path: root/lib/Analysis/ProfileInfo.cpp

//===- ProfileInfo.cpp - Profile Info Interface ---------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the abstract ProfileInfo interface, and the default
// "no profile" implementation.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "profile-info"
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/ProfileInfo.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Pass.h"
#include "llvm/Support/CFG.h"
#include "llvm/ADT/SmallSet.h"
#include <set>
#include <queue>
#include <limits>
using namespace llvm;

namespace llvm {
  template<> char ProfileInfoT<Function,BasicBlock>::ID = 0;
}

// Register the ProfileInfo interface, providing a nice name to refer to.
INITIALIZE_ANALYSIS_GROUP(ProfileInfo, "Profile Information", NoProfileInfo)

namespace llvm {

template <>
ProfileInfoT<MachineFunction, MachineBasicBlock>::ProfileInfoT() {}
template <>
ProfileInfoT<MachineFunction, MachineBasicBlock>::~ProfileInfoT() {}

template <>
ProfileInfoT<Function, BasicBlock>::ProfileInfoT() {
  MachineProfile = 0;
}
template <>
ProfileInfoT<Function, BasicBlock>::~ProfileInfoT() {
  if (MachineProfile) delete MachineProfile;
}

template<>
char ProfileInfoT<MachineFunction, MachineBasicBlock>::ID = 0;

template<>
const double ProfileInfoT<Function,BasicBlock>::MissingValue = -1;

template<> const
double ProfileInfoT<MachineFunction, MachineBasicBlock>::MissingValue = -1;

template<> double
ProfileInfoT<Function,BasicBlock>::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;
  }

  double Count = MissingValue;

  const_pred_iterator PI = pred_begin(BB), PE = pred_end(BB);

  // Are there zero predecessors of this block?
  if (PI == PE) {
    Edge e = getEdge(0, BB);
    Count = getEdgeWeight(e);
  } else {
    // Otherwise, if there are predecessors, the execution count of this block is
    // the sum of the edge frequencies from the incoming edges.
    std::set<const BasicBlock*> ProcessedPreds;
    Count = 0;
    for (; PI != PE; ++PI) {
      const BasicBlock *P = *PI;
      if (ProcessedPreds.insert(P).second) {
        double w = getEdgeWeight(getEdge(P, BB));
        if (w == MissingValue) {
          Count = MissingValue;
          break;
        }
        Count += w;
      }
    }
  }

  // If the predecessors did not suffice to get block weight, try successors.
  if (Count == MissingValue) {

    succ_const_iterator SI = succ_begin(BB), SE = succ_end(BB);

    // Are there zero successors of this block?
    if (SI == SE) {
      Edge e = getEdge(BB,0);
      Count = getEdgeWeight(e);
    } else {
      std::set<const BasicBlock*> ProcessedSuccs;
      Count = 0;
      for (; SI != SE; ++SI)
        if (ProcessedSuccs.insert(*SI).second) {
          double w = getEdgeWeight(getEdge(BB, <