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// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
// SPDX-FileCopyrightText: Bradley M. Bell <bradbell@seanet.com>
// SPDX-FileContributor: 2023-23 Bradley M. Bell
# include <cppad/local/val_graph/tape.hpp>
/*
{xrst_begin val_dead_xam.cpp dev}
Dead Code Elimination Example
#############################
{xrst_literal
// BEGIN_C++
// END_C++
}
{xrst_end val_dead_xam.cpp}
*/
// BEGIN_C++
bool dead_xam(void)
{ bool ok = true;
//
// tape_t, Vector, addr_t, add_op_enum, sub_op_enum;
using CppAD::local::val_graph::tape_t;
using CppAD::local::val_graph::Vector;
using CppAD::local::val_graph::addr_t;
using CppAD::local::val_graph::op_enum_t;
op_enum_t add_op_enum = CppAD::local::val_graph::add_op_enum;
op_enum_t sub_op_enum = CppAD::local::val_graph::sub_op_enum;
//
// tape
tape_t<double> tape;
addr_t n_ind = 2;
addr_t index_of_nan = tape.set_ind(n_ind);
ok &= index_of_nan == n_ind;
//
// op_arg
Vector<addr_t> op_arg(2);
op_arg[0] = 0; // x[0]
op_arg[1] = 1; // x[1]
//
// dep_vec
Vector<addr_t> dep_vec(2);
//
// operators that are not used
tape.record_op(add_op_enum, op_arg); // x[0] + x[1]
tape.record_con_op(5.0); // 5.0
//
// operators that are used
dep_vec[0] = tape.record_op(add_op_enum, op_arg); // x[0] + x[1]
op_arg[0] = dep_vec[0]; // x[0] + x[1]
op_arg[1] = tape.record_con_op(4.0); // 4.0
dep_vec[1] = tape.record_op(sub_op_enum, op_arg); // x[0] + x[1] - 4.0
//
// set_dep
tape.set_dep( dep_vec );
//
// x
Vector<double> x(2);
x[0] = 5.0;
x[1] = 6.0;
//
// trace
bool trace = false;
//
// val_vec
Vector<double> val_vec;
//
// val_vec, ok
// before optimizing
val_vec.resize( tape.n_val() );
for(addr_t i = 0; i < n_ind; ++i)
val_vec[i] = x[i];
tape.eval(trace, val_vec);
ok &= tape.n_op() == 6;
ok &= tape.arg_vec().size() == 9;
ok &= tape.con_vec().size() == 3;
//
// dead_code, val_vec
tape.dead_code();
val_vec.resize( tape.n_val() );
tape.eval(trace, val_vec);
//
// ok
ok &= tape.n_op() == 4;
ok &= tape.arg_vec().size() == 6;
ok &= tape.con_vec().size() == 2;
//
// dep_vec
dep_vec = tape.dep_vec();
//
// y
Vector<double> y(2);
for(size_t i = 0; i < 2; ++i)
y[i] = val_vec[ dep_vec[i] ];
//
// ok
ok &= y[0] == x[0] + x[1];
ok &= y[1] == x[0] + x[1] - 4.0;
//
return ok;
}
// END_C++
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