
Glossary-6
G2 PowerPC Core Reference Manual
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MOTOROLA
Floating-point unit.
The functional unit in the G2 processor responsible for
executing all floating-point instructions.
Flush.
An operation that causes a cache block to be invalidated and the data,
if modified, to be written to memory.
Folding.
See
Branch folding
.
Fraction.
In the binary representation of a floating-point number, the field
of the
significand
that lies to the right of its implied binary point.
G
General-purpose register
(GPR).
Any of the 32 registers in the
general-purpose register file. These registers provide the source
operands and destination results for all integer data manipulation
instructions. Integer load instructions move data from memory to
GPRs and store instructions move data from GPRs to memory.
Guarded.
The guarded attribute pertains to out-of-order execution. When a
page is designated as guarded, instructions and data cannot be
accessed out-of-order.
H
Harvard architecture.
An architectural model featuring separate caches
and other memory management resources for instructions and data.
Hashing.
An algorithm used in the
page table
search process.
I
IEEE 754.
A standard written by the Institute of Electrical and Electronics
Engineers that defines operations and representations of binary
floating-point numbers.
Illegal instructions.
A class of instructions that are not implemented for a
particular PowerPC processor. These include instructions not
defined by the PowerPC architecture. In addition, for 32-bit
implementations, instructions that are defined only for 64-bit
implementations are considered to be illegal instructions. For 64-bit
implementations instructions that are defined only for 32-bit
implementations are considered to be illegal instructions.
Implementation.
A particular processor that conforms to the PowerPC
architecture, but may differ from other architecture-compliant
implementations for example in design, feature set, and
implementation of
optional
features. The PowerPC architecture has
many different implementations.
F
Freescale Semiconductor, Inc.
n
.