1 files changed, 131 insertions, 35 deletions

diff --git a/lib/Analysis/ProfileInfo.cpp b/lib/Analysis/ProfileInfo.cpp
index a0965b6..9efdd23 100644
--- a/lib/Analysis/ProfileInfo.cpp
+++ b/lib/Analysis/ProfileInfo.cpp
@@ -17,6 +17,9 @@
 #include "llvm/Pass.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Format.h"
 #include <set>
 using namespace llvm;
 
@@ -26,56 +29,149 @@ char ProfileInfo::ID = 0;
 
 ProfileInfo::~ProfileInfo() {}
 
-unsigned ProfileInfo::getExecutionCount(BasicBlock *BB) const {
-  pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
+const double ProfileInfo::MissingValue = -1;
+
+double ProfileInfo::getExecutionCount(const BasicBlock *BB) {
+  std::map<const Function*, BlockCounts>::iterator J =
+    BlockInformation.find(BB->getParent());
+  if (J != BlockInformation.end()) {
+    BlockCounts::iterator I = J->second.find(BB);
+    if (I != J->second.end())
+      return I->second;
+  }
+
+  pred_const_iterator PI = pred_begin(BB), PE = pred_end(BB);
 
   // Are there zero predecessors of this block?
   if (PI == PE) {
     // If this is the entry block, look for the Null -> Entry edge.
     if (BB == &BB->getParent()->getEntryBlock())
-      return getEdgeWeight(0, BB);
+      return getEdgeWeight(getEdge(0, BB));
     else
       return 0;   // Otherwise, this is a dead block.
   }
 
   // Otherwise, if there are predecessors, the execution count of this block is
-  // the sum of the edge frequencies from the incoming edges.  Note that if
-  // there are multiple edges from a predecessor to this block that we don't
-  // want to count its weight multiple times.  For this reason, we keep track of
-  // the predecessors we've seen and only count them if we haven't run into them
-  // yet.
-  //
-  // We don't want to create an std::set unless we are dealing with a block that
-  // has a LARGE number of in-edges.  Handle the common case of having only a
-  // few in-edges with special code.
-  //
-  BasicBlock *FirstPred = *PI;
-  unsigned Count = getEdgeWeight(FirstPred, BB);
-  ++PI;
-  if (PI == PE) return Count;   // Quick exit for single predecessor blocks
-
-  BasicBlock *SecondPred = *PI;
-  if (SecondPred != FirstPred) Count += getEdgeWeight(SecondPred, BB);
-  ++PI;
-  if (PI == PE) return Count;   // Quick exit for two predecessor blocks
-
-  BasicBlock *ThirdPred = *PI;
-  if (ThirdPred != FirstPred && ThirdPred != SecondPred)
-    Count += getEdgeWeight(ThirdPred, BB);
-  ++PI;
-  if (PI == PE) return Count;   // Quick exit for three predecessor blocks
-
-  std::set<BasicBlock*> ProcessedPreds;
-  ProcessedPreds.insert(FirstPred);
-  ProcessedPreds.insert(SecondPred);
-  ProcessedPreds.insert(ThirdPred);
+  // the sum of the edge frequencies from the incoming edges.
+  std::set<const BasicBlock*> ProcessedPreds;
+  double Count = 0;
   for (; PI != PE; ++PI)
-    if (ProcessedPreds.insert(*PI).second)
-      Count += getEdgeWeight(*PI, BB);
+    if (ProcessedPreds.insert(*PI).second) {
+      double w = getEdgeWeight(getEdge(*PI, BB));
+      if (w == MissingValue) {
+        Count = MissingValue;
+        break;
+      }
+      Count += w;
+    }
+
+  if (Count != MissingValue) BlockInformation[BB->getParent()][BB] = Count;
+  return Count;
+}
+
+double ProfileInfo::getExecutionCount(const Function *F) {
+  std::map<const Function*, double>::iterator J =
+    FunctionInformation.find(F);
+  if (J != FunctionInformation.end())
+    return J->second;
+
+  // isDeclaration() is checked here and not at start of function to allow
+  // functions without a body still to have a execution count.
+  if (F->isDeclaration()) return MissingValue;
+
+  double Count = getExecutionCount(&F->getEntryBlock());
+  if (Count != MissingValue) FunctionInformation[F] = Count;
   return Count;
 }
 
