Initial skeleton of Subzero.

src/IceCfgNode.cpp

+//===- subzero/src/IceCfgNode.cpp - Basic block (node) implementation -----===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CfgNode class, including the
+// complexities of instruction insertion and in-edge calculation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IceCfg.h"
+#include "IceCfgNode.h"
+#include "IceInst.h"
+#include "IceOperand.h"
+
+namespace Ice {
+
+CfgNode::CfgNode(Cfg *Func, SizeT LabelNumber, IceString Name)
+    : Func(Func), Number(LabelNumber), Name(Name) {}
+
+// Returns the name the node was created with.  If no name was given,
+// it synthesizes a (hopefully) unique name.
+IceString CfgNode::getName() const {
+  if (!Name.empty())
+    return Name;
+  char buf[30];
+  snprintf(buf, llvm::array_lengthof(buf), "__%u", getIndex());
+  return buf;
+}
+
+// Adds an instruction to either the Phi list or the regular
+// instruction list.  Validates that all Phis are added before all
+// regular instructions.
+void CfgNode::appendInst(Inst *Inst) {
+  if (InstPhi *Phi = llvm::dyn_cast<InstPhi>(Inst)) {
+    if (!Insts.empty()) {
+      Func->setError("Phi instruction added to the middle of a block");
+      return;
+    }
+    Phis.push_back(Phi);
+  } else {
+    Insts.push_back(Inst);
+  }
+  Inst->updateVars(this);
+}
+
+// When a node is created, the OutEdges are immediately knows, but the
+// InEdges have to be built up incrementally.  After the CFG has been
+// constructed, the computePredecessors() pass finalizes it by
+// creating the InEdges list.
+void CfgNode::computePredecessors() {
+  OutEdges = (*Insts.rbegin())->getTerminatorEdges();
+  for (NodeList::const_iterator I = OutEdges.begin(), E = OutEdges.end();
+       I != E; ++I) {
+    CfgNode *Node = *I;
+    Node->InEdges.push_back(this);
+  }
+}
+
+// ======================== Dump routines ======================== //
+
+void CfgNode::dump(Cfg *Func) const {
+  Func->setCurrentNode(this);
+  Ostream &Str = Func->getContext()->getStrDump();
+  if (Func->getContext()->isVerbose(IceV_Instructions)) {
+    Str << getName() << ":\n";
+  }
+  // Dump list of predecessor nodes.
+  if (Func->getContext()->isVerbose(IceV_Preds) && !InEdges.empty()) {
+    Str << "    // preds = ";
+    for (NodeList::const_iterator I = InEdges.begin(), E = InEdges.end();
+         I != E; ++I) {
+      if (I != InEdges.begin())
+        Str << ", ";
+      Str << "%" << (*I)->getName();
+    }
+    Str << "\n";
+  }
+  // Dump each instruction.
+  if (Func->getContext()->isVerbose(IceV_Instructions)) {
+    for (PhiList::const_iterator I = Phis.begin(), E = Phis.end(); I != E;
+         ++I) {
+      const Inst *Inst = *I;
+      Inst->dumpDecorated(Func);
+    }
+    InstList::const_iterator I = Insts.begin(), E = Insts.end();
+    while (I != E) {
+      Inst *Inst = *I++;
+      Inst->dumpDecorated(Func);
+    }
+  }
+  // Dump list of successor nodes.
+  if (Func->getContext()->isVerbose(IceV_Succs)) {
+    Str << "    // succs = ";
+    for (NodeList::const_iterator I = OutEdges.begin(), E = OutEdges.end();
+         I != E; ++I) {
+      if (I != OutEdges.begin())
+        Str << ", ";
+      Str << "%" << (*I)->getName();
+    }
+    Str << "\n";
+  }
+}
+
+} // end of namespace Ice