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Diffstat (limited to 'contrib/llvm/lib/Transforms/Instrumentation/OptimalEdgeProfiling.cpp')
-rw-r--r-- | contrib/llvm/lib/Transforms/Instrumentation/OptimalEdgeProfiling.cpp | 225 |
1 files changed, 0 insertions, 225 deletions
diff --git a/contrib/llvm/lib/Transforms/Instrumentation/OptimalEdgeProfiling.cpp b/contrib/llvm/lib/Transforms/Instrumentation/OptimalEdgeProfiling.cpp deleted file mode 100644 index b45aef65..0000000 --- a/contrib/llvm/lib/Transforms/Instrumentation/OptimalEdgeProfiling.cpp +++ /dev/null @@ -1,225 +0,0 @@ -//===- OptimalEdgeProfiling.cpp - Insert counters for opt. edge profiling -===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This pass instruments the specified program with counters for edge profiling. -// Edge profiling can give a reasonable approximation of the hot paths through a -// program, and is used for a wide variety of program transformations. -// -//===----------------------------------------------------------------------===// -#define DEBUG_TYPE "insert-optimal-edge-profiling" -#include "llvm/Transforms/Instrumentation.h" -#include "MaximumSpanningTree.h" -#include "ProfilingUtils.h" -#include "llvm/ADT/DenseSet.h" -#include "llvm/ADT/Statistic.h" -#include "llvm/Analysis/Passes.h" -#include "llvm/Analysis/ProfileInfo.h" -#include "llvm/Analysis/ProfileInfoLoader.h" -#include "llvm/IR/Constants.h" -#include "llvm/IR/Module.h" -#include "llvm/Pass.h" -#include "llvm/Support/Debug.h" -#include "llvm/Support/raw_ostream.h" -#include "llvm/Transforms/Utils/BasicBlockUtils.h" -using namespace llvm; - -STATISTIC(NumEdgesInserted, "The # of edges inserted."); - -namespace { - class OptimalEdgeProfiler : public ModulePass { - bool runOnModule(Module &M); - public: - static char ID; // Pass identification, replacement for typeid - OptimalEdgeProfiler() : ModulePass(ID) { - initializeOptimalEdgeProfilerPass(*PassRegistry::getPassRegistry()); - } - - void getAnalysisUsage(AnalysisUsage &AU) const { - AU.addRequiredID(ProfileEstimatorPassID); - AU.addRequired<ProfileInfo>(); - } - - virtual const char *getPassName() const { - return "Optimal Edge Profiler"; - } - }; -} - -char OptimalEdgeProfiler::ID = 0; -INITIALIZE_PASS_BEGIN(OptimalEdgeProfiler, "insert-optimal-edge-profiling", - "Insert optimal instrumentation for edge profiling", - false, false) -INITIALIZE_PASS_DEPENDENCY(ProfileEstimatorPass) -INITIALIZE_AG_DEPENDENCY(ProfileInfo) -INITIALIZE_PASS_END(OptimalEdgeProfiler, "insert-optimal-edge-profiling", - "Insert optimal instrumentation for edge profiling", - false, false) - -ModulePass *llvm::createOptimalEdgeProfilerPass() { - return new OptimalEdgeProfiler(); -} - -inline static void printEdgeCounter(ProfileInfo::Edge e, - BasicBlock* b, - unsigned i) { - DEBUG(dbgs() << "--Edge Counter for " << (e) << " in " \ - << ((b)?(b)->getName():"0") << " (# " << (i) << ")\n"); -} - -bool OptimalEdgeProfiler::runOnModule(Module &M) { - Function *Main = M.getFunction("main"); - if (Main == 0) { - errs() << "WARNING: cannot insert edge profiling into a module" - << " with no main function!\n"; - return false; // No main, no instrumentation! - } - - // NumEdges counts all the edges that may be instrumented. Later on its - // decided which edges to actually instrument, to achieve optimal profiling. - // For the entry block a virtual edge (0,entry) is reserved, for each block - // with no successors an edge (BB,0) is reserved. These edges are necessary - // to calculate a truly optimal maximum spanning tree and thus an optimal - // instrumentation. - unsigned NumEdges = 0; - - for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) { - if (F->isDeclaration()) continue; - // Reserve space for (0,entry) edge. - ++NumEdges; - for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) { - // Keep track of which blocks need to be instrumented. We don't want to - // instrument blocks that are added as the result of breaking critical - // edges! - if (BB->getTerminator()->getNumSuccessors() == 0) { - // Reserve space for (BB,0) edge. - ++NumEdges; - } else { - NumEdges += BB->getTerminator()->getNumSuccessors(); - } - } - } - - // In the profiling output a counter for each edge is reserved, but only few - // are used. This is done to be able to read back in the profile without - // calulating the maximum spanning tree again, instead each edge counter that - // is not used is initialised with -1 to signal that this edge counter has to - // be calculated