+/// Replaces all occurences of RmBB in the ProfilingInfo with DestBB.
+/// This checks all edges of the function the blocks reside in and replaces the
+/// occurences of RmBB with DestBB.
+void ProfileInfo::replaceAllUses(const BasicBlock *RmBB, 
+                                 const BasicBlock *DestBB) {
+  DEBUG(errs() << "Replacing " << RmBB->getNameStr()
+               << " with " << DestBB->getNameStr() << "\n");
+  const Function *F = DestBB->getParent();
+  std::map<const Function*, EdgeWeights>::iterator J =
+    EdgeInformation.find(F);
+  if (J == EdgeInformation.end()) return;
+
+  for (EdgeWeights::iterator I = J->second.begin(), E = J->second.end();
+       I != E; ++I) {
+    Edge e = I->first;
+    Edge newedge; bool foundedge = false;
+    if (e.first == RmBB) {
+      newedge = getEdge(DestBB, e.second);
+      foundedge = true;
+    }
+    if (e.second == RmBB) {
+      newedge = getEdge(e.first, DestBB);
+      foundedge = true;
+    }
+    if (foundedge) {
+      double w = getEdgeWeight(e);
+      EdgeInformation[F][newedge] = w;
+      DEBUG(errs() << "Replacing " << e << " with " << newedge  << "\n");
+      J->second.erase(e);
+    }
+  }
+}
+
+/// Splits an edge in the ProfileInfo and redirects flow over NewBB.
+/// Since its possible that there is more than one edge in the CFG from FristBB
+/// to SecondBB its necessary to redirect the flow proporionally.
+void ProfileInfo::splitEdge(const BasicBlock *FirstBB,
+                            const BasicBlock *SecondBB,
+                            const BasicBlock *NewBB,
+                            bool MergeIdenticalEdges) {
+  const Function *F = FirstBB->getParent();
+  std::map<const Function*, EdgeWeights>::iterator J =
+    EdgeInformation.find(F);
+  if (J == EdgeInformation.end()) return;
+
+  // Generate edges and read current weight.
+  Edge e  = getEdge(FirstBB, SecondBB);
+  Edge n1 = getEdge(FirstBB, NewBB);
+  Edge n2 = getEdge(NewBB, SecondBB);
+  EdgeWeights &ECs = J->second;
+  double w = ECs[e];
+
+  int succ_count = 0;
+  if (!MergeIdenticalEdges) {
+    // First count the edges from FristBB to SecondBB, if there is more than
+    // one, only slice out a proporional part for NewBB.
+    for(succ_const_iterator BBI = succ_begin(FirstBB), BBE = succ_end(FirstBB);
+        BBI != BBE; ++BBI) {
+      if (*BBI == SecondBB) succ_count++;  
+    }
+    // When the NewBB is completely new, increment the count by one so that
+    // the counts are properly distributed.
+    if (getExecutionCount(NewBB) == ProfileInfo::MissingValue) succ_count++;
+  } else {
+    // When the edges are merged anyway, then redirect all flow.
+    succ_count = 1;
+  }
 
+  // We know now how many edges there are from FirstBB to SecondBB, reroute a
+  // proportional part of the edge weight over NewBB.
+  double neww = w / succ_count;
+  ECs[n1] += neww;
+  ECs[n2] += neww;
+  BlockInformation[F][NewBB] += neww;
+  if (succ_count == 1) {
+    ECs.erase(e);
+  } else {
+    ECs[e] -= neww;
+  }
+}
+
+raw_ostream& llvm::operator<<(raw_ostream &O, ProfileInfo::Edge E) {
+  O << "(";
+  O << (E.first ? E.first->getNameStr() : "0");
+  O << ",";
+  O << (E.second ? E.second->getNameStr() : "0");
+  return O << ")";
+}
 
 //===----------------------------------------------------------------------===//
 //  NoProfile ProfileInfo implementation