private void writeStatements(NodeBlock block)
{
for (NodeList.iterator iter = block.nodes.begin(); iter.more(); iter.next())
{
writeStatement(iter.node);
}
}
public static void CoalesceLoadsAndDeclarations(NodeGraph graph)
{
for (int i = 0; i < graph.numBlocks; i++)
{
NodeBlock block = graph[i];
for (NodeList.iterator iter = block.nodes.begin(); iter.more();)
{
DNode node = iter.node;
if (node.type == NodeType.DeclareLocal)
{
// Peephole next = store(this, expr)
DDeclareLocal local = (DDeclareLocal)node;
if (node.next.type == NodeType.Store)
{
DStore store = (DStore)node.next;
if (store.getOperand(0) == local)
{
local.replaceOperand(0, store.getOperand(1));
store.removeFromUseChains();
iter.next();
block.nodes.remove(iter);
continue;
}
}
}
iter.next();
}
}
}
private void rewriteBlock(NodeBlock block)
{
current_ = block;
iterator_ = block.nodes.begin();
while (iterator_.more())
{
// Iterate before accepting so we can replace the node.
iterator_.node.accept(this);
iterator_.next();
}
}
public void propagate()
{
for (int i = 0; i < graph_.numBlocks; i++)
{
block_ = graph_[i];
for (NodeList.iterator iter = block_.nodes.begin(); iter.more(); iter.next())
{
iter.node.accept(this);
}
}
}
private void renameBlock(NodeBlock block)
{
for (NodeList.iterator iter = block.nodes.begin(); iter.more();)
{
DNode node = iter.node;
switch (node.type)
{
case NodeType.TempName:
case NodeType.Jump:
case NodeType.JumpCondition:
case NodeType.Store:
case NodeType.Return:
case NodeType.IncDec:
case NodeType.DeclareStatic:
case NodeType.Switch:
{
iter.next();
continue;
}
case NodeType.DeclareLocal:
{
DDeclareLocal decl = (DDeclareLocal)node;
if (decl.var == null)
{
if (decl.uses.Count <= 1)
{
// This was probably just a stack temporary.
if (decl.uses.Count == 1)
{
DUse use = decl.uses.First.Value;
use.node.replaceOperand(use.index, decl.value);
}
block.nodes.remove(iter);
continue;
}
DTempName name = new DTempName(graph_.tempName());
node.replaceAllUsesWith(name);
name.init(decl.value);
block.nodes.replace(iter, name);
}
iter.next();
continue;
}
case NodeType.SysReq:
case NodeType.Call:
{
// Calls are statements or expressions, so we can't
// remove them if they have no uses.
if (node.uses.Count <= 1)
{
if (node.uses.Count == 1)
{
block.nodes.remove(iter);
}
else
{
iter.next();
}
continue;
}
break;
}
case NodeType.Constant:
{
// Constants can be deeply copied.
block.nodes.remove(iter);
continue;
}
default:
{
if (node.uses.Count <= 1)
{
// This node has one or zero uses, so instead of
// renaming it, we remove it from the instruction
// stream. This way the source printer will deep-
// print it instead of using its 'SSA' name.
block.nodes.remove(iter);
continue;
}
break;
}
}
// If we've reached here, the expression has more than one use
// and we have to wrap it in some kind of name, lest we
// duplicate it in the expression tree which may be illegal.
DTempName replacement = new DTempName(graph_.tempName());
node.replaceAllUsesWith(replacement);
replacement.init(node);
block.nodes.replace(iter, replacement);
iter.next();
}
}
private void rewriteBlock(NodeBlock block)
{
current_ = block;
iterator_ = block.nodes.begin();
while (iterator_.more())
{
// Iterate before accepting so we can replace the node.
iterator_.node.accept(this);
iterator_.next();
}
}