//Hoist det of loop.
//e.g: while (a=10,b+=3,c<a) {
// IR-List;
// }
//
//be replaced by
//
// a = 10;
// b += 3;
// while (c<a) {
// IR-List;
// a = 10;
// b += 3;
// }
bool IR_CFS_OPT::hoistLoop(IR ** head, IR * ir)
{
ASSERT0(ir->is_dowhile() || ir->is_whiledo() || ir->is_doloop());
ASSERT(LOOP_det(ir), ("DET is NULL"));
IR * det = LOOP_det(ir);
INT i = 0;
while (det != NULL) {
i++;
det = det->get_next();
}
IR * new_list = NULL, * new_body_list = NULL;
if (i > 1) {
det = LOOP_det(ir);
while (i > 1) {
IR * c = det;
ASSERT(c->is_stmt(), ("Non-stmt ir should be remove "
"during reshape_ir_tree()"));
det = det->get_next();
xcom::remove(&LOOP_det(ir), c);
xcom::add_next(&new_list, c);
i--;
}
new_body_list = m_ru->dupIRTreeList(new_list);
xcom::insertbefore(head, ir, new_list);
xcom::add_next(&LOOP_body(ir), new_body_list);
return true;
}
return false;
}
/* Hoist det of loop.
e.g: while (a=10,b+=3,c<a) {
IR-LIST;
}
be replaced by
a = 10;
b += 3;
while (c<a) {
IR-LIST;
a = 10;
b += 3;
} */
bool IR_CFS_OPT::hoist_loop(IR ** head, IR * ir)
{
IS_TRUE(IR_type(ir)==IR_DO_WHILE ||
IR_type(ir)==IR_WHILE_DO ||
IR_type(ir)==IR_DO_LOOP, ("need LOOP"));
IS_TRUE(LOOP_det(ir), ("DET is NULL"));
IR * det = LOOP_det(ir);
INT i = 0;
while (det != NULL) {
i++;
det = IR_next(det);
}
IR * new_list = NULL, * new_body_list = NULL;
if (i > 1) {
det = LOOP_det(ir);
while (i > 1) {
IR * c = det;
IS_TRUE(c->is_stmt(), ("Non-stmt ir should be remove "
"during reshape_ir_tree()"));
det = IR_next(det);
remove(&LOOP_det(ir), c);
add_next(&new_list, c);
i--;
}
new_body_list = m_ru->dup_irs_list(new_list);
insertbefore(head, ir, new_list);
add_next(&LOOP_body(ir), new_body_list);
return true;
}
return false;
}
//Control flow struct optimizations.
//Transform follow struct to do-while loop
//
// LABEL:
// IR-List
// IF DET
// GOTO LABEL
// ...(DEAD CODE)
// ELSE
// FALSE-PART
// ENDIF
//
//is replace by
//
// DO {
// IR-List
// } WHILE DET
// FALSE-PART
bool IR_CFS_OPT::transformToDoWhile(IR ** head, IR * ir)
{
ASSERT(head != NULL && *head != NULL, ("invalid parameter"));
if (!ir->is_lab()) { return false; }
for (IR * t = ir; t != NULL; t = t->get_next()) {
if (!t->is_if()) { continue; }
if (IF_truebody(t) != NULL &&
IF_truebody(t)->is_goto() &&
isSameLabel(LAB_lab(ir), GOTO_lab(IF_truebody(t)))) {
//Start transform.
IR * dowhile = m_ru->allocIR(IR_DO_WHILE);
LOOP_det(dowhile) = m_ru->dupIRTree(LOOP_det(t));
IR * if_stmt = t;
t = ir->get_next();
while (t != NULL && t != if_stmt) {
IR * c = t;
t = t->get_next();
xcom::remove(head, c);
xcom::add_next(&LOOP_body(dowhile), c);
}
ASSERT(t == if_stmt, ("illegal IR layout"));
xcom::remove(head, if_stmt);
if (IF_falsebody(if_stmt)) {
xcom::add_next(&dowhile, IF_falsebody(if_stmt));
IF_falsebody(if_stmt) = NULL;
}
xcom::insertafter(&ir, dowhile);
m_ru->freeIRTree(if_stmt); //free IF
xcom::remove(head, ir);
m_ru->freeIRTree(ir); //free LABEL
return true;
}
}
return false;
}
/*
Control flow struct optimizations.
