void LoopUnroller::unroll(otawa::CFG *cfg, BasicBlock *header, VirtualCFG *vcfg) {
VectorQueue<BasicBlock*> workList;
VectorQueue<BasicBlock*> loopList;
VectorQueue<BasicBlock*> virtualCallList;
genstruct::Vector<BasicBlock*> doneList;
typedef genstruct::Vector<Pair<VirtualBasicBlock*, Edge::kind_t> > BackEdgePairVector;
BackEdgePairVector backEdges;
bool dont_unroll = false;
BasicBlock *unrolled_from;
int start;
/* Avoid unrolling loops with LOOP_COUNT of 0, since it would create a LOOP_COUNT of -1 for the non-unrolled part of the loop*/
/*
if (header && (ipet::LOOP_COUNT(header) == 0)) {
dont_unroll = true;
}
*/
//if (header) dont_unroll = true;
start = dont_unroll ? 1 : 0;
for (int i = start; ((i < 2) && header) || (i < 1); i++) {
doneList.clear();
ASSERT(workList.isEmpty());
ASSERT(loopList.isEmpty());
ASSERT(doneList.isEmpty());
workList.put(header ? header : cfg->entry());
doneList.add(header ? header : cfg->entry());
genstruct::Vector<BasicBlock*> bbs;
while (!workList.isEmpty()) {
BasicBlock *current = workList.get();
if (LOOP_HEADER(current) && (current != header)) {
/* we enter another loop */
loopList.put(current);
/* add exit edges destinations to the worklist */
for (genstruct::Vector<Edge*>::Iterator exitedge(**EXIT_LIST(current)); exitedge; exitedge++) {
if (!doneList.contains(exitedge->target())) {
workList.put(exitedge->target());
doneList.add(exitedge->target());
}
}
} else {
VirtualBasicBlock *new_bb = 0;
if ((!current->isEntry()) && (!current->isExit())) {
/* Duplicate the current basic block */
new_bb = new VirtualBasicBlock(current);
new_bb->removeAllProp(&ENCLOSING_LOOP_HEADER);
new_bb->removeAllProp(&EXIT_LIST);
new_bb->removeAllProp(&REVERSE_DOM);
new_bb->removeAllProp(&LOOP_EXIT_EDGE);
new_bb->removeAllProp(&LOOP_HEADER);
new_bb->removeAllProp(&ENTRY);
/* Remember the call block so we can correct its destination when we have processed it */
if (VIRTUAL_RETURN_BLOCK(new_bb))
virtualCallList.put(new_bb);
if ((current == header) && (!dont_unroll)) {
if (i == 0) {
unrolled_from = new_bb;
} else {
UNROLLED_FROM(new_bb) = unrolled_from;
}
}
/*
if (ipet::LOOP_COUNT(new_bb) != -1) {
if (i == 0) {
new_bb->removeAllProp(&ipet::LOOP_COUNT);
}
else {
int old_count = ipet::LOOP_COUNT(new_bb);
new_bb->removeAllProp(&ipet::LOOP_COUNT);
ipet::LOOP_COUNT(new_bb) = old_count - (1 - start);
ASSERT(ipet::LOOP_COUNT(new_bb) >= 0);
}
}
*/
INDEX(new_bb) = idx;
idx++;
vcfg->addBB(new_bb);
bbs.add(current);
map.put(current, new_bb);
}
/* add successors which are in loop (including possible sub-loop headers) */
for (BasicBlock::OutIterator outedge(current); outedge; outedge++) {
if (outedge->target() == cfg->exit())
continue;
if (outedge->kind() == Edge::CALL)
continue;
if (ENCLOSING_LOOP_HEADER(outedge->target()) == header) {
// cout << "Test for add: " << outedge->target()->number() << "\n";
if (!doneList.contains(outedge->target())) {
workList.put(outedge->target());
doneList.add(outedge->target());
}
}
if (LOOP_EXIT_EDGE(outedge)) {
ASSERT(new_bb);
/* Connect exit edge */
VirtualBasicBlock *vdst = map.get(outedge->target());
new Edge(new_bb, vdst, outedge->kind());
}
}
}
}
while (!virtualCallList.isEmpty()) {
BasicBlock *vcall = virtualCallList.get();
BasicBlock *vreturn = map.get(VIRTUAL_RETURN_BLOCK(vcall), 0);
ASSERT(vreturn != 0);
VIRTUAL_RETURN_BLOCK(vcall) = vreturn;
}
while (!loopList.isEmpty()) {
BasicBlock *loop = loopList.get();
unroll(cfg, loop, vcfg);
}
/* Connect the internal edges for the current loop */
for (genstruct::Vector<BasicBlock*>::Iterator bb(bbs); bb; bb++) {
for (BasicBlock::OutIterator outedge(bb); outedge; outedge++) {
if (LOOP_EXIT_EDGE(outedge))
continue;
