public static void FindLoops(LBlock[] blocks)
{
// Mark backedges and headers.
for (int i = 1; i < blocks.Length; i++)
{
LBlock block = blocks[i];
for (int j = 0; j < block.numSuccessors; j++)
{
LBlock successor = block.getSuccessor(j);
if (successor.id < block.id)
{
successor.setLoopHeader(block);
block.setInLoop(successor);
break;
}
}
}
for (int i = 0; i < blocks.Length; i++)
{
LBlock block = blocks[i];
if (block.backedge != null)
{
MarkLoop(block.backedge);
}
}
}
// Split critical edges in the graph. A critical edge is an edge which
// is neither its successor's only predecessor, nor its predecessor's
// only successor. Critical edges must be split to prevent copy-insertion
// and code motion from affecting other edges. It is probably not strictly
// needed here.
public static void SplitCriticalEdges(LBlock[] blocks)
{
for (var i = 0; i < blocks.Length; i++)
{
var block = blocks[i];
if (block.numSuccessors < 2)
{
continue;
}
for (var j = 0; j < block.numSuccessors; j++)
{
var target = block.getSuccessor(j);
if (target.numPredecessors < 2)
{
continue;
}
// Create a new block inheriting from the predecessor.
var split = new LBlock(block.pc);
var ins = new LGoto(target);
LInstruction[] instructions = { ins };
split.setInstructions(instructions);
block.replaceSuccessor(j, split);
target.replacePredecessor(block, split);
split.addPredecessor(block);
}
}
}
public static void ComputeDominators(LBlock[] blocks)
{
BitArray[] doms = new BitArray[blocks.Length];
for (int i = 0; i < doms.Length; i++)
{
doms[i] = new BitArray(doms.Length);
}
doms[0].Set(0, true);
for (int i = 1; i < blocks.Length; i++)
{
for (int j = 0; j < blocks.Length; j++)
{
doms[i].SetAll(true);
}
}
// Compute dominators.
bool changed;
do
{
changed = false;
for (int i = 1; i < blocks.Length; i++)
{
LBlock block = blocks[i];
for (int j = 0; j < block.numPredecessors; j++)
{
LBlock pred = block.getPredecessor(j);
BitArray u = new BitArray(doms[i]);
doms[block.id].And(doms[pred.id]);
doms[block.id].Set(block.id, true);
if (!CompareBitArrays(doms[block.id], u))
{
changed = true;
}
}
}
}while (changed);
// Turn the bit vectors into lists.
for (int i = 0; i < blocks.Length; i++)
{
LBlock block = blocks[i];
List <LBlock> list = new List <LBlock>();
for (int j = 0; j < blocks.Length; j++)
{
if (doms[block.id][j])
{
list.Add(blocks[j]);
}
}
block.setDominators(list.ToArray());
}
}
public override void replaceSuccessor(int i, LBlock block)
{
if (i == 0)
{
defaultCase_ = block;
}
if (cases_.Count >= i && i > 0)
{
cases_[i - 1].target = block;
}
}
private void transitionBlocks(LBlock next)
{
//Debug.Assert(pending_.Count == 0 || block_ != null);
if (block_ != null)
{
//Debug.Assert(pending_[pending_.Count - 1].isControl());
//Debug.Assert(block_.pc >= lir_.entry_pc && block_.pc < lir_.exit_pc);
block_.setInstructions(pending_.ToArray());
pending_.Clear();
}
block_ = next;
}
private static void MarkLoop(LBlock backedge)
{
var worklist = new LoopBodyWorklist(backedge);
worklist.scan(backedge);
while (!worklist.empty)
{
var block = worklist.pop();
worklist.scan(block);
block.setInLoop(backedge.loop);
}
}
public void replacePredecessor(LBlock from, LBlock split)
{
//Debug.Assert(predecessors_.Contains(from));
for (int i = 0; i < numPredecessors; i++)
{
if (getPredecessor(i) == from)
{
predecessors_[i] = split;
break;
}
}
//Debug.Assert(!predecessors_.Contains(from));
}
public static void DumpGraph(LBlock[] blocks, TextWriter tw)
{
for (int i = 0; i < blocks.Length; i++)
{
tw.WriteLine("Block " + i + ": (" + blocks[i].pc + ")");
for (int j = 0; j < blocks[i].instructions.Length; j++)
{
tw.Write(" ");
blocks[i].instructions[j].print(tw);
tw.Write("\n");
}
tw.WriteLine("\n");
}
}
// Return a reverse post-order listing of reachable blocks.
public static LBlock[] Order(LBlock entry)
{
// Postorder traversal without recursion.
var pending = new Stack <LBlock>();
var successors = new Stack <int>();
var done = new Stack <LBlock>();
var current = entry;
var nextSuccessor = 0;
for (; ;)
{
if (!current.marked)
{
current.mark();
if (nextSuccessor < current.numSuccessors)
{
pending.Push(current);
successors.Push(nextSuccessor);
current = current.getSuccessor(nextSuccessor);
nextSuccessor = 0;
continue;
}
done.Push(current);
}
if (pending.Count == 0)
{
break;
}
current = pending.Pop();
current.unmark();
nextSuccessor = successors.Pop() + 1;
}
var blocks = new List <LBlock>();
while (done.Count > 0)
{
current = done.Pop();
current.unmark();
current.setId(blocks.Count);
blocks.Add(current);
}
return(blocks.ToArray());
}
private static LBlock SkipContainedLoop(LBlock block, LBlock header)
{
while (block.loop != null && block.loop == block)
{
if (block.loop != null)
{
block = block.loop;
}
if (block == header)
{
break;
}
block = block.getLoopPredecessor();
}
return(block);
}
// Return a reverse post-order listing of reachable blocks.
public static LBlock[] Order(LBlock entry)
{
// Postorder traversal without recursion.
