template<class Base >

size_t optimize_binary_match	(	const CppAD::vector< struct optimize_old_variable > &	tape,
		size_t	current,
		size_t	npar,
		const Base *	par,
		const CppAD::vector< size_t > &	hash_table_var,
		unsigned short &	code
	)		`[inline]`

Check a binary operator for a complete match with a previous operator,.

A complete match means that the result of the previous operator can be used inplace of the result for current operator.

Parameters:

tape	is a vector that maps a variable index, in the old operation sequence, to an `optimize_old_variable` information record. Note that the index for this vector must be greater than or equal zero and less than `tape.size()`.

tape[i].op is the operator in the old operation sequence corresponding to the old variable index i. Assertion: NumRes(tape[i].op) > 0.

tape[i].arg for j < NumArg( tape[i].op ), tape[i].arg[j] is the j-th the argument, in the old operation sequence, corresponding to the old variable index i. Assertion: tape[i].arg[j] < i.

tape[i].new_var Suppose i <= current, j < NumArg( tape[i].op ), and k = tape[i].arg[j], and j corresponds to a varialbe for operator tape[i].op. It follows that tape[k].new_var has alread been set to the variable in the new operation sequence corresponding to the old variable index k. This means that the new_var value has been set for all the possible arguments that come before current.

Parameters:

current	is the index in the old operation sequence for the variable corresponding to the result for the current operator. Assertions: `current < tape.size(), NumRes( tape[current].op ) > 0.`
npar	is the number of paraemters corresponding to this operation sequence.
par	is a vector of length npar containing the parameters for this operation sequence; i.e., given a parameter index `i`, the corresponding parameter value is `par[i]`.

Parameters:

hash_table_var	is a vector with size CPPAD_HASH_TABLE_SIZE that maps a hash code to the corresponding variable index in the old operation sequence. All the values in this table must be less than current.
code	The input value of code does not matter. The output value of code is the hash code corresponding to this operation in the new operation sequence.

Returns:: If the return value is zero, no match was found. If the return value is greater than zero, it is the index of a new variable that can be used to replace the old variable.

Restrictions:: The binary operator must be an addition, subtraction, multiplication, division or power operator.

Definition at line 333 of file optimize.hpp.

Referenced by optimize().