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.

llvm-svn: 191835

1 files changed, 0 insertions, 117 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/EdgeProfiling.cpp b/llvm/lib/Transforms/Instrumentation/EdgeProfiling.cpp
deleted file mode 100644
index a2459fbafe1..00000000000
--- a/llvm/lib/Transforms/Instrumentation/EdgeProfiling.cpp
+++ /dev/null
@@ -1,117 +0,0 @@
-//===- EdgeProfiling.cpp - Insert counters for 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.
-//
-// Note that this implementation is very naive.  We insert a counter for *every*
-// edge in the program, instead of using control flow information to prune the
-// number of counters inserted.
-//
-//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "insert-edge-profiling"
-
-#include "llvm/Transforms/Instrumentation.h"
-#include "ProfilingUtils.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include <set>
-using namespace llvm;
-
-STATISTIC(NumEdgesInserted, "The # of edges inserted.");
-
-namespace {
-  class EdgeProfiler : public ModulePass {
-    bool runOnModule(Module &M);
-  public:
-    static char ID; // Pass identification, replacement for typeid
-    EdgeProfiler() : ModulePass(ID) {
-      initializeEdgeProfilerPass(*PassRegistry::getPassRegistry());
-    }
-
-    virtual const char *getPassName() const {
-      return "Edge Profiler";
-    }
-  };
-}
-
-char EdgeProfiler::ID = 0;
-INITIALIZE_PASS(EdgeProfiler, "insert-edge-profiling",
-                "Insert instrumentation for edge profiling", false, false)
-
-ModulePass *llvm::createEdgeProfilerPass() { return new EdgeProfiler(); }
-
-bool EdgeProfiler::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!
-  }
-
-  std::set<BasicBlock*> BlocksToInstrument;
-  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!
-      BlocksToInstrument.insert(BB);
-      NumEdges += BB->getTerminator()->getNumSuccessors();
-    }
-  }
-
-  Type *ATy = ArrayType::get(Type::getInt32Ty(M.getContext()), NumEdges);
-  GlobalVariable *Counters =
-    new GlobalVariable(M, ATy, false, GlobalValue::InternalLinkage,
-                       Constant::getNullValue(ATy), "EdgeProfCounters");
-  NumEdgesInserted = NumEdges;
-
-  // Instrument all of the edges...
-  unsigned i = 0;
-  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
-    if (F->isDeclaration()) continue;
-    // Create counter for (0,entry) edge.
-    IncrementCounterInBlock(&F->getEntryBlock(), i++, Counters);
-    for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
-      if (BlocksToInstrument.count(BB)) {  // Don't instrument inserted blocks
-        // Okay, we have to add a counter of each outgoing edge.  If the
-        // outgoing edge is not critical don't split it, just insert the counter
-        // in the source or destination of the edge.
-        TerminatorInst *TI = BB->getTerminator();
-        for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
-          // If the edge is critical, split it.
-          SplitCriticalEdge(TI, s, this);
-
-          // 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
-            IncrementCounterInBlock(BB, i++, Counters, false);
-          } else {
-            // Insert counter at the start of the block
-            IncrementCounterInBlock(TI->getSuccessor(s), i++, Counters);
-          }
-        }
-      }
-  }
-
-  // Add the initialization call to main.
-  InsertProfilingInitCall(Main, "llvm_start_edge_profiling", Counters);
-  return true;
-}
-