Stack<LBlock> pending = new Stack<LBlock>();
Stack<int> successors = new Stack<int>();
Stack<LBlock> done = new Stack<LBlock>();
LBlock current = entry;
int nextSuccessor = 0;
for (; ; )
{
if (!current.marked)
{
current.mark();
if (nextSuccessor < current.numSuccessors)
{
pending.Push(current);
successors.Push(nextSuccessor);
current = current.getSuccessor(nextSuccessor);
nextSuccessor = 0;
continue;
}
done.Push(current);
}
if (pending.Count == 0)
break;
current = pending.Pop();
current.unmark();
nextSuccessor = successors.Pop() + 1;
}
List<LBlock> blocks = new List<LBlock>();
while (done.Count > 0)
{
current = done.Pop();
current.unmark();
current.setId(blocks.Count);
blocks.Add(current);
}
return blocks.ToArray();
}
private static bool StrictlyDominatesADominator(LBlock from, LBlock dom)
{
for (var i = 0; i < from.dominators.Length; i++)
{
var other = from.dominators[i];
if (other == from || other == dom)
{
continue;
}
if (other.dominators.Contains(dom))
{
return(true);
}
}
return(false);
}
// The immediate dominator or idom of a node n is the unique node that
// strictly dominates n but does not strictly dominate any other node
// that strictly dominates n.
private static void ComputeImmediateDominator(LBlock block)
{
for (var i = 0; i < block.dominators.Length; i++)
{
var dom = block.dominators[i];
if (dom == block)
{
continue;
}
if (!StrictlyDominatesADominator(block, dom))
{
block.setImmediateDominator(dom);
return;
}
}
//Debug.Assert(false, "not reached");
}
public static void ComputeDominatorTree(LBlock[] blocks)
{
List <LBlock>[] idominated = new List <LBlock> [blocks.Length];
for (int i = 0; i < blocks.Length; i++)
{
idominated[i] = new List <LBlock>();
}
for (int i = 1; i < blocks.Length; i++)
{
LBlock block = blocks[i];
idominated[block.idom.id].Add(block);
}
for (int i = 0; i < blocks.Length; i++)
{
blocks[i].setImmediateDominated(idominated[i].ToArray());
}
}
private LGraph buildBlocks()
{
lir_.entry = new LBlock(lir_.entry_pc);
BlockBuilder builder = new BlockBuilder(lir_);
LBlock entry = builder.parse();
// Get an RPO ordering of the blocks, since we don't have predecessors yet.
LBlock[] blocks = BlockAnalysis.Order(entry);
if (!BlockAnalysis.IsReducible(blocks))
{
throw new Exception("control flow graph is not reducible");
}
// Split critical edges in the graph (is this even needed?)
BlockAnalysis.SplitCriticalEdges(blocks);
// Reorder the blocks since we could have introduced new nodes.
blocks = BlockAnalysis.Order(entry);
//Debug.Assert(BlockAnalysis.IsReducible(blocks));
BlockAnalysis.ComputeDominators(blocks);
BlockAnalysis.ComputeImmediateDominators(blocks);
BlockAnalysis.ComputeDominatorTree(blocks);
BlockAnalysis.FindLoops(blocks);
LGraph graph = new LGraph();
graph.blocks = blocks;
graph.entry = blocks[0];
if (lir_.argDepth > 0)
{
graph.nargs = ((lir_.argDepth - 12) / 4) + 1;
}
else
{
graph.nargs = 0;
}
return(graph);
}
// Split critical edges in the graph. A critical edge is an edge which
// is neither its successor's only predecessor, nor its predecessor's
// only successor. Critical edges must be split to prevent copy-insertion
// and code motion from affecting other edges. It is probably not strictly
// needed here.
public static void SplitCriticalEdges(LBlock[] blocks)
{
for (int i = 0; i < blocks.Length; i++)
{
LBlock block = blocks[i];
if (block.numSuccessors < 2)
continue;
for (int j = 0; j < block.numSuccessors; j++)
{
LBlock target = block.getSuccessor(j);
if (target.numPredecessors < 2)
continue;
// Create a new block inheriting from the predecessor.
LBlock split = new LBlock(block.pc);
LGoto ins = new LGoto(target);
LInstruction[] instructions = { ins };
split.setInstructions(instructions);
block.replaceSuccessor(j, split);
target.replacePredecessor(block, split);
split.addPredecessor(block);
}
}
}
public void scan(LBlock block)
{
for (var i = 0; i < block.numPredecessors; i++)
{
var pred = block.getPredecessor(i);
// Has this block already been scanned?
if (pred.loop == backedge_.loop)
{
continue;
}
pred = SkipContainedLoop(pred, backedge_.loop);
// If this assert hits, there is probably a |break| keyword.
//Debug.Assert(pred.loop == null || pred.loop == backedge_.loop);
if (pred.loop != null)
{
continue;
}
stack_.Push(pred);
}
}
public void setDominators(LBlock[] dominators)
{
dominators_ = dominators;
}
public virtual void replaceSuccessor(int i, LBlock block)
{
successors_[i] = block;
}
public SwitchCase(int value, LBlock target)
{
value_ = value;
this.target = target;
}
public void setInLoop(LBlock loop)
{
loop_ = loop;
}
private void transitionBlocks(LBlock next)
{
//Debug.Assert(pending_.Count == 0 || block_ != null);
if (block_ != null)
{
//Debug.Assert(pending_[pending_.Count - 1].isControl());
//Debug.Assert(block_.pc >= lir_.entry_pc && block_.pc < lir_.exit_pc);
block_.setInstructions(pending_.ToArray());
pending_.Clear();
}
block_ = next;
}
public void traverse(NodeBlock block)
{
for (int i = 0; i < block.lir.numPredecessors; i++)
{
NodeBlock pred = blocks_[block.lir.getPredecessor(i).id];
// Don't bother with backedges yet.
if (pred.lir.id >= block.lir.id)
{
continue;
}
block.inherit(graph_, pred);
}
foreach (LInstruction uins in block.lir.instructions)
{
// Attempt to find static declarations. This is really
// expensive - we could cheapen it by creating per-method
// lists of statics.
