Reduced chained constant subtractions. (7a485d11) · Commits · Cianciosa, Mark / graph_framework

graph_framework/arithmetic.hpp

+39 −4

Original line number	Diff line number	Diff line
		@@ -919,6 +919,42 @@ namespace graph {
		pl2->get_left(),
		pl2->get_right());
		}
		// (c1 + a) - c2 -> c3 + a
		// c1 - (c2 + a) -> c3 + a
		auto la = add_cast(this->left);
		if (la.get()) {
		if (is_constant_combineable(la->get_left(), this->right)) {
		return (la->get_left() - this->right) + la->get_right();
		}
		}
		auto ra = add_cast(this->right);
		if (ra.get()) {
		if (is_constant_combineable(this->left, ra->get_left())) {
		return (this->left - ra->get_left()) + ra->get_right();
		}
		}

		// (c1 - a) - c2 -> c3 - a
		// (a - c3) - c2 -> a + c3
		auto ls = subtract_cast(this->left);
		if (ls.get()) {
		if (is_constant_combineable(ls->get_left(), this->right)) {
		return (ls->get_left() - this->right) - ls->get_right();
		} else if (is_constant_combineable(ls->get_right(),
		this->right)) {
		return -(ls->get_right() + this->right) - ls->get_left();
		}
		}
		// c1 - (c2 - a) -> c3 - a
		// c1 - (a - c2) -> c3 - a
		auto rs = subtract_cast(this->right);
		if (rs.get()) {
		if (is_constant_combineable(this->left, rs->get_left())) {
		return (this->left - rs->get_left()) - rs->get_right();
		} else if (is_constant_combineable(this->left, rs->get_right())) {
		return (this->left + rs->get_right()) - rs->get_left();
		}
		}

		// Common factor reduction. If the left and right are both muliply nodes check
		// for a common factor. So you can change ab - ac -> a*(b - c).
		@@ -938,7 +974,7 @@ namespace graph {
		lm->get_left()*lmra->get_left() - this->right);
		}
		}

		// c1(c2 - a) - c3 -> c4 - c1a
		auto lmrs = subtract_cast(lm->get_right());
		if (lmrs.get()) {
		if (is_constant_combineable(lm->get_left(),
		@@ -1077,7 +1113,6 @@ namespace graph {
		}

		// Chained subtraction reductions.
		auto ls = subtract_cast(this->left);
		if (ls.get()) {
		auto lrm = multiply_cast(ls->get_right());
		if (lrm.get() && rm.get()) {
		@@ -4666,8 +4701,8 @@ namespace graph {
		this->left->to_latex();
		}
		std::cout << " ";
		if (add_cast(this->right).get() \|\|
		subtract_cast(this->right).get()) {
		if (add_cast(this->middle).get() \|\|
		subtract_cast(this->middle).get()) {
		std::cout << "\\left(";
		this->middle->to_latex();
		std::cout << "\\right)";

graph_tests/arithmetic_test.cpp

+43 −0

Original line number	Diff line number	Diff line
		@@ -872,6 +872,49 @@ template<jit::float_scalar T> void test_subtract() {
		"Expected var_a");
		assert(common_var5_cast->get_left()->is_match(2.0/var_a - 3.0/var_b) &&
		"Expected 2/a - 3/b");

		auto constant_combine = (1.0 - var_a) - 2.0;
		auto constant_combine_cast = graph::subtract_cast(constant_combine);
		assert(constant_combine_cast.get() && "Expected a subtract node.");
		assert(constant_combine_cast->get_left()->evaluate().at(0) == static_cast<T> (-1.0) &&
		"Expected -1 on the left.");
		assert(constant_combine_cast->get_right()->is_match(var_a) &&
		"Expected a on the right.");
		auto constant_combine2 = (1.0 + var_a) - 2.0;
		auto constant_combine_cast2 = graph::add_cast(constant_combine2);
		assert(constant_combine_cast2.get() && "Expected a add node.");
		assert(constant_combine_cast2->get_left()->evaluate().at(0) == static_cast<T> (-1.0) &&
		"Expected -1 on the left.");
		assert(constant_combine_cast2->get_right()->is_match(var_a) &&
		"Expected a on the right.");
		auto constant_combine3 = (var_a - 1.0) - 2.0;
		auto constant_combine3_cast = graph::subtract_cast(constant_combine3);
		assert(constant_combine3_cast.get() && "Expected a subtract node.");
		assert(constant_combine3_cast->get_left()->evaluate().at(0) == static_cast<T> (-3.0) &&
		"Expected -1 on the left.");
		assert(constant_combine3_cast->get_right()->is_match(var_a) &&
		"Expected a on the right.");
		auto constant_combine4 = 2.0 - (1.0 - var_a);
		auto constant_combine4_cast = graph::subtract_cast(constant_combine4);
		assert(constant_combine4_cast.get() && "Expected a subtract node.");
		assert(constant_combine4_cast->get_left()->evaluate().at(0) == static_cast<T> (1.0) &&
		"Expected 1 on the left.");
		assert(constant_combine4_cast->get_right()->is_match(var_a) &&
		"Expected a on the right.");
		auto constant_combine5 = 2.0 - (1.0 + var_a);
		auto constant_combine5_cast = graph::add_cast(constant_combine5);
		assert(constant_combine5_cast.get() && "Expected an add node.");
		assert(constant_combine5_cast->get_left()->evaluate().at(0) == static_cast<T> (1.0) &&
		"Expected 1 on the left.");
		assert(constant_combine5_cast->get_right()->is_match(var_a) &&
		"Expected a on the right.");
		auto constant_combine6 = 2.0 - (var_a - 1.0);
		auto constant_combine6_cast = graph::subtract_cast(constant_combine6);
		assert(constant_combine6_cast.get() && "Expected a subtract node.");
		assert(constant_combine6_cast->get_left()->evaluate().at(0) == static_cast<T> (3.0) &&
		"Expected 3 on the left.");
		assert(constant_combine6_cast->get_right()->is_match(var_a) &&
		"Expected a on the right.");
		}

		//------------------------------------------------------------------------------