Analog Devices VISUALDSP++ 3.5 Manual page 108

C/C++ Compiler Language Extensions
• + symbol
• ? symbol
• & symbol
1-70
expression must be one that would be valid as the
left-hand side of an assignment.
Example:
=d
The operand is both an input and an output. It must
appear as part of the second argument to the
construct. The allocated register is loaded with the
C/C++ expression value, the
cuted, and then the allocated register's new value is
stored back into the C/C++ expression. Therefore, as
with pure outputs, the C/C++ expression must be
one that is valid on the left-hand side of an assign-
ment.
Example:
+d
The operand is temporary. It must appear as part of
the third argument to the
is allocated as working space for the duration of the
template execution. The register's initial value
asm()
is undefined, and the register's final value is dis-
carded. The corresponding C/C++ expression is not
loaded into the register, but must be present. This
expression is normally specified using a literal zero.
Example:
?d
This operand constraint may be applied to inputs
and outputs. It indicates that the register allocated to
the input (or output) may not be one of the registers
that are allocated to the outputs (or inputs). This
operand constraint is used when one or more output
registers are set while one or more inputs are still to
VisualDSP++ 3.5 C/C++ Compiler and Library Manual
template is exe-
asm()
construct. A register
asm()
for ADSP-219x DSPs
asm()