{
int i = -1;
do
{
Variable var = file_.lookupDeclarations(uins.pc, ref i, Scope.Static);
if (var == null)
{
break;
}
block.add(new DDeclareStatic(var));
} while (true);
}
switch (uins.op)
{
case Opcode.DebugBreak:
break;
case Opcode.Stack:
{
LStack ins = (LStack)uins;
if (ins.amount < 0)
{
for (int i = 0; i < -ins.amount / 4; i++)
{
DDeclareLocal local = new DDeclareLocal(ins.pc, null);
block.stack.push(local);
block.add(local);
}
}
else
{
for (int i = 0; i < ins.amount / 4; i++)
{
block.stack.pop();
}
}
break;
}
case Opcode.Fill:
{
LFill ins = (LFill)uins;
DNode node = block.stack.alt;
DDeclareLocal local = (DDeclareLocal)node;
//Debug.Assert(block.stack.pri.type == NodeType.Constant);
for (int i = 0; i < ins.amount; i += 4)
{
block.stack.set(local.offset + i, block.stack.pri);
}
break;
}
case Opcode.Constant:
{
LConstant ins = (LConstant)uins;
DConstant v = new DConstant(ins.val, ins.pc);
block.stack.set(ins.reg, v);
block.add(v);
break;
}
case Opcode.PushConstant:
{
LPushConstant ins = (LPushConstant)uins;
DConstant v = new DConstant(ins.val);
DDeclareLocal local = new DDeclareLocal(ins.pc, v);
block.stack.push(local);
block.add(v);
block.add(local);
break;
}
case Opcode.PushReg:
{
LPushReg ins = (LPushReg)uins;
DDeclareLocal local = new DDeclareLocal(ins.pc, block.stack.reg(ins.reg));
block.stack.push(local);
block.add(local);
break;
}
case Opcode.Pop:
{
LPop ins = (LPop)uins;
DNode node = block.stack.popAsTemp();
block.stack.set(ins.reg, node);
break;
}
case Opcode.StackAddress:
{
LStackAddress ins = (LStackAddress)uins;
DDeclareLocal local = block.stack.getName(ins.offset);
block.stack.set(ins.reg, local);
break;
}
case Opcode.PushStackAddress:
{
LPushStackAddress ins = (LPushStackAddress)uins;
DLocalRef lref = new DLocalRef(block.stack.getName(ins.offset));
DDeclareLocal local = new DDeclareLocal(ins.pc, lref);
block.stack.push(local);
block.add(lref);
block.add(local);
break;
}
case Opcode.Goto:
{
LGoto ins = (LGoto)uins;
DJump node = new DJump(blocks_[ins.target.id]);
block.add(node);
break;
}
case Opcode.Jump:
{
LJump ins = (LJump)uins;
DJump node = new DJump(blocks_[ins.target.id]);
block.add(node);
break;
}
case Opcode.JumpCondition:
{
LJumpCondition ins = (LJumpCondition)uins;
NodeBlock lhtarget = blocks_[ins.trueTarget.id];
NodeBlock rhtarget = blocks_[ins.falseTarget.id];
DNode cmp = block.stack.pri;
SPOpcode jmp = ins.spop;
if (jmp != SPOpcode.jzer && jmp != SPOpcode.jnz)
{
SPOpcode newop;
switch (ins.spop)
{
case SPOpcode.jeq:
newop = SPOpcode.neq;
jmp = SPOpcode.jzer;
break;
case SPOpcode.jneq:
newop = SPOpcode.eq;
jmp = SPOpcode.jzer;
break;
case SPOpcode.jsgeq:
newop = SPOpcode.sless;
jmp = SPOpcode.jzer;
break;
case SPOpcode.jsgrtr:
newop = SPOpcode.sleq;
jmp = SPOpcode.jzer;
break;
case SPOpcode.jsleq:
newop = SPOpcode.sgrtr;
jmp = SPOpcode.jzer;
break;
case SPOpcode.jsless:
newop = SPOpcode.sgeq;
jmp = SPOpcode.jzer;
break;
default:
//Debug.Assert(false);
return;
}
cmp = new DBinary(newop, block.stack.pri, block.stack.alt);
block.add(cmp);
}
DJumpCondition jcc = new DJumpCondition(jmp, cmp, lhtarget, rhtarget);
block.add(jcc);
break;
}
case Opcode.LoadLocal:
{
LLoadLocal ins = (LLoadLocal)uins;
DLoad load = new DLoad(block.stack.getName(ins.offset));
block.stack.set(ins.reg, load);
block.add(load);
break;
}
case Opcode.LoadLocalRef:
{
LLoadLocalRef ins = (LLoadLocalRef)uins;
DLoad load = new DLoad(block.stack.getName(ins.offset));
load = new DLoad(load);
block.stack.set(ins.reg, load);
block.add(load);
break;
}
case Opcode.StoreLocal:
{
LStoreLocal ins = (LStoreLocal)uins;
DStore store = new DStore(block.stack.getName(ins.offset), block.stack.reg(ins.reg));
block.add(store);
break;
}
case Opcode.StoreLocalRef:
{
LStoreLocalRef ins = (LStoreLocalRef)uins;
DLoad load = new DLoad(block.stack.getName(ins.offset));
DStore store = new DStore(load, block.stack.reg(ins.reg));
block.add(store);
break;
}
case Opcode.SysReq:
{
LSysReq sysreq = (LSysReq)uins;
DConstant ins = (DConstant)block.stack.popValue();
List <DNode> arguments = new List <DNode>();
for (int i = 0; i < ins.value; i++)
{
arguments.Add(block.stack.popName());
}
DSysReq call = new DSysReq(sysreq.native, arguments.ToArray());
block.stack.set(Register.Pri, call);
block.add(call);
break;
}
case Opcode.AddConstant:
{
LAddConstant ins = (LAddConstant)uins;
DConstant val = new DConstant(ins.amount);
DBinary node = new DBinary(SPOpcode.add, block.stack.pri, val);
block.stack.set(Register.Pri, node);
block.add(val);
block.add(node);
break;
}
case Opcode.MulConstant:
{
LMulConstant ins = (LMulConstant)uins;
DConstant val = new DConstant(ins.amount);
DBinary node = new DBinary(SPOpcode.smul, block.stack.pri, val);
block.stack.set(Register.Pri, node);
block.add(val);
block.add(node);
break;
}
case Opcode.Bounds:
{
LBounds ins = (LBounds)uins;
DBoundsCheck node = new DBoundsCheck(block.stack.pri);
block.add(node);
break;
}
case Opcode.IndexAddress:
{
LIndexAddress ins = (LIndexAddress)uins;
DArrayRef node = new DArrayRef(block.stack.alt, block.stack.pri, ins.shift);
block.stack.set(Register.Pri, node);
block.add(node);
break;
}
case Opcode.Move:
{
LMove ins = (LMove)uins;
if (ins.reg == Register.Pri)
{
block.stack.set(Register.Pri, block.stack.alt);
}
else
{
block.stack.set(Register.Alt, block.stack.pri);
}
break;
}
case Opcode.Store:
{
LStore ins = (LStore)uins;
DStore store = new DStore(block.stack.alt, block.stack.pri);
block.add(store);
break;
}
case Opcode.Load:
{
LLoad ins = (LLoad)uins;
DLoad load = new DLoad(block.stack.pri);
block.stack.set(Register.Pri, load);
block.add(load);
break;
}
case Opcode.Swap:
{
LSwap ins = (LSwap)uins;
DNode lhs = block.stack.popAsTemp();
DNode rhs = block.stack.reg(ins.reg);
DDeclareLocal local = new DDeclareLocal(ins.pc, rhs);
block.stack.set(ins.reg, lhs);
block.stack.push(local);
block.add(local);
break;
}
case Opcode.IncI:
{
DIncDec inc = new DIncDec(block.stack.pri, 1);
