OptimalEdgeProfiling: Reading in Profiles.

This enables LLVM to read the OptimalEdgeProfiles.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80715 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/ProfileInfoLoader.h

@@ -33,6 +33,7 @@ class ProfileInfoLoader {
   std::vector<unsigned>    FunctionCounts;
   std::vector<unsigned>    BlockCounts;
   std::vector<unsigned>    EdgeCounts;
+  std::vector<unsigned>    OptimalEdgeCounts;
   std::vector<unsigned>    BBTrace;
   bool Warned;
 public:
@@ -66,6 +67,14 @@ public:
   const std::vector<unsigned> &getRawEdgeCounts() const {
     return EdgeCounts;
   }
+
+  // getEdgeOptimalCounts - This method is used by consumers of optimal edge 
+  // counting information.
+  //
+  const std::vector<unsigned> &getRawOptimalEdgeCounts() const {
+    return OptimalEdgeCounts;
+  }
+
 };
 
 } // End llvm namespace

lib/Analysis/ProfileInfoLoader.cpp

@@ -54,17 +54,34 @@ static void ReadProfilingBlock(const char *ToolName, FILE *F,
     exit(1);
   }
 
-  // Make sure we have enough space...
+  // Make sure we have enough space... The space is initialised to -1 to
+  // facitiltate the loading of missing values for OptimalEdgeProfiling.
   if (Data.size() < NumEntries)
-    Data.resize(NumEntries);
+    Data.resize(NumEntries, -1);
 
   // Accumulate the data we just read into the data.
   if (!ShouldByteSwap) {
-    for (unsigned i = 0; i != NumEntries; ++i)
-      Data[i] += TempSpace[i];
+    for (unsigned i = 0; i != NumEntries; ++i) {
+      unsigned data = TempSpace[i];
+      if (data != (unsigned)-1) {       // only load data if its not MissingVal
+        if (Data[i] == (unsigned)-1) {
+          Data[i] = data;               // if data is still initialised
+        } else {
+          Data[i] += data;
+        }
+      }
+    }
   } else {
-    for (unsigned i = 0; i != NumEntries; ++i)
-      Data[i] += ByteSwap(TempSpace[i], true);
+    for (unsigned i = 0; i != NumEntries; ++i) {
+      unsigned data = ByteSwap(TempSpace[i], true);
+      if (data != (unsigned)-1) {       // only load data if its not MissingVal
+        if (Data[i] == (unsigned)-1) {
+          Data[i] = data;
+        } else {
+          Data[i] += data;
+        }
+      }
+    }
   }
 }
 
@@ -127,6 +144,10 @@ ProfileInfoLoader::ProfileInfoLoader(const char *ToolName,
       ReadProfilingBlock(ToolName, F, ShouldByteSwap, EdgeCounts);
       break;
 
+    case OptEdgeInfo:
+      ReadProfilingBlock(ToolName, F, ShouldByteSwap, OptimalEdgeCounts);
+      break;
+
     case BBTraceInfo:
       ReadProfilingBlock(ToolName, F, ShouldByteSwap, BBTrace);
       break;

lib/Analysis/ProfileInfoLoaderPass.cpp

@@ -11,7 +11,7 @@
 // loads the information from a profile dump file.
 //
 //===----------------------------------------------------------------------===//
-
+#define DEBUG_TYPE "profile-loader"
 #include "llvm/BasicBlock.h"
 #include "llvm/InstrTypes.h"
 #include "llvm/Module.h"
@@ -21,9 +21,17 @@
 #include "llvm/Analysis/ProfileInfoLoader.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Format.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/SmallSet.h"
+#include <set>
 using namespace llvm;
 
+STATISTIC(NumEdgesRead, "The # of edges read.");
+
 static cl::opt<std::string>
 ProfileInfoFilename("profile-info-file", cl::init("llvmprof.out"),
                     cl::value_desc("filename"),
@@ -32,6 +40,8 @@ ProfileInfoFilename("profile-info-file", cl::init("llvmprof.out"),
 namespace {
   class VISIBILITY_HIDDEN LoaderPass : public ModulePass, public ProfileInfo {
     std::string Filename;
+    std::set<Edge> SpanningTree;
+    std::set<const BasicBlock*> BBisUnvisited;
   public:
     static char ID; // Class identification, replacement for typeinfo
     explicit LoaderPass(const std::string &filename = "")
@@ -47,6 +57,13 @@ namespace {
       return "Profiling information loader";
     }
 
+    // recurseBasicBlock() - Calculates the edge weights for as much basic
+    // blocks as possbile.
+    virtual void recurseBasicBlock(const BasicBlock *BB);
+    virtual void readEdgeOrRemember(Edge, Edge&, unsigned &, unsigned &);
+    virtual void readOrRememberEdge(ProfileInfo::Edge, unsigned,
+                                    unsigned, Function*);
+
     /// run - Load the profile information from the specified file.
     virtual bool runOnModule(Module &M);
   };
@@ -67,6 +84,90 @@ Pass *llvm::createProfileLoaderPass(const std::string &Filename) {
   return new LoaderPass(Filename);
 }
 
