bool foldConstants(BlockIndex blockIndex)
{
#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
dataLog("Constant folding considering Block #%u.\n", blockIndex);
#endif
BasicBlock* block = m_graph.m_blocks[blockIndex].get();
bool changed = false;
m_state.beginBasicBlock(block);
for (unsigned indexInBlock = 0; indexInBlock < block->size(); ++indexInBlock) {
NodeIndex nodeIndex = block->at(indexInBlock);
Node& node = m_graph[nodeIndex];
if (!m_state.isValid())
break;
bool eliminated = false;
switch (node.op()) {
case CheckArgumentsNotCreated: {
if (!isEmptySpeculation(
m_state.variables().operand(
m_graph.argumentsRegisterFor(node.codeOrigin)).m_type))
break;
ASSERT(node.refCount() == 1);
node.setOpAndDefaultFlags(Phantom);
eliminated = true;
break;
}
// FIXME: This would be a great place to remove CheckStructure's.
default:
break;
}
if (eliminated) {
changed = true;
continue;
}
m_state.execute(indexInBlock);
if (!node.shouldGenerate() || m_state.didClobber() || node.hasConstant())
continue;
JSValue value = m_state.forNode(nodeIndex).value();
if (!value)
continue;
Node phantom(Phantom, node.codeOrigin);
if (node.op() == GetLocal) {
NodeIndex previousLocalAccess = NoNode;
if (block->variablesAtHead.operand(node.local()) == nodeIndex
&& m_graph[node.child1()].op() == Phi) {
// We expect this to be the common case.
ASSERT(block->isInPhis(node.child1().index()));
previousLocalAccess = node.child1().index();
block->variablesAtHead.operand(node.local()) = previousLocalAccess;
} else {
ASSERT(indexInBlock > 0);
// Must search for the previous access to this local.
for (BlockIndex subIndexInBlock = indexInBlock; subIndexInBlock--;) {
NodeIndex subNodeIndex = block->at(subIndexInBlock);
Node& subNode = m_graph[subNodeIndex];
if (!subNode.shouldGenerate())
continue;
if (!subNode.hasVariableAccessData())
continue;
if (subNode.local() != node.local())
continue;
// The two must have been unified.
ASSERT(subNode.variableAccessData() == node.variableAccessData());
previousLocalAccess = subNodeIndex;
break;
}
if (previousLocalAccess == NoNode) {
// The previous access must have been a Phi.
for (BlockIndex phiIndexInBlock = block->phis.size(); phiIndexInBlock--;) {
NodeIndex phiNodeIndex = block->phis[phiIndexInBlock];
Node& phiNode = m_graph[phiNodeIndex];
if (!phiNode.shouldGenerate())
continue;
if (phiNode.local() != node.local())
continue;
// The two must have been unified.
ASSERT(phiNode.variableAccessData() == node.variableAccessData());
previousLocalAccess = phiNodeIndex;
break;
}
ASSERT(previousLocalAccess != NoNode);
}
}
ASSERT(previousLocalAccess != NoNode);
NodeIndex tailNodeIndex = block->variablesAtTail.operand(node.local());
if (tailNodeIndex == nodeIndex)
block->variablesAtTail.operand(node.local()) = previousLocalAccess;
else {
ASSERT(m_graph[tailNodeIndex].op() == Flush
|| m_graph[tailNodeIndex].op() == SetLocal);
}
}
phantom.children = node.children;
phantom.ref();
m_graph.convertToConstant(nodeIndex, value);
NodeIndex phantomNodeIndex = m_graph.size();
m_graph.append(phantom);
m_insertionSet.append(indexInBlock, phantomNodeIndex);
changed = true;
}
m_state.reset();
m_insertionSet.execute(*block);
return changed;
}
static complex float krn(void* _data, const double mpos[2])
{
struct krn_data* data = _data;
return phantom(data->N, data->el, mpos, data->kspace);
}
bool run()
{
bool changed = false;
AbstractState state(m_graph);
InsertionSet<NodeIndex> insertionSet;
for (BlockIndex blockIndex = 0; blockIndex < m_graph.m_blocks.size(); ++blockIndex) {
BasicBlock* block = m_graph.m_blocks[blockIndex].get();
if (!block)
continue;
if (!block->cfaFoundConstants)
continue;
state.beginBasicBlock(block);
for (unsigned indexInBlock = 0; indexInBlock < block->size(); ++indexInBlock) {
if (!state.isValid())
break;
state.execute(indexInBlock);
NodeIndex nodeIndex = block->at(indexInBlock);
Node& node = m_graph[nodeIndex];
if (!node.shouldGenerate()
|| m_graph.clobbersWorld(node)
|| node.hasConstant())
continue;
JSValue value = state.forNode(nodeIndex).value();
if (!value)
continue;
Node phantom(Phantom, node.codeOrigin);
if (node.op() == GetLocal) {
ASSERT(m_graph[node.child1()].op() == Phi);
ASSERT(!m_graph[node.child1()].hasResult());
ASSERT(block->variablesAtHead.operand(node.local()) == nodeIndex);
ASSERT(block->isInPhis(node.child1().index()));
block->variablesAtHead.operand(node.local()) = node.child1().index();
NodeIndex tailNodeIndex = block->variablesAtTail.operand(node.local());
if (tailNodeIndex == nodeIndex)
block->variablesAtTail.operand(node.local()) = node.child1().index();
else {
ASSERT(m_graph[tailNodeIndex].op() == Flush
|| m_graph[tailNodeIndex].op() == SetLocal);
}
}
phantom.children = node.children;
phantom.ref();
m_graph.convertToConstant(nodeIndex, value);
NodeIndex phantomNodeIndex = m_graph.size();
m_graph.append(phantom);
insertionSet.append(indexInBlock, phantomNodeIndex);
changed = true;
}
insertionSet.execute(*block);
state.reset();
}
return changed;
}