block.add(inc);
break;
}
case Opcode.DecI:
{
DIncDec dec = new DIncDec(block.stack.pri, -1);
block.add(dec);
break;
}
case Opcode.IncLocal:
{
LIncLocal ins = (LIncLocal)uins;
DDeclareLocal local = block.stack.getName(ins.offset);
DIncDec inc = new DIncDec(local, 1);
block.add(inc);
break;
}
case Opcode.IncReg:
{
LIncReg ins = (LIncReg)uins;
DIncDec dec = new DIncDec(block.stack.reg(ins.reg), 1);
block.add(dec);
break;
}
case Opcode.DecLocal:
{
LDecLocal ins = (LDecLocal)uins;
DDeclareLocal local = block.stack.getName(ins.offset);
DIncDec dec = new DIncDec(local, -1);
block.add(dec);
break;
}
case Opcode.DecReg:
{
LDecReg ins = (LDecReg)uins;
DIncDec dec = new DIncDec(block.stack.reg(ins.reg), -1);
block.add(dec);
break;
}
case Opcode.Return:
{
DReturn node = new DReturn(block.stack.pri);
block.add(node);
break;
}
case Opcode.PushLocal:
{
LPushLocal ins = (LPushLocal)uins;
DLoad load = new DLoad(block.stack.getName(ins.offset));
DDeclareLocal local = new DDeclareLocal(ins.pc, load);
block.stack.push(local);
block.add(load);
block.add(local);
break;
}
case Opcode.Exchange:
{
DNode node = block.stack.alt;
block.stack.set(Register.Alt, block.stack.pri);
block.stack.set(Register.Pri, node);
break;
}
case Opcode.Unary:
{
LUnary ins = (LUnary)uins;
DUnary unary = new DUnary(ins.spop, block.stack.reg(ins.reg));
block.stack.set(Register.Pri, unary);
block.add(unary);
break;
}
case Opcode.Binary:
{
LBinary ins = (LBinary)uins;
DBinary binary = new DBinary(ins.spop, block.stack.reg(ins.lhs), block.stack.reg(ins.rhs));
block.stack.set(Register.Pri, binary);
block.add(binary);
break;
}
case Opcode.PushGlobal:
{
LPushGlobal ins = (LPushGlobal)uins;
Variable global = file_.lookupGlobal(ins.address);
if (global == null)
{
global = file_.lookupVariable(ins.pc, ins.address, Scope.Static);
}
DGlobal dglobal = new DGlobal(global);
DNode node = new DLoad(dglobal);
DDeclareLocal local = new DDeclareLocal(ins.pc, node);
block.stack.push(local);
block.add(dglobal);
block.add(node);
block.add(local);
break;
}
case Opcode.LoadGlobal:
{
LLoadGlobal ins = (LLoadGlobal)uins;
Variable global = file_.lookupGlobal(ins.address);
if (global == null)
{
global = file_.lookupVariable(ins.pc, ins.address, Scope.Static);
}
DNode dglobal = new DGlobal(global);
DNode node = new DLoad(dglobal);
block.stack.set(ins.reg, node);
block.add(dglobal);
block.add(node);
break;
}
case Opcode.StoreGlobal:
{
LStoreGlobal ins = (LStoreGlobal)uins;
Variable global = file_.lookupGlobal(ins.address);
if (global == null)
{
global = file_.lookupVariable(ins.pc, ins.address, Scope.Static);
}
DGlobal node = new DGlobal(global);
DStore store = new DStore(node, block.stack.reg(ins.reg));
block.add(node);
block.add(store);
break;
}
case Opcode.Call:
{
LCall ins = (LCall)uins;
Function f = file_.lookupFunction((uint)ins.address);
DConstant args = (DConstant)block.stack.popValue();
List <DNode> arguments = new List <DNode>();
for (int i = 0; i < args.value; i++)
{
arguments.Add(block.stack.popName());
}
DCall call = new DCall(f, arguments.ToArray());
block.stack.set(Register.Pri, call);
block.add(call);
break;
}
case Opcode.EqualConstant:
{
LEqualConstant ins = (LEqualConstant)uins;
DConstant c = new DConstant(ins.value);
DBinary node = new DBinary(SPOpcode.eq, block.stack.reg(ins.reg), c);
block.stack.set(Register.Pri, node);
block.add(c);
block.add(node);
break;
}
case Opcode.LoadIndex:
{
LLoadIndex ins = (LLoadIndex)uins;
DArrayRef aref = new DArrayRef(block.stack.alt, block.stack.pri, ins.shift);
DLoad load = new DLoad(aref);
block.stack.set(Register.Pri, load);
block.add(aref);
block.add(load);
break;
}
case Opcode.ZeroGlobal:
{
LZeroGlobal ins = (LZeroGlobal)uins;
Variable global = file_.lookupGlobal(ins.address);
DNode dglobal = new DGlobal(global);
DConstant rhs = new DConstant(0);
DStore lhs = new DStore(dglobal, rhs);
block.add(dglobal);
block.add(rhs);
block.add(lhs);
break;
}
case Opcode.IncGlobal:
{
LIncGlobal ins = (LIncGlobal)uins;
Variable global = file_.lookupGlobal(ins.address);
DNode dglobal = new DGlobal(global);
DLoad load = new DLoad(dglobal);
DConstant val = new DConstant(1);
DBinary add = new DBinary(SPOpcode.add, load, val);
DStore store = new DStore(dglobal, add);
block.add(load);
block.add(val);
block.add(add);
block.add(store);
break;
}
case Opcode.StoreGlobalConstant:
{
LStoreGlobalConstant lstore = (LStoreGlobalConstant)uins;
Variable var = file_.lookupGlobal(lstore.address);
DConstant val = new DConstant(lstore.value);
DGlobal global = new DGlobal(var);
DStore store = new DStore(global, val);
block.add(val);
block.add(global);
block.add(store);
break;
}
case Opcode.StoreLocalConstant:
{
LStoreLocalConstant lstore = (LStoreLocalConstant)uins;
DDeclareLocal var = block.stack.getName(lstore.address);
DConstant val = new DConstant(lstore.value);
DStore store = new DStore(var, val);
block.add(val);
block.add(store);
break;
}
case Opcode.ZeroLocal:
{
LZeroLocal lstore = (LZeroLocal)uins;
DDeclareLocal var = block.stack.getName(lstore.address);
DConstant val = new DConstant(0);
DStore store = new DStore(var, val);
block.add(val);
block.add(store);
break;
}
case Opcode.Heap:
{
LHeap ins = (LHeap)uins;
DHeap heap = new DHeap(ins.amount);
block.add(heap);
block.stack.set(Register.Alt, heap);
break;
}
case Opcode.MemCopy:
{
LMemCopy ins = (LMemCopy)uins;
DMemCopy copy = new DMemCopy(block.stack.alt, block.stack.pri, ins.bytes);
block.add(copy);
break;
}
case Opcode.Switch:
{
LSwitch ins = (LSwitch)uins;
DSwitch switch_ = new DSwitch(block.stack.pri, ins);
block.add(switch_);
break;
}
default:
throw new Exception("unhandled opcode");
}
}
for (int i = 0; i < block.lir.idominated.Length; i++)
{
LBlock lir = block.lir.idominated[i];
traverse(blocks_[lir.id]);
}
}
public void scan(LBlock block)
{
for (int i = 0; i < block.numPredecessors; i++)
{
LBlock pred = block.getPredecessor(i);
// Has this block already been scanned?
