bool dFlowControlBlock::ApplySubExpressionsElimination(dCIL& program)
{
bool ret = false;
const dCIL::dListNode* const lastNode = m_end->GetNext();
_ASSERTE (lastNode);
for (dCIL::dListNode* node = m_leader; node != lastNode; node = node->GetNext()) {
dTreeAdressStmt& stmt = node->GetInfo();
if (stmt.m_instruction == dTreeAdressStmt::m_assigment) {
dCIL::dListNode* next = NULL;
for (dCIL::dListNode* node1 = node->GetNext(); node1 != lastNode; node1 = next) {
dTreeAdressStmt& stmt1 = node1->GetInfo();
next = node1->GetNext();
if (stmt.m_arg0.m_label == stmt1.m_arg0.m_label) {
break;
}
if ((stmt.m_instruction == stmt1.m_instruction) && (stmt.m_operator == stmt1.m_operator) && (stmt.m_arg1.m_label == stmt1.m_arg1.m_label) && (stmt.m_arg2.m_label == stmt1.m_arg2.m_label)) {
for (dCIL::dListNode* node2 = node1->GetNext(); node2 != lastNode; node2 = node2->GetNext()) {
dTreeAdressStmt& stmt2 = node2->GetInfo();
if (stmt2.m_arg0.m_label == stmt1.m_arg0.m_label) {
ret = true;
stmt2.m_arg0.m_label = stmt.m_arg0.m_label;
}
if (stmt2.m_arg1.m_label == stmt1.m_arg0.m_label) {
ret = true;
stmt2.m_arg1.m_label = stmt.m_arg0.m_label;
}
if (stmt2.m_arg2.m_label == stmt1.m_arg0.m_label) {
ret = true;
stmt2.m_arg2.m_label = stmt.m_arg0.m_label;
}
}
if (stmt1.m_arg0.m_label[0] == 't') {
program.Remove(node1);
//Trace();
}
}
}
}
}
return ret;
}
bool dFlowControlBlock::ApplyCopyPropagation(dCIL& program)
{
bool ret = false;
const dCIL::dListNode* const lastNode = m_end->GetNext();
_ASSERTE (lastNode);
dCIL::dListNode* next = NULL;
for (dCIL::dListNode* node = m_leader; node != lastNode; node = next) {
dTreeAdressStmt& stmt = node->GetInfo();
next = node->GetNext();
if (stmt.m_instruction == dTreeAdressStmt::m_assigment) {
bool alive = true;
if (stmt.m_operator == dTreeAdressStmt::m_nothing) {
for (dCIL::dListNode* node1 = node->GetNext(); node1 != lastNode; node1 = node1->GetNext()) {
dTreeAdressStmt& stmt1 = node1->GetInfo();
switch (stmt1.m_instruction)
{
case dTreeAdressStmt::m_assigment:
{
if (stmt1.m_arg1.m_label == stmt.m_arg0.m_label) {
alive = false;
ret = true;
stmt1.m_arg1.m_label = stmt.m_arg1.m_label;
}
if (stmt1.m_arg2.m_label == stmt.m_arg0.m_label) {
alive = false;
ret = true;
stmt1.m_arg2.m_label = stmt.m_arg1.m_label;
}
break;
}
case dTreeAdressStmt::m_if:
_ASSERTE (0);
}
}
} else {
for (dCIL::dListNode* node1 = node->GetNext(); node1 != lastNode; node1 = node1->GetNext()) {
dTreeAdressStmt& stmt1 = node1->GetInfo();
switch (stmt1.m_instruction)
{
case dTreeAdressStmt::m_assigment:
{
if (stmt1.m_operator == dTreeAdressStmt::m_nothing) {
if (stmt1.m_arg1.m_label == stmt.m_arg0.m_label) {
alive = false;
ret = true;
stmt1.m_operator = stmt.m_operator;
stmt1.m_arg1.m_label = stmt.m_arg1.m_label;
stmt1.m_arg2.m_label = stmt.m_arg2.m_label;
}
}
break;
}
case dTreeAdressStmt::m_if:
{
if (program.m_conditinals[stmt.m_operator]) {
switch (stmt1.m_operator)
{
case dTreeAdressStmt::m_equal:
{
if (stmt1.m_arg1.m_label == "0") {
alive = false;
ret = true;
stmt1.m_operator = program.m_operatorComplement[stmt.m_operator];
stmt1.m_arg0.m_label = stmt.m_arg1.m_label;
stmt1.m_arg1.m_label = stmt.m_arg2.m_label;
}
break;
}
case dTreeAdressStmt::m_different:
{
if (stmt1.m_arg1.m_label == "0") {
alive = false;
ret = true;
stmt1.m_operator = stmt.m_operator;
stmt1.m_arg0.m_label = stmt.m_arg1.m_label;
stmt1.m_arg1.m_label = stmt.m_arg2.m_label;
}
break;
}
default:
break;
}
}
}
}
}
}
if (!alive && (stmt.m_arg0.m_label[0] == 't')) {
if (m_leader == node) {
m_leader = node->GetNext();
}
program.Remove(node);
}
} else if (stmt.m_instruction == dTreeAdressStmt::m_load) {
bool alive = true;
for (dCIL::dListNode* node1 = node->GetNext(); alive && (node1 != lastNode); node1 = node1->GetNext()) {
dTreeAdressStmt& stmt1 = node1->GetInfo();
alive |= stmt1.m_instruction != dTreeAdressStmt::m_store;
if (alive && (stmt1.m_instruction == dTreeAdressStmt::m_assigment) &&
(stmt1.m_operator == dTreeAdressStmt::m_nothing) && (stmt1.m_arg1.m_label == stmt.m_arg0.m_label)) {
alive = false;
ret = true;
stmt1.m_instruction = dTreeAdressStmt::m_load;
stmt1.m_arg1.m_label = stmt.m_arg1.m_label;
stmt1.m_arg2.m_label = stmt.m_arg2.m_label;
if (stmt.m_arg0.m_label[0] == 't') {
if (m_leader == node) {
m_leader = node->GetNext();
}
program.Remove(node);
}
}
}
}
}
return ret;
}
