Remove the very substantial, largely unmaintained legacy PGO

infrastructure.

This was essentially work toward PGO based on a design that had several
flaws, partially dating from a time when LLVM had a different
architecture, and with an effort to modernize it abandoned without being
completed. Since then, it has bitrotted for several years further. The
result is nearly unusable, and isn't helping any of the modern PGO
efforts. Instead, it is getting in the way, adding confusion about PGO
in LLVM and distracting everyone with maintenance on essentially dead
code. Removing it paves the way for modern efforts around PGO.

Among other effects, this removes the last of the runtime libraries from
LLVM. Those are being developed in the separate 'compiler-rt' project
now, with somewhat different licensing specifically more approriate for
runtimes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191835 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 225 deletions

diff --git a/lib/Transforms/Instrumentation/OptimalEdgeProfiling.cpp b/lib/Transforms/Instrumentation/OptimalEdgeProfiling.cpp
deleted file mode 100644
index b45aef6..0000000
--- a/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;
-}
-