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Volume 3: Instruction Reference
3:157
ldf
ldf — Floating-point Load
Format:
(
qp
) ldf
fsz
.
fldtype
.
ldhint f
1
= [
r
3
]
no_base_update_form
(
qp
) ldf
fsz
.
fldtype
.
ldhint f
1
= [
r
3
],
r
2
reg_base_update_form
(
qp
) ldf
fsz
.
fldtype
.
ldhint f
1
= [
r
3
],
imm
9
imm_base_update_form
(
qp
) ldf8.
fldtype
.
ldhint f
1
= [
r
3
]
integer_form, no_base_update_form
(
qp
) ldf8.
fldtype
.
ldhint f
1
= [
r
3
],
r
2
integer_form, reg_base_update_form
(
qp
) ldf8.
fldtype
.
ldhint f
1
= [
r
3
],
imm
9
integer_form, imm_base_update_form
(
qp
) ldf.fill.
ldhint f
1
= [
r
3
]
fill_form, no_base_update_form
(
qp
) ldf.fill.
ldhint f
1
= [
r
3
],
r
2
fill_form, reg_base_update_form
(
qp
) ldf.fill.
ldhint f
1
= [
r
3
],
imm
9
fill_form, imm_base_update_form
Description:
A value consisting of
fsz
bytes is read from memory starting at the address specified by
the value in GR
r
3
. The value is then converted into the floating-point register format
and placed in FR
f
1
. See
Section 5.1, “Data Types and Formats” on page 1:85
for details
on conversion to floating-point register format. The values of the
fsz
completer are
fldtype
completer specifies special load operations, which are
described in
.
For the integer_form, an 8-byte value is loaded and placed in the significand field of FR
f
1
without conversion. The exponent field of FR
f
1
is set to the biased exponent for 2.0
63
(0x1003E) and the sign field of FR
f
1
is set to positive (0).
For the fill_form, a 16-byte value is loaded, and the appropriate fields are placed in FR
f
1
without conversion. This instruction is used for reloading a spilled register. See
Section 4.4.4, “Control Speculation” on page 1:60
for details.
In the base update forms, the value in GR
r
3
is added to either a signed immediate
value (
imm
9
) or a value from GR
r
2
, and the result is placed back in GR
r
3
. This base
register update is done after the load, and does not affect the load address. In the
reg_base_update_form, if the NaT bit corresponding to GR
r
2
is set, then the NaT bit
corresponding to GR
r
3
is set and no fault is raised.
Table 2-35.
fsz
Completers
fsz
Completer
Bytes Accessed
Memory Format
s
4 bytes
Single precision
d
8 bytes
Double precision
e
10 bytes
Extended precision
Table 2-36.
FP Load Types
fldtype
Completer
Interpretation
Special Load Operation
none
Normal load
s
Speculative load
Certain exceptions may be deferred rather than generating a fault.
Deferral causes NaTVal to be placed in the target register. The NaTVal
value is later used to detect deferral.
a
Advanced load
An entry is added to the ALAT. This allows later instructions to check for
colliding stores. If the referenced data page has a non-speculative
attribute, no ALAT entry is added to the ALAT and the target register is
set as follows: for the integer_form, the exponent is set to 0x1003E and
the sign and significand are set to zero; for all other forms, the sign,
exponent and significand are set to zero. The absence of an ALAT entry
is later used to detect deferral or collision.
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 ...