National Instruments AutoCode NI MATRIX - Manual (Page 139)

Chapter 5 Generated Code Architecture
© National Instruments Corporation 5-31 AutoCode Reference
Example 5-11 Local Variables Used to Allow Loops in Scalar Code Generation
Inputs: u;
Outputs: y;
float u(:), y(u.size), local_u(u.size), local_y(y.size);
integer i,j;
for i = 1:u.size do
local_u(i) = u(i);
endfor;
for i = 1:u.size do
for j = i:u.size do
local_y(i) = local_u(i) + local_u(j);
endfor;
endfor;
for i = 1:y.size do
y(i) = local_y(i);
endfor;
Although the generated code is not very efficient, the amount of code that
is generated for Example 5-11 is far less than if the local variables were not
used for the same algorithm.
Vectorized Code
AutoCode can generate vectorized code (refer to Chapter 6, Vectorized
Code Generation ) and at the most basic level, it means that arrays will be
used instead of scalar variables. Given that, AutoCode does not have to
translate the BlockScript inputs, outputs, and states into scalars, rather it
will generate arrays. As a result, when AutoCode is generating vectorized
code, the soft-script limitation does not apply. Therefore, if generating
vectorized code, Example 5-10 generates code, and the trick to use local
variable as shown in Example 5-11 is not needed.
Types of Loops
BlockScript provides two different types of loops. Each loop type has a
specific usage that effects what you are allowed to use within the loop
body.
• WHILE Loop—Always generate a rolled loop for both scalar and
vectorized code. A soft-subscript is never allowed to access inputs,
outputs, or states.