if (pred.loop == backedge_.loop)
continue;
pred = SkipContainedLoop(pred, backedge_.loop);
// If this assert hits, there is probably a |break| keyword.
//Debug.Assert(pred.loop == null || pred.loop == backedge_.loop);
if (pred.loop != null)
continue;
stack_.Push(pred);
}
}
public static void FindLoops(LBlock[] blocks)
{
// Mark backedges and headers.
for (int i = 1; i < blocks.Length; i++)
{
LBlock block = blocks[i];
for (int j = 0; j < block.numSuccessors; j++)
{
LBlock successor = block.getSuccessor(j);
if (successor.id < block.id)
{
successor.setLoopHeader(block);
block.setInLoop(successor);
break;
}
}
}
for (int i = 0; i < blocks.Length; i++)
{
LBlock block = blocks[i];
if (block.backedge != null)
MarkLoop(block.backedge);
}
}
public LJump(LBlock target, uint target_offs)
: base(target_offs, target)
{
}
public LJumpCondition(SPOpcode op, LBlock true_target, LBlock false_target, uint target_offs)
: base(target_offs, true_target, false_target)
{
op_ = op;
}
public LGoto(LBlock target)
: base(target)
{
}
public override void replaceSuccessor(int i, LBlock block)
{
if (i == 0)
defaultCase_ = block;
if (cases_.Count >= i && i > 0)
{
cases_[i - 1].target = block;
}
}
public LSwitch(LBlock defaultCase, List<SwitchCase> cases)
{
defaultCase_ = defaultCase;
cases_ = cases;
}
public LSwitch(LBlock defaultCase, List <SwitchCase> cases)
{
defaultCase_ = defaultCase;
cases_ = cases;
}
public LoopBodyWorklist(LBlock backedge)
{
backedge_ = backedge;
}
public LGoto(LBlock target)
: base(target)
{
}
private static LBlock SkipContainedLoop(LBlock block, LBlock header)
{
while (block.loop != null && block.loop == block)
{
if (block.loop != null)
block = block.loop;
if (block == header)
break;
block = block.getLoopPredecessor();
}
return block;
}
public void setImmediateDominator(LBlock idom)
{
idom_ = idom;
}
public void replaceSuccessor(int pos, LBlock split)
{
last.replaceSuccessor(pos, split);
}
public BlockBuilder(LIR lir)
{
lir_ = lir;
block_ = lir_.entry;
}
public void addPredecessor(LBlock pred)
{
//Debug.Assert(!predecessors_.Contains(pred));
predecessors_.Add(pred);
}
private ControlType findLoopJoinAndBody(NodeBlock header, NodeBlock effectiveHeader,
out NodeBlock join, out NodeBlock body, out NodeBlock cond)
{
//Debug.Assert(effectiveHeader.lir.numSuccessors == 2);
LBlock succ1 = effectiveHeader.lir.getSuccessor(0);
LBlock succ2 = effectiveHeader.lir.getSuccessor(1);
if (succ1.loop != header.lir || succ2.loop != header.lir)
{
//Debug.Assert(succ1.loop == header.lir || succ2.loop == header.lir);
if (succ1.loop != header.lir)
{
join = graph_[succ1.id];
body = graph_[succ2.id];
}
else
{
join = graph_[succ2.id];
body = graph_[succ1.id];
}
cond = header;
// If this is a self-loop, it is more correct to decompose it
// to a do-while loop. This may not be source accurate in the
// case of something like |while (x);| but it catches many more
// source-accurate cases.
if (header == effectiveHeader &&
BlockAnalysis.GetEmptyTarget(body) == header)
{
body = null;
return(ControlType.DoWhileLoop);
}
return(ControlType.WhileLoop);
}
else
{
// Neither successor of the header exits the loop, so this is
// probably a do-while loop. For now, assume it's simple.
//Debug.Assert(header == effectiveHeader);
LBlock backedge = header.lir.backedge;
if (BlockAnalysis.GetEmptyTarget(graph_[backedge.id]) == header)
{
// Skip an empty block sitting in between the backedge and
// the condition.
