Shape *MakeLoop(BlockSet &Blocks, BlockSet& Entries, BlockSet &NextEntries) {
// Find the inner blocks in this loop. Proceed backwards from the entries until
// you reach a seen block, collecting as you go.
BlockSet InnerBlocks;
BlockSet Queue = Entries;
while (Queue.size() > 0) {
Block *Curr = *(Queue.begin());
Queue.erase(Queue.begin());
if (InnerBlocks.find(Curr) == InnerBlocks.end()) {
// This element is new, mark it as inner and remove from outer
InnerBlocks.insert(Curr);
Blocks.erase(Curr);
// Add the elements prior to it
for (BlockBranchMap::iterator iter = Curr->BranchesIn.begin(); iter != Curr->BranchesIn.end(); iter++) {
Queue.insert(iter->first);
}
}
}
assert(InnerBlocks.size() > 0);
for (BlockSet::iterator iter = InnerBlocks.begin(); iter != InnerBlocks.end(); iter++) {
Block *Curr = *iter;
for (BlockBranchMap::iterator iter = Curr->BranchesOut.begin(); iter != Curr->BranchesOut.end(); iter++) {
Block *Possible = iter->first;
if (InnerBlocks.find(Possible) == InnerBlocks.end() &&
NextEntries.find(Possible) == NextEntries.find(Possible)) {
NextEntries.insert(Possible);
}
}
}
PrintDebug("creating loop block:\n");
DebugDump(InnerBlocks, " inner blocks:");
DebugDump(Entries, " inner entries:");
DebugDump(Blocks, " outer blocks:");
DebugDump(NextEntries, " outer entries:");
// TODO: Optionally hoist additional blocks into the loop
LoopShape *Loop = new LoopShape();
Notice(Loop);
// Solipsize the loop, replacing with break/continue and marking branches as Processed (will not affect later calculations)
// A. Branches to the loop entries become a continue to this shape
for (BlockSet::iterator iter = Entries.begin(); iter != Entries.end(); iter++) {
Solipsize(*iter, Branch::Continue, Loop, InnerBlocks);
}
// B. Branches to outside the loop (a next entry) become breaks on this shape
for (BlockSet::iterator iter = NextEntries.begin(); iter != NextEntries.end(); iter++) {
Solipsize(*iter, Branch::Break, Loop, InnerBlocks);
}
// Finish up
Shape *Inner = Process(InnerBlocks, Entries, NULL);
Loop->Inner = Inner;
return Loop;
}
Shape *MakeEmulated(BlockSet &Blocks, Block *Entry, BlockSet &NextEntries) {
PrintDebug("creating emulated block with entry #%d and everything it can reach, %d blocks\n", Entry->Id, Blocks.size());
EmulatedShape *Emulated = new EmulatedShape;
Notice(Emulated);
Emulated->Entry = Entry;
for (BlockSet::iterator iter = Blocks.begin(); iter != Blocks.end(); iter++) {
Block *Curr = *iter;
Emulated->Blocks.insert(Curr);
Curr->Parent = Emulated;
Solipsize(Curr, Branch::Continue, Emulated, Blocks);
}
Blocks.clear();
return Emulated;
}
Shape *MakeMultiple(BlockSet &Blocks, BlockSet& Entries, BlockBlockSetMap& IndependentGroups, Shape *Prev, BlockSet &NextEntries) {
PrintDebug("creating multiple block with %d inner groups\n", IndependentGroups.size());
bool Fused = !!(Shape::IsSimple(Prev));
MultipleShape *Multiple = new MultipleShape();
Notice(Multiple);
BlockSet CurrEntries;
for (BlockBlockSetMap::iterator iter = IndependentGroups.begin(); iter != IndependentGroups.end(); iter++) {
Block *CurrEntry = iter->first;
BlockSet &CurrBlocks = iter->second;
PrintDebug(" multiple group with entry %d:\n", CurrEntry->Id);
DebugDump(CurrBlocks, " ");
// Create inner block
CurrEntries.clear();
CurrEntries.insert(CurrEntry);
for (BlockSet::iterator iter = CurrBlocks.begin(); iter != CurrBlocks.end(); iter++) {
Block *CurrInner = *iter;
// Remove the block from the remaining blocks
Blocks.erase(CurrInner);
// Find new next entries and fix branches to them
for (BlockBranchMap::iterator iter = CurrInner->BranchesOut.begin(); iter != CurrInner->BranchesOut.end();) {
Block *CurrTarget = iter->first;
BlockBranchMap::iterator Next = iter;
Next++;
if (CurrBlocks.find(CurrTarget) == CurrBlocks.end()) {
NextEntries.insert(CurrTarget);
Solipsize(CurrTarget, Branch::Break, Multiple, CurrBlocks);
}
iter = Next; // increment carefully because Solipsize can remove us
}
}
Multiple->InnerMap[CurrEntry] = Process(CurrBlocks, CurrEntries, NULL);
// If we are not fused, then our entries will actually be checked
if (!Fused) {
CurrEntry->IsCheckedMultipleEntry = true;
}
}
DebugDump(Blocks, " remaining blocks after multiple:");
// Add entries not handled as next entries, they are deferred
for (BlockSet::iterator iter = Entries.begin(); iter != Entries.end(); iter++) {
Block *Entry = *iter;
if (IndependentGroups.find(Entry) == IndependentGroups.end()) {
NextEntries.insert(Entry);
}
}
return Multiple;
}
Shape *MakeSimple(BlockSet &Blocks, Block *Inner, BlockSet &NextEntries) {
PrintDebug("creating simple block with block #%d\n", Inner->Id);
SimpleShape *Simple = new SimpleShape;
Notice(Simple);
Simple->Inner = Inner;
Inner->Parent = Simple;
if (Blocks.size() > 1) {
Blocks.erase(Inner);
GetBlocksOut(Inner, NextEntries, &Blocks);
BlockSet JustInner;
JustInner.insert(Inner);
for (BlockSet::iterator iter = NextEntries.begin(); iter != NextEntries.end(); iter++) {
Solipsize(*iter, Branch::Direct, Simple, JustInner);
}
}
return Simple;
}
Shape *MakeLoop(BlockSet &Blocks, BlockSet& Entries, BlockSet &NextEntries) {
// Find the inner blocks in this loop. Proceed backwards from the entries until
// you reach a seen block, collecting as you go.
