//===- ProfileInfo.cpp - Profile Info Interface ---------------------------===//
-//
+//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and 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
//
//===----------------------------------------------------------------------===//
+#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 AliasAnalysis interface, providing a nice name to refer to.
+// Register the ProfileInfo interface, providing a nice name to refer to.
namespace {
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 NoProfileInfo : public ImmutablePass, public ProfileInfo {
- unsigned getExecutionCount(BasicBlock *BB) { return 0; }
+ struct VISIBILITY_HIDDEN NoProfileInfo
+ : public ImmutablePass, public ProfileInfo {
+ static char ID; // Class identification, replacement for typeinfo
+ NoProfileInfo() : ImmutablePass((intptr_t)&ID) {}
};
-
+
+ char NoProfileInfo::ID = 0;
// Register this pass...
- RegisterOpt<NoProfileInfo>
+ RegisterPass<NoProfileInfo>
X("no-profile", "No Profile Information");
- // Declare that we implement the AliasAnalysis interface
- RegisterAnalysisGroup<ProfileInfo, NoProfileInfo> Y;
+ // Declare that we implement the ProfileInfo interface
+ RegisterAnalysisGroup<ProfileInfo, true> Y(X);
} // End of anonymous namespace
+
+ImmutablePass *llvm::createNoProfileInfoPass() { return new NoProfileInfo(); }