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(IceCfg *Cfg, IceSize_t LabelNumber, IceString Name)
+    : Cfg(Cfg), 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 != "")

[JF, 2014/04/23 03:51:28]

!Name.empty()

[Jim Stichnoth, 2014/04/26 15:02:11]

Done (here and 2 other places).

+    return Name;
+  const static size_t BufLen = 30;

[JF, 2014/04/23 03:51:28]

Here and other places: LLVM has array_lengthof with you could just use in
snprintf (and do away with BufLen).

[Jim Stichnoth, 2014/04/26 15:02:11]

Done.  I couldn't make this work in IceGlobalContext.cpp where the array size
depends on input arguments, let me know if you think that should be possible.

+  char buf[BufLen];
+  snprintf(buf, BufLen, "__%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()) {
+      Cfg->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(IceCfg *Cfg) const {
+  Cfg->setCurrentNode(this);
+  IceOstream &Str = Cfg->getContext()->getStrDump();
+  if (Cfg->getContext()->isVerbose(IceV_Instructions)) {
+    Str << getName() << ":\n";
+  }
+  // Dump list of predecessor nodes.
+  if (Cfg->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 (Cfg->getContext()->isVerbose(IceV_Instructions)) {
+    for (PhiList::const_iterator I = Phis.begin(), E = Phis.end(); I != E;
+         ++I) {
+      const Inst *Inst = *I;
+      Inst->dumpDecorated(Cfg);
+    }
+    InstList::const_iterator I = Insts.begin(), E = Insts.end();
+    while (I != E) {
+      Inst *Inst = *I++;
+      Inst->dumpDecorated(Cfg);
+    }
+  }
+  // Dump list of successor nodes.
+  if (Cfg->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