//Debug.Assert(backedge.numPredecessors == 1);
backedge = backedge.getPredecessor(0);
}
//Debug.Assert(backedge.numSuccessors == 2);
succ1 = backedge.getSuccessor(0);
succ2 = backedge.getSuccessor(1);
body = header;
cond = graph_[backedge.id];
if (succ1.loop != header.lir)
{
join = graph_[succ1.id];
}
else
{
//Debug.Assert(succ2.loop != header.lir);
join = graph_[succ2.id];
}
return(ControlType.DoWhileLoop);
}
}
public virtual void replaceSuccessor(int i, LBlock block)
{
successors_[i] = block;
}
public void replacePredecessor(LBlock from, LBlock split)
{
//Debug.Assert(predecessors_.Contains(from));
for (int i = 0; i < numPredecessors; i++)
{
if (getPredecessor(i) == from)
{
predecessors_[i] = split;
break;
}
}
//Debug.Assert(!predecessors_.Contains(from));
}
private static bool StrictlyDominatesADominator(LBlock from, LBlock dom)
{
for (int i = 0; i < from.dominators.Length; i++)
{
LBlock other = from.dominators[i];
if (other == from || other == dom)
continue;
if (other.dominators.Contains(dom))
return true;
}
return false;
}
public void setLoopHeader(LBlock backedge)
{
backedge_ = backedge;
loop_ = this;
}
public static void ComputeDominators(LBlock[] blocks)
{
BitArray[] doms = new BitArray[blocks.Length];
for (int i = 0; i < doms.Length; i++)
doms[i] = new BitArray(doms.Length);
doms[0].Set(0, true);
for (int i = 1; i < blocks.Length; i++)
{
for (int j = 0; j < blocks.Length; j++)
doms[i].SetAll(true);
}
// Compute dominators.
bool changed;
do
{
changed = false;
for (int i = 1; i < blocks.Length; i++)
{
LBlock block = blocks[i];
for (int j = 0; j < block.numPredecessors; j++)
{
LBlock pred = block.getPredecessor(j);
BitArray u = new BitArray(doms[i]);
doms[block.id].And(doms[pred.id]);
doms[block.id].Set(block.id, true);
if (!CompareBitArrays(doms[block.id], u))
changed = true;
}
}
}
while (changed);
// Turn the bit vectors into lists.
for (int i = 0; i < blocks.Length; i++)
{
LBlock block = blocks[i];
List<LBlock> list = new List<LBlock>();
for (int j = 0; j < blocks.Length; j++)
{
if (doms[block.id][j])
list.Add(blocks[j]);
}
block.setDominators(list.ToArray());
}
}
public void setImmediateDominator(LBlock idom)
{
idom_ = idom;
}
public LJumpCondition(SPOpcode op, LBlock true_target, LBlock false_target, uint target_offs)
: base(target_offs, true_target, false_target)
{
op_ = op;
}
public void setImmediateDominated(LBlock[] idominated)
{
idominated_ = idominated;
}
public BlockBuilder(LIR lir)
{
lir_ = lir;
block_ = lir_.entry;
}
public SwitchCase(int value, LBlock target)
{
value_ = value;
this.target = target;
}
public static void ComputeImmediateDominators(LBlock[] blocks)
{
blocks[0].setImmediateDominator(blocks[0]);
for (int i = 1; i < blocks.Length; i++)
ComputeImmediateDominator(blocks[i]);
}
public static void ComputeDominatorTree(LBlock[] blocks)
{
List<LBlock>[] idominated = new List<LBlock>[blocks.Length];
for (int i = 0; i < blocks.Length; i++)
idominated[i] = new List<LBlock>();
for (int i = 1; i < blocks.Length; i++)
{
LBlock block = blocks[i];
idominated[block.idom.id].Add(block);
}
for (int i = 0; i < blocks.Length; i++)
blocks[i].setImmediateDominated(idominated[i].ToArray());
}
public void setInLoop(LBlock loop)
{
loop_ = loop;
}
public LJump(LBlock target, uint target_offs)
: base(target_offs, target)
{
}
private static void MarkLoop(LBlock backedge)
{
var worklist = new LoopBodyWorklist(backedge);
worklist.scan(backedge);
while (!worklist.empty)
{
LBlock block = worklist.pop();
worklist.scan(block);
block.setInLoop(backedge.loop);
}
}
public void addPredecessor(LBlock pred)
{
//Debug.Assert(!predecessors_.Contains(pred));
predecessors_.Add(pred);
}
public void setLoopHeader(LBlock backedge)
{
backedge_ = backedge;
loop_ = this;
}
public LBlock parse()
{
for (int i = 0; i < lir_.instructions.Count; i++)
{
LInstruction ins = lir_.instructions[i];
if (lir_.isTarget(ins.pc))
{
// This instruction is the target of a basic block, so
// finish the old one.
LBlock next = lir_.blockOfTarget(ins.pc);
// Multiple instructions could be at the same pc,
// because of decomposition, so make sure we're not
// transitioning to the same block.
if (block_ != next)
{
// Add implicit control flow to make further algorithms easier.
if (block_ != null)
{
//Debug.Assert(!pending_[pending_.Count - 1].isControl());
pending_.Add(new LGoto(next));
next.addPredecessor(block_);
}
// Fallthrough to the next block.
transitionBlocks(next);
}
}
// If there is no block present, we assume this is dead code.
if (block_ == null)
{
continue;
}
pending_.Add(ins);
switch (ins.op)
{
case Opcode.Return:
{
// A return terminates the current block.
transitionBlocks(null);
break;
}
case Opcode.Jump:
{
LJump jump = (LJump)ins;
jump.target.addPredecessor(block_);
transitionBlocks(null);
break;
}
case Opcode.JumpCondition:
{
LJumpCondition jcc = (LJumpCondition)ins;
jcc.trueTarget.addPredecessor(block_);
jcc.falseTarget.addPredecessor(block_);
// The next iteration will pick the false target up.
