Volume 1, Part 1: Floating-point Programming Model
1:89
The Denormal/Unnormal Operand status flag is an IEEE-style sticky flag that is set if
the value is used in an arithmetic instruction and in an arithmetic calculation; e.g.
unorm*NaN doesn’t set this flag. As depicted in
, canonical
single/double/double-extended denormal, double-extended pseudo-denormal and
register format denormal encodings are a subset of the floating-point register format
unnormalized numbers.
Note:
The Floating-Point Exception fault/trap occurs only if an enabled floating-point
exception occurs during the processing of the instruction. Hence, setting a flag
bit of a status field to 1 in software will not cause an interruption. The status
Table 5-3.
Floating-point Status Register Field Description
Field
Bits
Description
traps.vd
0
Invalid Operation Floating-Point Exception fault (IEEE Trap) disabled when this
bit is set
traps.dd
1
Denormal/Unnormal Operand Floating-Point Exception fault disabled when this
bit is set
traps.zd
2
Zero Divide Floating-Point Exception fault (IEEE Trap) disabled when this bit is
set
traps.od
3
Overflow Floating-Point Exception trap (IEEE Trap) disabled when this bit is set
traps.ud
4
Underflow Floating-Point Exception trap (IEEE Trap) disabled when this bit is set
traps.id
5
Inexact Floating-Point Exception trap (IEEE Trap) disabled when this bit is set
sf0
18:6
Main status field
sf1
31:19
Alternate status field 1
sf2
44:32
Alternate status field 2
sf3
57:45
Alternate status field 3
rv
63:58
Reserved
Figure 5-3.
Floating-point Status Field Format
12 11 10 9
8
7
6
5
4
3
2
1
0
FPSR.sfx
flags
controls
i
u o z d v td
rc
pc
wre ftz
6
7
Table 5-4.
Floating-point Status Register’s Status Field Description
Field
Bits
Description
ftz
0
Flush-to-Zero mode
wre
1
Widest range exponent (see
)
pc
3:2
)
rc
5:4
)
td
6
Traps disabled
a
a. td is a reserved bit in the main status field, FPSR.sf0
v
7
Invalid Operation (IEEE Flag)
d
8
Denormal/Unnormal Operand
z
9
Zero Divide (IEEE Flag)
o
10
Overflow (IEEE Flag)
u
11
Underflow (IEEE Flag)
i
12
Inexact (IEEE Flag)
Summary of Contents for ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
Page 1: ......
Page 11: ...x Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 13: ...1 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 33: ...1 22 Volume 1 Part 1 Introduction to the Intel Itanium Architecture ...
Page 57: ...1 46 Volume 1 Part 1 Execution Environment ...
Page 147: ...1 136 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 149: ...1 138 Volume 1 Part 2 About the Optimization Guide ...
Page 191: ...1 180 Volume 1 Part 2 Predication Control Flow and Instruction Stream ...
Page 230: ......
Page 248: ...236 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 250: ...2 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 264: ...2 16 Volume 2 Part 1 Intel Itanium System Environment ...
Page 380: ...2 132 Volume 2 Part 1 Interruptions ...
Page 398: ...2 150 Volume 2 Part 1 Register Stack Engine ...
Page 486: ...2 238 Volume 2 Part 1 IA 32 Interruption Vector Descriptions ...
Page 750: ...2 502 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 754: ...2 506 Volume 2 Part 2 About the System Programmer s Guide ...
Page 796: ...2 548 Volume 2 Part 2 Interruptions and Serialization ...
Page 808: ...2 560 Volume 2 Part 2 Context Management ...
Page 842: ...2 594 Volume 2 Part 2 Floating point System Software ...
Page 850: ...2 602 Volume 2 Part 2 IA 32 Application Support ...
Page 862: ...2 614 Volume 2 Part 2 External Interrupt Architecture ...
Page 870: ...2 622 Volume 2 Part 2 Performance Monitoring Support ...
Page 891: ......
Page 1099: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault ...
Page 1295: ...3 396 Volume 3 Resource and Dependency Semantics ...
Page 1296: ......
Page 1302: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1494: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Page 1647: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Page 1884: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Page 1885: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Page 1886: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1898: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...