1:36
Volume 1, Part 1: Execution Environment
3.2
Memory
This section describes an Itanium architecture-based application program’s view of
memory. This includes a description of how memory is accessed, for both 32-bit and
64-bit applications. The size and alignment of addressable units in memory is also
given, along with a description of how byte ordering is handled.
The system view of memory and of virtual memory management is given in
“Addressing and Protection” in Volume 2
. The IA-32 instruction set view of memory
and virtual memory management is defined in
Section 10.6, “System Memory Model”
.
3.2.1
Application Memory Addressing Model
Memory is byte addressable and is accessed with 64-bit pointers. A 32-bit pointer
model without a hardware mode is supported architecturally. Pointers which are 32 bits
in memory are loaded and manipulated in 64-bit registers. Software must explicitly
convert 32-bit pointers into 64-bit pointers before use. For details on 32-bit addressing,
refer to
“32-bit Virtual Addressing” on page 2:71
3.2.2
Addressable Units and Alignment
Memory can be addressed in units of 1, 2, 4, 8, 10 and 16 bytes.
It is recommended that all addressable units be stored on their naturally aligned
boundaries. Hardware and/or operating system software may have support for
unaligned accesses, possibly with some performance cost. 10-byte floating-point values
should be stored on 16-byte aligned boundaries.
Bits within larger units are always numbered from 0 starting with the least-significant
bit. Quantities loaded from memory to general registers are always placed in the
least-significant portion of the register (loaded values are placed right justified in the
target general register).
Instruction bundles (three instructions per bundle) are 16-byte units that are always
aligned on 16-byte boundaries.
3.2.3
Byte Ordering
The UM.be bit in the User Mask controls whether loads and stores use little-endian or
big-endian byte ordering for Itanium architecture-based code. When the UM.be bit is 0,
larger-than-byte loads and stores are little endian (lower-addressed bytes in memory
correspond to the lower-order bytes in the register). When the UM.be bit is 1,
x2
33
Processor implements
mpy4
and
mpyshl4
instructions (see
instruction in
rv
63:34
Table 3-8.
CPUID Register 4 Fields (Continued)
Field
Bits
Description
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 ...