llvm-mirror/lib/Analysis/ProfileInfo.cpp
Dan Gohman bab18cae46 Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.

llvm-svn: 51017
2008-05-13 00:00:25 +00:00

101 lines
3.4 KiB
C++

//===- 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.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/ProfileInfo.h"
#include "llvm/Pass.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/Compiler.h"
#include <set>
using namespace llvm;
// Register the ProfileInfo interface, providing a nice name to refer to.
static RegisterAnalysisGroup<ProfileInfo> Z("Profile Information");
char ProfileInfo::ID = 0;
ProfileInfo::~ProfileInfo() {}
unsigned ProfileInfo::getExecutionCount(BasicBlock *BB) const {
pred_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);
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);
for (; PI != PE; ++PI)
if (ProcessedPreds.insert(*PI).second)
Count += getEdgeWeight(*PI, BB);
return Count;
}
//===----------------------------------------------------------------------===//
// NoProfile ProfileInfo implementation
//
namespace {
struct VISIBILITY_HIDDEN NoProfileInfo
: public ImmutablePass, public ProfileInfo {
static char ID; // Class identification, replacement for typeinfo
NoProfileInfo() : ImmutablePass((intptr_t)&ID) {}
};
} // End of anonymous namespace
char NoProfileInfo::ID = 0;
// Register this pass...
static RegisterPass<NoProfileInfo>
X("no-profile", "No Profile Information", false, true);
// Declare that we implement the ProfileInfo interface
static RegisterAnalysisGroup<ProfileInfo, true> Y(X);
ImmutablePass *llvm::createNoProfileInfoPass() { return new NoProfileInfo(); }