if (LOOP_HEADER(outedge->target()) && (outedge->target() != header))
continue;
if (outedge->target() == cfg->exit())
continue;
VirtualBasicBlock *vsrc = map.get(*bb, 0);
VirtualBasicBlock *vdst = map.get(outedge->target(), 0);
if (outedge->kind() == Edge::CALL) {
CFG *called_cfg = outedge->calledCFG();
int called_idx = INDEX(called_cfg);
CFG *called_vcfg = coll->get(called_idx);
Edge *vedge = new Edge(vsrc, called_vcfg->entry(), Edge::CALL);
CALLED_BY(called_vcfg).add(vedge);
ENTRY(called_vcfg->entry()) = called_vcfg;
CALLED_CFG(outedge) = called_vcfg; /* XXX: ??!? */
} else if ((outedge->target() != header) || ((i == 1) /* XXX && !dont_unroll XXX*/ )) {
new Edge(vsrc, vdst, outedge->kind());
} else {
backEdges.add(pair(vsrc, outedge->kind()));
}
}
}
if (i == start) {
/* Connect virtual entry edges */
if (header) {
for (BasicBlock::InIterator inedge(header); inedge; inedge++) {
if (Dominance::dominates(header, inedge->source()))
continue; /* skip back edges */
if (inedge->source() == cfg->entry())
continue;
VirtualBasicBlock *vsrc = map.get(inedge->source());
VirtualBasicBlock *vdst = map.get(header);
new Edge(vsrc, vdst, inedge->kind());
}
}
} else {
/* Connect virtual backedges from the first to the other iterations */
for (BackEdgePairVector::Iterator iter(backEdges); iter; iter++) {
VirtualBasicBlock *vdst = map.get(header);
new Edge((*iter).fst, vdst, (*iter).snd);
}
}
}
if (!header) {
/* add main entry edges */
for (BasicBlock::OutIterator outedge(cfg->entry()); outedge; outedge++) {
VirtualBasicBlock *vdst = map.get(outedge->target());
new Edge(vcfg->entry(), vdst, Edge::VIRTUAL_CALL);
}
/* add main exit edges */
for (BasicBlock::InIterator inedge(cfg->exit()); inedge; inedge++) {
VirtualBasicBlock *vsrc = map.get(inedge->source());
new Edge(vsrc, vcfg->exit(), Edge::VIRTUAL_RETURN);
}
}
}
/**
* Scan the CFG for finding exit and builds virtual edges with entry and exit.
* For memory-place and time purposes, this method is only called when the CFG
* is used (call to an accessors method).
*/
void CFG::scan(void) {
// Prepare data
typedef HashTable<BasicBlock *, BasicBlock *> map_t;
map_t map;
VectorQueue<BasicBlock *> todo;
todo.put(ent);
// Find all BB
_bbs.add(&_entry);
while(todo) {
BasicBlock *bb = todo.get();
ASSERT(bb);
// second case : calling jump to a function
if(map.exists(bb) || (bb != ent && ENTRY(bb)))
continue;
// build the virtual BB
BasicBlock *vbb = new VirtualBasicBlock(bb);
_bbs.add(vbb);
map.put(bb, vbb);
ASSERTP(map.exists(bb), "not for " << bb->address());
// resolve targets
for(BasicBlock::OutIterator edge(bb); edge; edge++) {
ASSERT(edge->target());
if(edge->kind() != Edge::CALL)
todo.put(edge->target());
}
}
// Relink the BB
BasicBlock *vent = map.get(ent, 0);
ASSERT(vent);
new Edge(&_entry, vent, Edge::VIRTUAL);
for(bbs_t::Iterator vbb(_bbs); vbb; vbb++) {
if(vbb->isEnd())
continue;
BasicBlock *bb = ((VirtualBasicBlock *)*vbb)->bb();
if(bb->isReturn())
new Edge(vbb, &_exit, Edge::VIRTUAL);
for(BasicBlock::OutIterator edge(bb); edge; edge++) {
// A call
if(edge->kind() == Edge::CALL) {
Edge *vedge = new Edge(vbb, edge->target(), Edge::CALL);
vedge->toCall();
}
// Pending edge
else if(!edge->target()) {
new Edge(vbb, 0, edge->kind());
}
// Possibly a not explicit call
else {
ASSERT(edge->target());
BasicBlock *vtarget = map.get(edge->target(), 0);
if(vtarget)
new Edge(vbb, vtarget, edge->kind());
else { // calling jump to a function
Edge *nedge = new Edge(vbb, edge->target(), Edge::CALL);
vbb->flags |= BasicBlock::FLAG_Call;
new Edge(vbb, &_exit, Edge::VIRTUAL);
}
}
}
}
_bbs.add(&_exit);
// Number the BB
for(int i = 0; i < _bbs.length(); i++) {
INDEX(_bbs[i]) = i;
_bbs[i]->_cfg = this;
}
flags |= FLAG_Scanned;
}