Transform follow struct to do-while loop
LABEL:
IR-LIST
IF DET
GOTO LABEL
...(DEAD CODE)
ELSE
FALSE-PART
ENDIF
is replace by
DO {
IR-LIST
} WHILE DET
FALSE-PART
*/
bool IR_CFS_OPT::trans_to_do_while_loop(IR ** head, IR * ir)
{
IS_TRUE(head != NULL && *head != NULL, ("invalid parameter"));
if (ir->is_lab()) {
IR * t = ir;
LABEL_INFO * li = LAB_lab(ir);
while (t != NULL) {
if (IR_type(t) == IR_IF) {
if (IF_truebody(t) != NULL &&
IR_type(IF_truebody(t)) == IR_GOTO &&
is_same_label(LAB_lab(ir), GOTO_lab(IF_truebody(t)))) {
//start transform...
IR * dowhile = m_ru->new_ir(IR_DO_WHILE);
LOOP_det(dowhile) = m_ru->dup_irs(LOOP_det(t));
IR * if_stmt = t;
t = IR_next(ir);
while (t != NULL && t != if_stmt) {
IR * c = t;
t = IR_next(t);
remove(head, c);
add_next(&LOOP_body(dowhile), c);
}
IS_TRUE(t == if_stmt, ("???"));
remove(head, if_stmt);
if (IF_falsebody(if_stmt)) {
add_next(&dowhile, IF_falsebody(if_stmt));
IF_falsebody(if_stmt) = NULL;
}
insertafter(&ir, dowhile);
m_ru->free_irs(if_stmt); //free IF
remove(head, ir);
m_ru->free_irs(ir); //free LABEL
return true;
}
}
t = IR_next(t);
}
}
return false;
}
bool IR_CFS_OPT::CfsOpt(
IN OUT IR ** ir_list,
SimpCtx const& sc)
{
bool change = false;
for (IR * ir = *ir_list; ir != NULL;) {
if (transformToDoWhile(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (ir->is_if() && transformIf1(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (ir->is_if() && transformIf2(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (ir->is_if() && transformIf3(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
switch (ir->get_code()) {
case IR_IF:
if (hoistIf(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (CfsOpt(&IF_truebody(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
if (CfsOpt(&IF_falsebody(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
break;
case IR_DO_WHILE:
case IR_WHILE_DO:
case IR_DO_LOOP:
if (hoistLoop(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (CfsOpt(&LOOP_body(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
break;
case IR_SWITCH:
if (CfsOpt(&SWITCH_body(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
break;
default:;
} //end switch
ir = ir->get_next();
}
return change;
}
bool IR_CFS_OPT::perform_cfs_optimization(IN OUT IR ** ir_list,
IN SIMP_CTX const& sc)
{
bool change = false;
for (IR * ir = *ir_list; ir != NULL;) {
if (trans_to_do_while_loop(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (IR_type(ir) == IR_IF && trans_if1(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (IR_type(ir) == IR_IF && trans_if2(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (IR_type(ir) == IR_IF && trans_if3(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
switch (IR_type(ir)) {
case IR_IF:
if (hoist_if(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (perform_cfs_optimization(&IF_truebody(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
if (perform_cfs_optimization(&IF_falsebody(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
break;
case IR_DO_WHILE:
case IR_WHILE_DO:
case IR_DO_LOOP:
if (hoist_loop(ir_list, ir)) {
change = true;
ir = *ir_list;
continue;
}
if (perform_cfs_optimization(&LOOP_body(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
break;
case IR_SWITCH:
if (perform_cfs_optimization(&SWITCH_body(ir), sc)) {
change = true;
ir = *ir_list;
continue;
}
break;
default:;
} //end switch
ir = IR_next(ir);
}
return change;
}