//Debug.Assert(lir_.instructions[i + 1].pc == jcc.falseTarget.pc);
transitionBlocks(null);
break;
}
case Opcode.Switch:
{
LSwitch switch_ = (LSwitch)ins;
for (int j = 0; j < switch_.numSuccessors; j++)
{
switch_.getSuccessor(j).addPredecessor(block_);
}
transitionBlocks(null);
break;
}
}
}
return(lir_.entry);
}
// The immediate dominator or idom of a node n is the unique node that
// strictly dominates n but does not strictly dominate any other node
// that strictly dominates n.
private static void ComputeImmediateDominator(LBlock block)
{
for (int i = 0; i < block.dominators.Length; i++)
{
LBlock dom = block.dominators[i];
if (dom == block)
continue;
if (!StrictlyDominatesADominator(block, dom))
{
block.setImmediateDominator(dom);
return;
}
}
//Debug.Assert(false, "not reached");
}
private LInstruction readInstruction(SPOpcode op)
{
switch (op)
{
case SPOpcode.load_pri:
case SPOpcode.load_alt:
{
Register reg = (op == SPOpcode.load_pri) ? Register.Pri : Register.Alt;
return(new LLoadGlobal(readInt32(), reg));
}
case SPOpcode.load_s_pri:
case SPOpcode.load_s_alt:
{
Register reg = (op == SPOpcode.load_s_pri) ? Register.Pri : Register.Alt;
return(new LLoadLocal(trackStack(readInt32()), reg));
}
case SPOpcode.lref_s_pri:
case SPOpcode.lref_s_alt:
{
Register reg = (op == SPOpcode.lref_s_pri) ? Register.Pri : Register.Alt;
return(new LLoadLocalRef(trackStack(readInt32()), reg));
}
case SPOpcode.stor_s_pri:
case SPOpcode.stor_s_alt:
{
Register reg = (op == SPOpcode.stor_s_pri) ? Register.Pri : Register.Alt;
return(new LStoreLocal(reg, trackStack(readInt32())));
}
case SPOpcode.sref_s_pri:
case SPOpcode.sref_s_alt:
{
Register reg = (op == SPOpcode.sref_s_pri) ? Register.Pri : Register.Alt;
return(new LStoreLocalRef(reg, trackStack(readInt32())));
}
case SPOpcode.load_i:
return(new LLoad(4));
case SPOpcode.lodb_i:
return(new LLoad(readInt32()));
case SPOpcode.const_pri:
case SPOpcode.const_alt:
{
Register reg = (op == SPOpcode.const_pri) ? Register.Pri : Register.Alt;
return(new LConstant(readInt32(), reg));
}
case SPOpcode.addr_pri:
case SPOpcode.addr_alt:
{
Register reg = (op == SPOpcode.addr_pri) ? Register.Pri : Register.Alt;
return(new LStackAddress(trackStack(readInt32()), reg));
}
case SPOpcode.stor_pri:
case SPOpcode.stor_alt:
{
Register reg = (op == SPOpcode.stor_pri) ? Register.Pri : Register.Alt;
return(new LStoreGlobal(readInt32(), reg));
}
case SPOpcode.stor_i:
return(new LStore(4));
case SPOpcode.strb_i:
return(new LStore(readInt32()));
case SPOpcode.lidx:
return(new LLoadIndex(4));
case SPOpcode.lidx_b:
return(new LLoadIndex(readInt32()));
case SPOpcode.idxaddr:
return(new LIndexAddress(2));
case SPOpcode.idxaddr_b:
return(new LIndexAddress(readInt32()));
case SPOpcode.move_pri:
case SPOpcode.move_alt:
{
Register reg = (op == SPOpcode.move_pri) ? Register.Pri : Register.Alt;
return(new LMove(reg));
}
case SPOpcode.xchg:
return(new LExchange());
case SPOpcode.push_pri:
case SPOpcode.push_alt:
{
Register reg = (op == SPOpcode.push_pri) ? Register.Pri : Register.Alt;
return(new LPushReg(reg));
}
case SPOpcode.push_c:
return(new LPushConstant(readInt32()));
case SPOpcode.push:
return(new LPushGlobal(readInt32()));
case SPOpcode.push_s:
return(new LPushLocal(trackStack(readInt32())));
case SPOpcode.pop_pri:
case SPOpcode.pop_alt:
{
Register reg = (op == SPOpcode.pop_pri) ? Register.Pri : Register.Alt;
return(new LPop(reg));
}
case SPOpcode.stack:
return(new LStack(readInt32()));
case SPOpcode.retn:
return(new LReturn());
case SPOpcode.call:
return(new LCall(readInt32()));
case SPOpcode.jump:
{
uint offset = readUInt32();
return(new LJump(prepareJumpTarget(offset), offset));
}
case SPOpcode.jeq:
case SPOpcode.jneq:
case SPOpcode.jnz:
case SPOpcode.jzer:
case SPOpcode.jsgeq:
case SPOpcode.jsless:
case SPOpcode.jsgrtr:
case SPOpcode.jsleq:
{
uint offset = readUInt32();
if (offset == pc_)
{
return(new LJump(prepareJumpTarget(offset), offset));
}
return(new LJumpCondition(op, prepareJumpTarget(offset), prepareJumpTarget(pc_), offset));
}
case SPOpcode.sdiv_alt:
case SPOpcode.sub_alt:
return(new LBinary(op, Register.Alt, Register.Pri));
case SPOpcode.add:
case SPOpcode.and:
case SPOpcode.or:
case SPOpcode.smul:
case SPOpcode.shr:
case SPOpcode.shl:
case SPOpcode.sub:
case SPOpcode.sshr:
case SPOpcode.xor:
return(new LBinary(op, Register.Pri, Register.Alt));
case SPOpcode.not:
case SPOpcode.invert:
return(new LUnary(op, Register.Pri));
case SPOpcode.add_c:
return(new LAddConstant(readInt32()));
case SPOpcode.smul_c:
return(new LMulConstant(readInt32()));
case SPOpcode.zero_pri:
case SPOpcode.zero_alt:
{
Register reg = (op == SPOpcode.zero_pri) ? Register.Pri : Register.Alt;
return(new LConstant(0, reg));
}
case SPOpcode.zero_s:
return(new LZeroLocal(trackStack(readInt32())));
case SPOpcode.zero:
return(new LZeroGlobal(readInt32()));
case SPOpcode.eq:
case SPOpcode.neq:
case SPOpcode.sleq:
case SPOpcode.sgeq:
case SPOpcode.sgrtr:
case SPOpcode.sless:
return(new LBinary(op, Register.Pri, Register.Alt));
case SPOpcode.eq_c_pri:
case SPOpcode.eq_c_alt:
{
Register reg = (op == SPOpcode.eq_c_pri) ? Register.Pri : Register.Alt;
return(new LEqualConstant(reg, readInt32()));
}
case SPOpcode.inc:
return(new LIncGlobal(readInt32()));
case SPOpcode.inc_s:
return(new LIncLocal(trackStack(readInt32())));
