Volume 4: IA-32 SSE Instruction Reference
4:481
4.8
Data Formats
4.8.1
Memory Data Formats
The Intel SSE architecture introduces a new packed 128-bit data type which consists of
4 single-precision floating-point numbers. The 128 bits are numbered 0 through 127.
Bit 0 is the least significant bit (LSB), and bit 127 is the most significant bit (MSB).
Bytes in the new data type format have consecutive memory addresses. The ordering is
always little endian, that is, the bytes with the lower addresses are less significant than
the bytes with the higher addresses.
4.8.2
SSE Register Data Formats
Values in SSE registers have the same format as a 128-bit quantity in memory. They
have two data access modes: 128-bit access mode and 32-bit access mode. The data
type corresponds directly to the single-precision format in the IEEE standard.
gives the precision and range of this data type. Only the fraction part of the significand
is encoded. The integer is assumed to be 1 for all numbers except 0 and denormalized
finite numbers. The exponent of the single-precision data type is encoded in biased
format. The biasing constant is 127 for the single-precision format.
Table 4-3.
Results of Operations with NAN Operands
Source Operands
NaN Result
(invalid operation exception is masked)
An SNaN and a QNaN.
Src1 NaN (converted to QNaN if Src1 is an SNaN).
Two SNaNs.
Src1 NaN (converted to QNaN)
Two QNaNs.
Src1 QNaN
An SNaN and a real value.
The SNaN converted into a QNaN.
A QNaN and a real value.
The QNaN source operand.
An SNaN/QNaN value (for instructions
which take only one operand i.e.
RCPPS, RCPSS, RSQRTPS,
RSQRTSS)
The SNaN converted into a QNaN/the source QNaN.
Neither source operand is a NaN and a
floating-point invalid-operation
exception is signaled.
The default QNaN
real indefinite
.
Figure 4-11. Four Packed FP Data in Memory (at address 1000H)
0
2
1
6
3
4
5
7
9
8
13
10
11
12
15 14
Byte 0
Memory Address 1000d
Memory Address 1016d
Byte 15
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 ...