//------------------------------DFS--------------------------------------------
// Perform DFS search. Setup 'vertex' as DFS to vertex mapping. Setup
// 'semi' as vertex to DFS mapping. Set 'parent' to DFS parent.
uint PhaseCFG::DFS( Tarjan *tarjan ) {
Block *b = _broot;
uint pre_order = 1;
// Allocate stack of size _num_blocks+1 to avoid frequent realloc
Block_Stack bstack(tarjan, _num_blocks+1);
// Push on stack the state for the first block
bstack.push(pre_order, b);
++pre_order;
while (bstack.is_nonempty()) {
if (!bstack.last_successor()) {
// Walk over all successors in pre-order (DFS).
Block *s = bstack.next_successor();
if (s->_pre_order == 0) { // Check for no-pre-order, not-visited
// Push on stack the state of successor
bstack.push(pre_order, s);
++pre_order;
}
}
else {
// Build a reverse post-order in the CFG _blocks array
_blocks.map(--_rpo_ctr, bstack.pop());
}
}
return pre_order;
}
// Perform DFS search. Setup 'vertex' as DFS to vertex mapping. Setup
// 'semi' as vertex to DFS mapping. Set 'parent' to DFS parent.
uint PhaseCFG::do_DFS(Tarjan *tarjan, uint rpo_counter) {
Block* root_block = get_root_block();
uint pre_order = 1;
// Allocate stack of size number_of_blocks() + 1 to avoid frequent realloc
Block_Stack bstack(tarjan, number_of_blocks() + 1);
// Push on stack the state for the first block
bstack.push(pre_order, root_block);
++pre_order;
while (bstack.is_nonempty()) {
if (!bstack.last_successor()) {
// Walk over all successors in pre-order (DFS).
Block* next_block = bstack.next_successor();
if (next_block->_pre_order == 0) { // Check for no-pre-order, not-visited
// Push on stack the state of successor
bstack.push(pre_order, next_block);
++pre_order;
}
}
else {
// Build a reverse post-order in the CFG _blocks array
Block *stack_top = bstack.pop();
stack_top->_rpo = --rpo_counter;
_blocks.map(stack_top->_rpo, stack_top);
}
}
return pre_order;
}
