Different classes of operations require different formats. The earlier
sections cover the common formats and the five separate modes have their own
section later:
+
* CR operations (crops),
* Arithmetic/Logical (termed "normal"),
* Load/Store Immediate,
* Load/Store Indexed,
* Branch-Conditional.
-## Definition of Reserved in this spec.
-
-For the new fields added in SVP64, instructions that have any of their
-fields set to a reserved value must cause an illegal instruction trap,
-to allow emulation of future instruction sets, or for subsets of SVP64 to
-be implemented in hardware and the rest emulated. This includes SVP64
-SPRs: reading or writing values which are not supported in hardware
-must also raise illegal instruction traps in order to allow emulation.
-Unless otherwise stated, reserved values are always all zeros.
-
-This is unlike OpenPower ISA v3.1, which in many instances does not
-require a trap if reserved fields are nonzero, instead relying on software
-to avoid use of such fields. Where the standard Power
-ISA definition is intended the red keyword `RESERVED` is used.
-
## Definition of "PO9-Prefixed"
Used in the context of "A PO9-Prefixed Word" this is a new area similar to EXT100-163
that is shared between SVP64-Single, SVP64, 32 Vectorizable new Opcode areas
-EXT200-231, one RESERVED 57-bit future Opcode space, and three new Unvectorizable
-RESERVED 32-bit future Opcode spaces. See [[sv/po9_encoding]].
+EXT232-263, and a 32-bit area, EXT900, that is also Vectorizable
+and SVP64-Single extensible in future. See [[sv/po9_encoding]].
## Definition of "SVP64-Prefix"
-A 24-bit RISC-Paradigm Encoding area for Loop-Augmentation of the following
+A 24-bit RISC-Paradigm Encoding area for Loop-Augmentation of the
+next
"Defined Word-instruction-instruction".
Used in the context of "An SVP64-Prefixed Defined Word-instruction", as separate and
-distinct from the 32-bit PO9-Prefix that holds a 24-bit SVP64 Prefix.
+distinct from the 32-bit PO9-Prefix that *holds* a 24-bit SVP64 Prefix.
## Definition of "Vectorizable" and "Unvectorizable"
which have no registers. `mtmsr` is also classed as Unvectorizable
because there is only one `MSR`.
-UnVectorized instructions are required to be detected as such if
+Unvectorized instructions are required to be detected as such if
Prefixed (either SVP64 or SVP64Single) and an Illegal Instruction
Trap raised.
*ISA Working Group note: Vectorized PackedSIMD instructions if ever proposed
should be considered Unvectorizable and except in extreme mitigating circumstances
-rejected outright.*
+rejected immediately.*
## Definition of Strict Element-Level Execution Order<a name="svp64_eeo"> </a>
Where Instruction Execution Order[^ieo] guarantees the appearance of sequential
execution of instructions, Simple-V requires a corresponding guarantee for Elements
-because in Simple-V Execution of Elements is synonymous with Execution of
-instructions.
+because in Simple-V "Execution of Elements" is synonymous with "Execution of
+instructions".
[^ieo]: Strict Instruction Execution Order is defined in Public v3.1 Book I Section 2.2