Volume 1, Part 1: Execution Environment
1:27
3.1.6
Instruction Pointer
The Instruction Pointer (IP) holds the address of the bundle which contains the current
executing instruction. The IP can be read directly with a mov ip instruction. The IP
cannot be directly written, but is incremented as instructions are executed, and can be
set to a new value with a branch. Because instruction bundles are 16 bytes, and are
16-byte aligned, the least significant 4 bits of IP are always zero. See
Encoding Overview” on page 1:38
. For IA-32 instruction set execution, IP holds the
zero extended 32-bit virtual linear address of the currently executing IA-32 instruction.
IA-32 instructions are byte-aligned, therefore the least significant 4 bits of IP are
preserved for IA-32 instruction set execution. See
“IA-32 Instruction Pointer” on
for IA-32 instruction set execution details.
3.1.7
Current Frame Marker
Each general register stack frame is associated with a frame marker. The frame marker
describes the state of the general register stack. The Current Frame Marker (CFM)
holds the state of the current stack frame. The CFM cannot be directly read or written
(see
The frame markers contain the sizes of the various portions of the stack frame, plus
three Register Rename Base values (used in register rotation). The layout of the frame
markers is shown in
and the fields are described in
On a call, the CFM is copied to the Previous Frame Marker field in the Previous Function
State register (see Section 3.1.8.12, “Previous Function State (PFS – AR 64)”). A new
value is written to the CFM, creating a new stack frame with no locals or rotating
registers, but with a set of output registers which are the caller’s output registers.
Additionally, all Register Rename Base registers (RRBs) are set to 0. See
“Modulo-scheduled Loop Support” on page 1:75
Figure 3-2.
Frame Marker Format
37
32 31
25 24
18 17
14 13
7 6
0
rrb.pr
rrb.fr
rrb.gr
sor
sol
sof
6
7
7
4
7
7
Table 3-2.
Frame Marker Field Description
Field
Bits
Description
sof
6:0
Size of stack frame
sol
13:7
Size of locals portion of stack frame
sor
17:14
Size of rotating portion of stack frame
(the number of rotating registers is 8 * sor)
rrb.gr
24:18
Register Rename Base for general registers
rrb.fr
31:25
Register Rename Base for floating-point registers
rrb.pr
37:32
Register Rename Base for predicate registers
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 ...