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Aligned Operands
An architecture can impose a programming restriction on the placement of
operands. Typically, operands will be restricted to starting addresses
that are evenly divisible by the size of the object. This can assure
that any part of the operand never crosses a boundary of the size of the
object. The main advantage of Aligned Operands is that each fundamental
data type will be fully contained in a single line of memory. With
this restriction the chip does not have to concern itself with obtaining
an operand from portions of two different lines. Although this restricts
what operations the chip can perform, it eliminates the need for circuitry
that impeds the overall performance of the chip. For examle, without
this restriction, all unalligned oprands will have to spend two cycles
in B stage of the pipe line: one to handle each line that the data is within.
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