Power ISA™ Version 2.03 - Power.org

Version 2.03
Appendix A. Assembler Extended Mnemonics
In order to make assembler language programs simpler
to write and easier to understand, a set of extended
mnemonics and symbols is provided for certain instructions.
This appendix defines extended mnemonics and
symbols related to instructions defined in Book III.
Assemblers should provide the extended mnemonics
and symbols listed here, and may provide others.
A.1 Move To/From Special Purpose Register Mnemonics
This section defines extended mnemonics for the
mtspr and mfspr instructions, including the Special
Purpose Registers (SPRs) defined in Book I and certain
privileged SPRs, and for the Move From Time
Base instruction defined in Book II.
The mtspr and mfspr instructions specify an SPR as a
numeric operand; extended mnemonics are provided
that represent the SPR in the mnemonic rather than
requiring it to be coded as an operand. Similar
extended mnemonics are provided for the Move From
Time Base instruction, which specifies the portion of
the Time Base as a numeric operand.
Note: mftb serves as both a basic and an extended
mnemonic. The Assembler will recognize an mftb mnemonic
with two operands as the basic form, and an
mftb mnemonic with one operand as the extended
form. In the extended form the TBR operand is omitted
and assumed to be 268 (the value that corresponds to
TB).
Programming Note
The extended mnemonics in Table 3 for SPRs
associated with the Performance Monitor facility
are based on the definitions in Appendix B.
Other versions of Performance Monitor facilities
used different sets of SPR numbers (all 32-bit PowerPC
processors used a different set, and some
early Power ISA processors used yet a different
set).
Appendix A. Assembler Extended Mnemonics
471