COMPILER TECHNIQUES FOR MATLAB PROGRAMS ... - CiteSeerX

information:
number of rows
number of columns
rank
intrinsic type
structure
maximum estimated value
minimum estimated value
Our inference mechanism considers only scalars, vectors, andtwo-dimensional matrices
hence, only two attributes are necessary for the representation of shape, namely
number of rows and number of columns.
The attribute structure is used for the structural inference, as described in Section 5.5.
Finally, the elds minimum and maximum estimated value are used to store and propagate
the value information used by ourvalue-propagation technique, described in Section 5.2.
All attribute elds, with the exception of the estimated values, are initialized as unknown.
The maximum and minimum estimated values are initialized as +1 and ;1
respectively. These attribute elds are lled during the inference phases and propagated
through the AST and the symbol table whenever a new attribute is synthesized.
These attribute elds are used by the inference mechanism to synthesize information.
In some cases, a node representing a variable in the AST and its corresponding instance in
the symbol table may have the same values for their attribute elds. This, however, is not
always the case. The node in the AST contains the information for the operand represented
by the variable, while the attribute elds in the symbol table contain the information for
the instance of the variable. Consider for example Statement S5 in Figure 3.3(b). The node
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