BlockSet InnerBlocks;
BlockSet Queue = Entries;
while (Queue.size() > 0) {
Block *Curr = *(Queue.begin());
Queue.erase(Queue.begin());
if (!contains(InnerBlocks, Curr)) {
// This element is new, mark it as inner and remove from outer
InnerBlocks.insert(Curr);
Blocks.erase(Curr);
// Add the elements prior to it
for (BlockSet::iterator iter = Curr->BranchesIn.begin(); iter != Curr->BranchesIn.end(); iter++) {
Queue.insert(*iter);
}
#if 0
// Add elements it leads to, if they are dead ends. There is no reason not to hoist dead ends
// into loops, as it can avoid multiple entries after the loop
for (BlockBranchMap::iterator iter = Curr->BranchesOut.begin(); iter != Curr->BranchesOut.end(); iter++) {
Block *Target = iter->first;
if (Target->BranchesIn.size() <= 1 && Target->BranchesOut.size() == 0) {
Queue.insert(Target);
}
}
#endif
}
}
assert(InnerBlocks.size() > 0);
for (BlockSet::iterator iter = InnerBlocks.begin(); iter != InnerBlocks.end(); iter++) {
Block *Curr = *iter;
for (BlockBranchMap::iterator iter = Curr->BranchesOut.begin(); iter != Curr->BranchesOut.end(); iter++) {
Block *Possible = iter->first;
if (!contains(InnerBlocks, Possible)) {
NextEntries.insert(Possible);
}
}
}
#if 0
// We can avoid multiple next entries by hoisting them into the loop.
if (NextEntries.size() > 1) {
BlockBlockSetMap IndependentGroups;
FindIndependentGroups(NextEntries, IndependentGroups, &InnerBlocks);
while (IndependentGroups.size() > 0 && NextEntries.size() > 1) {
Block *Min = NULL;
int MinSize = 0;
for (BlockBlockSetMap::iterator iter = IndependentGroups.begin(); iter != IndependentGroups.end(); iter++) {
Block *Entry = iter->first;
BlockSet &Blocks = iter->second;
if (!Min || Blocks.size() < MinSize) { // TODO: code size, not # of blocks
Min = Entry;
MinSize = Blocks.size();
}
}
// check how many new entries this would cause
BlockSet &Hoisted = IndependentGroups[Min];
bool abort = false;
for (BlockSet::iterator iter = Hoisted.begin(); iter != Hoisted.end() && !abort; iter++) {
Block *Curr = *iter;
for (BlockBranchMap::iterator iter = Curr->BranchesOut.begin(); iter != Curr->BranchesOut.end(); iter++) {
Block *Target = iter->first;
if (Hoisted.find(Target) == Hoisted.end() && NextEntries.find(Target) == NextEntries.end()) {
// abort this hoisting
abort = true;
break;
}
}
}
if (abort) {
IndependentGroups.erase(Min);
continue;
}
// hoist this entry
PrintDebug("hoisting %d into loop\n", Min->Id);
NextEntries.erase(Min);
for (BlockSet::iterator iter = Hoisted.begin(); iter != Hoisted.end(); iter++) {
Block *Curr = *iter;
InnerBlocks.insert(Curr);
Blocks.erase(Curr);
}
IndependentGroups.erase(Min);
}
}
#endif
PrintDebug("creating loop block:\n");
DebugDump(InnerBlocks, " inner blocks:");
DebugDump(Entries, " inner entries:");
DebugDump(Blocks, " outer blocks:");
DebugDump(NextEntries, " outer entries:");
LoopShape *Loop = new LoopShape();
Notice(Loop);
// Solipsize the loop, replacing with break/continue and marking branches as Processed (will not affect later calculations)
// A. Branches to the loop entries become a continue to this shape
for (BlockSet::iterator iter = Entries.begin(); iter != Entries.end(); iter++) {
Solipsize(*iter, Branch::Continue, Loop, InnerBlocks);
}
// B. Branches to outside the loop (a next entry) become breaks on this shape
for (BlockSet::iterator iter = NextEntries.begin(); iter != NextEntries.end(); iter++) {
Solipsize(*iter, Branch::Break, Loop, InnerBlocks);
}
// Finish up
Shape *Inner = Process(InnerBlocks, Entries, NULL);
Loop->Inner = Inner;
return Loop;
}