+void LoaderPass::readEdgeOrRemember(Edge edge, Edge &tocalc, 
+                                    unsigned &uncalc, unsigned &count) {
+  double w;
+  if ((w = getEdgeWeight(edge)) == MissingValue) {
+    tocalc = edge;
+    uncalc++;
+  } else {
+    count+=w;
+  }
+}
+
+// recurseBasicBlock - Visits all neighbours of a block and then tries to
+// calculate the missing edge values.
+void LoaderPass::recurseBasicBlock(const BasicBlock *BB) {
+
+  // break recursion if already visited
+  if (BBisUnvisited.find(BB) == BBisUnvisited.end()) return;
+  BBisUnvisited.erase(BB);
+  if (!BB) return;
+
+  for (succ_const_iterator bbi = succ_begin(BB), bbe = succ_end(BB);
+       bbi != bbe; ++bbi) {
+    recurseBasicBlock(*bbi);
+  }
+  for (pred_const_iterator bbi = pred_begin(BB), bbe = pred_end(BB);
+       bbi != bbe; ++bbi) {
+    recurseBasicBlock(*bbi);
+  }
+
+  Edge edgetocalc;
+  unsigned uncalculated = 0;
+
+  // collect weights of all incoming and outgoing edges, rememer edges that
+  // have no value
+  unsigned incount = 0;
+  SmallSet<const BasicBlock*,8> pred_visited;
+  pred_const_iterator bbi = pred_begin(BB), bbe = pred_end(BB);
+  if (bbi==bbe) {
+    readEdgeOrRemember(getEdge(0, BB),edgetocalc,uncalculated,incount);
+  }
+  for (;bbi != bbe; ++bbi) {
+    if (pred_visited.insert(*bbi)) {
+      readEdgeOrRemember(getEdge(*bbi, BB),edgetocalc,uncalculated,incount);
+    }
+  }
+
+  unsigned outcount = 0;
+  SmallSet<const BasicBlock*,8> succ_visited;
+  succ_const_iterator sbbi = succ_begin(BB), sbbe = succ_end(BB);
+  if (sbbi==sbbe) {
+    readEdgeOrRemember(getEdge(BB, 0),edgetocalc,uncalculated,outcount);
+  }
+  for (;sbbi != sbbe; ++sbbi) {
+    if (succ_visited.insert(*sbbi)) {
+      readEdgeOrRemember(getEdge(BB, *sbbi),edgetocalc,uncalculated,outcount);
+    }
+  }
+
+  // if exactly one edge weight was missing, calculate it and remove it from
+  // spanning tree
+  if (uncalculated == 1) {
+    if (incount < outcount) {
+      EdgeInformation[BB->getParent()][edgetocalc] = outcount-incount;
+    } else {
+      EdgeInformation[BB->getParent()][edgetocalc] = incount-outcount;
+    }
+    DEBUG(errs() << "--Calc Edge Counter for " << edgetocalc << ": "
+                 << format("%g", getEdgeWeight(edgetocalc)) << "\n");
+    SpanningTree.erase(edgetocalc);
+  }
+}
+
+void LoaderPass::readOrRememberEdge(ProfileInfo::Edge e,
+                                    unsigned weight, unsigned ei,
+                                    Function *F) {
+  if (weight != (unsigned)MissingValue) {
+    EdgeInformation[F][e] += weight;
+    DEBUG(errs()<<"--Read Edge Counter for " << e 
+                <<" (# "<<ei<<"): "<<(unsigned)getEdgeWeight(e)<<"\n");
+  } else {
+    SpanningTree.insert(e);
+  }
+}
+
 bool LoaderPass::runOnModule(Module &M) {
   ProfileInfoLoader PIL("profile-loader", Filename, M);
 
@@ -95,6 +196,64 @@ bool LoaderPass::runOnModule(Module &M) {
       errs() << "WARNING: profile information is inconsistent with "
              << "the current program!\n";
     }
+    NumEdgesRead = ei;
+  }
+
+  ECs = PIL.getRawOptimalEdgeCounts();
+  if (ECs.size() > 0) {
+    unsigned ei = 0;
+    for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
+      if (F->isDeclaration()) continue;
+      DEBUG(errs()<<"Working on "<<F->getNameStr()<<"\n");
+      if (ei < ECs.size()) {
+        readOrRememberEdge(getEdge(0,&F->getEntryBlock()), ECs[ei], ei, F); 
+        ei++;
+      }
+      for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+        TerminatorInst *TI = BB->getTerminator();
+        if (TI->getNumSuccessors() == 0) {
+          if (ei < ECs.size()) {
+            readOrRememberEdge(getEdge(BB,0), ECs[ei], ei, F); ei++;
+          }
+        }
+        for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
+          if (ei < ECs.size()) {
+            readOrRememberEdge(getEdge(BB,TI->getSuccessor(s)), ECs[ei], ei, F);
+            ei++;
+          }
+        }
+      }
+      while (SpanningTree.size() > 0) {
+#if 0
+        unsigned size = SpanningTree.size();
+#endif
+        BBisUnvisited.clear();
+        for (std::set<Edge>::iterator ei = SpanningTree.begin(),
+             ee = SpanningTree.end(); ei != ee; ++ei) {
+          BBisUnvisited.insert(ei->first);
+          BBisUnvisited.insert(ei->second);
+        }
+        while (BBisUnvisited.size() > 0) {
+          recurseBasicBlock(*BBisUnvisited.begin());
+        }
+#if 0
+        if (SpanningTree.size() == size) {
+          DEBUG(errs()<<"{");
+          for (std::set<Edge>::iterator ei = SpanningTree.begin(),
+               ee = SpanningTree.end(); ei != ee; ++ei) {
+            DEBUG(errs()<<"("<<(ei->first?ei->first->getName():"0")<<","
+                        <<(ei->second?ei->second->getName():"0")<<"),");
+          }
+          assert(0 && "No edge calculated!");
+        }
+#endif
+      }
+    }
+    if (ei != ECs.size()) {
+      errs() << "WARNING: profile information is inconsistent with "
+             << "the current program!\n";
+    }
+    NumEdgesRead = ei;
   }
 
   BlockInformation.clear();