case SPOpcode.dec_s:
return(new LDecLocal(trackStack(readInt32())));
case SPOpcode.inc_i:
return(new LIncI());
case SPOpcode.inc_pri:
case SPOpcode.inc_alt:
{
Register reg = (op == SPOpcode.inc_pri) ? Register.Pri : Register.Alt;
return(new LIncReg(reg));
}
case SPOpcode.dec_pri:
case SPOpcode.dec_alt:
{
Register reg = (op == SPOpcode.dec_pri) ? Register.Pri : Register.Alt;
return(new LDecReg(reg));
}
case SPOpcode.dec_i:
return(new LDecI());
case SPOpcode.fill:
return(new LFill(readInt32()));
case SPOpcode.bounds:
return(new LBounds(readInt32()));
case SPOpcode.swap_pri:
case SPOpcode.swap_alt:
{
Register reg = (op == SPOpcode.swap_pri) ? Register.Pri : Register.Alt;
return(new LSwap(reg));
}
case SPOpcode.push_adr:
return(new LPushStackAddress(trackStack(readInt32())));
case SPOpcode.sysreq_n:
{
int index = readInt32();
add(new LPushConstant(readInt32()));
return(new LSysReq(file_.natives[index]));
}
case SPOpcode.dbreak:
return(new LDebugBreak());
case SPOpcode.endproc:
return(null);
case SPOpcode.push2_s:
{
add(new LPushLocal(trackStack(readInt32())));
return(new LPushLocal(trackStack(readInt32())));
}
case SPOpcode.push2_adr:
{
add(new LPushStackAddress(trackStack(readInt32())));
return(new LPushStackAddress(trackStack(readInt32())));
}
case SPOpcode.push2_c:
{
add(new LPushConstant(readInt32()));
return(new LPushConstant(readInt32()));
}
case SPOpcode.push2:
{
add(new LPushGlobal(readInt32()));
return(new LPushGlobal(readInt32()));
}
case SPOpcode.push3_s:
{
add(new LPushLocal(trackStack(readInt32())));
add(new LPushLocal(trackStack(readInt32())));
return(new LPushLocal(trackStack(readInt32())));
}
case SPOpcode.push3_adr:
{
add(new LPushStackAddress(trackStack(readInt32())));
add(new LPushStackAddress(trackStack(readInt32())));
return(new LPushStackAddress(trackStack(readInt32())));
}
case SPOpcode.push3_c:
{
add(new LPushConstant(readInt32()));
add(new LPushConstant(readInt32()));
return(new LPushConstant(readInt32()));
}
case SPOpcode.push3:
{
add(new LPushGlobal(readInt32()));
add(new LPushGlobal(readInt32()));
return(new LPushGlobal(readInt32()));
}
case SPOpcode.push4_s:
{
add(new LPushLocal(trackStack(readInt32())));
add(new LPushLocal(trackStack(readInt32())));
add(new LPushLocal(trackStack(readInt32())));
return(new LPushLocal(trackStack(readInt32())));
}
case SPOpcode.push4_adr:
{
add(new LPushStackAddress(trackStack(readInt32())));
add(new LPushStackAddress(trackStack(readInt32())));
add(new LPushStackAddress(trackStack(readInt32())));
return(new LPushStackAddress(trackStack(readInt32())));
}
case SPOpcode.push4_c:
{
add(new LPushConstant(readInt32()));
add(new LPushConstant(readInt32()));
add(new LPushConstant(readInt32()));
return(new LPushConstant(readInt32()));
}
case SPOpcode.push4:
{
add(new LPushGlobal(readInt32()));
add(new LPushGlobal(readInt32()));
add(new LPushGlobal(readInt32()));
return(new LPushGlobal(readInt32()));
}
case SPOpcode.push5_s:
{
add(new LPushLocal(trackStack(readInt32())));
add(new LPushLocal(trackStack(readInt32())));
add(new LPushLocal(trackStack(readInt32())));
add(new LPushLocal(trackStack(readInt32())));
return(new LPushLocal(trackStack(readInt32())));
}
case SPOpcode.push5_c:
{
add(new LPushConstant(readInt32()));
add(new LPushConstant(readInt32()));
add(new LPushConstant(readInt32()));
add(new LPushConstant(readInt32()));
return(new LPushConstant(readInt32()));
}
case SPOpcode.push5_adr:
{
add(new LPushStackAddress(trackStack(readInt32())));
add(new LPushStackAddress(trackStack(readInt32())));
add(new LPushStackAddress(trackStack(readInt32())));
add(new LPushStackAddress(trackStack(readInt32())));
return(new LPushStackAddress(trackStack(readInt32())));
}
case SPOpcode.push5:
{
add(new LPushGlobal(readInt32()));
add(new LPushGlobal(readInt32()));
add(new LPushGlobal(readInt32()));
add(new LPushGlobal(readInt32()));
return(new LPushGlobal(readInt32()));
}
case SPOpcode.load_both:
{
add(new LLoadLocal(readInt32(), Register.Pri));
return(new LLoadLocal(readInt32(), Register.Alt));
}
case SPOpcode.load_s_both:
{
add(new LLoadLocal(trackStack(readInt32()), Register.Pri));
return(new LLoadLocal(trackStack(readInt32()), Register.Alt));
}
case SPOpcode.const_:
{
return(new LStoreGlobalConstant(readInt32(), readInt32()));
}
case SPOpcode.const_s:
{
return(new LStoreLocalConstant(trackStack(readInt32()), readInt32()));
}
case SPOpcode.heap:
{
return(new LHeap(readInt32()));
}
case SPOpcode.movs:
{
return(new LMemCopy(readInt32()));
}
case SPOpcode.switch_:
{
uint table = readUInt32();
uint savePc = pc_;
pc_ = table;
SPOpcode casetbl = (SPOpcode)readUInt32();
//Debug.Assert(casetbl == SPOpcode.casetbl);
int ncases = readInt32();
uint defaultCase = readUInt32();
var cases = new List <SwitchCase>();
for (int i = 0; i < ncases; i++)
{
int value = readInt32();
uint pc = readUInt32();
LBlock target = prepareJumpTarget(pc);
cases.Add(new SwitchCase(value, target));
}
pc_ = savePc;
return(new LSwitch(prepareJumpTarget(defaultCase), cases));
}
case SPOpcode.casetbl:
{
int ncases = readInt32();
pc_ += (uint)ncases * 8 + 4;
return(new LDebugBreak());
}
default:
{
throw new OpCodeNotKnownException("Unrecognized opcode " + op);
}
}
}
public void replaceSuccessor(int pos, LBlock split)
{
last.replaceSuccessor(pos, split);
}
