bool
MIRGraph::removeSuccessorBlocks(MBasicBlock* start)
{
if (!start->hasLastIns())
return true;
start->mark();
// Mark all successors.
Vector<MBasicBlock*, 4, SystemAllocPolicy> blocks;
for (size_t i = 0; i < start->numSuccessors(); i++) {
if (start->getSuccessor(i)->isMarked())
continue;
if (!blocks.append(start->getSuccessor(i)))
return false;
start->getSuccessor(i)->mark();
}
for (size_t i = 0; i < blocks.length(); i++) {
MBasicBlock* block = blocks[i];
if (!block->hasLastIns())
continue;
for (size_t j = 0; j < block->numSuccessors(); j++) {
if (block->getSuccessor(j)->isMarked())
continue;
if (!blocks.append(block->getSuccessor(j)))
return false;
block->getSuccessor(j)->mark();
}
}
if (osrBlock()) {
if (osrBlock()->getSuccessor(0)->isMarked())
osrBlock()->mark();
}
// Remove blocks.
// If they don't have any predecessor
for (size_t i = 0; i < blocks.length(); i++) {
MBasicBlock* block = blocks[i];
bool allMarked = true;
for (size_t i = 0; i < block->numPredecessors(); i++) {
if (block->getPredecessor(i)->isMarked())
continue;
allMarked = false;
break;
}
if (allMarked) {
removeBlock(block);
} else {
MOZ_ASSERT(block != osrBlock());
for (size_t j = 0; j < block->numPredecessors(); ) {
if (!block->getPredecessor(j)->isMarked()) {
j++;
continue;
}
block->removePredecessor(block->getPredecessor(j));
}
// This shouldn't have any instructions yet.
MOZ_ASSERT(block->begin() == block->end());
}
}
if (osrBlock()) {
if (osrBlock()->getSuccessor(0)->isDead())
removeBlock(osrBlock());
}
for (size_t i = 0; i < blocks.length(); i++)
blocks[i]->unmark();
start->unmark();
return true;
}
