Add new RegionInfo pass.

The RegionInfo pass detects single entry single exit regions in a function,
where a region is defined as any subgraph that is connected to the remaining
graph at only two spots.
Furthermore an hierarchical region tree is built.
Use it by calling "opt -regions analyze" or "opt -view-regions".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109089 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 182 insertions, 0 deletions

diff --git a/lib/Analysis/RegionPrinter.cpp b/lib/Analysis/RegionPrinter.cpp
new file mode 100644
index 0000000..c657143
--- /dev/null
+++ b/lib/Analysis/RegionPrinter.cpp
@@ -0,0 +1,182 @@
+//===- RegionPrinter.cpp - Print regions tree pass ------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Print out the region tree of a function using dotty/graphviz.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/RegionInfo.h"
+#include "llvm/Analysis/RegionIterator.h"
+#include "llvm/Analysis/RegionPrinter.h"
+#include "llvm/Analysis/Passes.h"
+#include "llvm/Analysis/DOTGraphTraitsPass.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+/// onlySimpleRegion - Show only the simple regions in the RegionViewer.
+static cl::opt<bool>
+onlySimpleRegions("only-simple-regions",
+                  cl::desc("Show only simple regions in the graphviz viewer"),
+                  cl::Hidden,
+                  cl::init(false));
+
+namespace llvm {
+template<>
+struct DOTGraphTraits<RegionNode*> : public DefaultDOTGraphTraits {
+
+  DOTGraphTraits (bool isSimple=false)
+    : DefaultDOTGraphTraits(isSimple) {}
+
+  std::string getNodeLabel(RegionNode *Node, RegionNode *Graph) {
+
+    if (!Node->isSubRegion()) {
+      BasicBlock *BB = Node->getNodeAs<BasicBlock>();
+
+      if (isSimple())
+        return DOTGraphTraits<const Function*>
+          ::getSimpleNodeLabel(BB, BB->getParent());
+      else
+        return DOTGraphTraits<const Function*>
+          ::getCompleteNodeLabel(BB, BB->getParent());
+    }
+
+    return "Not implemented";
+  }
+};
+
+template<>
+struct DOTGraphTraits<RegionInfo*> : public DOTGraphTraits<RegionNode*> {
+
+  DOTGraphTraits (bool isSimple=false)
+    : DOTGraphTraits<RegionNode*>(isSimple) {}
+
+  static std::string getGraphName(RegionInfo *DT) {
+    return "Region Graph";
+  }
+
+  std::string getNodeLabel(RegionNode *Node, RegionInfo *G) {
+    return DOTGraphTraits<RegionNode*>::getNodeLabel(Node,
+                                                     G->getTopLevelRegion());
+  }
+
+  // Print the cluster of the subregions. This groups the single basic blocks
+  // and adds a different background color for each group.
+  static void printRegionCluster(const Region *R, GraphWriter<RegionInfo*> &GW,
+                                 unsigned depth = 0) {
+    raw_ostream &O = GW.getOStream();
+    O.indent(2 * depth) << "subgraph cluster_" << static_cast<const void*>(R)
+      << " {\n";
+    O.indent(2 * (depth + 1)) << "label = \"\";\n";
+
+    if (!onlySimpleRegions || R->isSimple()) {
+      O.indent(2 * (depth + 1)) << "style = filled;\n";
+      O.indent(2 * (depth + 1)) << "color = "
+        << ((R->getDepth() * 2 % 12) + 1) << "\n";
+
+    } else {
+      O.indent(2 * (depth + 1)) << "style = solid;\n";
+      O.indent(2 * (depth + 1)) << "color = "
+        << ((R->getDepth() * 2 % 12) + 2) << "\n";
+    }
+
+    for (Region::const_iterator RI = R->begin(), RE = R->end(); RI != RE; ++RI)
+      printRegionCluster(*RI, GW, depth + 1);
+
+    RegionInfo *RI = R->getRegionInfo();
+
+    for (Region::const_block_iterator BI = R->block_begin(),
+         BE = R->block_end(); BI != BE; ++BI) {
+      BasicBlock *BB = (*BI)->getNodeAs<BasicBlock>();
+      if (RI->getRegionFor(BB) == R)
+        O.indent(2 * (depth + 1)) << "Node"
+          << static_cast<const void*>(RI->getTopLevelRegion()->getBBNode(BB))
+          << ";\n";
+    }
+
+    O.indent(2 * depth) << "}\n";
+  }
+
+  static void addCustomGraphFeatures(const RegionInfo* RI,
+                                     GraphWriter<RegionInfo*> &GW) {
+    raw_ostream &O = GW.getOStream();
+    O << "\tcolorscheme = \"paired12\"\n";
+    printRegionCluster(RI->getTopLevelRegion(), GW, 4);
+  }
+};
+} //end namespace llvm
+
+namespace {
+
+struct RegionViewer
+  : public DOTGraphTraitsViewer<RegionInfo, false> {
+  static char ID;
+  RegionViewer() : DOTGraphTraitsViewer<RegionInfo, false>("reg", &ID){}
+};
+
+char RegionViewer::ID = 0;
+INITIALIZE_PASS(RegionViewer, "view-regions", "View regions of function",
+                true, true);
+
+struct RegionOnlyViewer
+  : public DOTGraphTraitsViewer<RegionInfo, true> {
+  static char ID;
+  RegionOnlyViewer() : DOTGraphTraitsViewer<RegionInfo, true>("regonly", &ID){}
+};
+
+char RegionOnlyViewer::ID = 0;
+INITIALIZE_PASS(RegionOnlyViewer, "view-regions-only",
+                "View regions of function (with no function bodies)",
+                true, true);
+
+struct RegionPrinter
+  : public DOTGraphTraitsPrinter<RegionInfo, false> {
+  static char ID;
+  RegionPrinter() :
+    DOTGraphTraitsPrinter<RegionInfo, false>("reg", &ID) {}
+};
+} //end anonymous namespace
+
+char RegionPrinter::ID = 0;
+INITIALIZE_PASS(RegionPrinter, "dot-regions",
+                "Print regions of function to 'dot' file", true, true);
+
+struct RegionOnlyPrinter
+  : public DOTGraphTraitsPrinter<RegionInfo, true> {
+  static char ID;
+  RegionOnlyPrinter() :
+    DOTGraphTraitsPrinter<RegionInfo, true>("reg", &ID) {}
+};
+
+char RegionOnlyPrinter::ID = 0;
+INITIALIZE_PASS(RegionOnlyPrinter, "dot-regions-only",
+                "Print regions of function to 'dot' file "
+                "(with no function bodies)",
+                true, true);
+
+FunctionPass* llvm::createRegionViewerPass() {
+  return new RegionViewer();
+}
+
+FunctionPass* llvm::createRegionOnlyViewerPass() {
+  return new RegionOnlyViewer();
+}
+
+FunctionPass* llvm::createRegionPrinterPass() {
+  return new RegionPrinter();
+}
+
+FunctionPass* llvm::createRegionOnlyPrinterPass() {
+  return new RegionOnlyPrinter();
+}
+