from other edge counters on reading the profile info back - // in. - - Type *Int32 = Type::getInt32Ty(M.getContext()); - ArrayType *ATy = ArrayType::get(Int32, NumEdges); - GlobalVariable *Counters = - new GlobalVariable(M, ATy, false, GlobalValue::InternalLinkage, - Constant::getNullValue(ATy), "OptEdgeProfCounters"); - NumEdgesInserted = 0; - - std::vector<Constant*> Initializer(NumEdges); - Constant *Zero = ConstantInt::get(Int32, 0); - Constant *Uncounted = ConstantInt::get(Int32, ProfileInfoLoader::Uncounted); - - // Instrument all of the edges not in MST... - unsigned i = 0; - for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) { - if (F->isDeclaration()) continue; - DEBUG(dbgs() << "Working on " << F->getName() << "\n"); - - // Calculate a Maximum Spanning Tree with the edge weights determined by - // ProfileEstimator. ProfileEstimator also assign weights to the virtual - // edges (0,entry) and (BB,0) (for blocks with no successors) and this - // edges also participate in the maximum spanning tree calculation. - // The third parameter of MaximumSpanningTree() has the effect that not the - // actual MST is returned but the edges _not_ in the MST. - - ProfileInfo::EdgeWeights ECs = - getAnalysis<ProfileInfo>(*F).getEdgeWeights(F); - std::vector<ProfileInfo::EdgeWeight> EdgeVector(ECs.begin(), ECs.end()); - MaximumSpanningTree<BasicBlock> MST(EdgeVector); - std::stable_sort(MST.begin(), MST.end()); - - // Check if (0,entry) not in the MST. If not, instrument edge - // (IncrementCounterInBlock()) and set the counter initially to zero, if - // the edge is in the MST the counter is initialised to -1. - - BasicBlock *entry = &(F->getEntryBlock()); - ProfileInfo::Edge edge = ProfileInfo::getEdge(0, entry); - if (!std::binary_search(MST.begin(), MST.end(), edge)) { - printEdgeCounter(edge, entry, i); - IncrementCounterInBlock(entry, i, Counters); ++NumEdgesInserted; - Initializer[i++] = (Zero); - } else{ - Initializer[i++] = (Uncounted); - } - - // InsertedBlocks contains all blocks that were inserted for splitting an - // edge, this blocks do not have to be instrumented. - DenseSet<BasicBlock*> InsertedBlocks; - for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) { - // Check if block was not inserted and thus does not have to be - // instrumented. - if (InsertedBlocks.count(BB)) continue; - - // Okay, we have to add a counter of each outgoing edge not in MST. If - // the outgoing edge is not critical don't split it, just insert the - // counter in the source or destination of the edge. Also, if the block - // has no successors, the virtual edge (BB,0) is processed. - TerminatorInst *TI = BB->getTerminator(); - if (TI->getNumSuccessors() == 0) { - ProfileInfo::Edge edge = ProfileInfo::getEdge(BB, 0); - if (!std::binary_search(MST.begin(), MST.end(), edge)) { - printEdgeCounter(edge, BB, i); - IncrementCounterInBlock(BB, i, Counters); ++NumEdgesInserted; - Initializer[i++] = (Zero); - } else{ - Initializer[i++] = (Uncounted); - } - } - for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) { - BasicBlock *Succ = TI->getSuccessor(s); - ProfileInfo::Edge edge = ProfileInfo::getEdge(BB,Succ); - if (!std::binary_search(MST.begin(), MST.end(), edge)) { - - // If the edge is critical, split it. - bool wasInserted = SplitCriticalEdge(TI, s, this); - Succ = TI->getSuccessor(s); - if (wasInserted) - InsertedBlocks.insert(Succ); - - // Okay, we are guaranteed that the edge is no longer critical. If - // we only have a single successor, insert the counter in this block, - // otherwise insert it in the successor block. - if (TI->getNumSuccessors() == 1) { - // Insert counter at the start of the block - printEdgeCounter(edge, BB, i); - IncrementCounterInBlock(BB, i, Counters); ++NumEdgesInserted; - } else { - // Insert counter at the start of the block - printEdgeCounter(edge, Succ, i); - IncrementCounterInBlock(Succ, i, Counters); ++NumEdgesInserted; - } - Initializer[i++] = (Zero); - } else { - Initializer[i++] = (Uncounted); - } - } - } - } - - // Check if the number of edges counted at first was the number of edges we - // considered for instrumentation. - assert(i == NumEdges && "the number of edges in counting array is wrong"); - - // Assign the now completely defined initialiser to the array. - Constant *init = ConstantArray::get(ATy, Initializer); - Counters->setInitializer(init); - - // Add the initialization call to main. - InsertProfilingInitCall(Main, "llvm_start_opt_edge_profiling", Counters); - return true; -} - |