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Volume 1, Part 1: Application Programming Model
1:57
4.3.4
Predicate Register Transfers
Instructions are provided to transfer between the predicate register file and a general
register. These instructions operate in a “broadside” manner whereby multiple predicate
registers are transferred in parallel, such that predicate register N is transferred
to/from bit N of a general register.
The move to predicates instruction (
mov pr=
) loads multiple predicate registers from a
general register according to a mask specified by an immediate. The mask contains one
bit for each of PR 1 through PR 15 (PR 0 is hardwired to 1) and one bit for all of PR 16
through PR63 (the rotating predicates). A predicate register is written from the
corresponding bit in a general register if the corresponding mask bit is 1; if the mask bit
is 0 the predicate register is not modified.
The move to rotating predicates instruction (
mov pr.rot=
) copies 48 bits from an
immediate value into the 48 rotating predicates (PR 16 through PR 63). The immediate
value includes 28 bits, and is sign-extended. Thus PR 16 through PR 42 can be
independently set to new values, and PR 43 through PR 63 are all set to either 0 or 1.
The move from predicates instruction (
mov =pr
) transfers the entire predicate register
file into a general register target.
For all of these predicate register transfers, the predicate registers are accessed as
though the register rename base (CFM.rrb.pr) were 0. Typically, therefore, software
should clear CFM.rrb.pr before initializing rotating predicates.
4.4
Memory Access Instructions
Memory is accessed by simple load, store and semaphore instructions, which transfer
data to and from general registers or floating-point registers. The memory address is
specified by the contents of a general register.
Most load and store instructions can also specify base-address-register update. Base
update adds either an immediate value or the contents of a general register to the
address register, and places the result back in the address register. The update is done
after the load or store operation, i.e., it is performed as an address post-increment.
For highest performance, data should be aligned on natural boundaries. Within a
4K-byte boundary, accesses misaligned with respect to their natural boundaries will
always fault if UM.ac (alignment check bit in the User Mask register) is 1. If UM.ac is 0,
then an unaligned access will succeed if it is supported by the implementation;
otherwise it will cause an Unaligned Data Reference fault. Please see the
processor-specific documentation for further information. All memory accesses that
cross a 4K-byte boundary will cause an Unaligned Data Reference fault independent of
UM.ac. Additionally, all semaphore instructions will cause an Unaligned Data Reference
fault if the access is not aligned to its natural boundary, independent of UM.ac.
Accesses to memory quantities larger than a byte may be done in a big-endian or
little-endian fashion. The byte ordering for all memory access instructions is
determined by UM.be in the User Mask register. All IA-32 memory references are
performed little-endian.
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 ...
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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 ...
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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 ...
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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 ...