependencies are honored, Itanium loads see the results of all prior IA-32
stores
• Itanium stores or loads can not pass prior IA-32 loads (
acquire
)
• Itanium unordered stores or any Itanium load can pass prior IA-32 stores (
release
)
to a different address. Itanium architecture-based software can prevent Itanium
loads and stores from passing prior IA-32 stores by issuing a
release
operation (or
mf
) after the instruction set transition.
6.2.4
IA-32 Usage of Intel
®
Itanium
®
Registers
This section lists software considerations for the Itanium general and floating-point
registers, and the ALAT when interacting with IA-32 code.
6.2.4.1
Register Stack Engine
Software must ensure that all dirty registers in the register stack have been flushed to
the backing store using a
flushrs
instruction before starting IA-32 execution via either
the
br.ia
or
rfi
. Any dirty registers left in the current and prior register stack frames
are left in an undefined state. Software can not rely on the value of these registers
across an instruction set transition.
Once IA-32 instruction set execution is entered, the RSE is effectively disabled,
regardless of any RSE control register enabling conditions.
After exiting the IA-32 instruction set due to a
jmpe
instruction or interruption, all
stacked registers are marked as invalid and the number of clean registers is set to zero.
6.2.4.2
ALAT
IA-32 instruction set execution leaves the contents of the ALAT undefined. Software
cannot rely on ALAT state being preserved across an instruction set transition. On entry
to IA-32 code, existing entries in the ALAT are ignored. For details on the ALAT, refer to
Section 4.4.5.2, “Data Speculation and Instructions” on page 1:64
.
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 ...