1:112
Volume 1, Part 1: IA-32 Application Execution Model in an Intel
®
Itanium
®
System Environment
IP{31:0} =disp16/32 + CSD.base
IP{63:32} = 0
The indirect form reads a 16/32-bit register location and then computes the Itanium
target address as follows:
IP{31:0} = [reg16/32] + CSD.base
IP{63:32} = 0
jmpe
targets are forced to be 16-byte aligned, and are constrained to the lower
4G-bytes of the 64-bit virtual address space due to limited IA-32 addressability. If there
are any pending IA-32 numeric exceptions,
jmpe
is nullified, and an IA-32 floating-point
exception fault is generated.
Transitions into the Itanium instruction set do not change the privilege level of the
processor.
6.2.1.3.2
Branch to IA Instruction
The
br.ia
instruction is used to unconditionally branch to the IA-32 instruction set.
IA-32 targets are specified by a 32-bit virtual address target (not an effective address).
The IA-32 virtual address is truncated to 32-bits. The
br.ia
branch hints should always
be set to predicted static taken. The processor transitions to the IA-32 instruction set as
follows:
IP{31:0} = BR[b]{31:0}
IP{63:32} = 0
EIP{31:0} = IP{31:0} - CSD.base
Transitions into the IA-32 instruction set do not change the privilege level of the
processor.
Software should ensure the code segment descriptor and selector are properly loaded
before issuing the branch. If the target EIP value exceeds the code segment limit or has
a code segment privilege violation, an IA-32 GPFault(0) exception is reported on the
target IA-32 instruction.
The processor does not ensure Itanium instruction set generated writes into the IA-32
instruction stream are observed by the processor. For details, see
. Before entering the IA-32 instruction set, Itanium architecture-based
software must ensure all prior register stack frames have been flushed to memory. All
registers left in the current and prior register stack frames are left in an undefined state
after IA-32 instruction set execution. Software can not rely on the value of these
registers across an instruction set transition. For details, see
6.2.1.4
IA-32 Operating Mode Transitions
As described in
“IA-32 Instruction Set Execution” on page 1:111
jmpe
,
br.ia
, and
rfi
instructions and interruptions can transition the processor between the two instruction
set modes. Transitions are allowed between the Itanium architecture and all major
IA-32 modes. As shown in
,
br.ia
and
rfi
will transition the processor from
the Itanium instruction set into IA-32 VM86, Real Mode or Protected Mode. While
jmpe
and interruptions will transition the processor from either IA-32 VM86, Real Mode or
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 ...