Temporarily Revert "[Attributor] Liveness analysis." as it's breaking the build.

This reverts commit 9285295f75a231dc446fa7cbc10a0a391b3434a5.

llvm-svn: 366737

2 files changed, 1 insertions, 175 deletions

diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index f4e2ed4df98..fa5dbc23014 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -16,7 +16,6 @@
 #include "llvm/Transforms/IPO/Attributor.h"
 
 #include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
@@ -32,9 +31,6 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
-
 #include <cassert>
 
 using namespace llvm;
@@ -1415,173 +1411,6 @@ ChangeStatus AANoAliasReturned::updateImpl(Attributor &A) {
   return ChangeStatus::UNCHANGED;
 }
 
-/// -------------------AAIsDead Function Attribute-----------------------
-
-struct AAIsDeadFunction : AAIsDead, BooleanState {
-
-  AAIsDeadFunction(Function &F, InformationCache &InfoCache)
-      : AAIsDead(F, InfoCache) {}
-
-  /// See AbstractAttribute::getState()
-  /// {
-  AbstractState &getState() override { return *this; }
-  const AbstractState &getState() const override { return *this; }
-  /// }
-
-  /// See AbstractAttribute::getManifestPosition().
-  ManifestPosition getManifestPosition() const override { return MP_FUNCTION; }
-
-  void initialize(Attributor &A) override {
-    Function &F = getAnchorScope();
-
-    ToBeExploredPaths.insert(&(F.getEntryBlock().front()));
-    AssumedLiveBlocks.insert(&(F.getEntryBlock()));
-    for (size_t i = 0; i < ToBeExploredPaths.size(); ++i)
-      explorePath(A, ToBeExploredPaths[i]);
-  }
-
-  /// Explores new instructions starting from \p I. If instruction is dead, stop
-  /// and return true if it discovered a new instruction.
-  bool explorePath(Attributor &A, Instruction *I);
-
-  const std::string getAsStr() const override {
-    return "LiveBBs(" + std::to_string(AssumedLiveBlocks.size()) + "/" +
-           std::to_string(getAnchorScope().size()) + ")";
-  }
-
-  /// See AbstractAttribute::manifest(...).
-  ChangeStatus manifest(Attributor &A) override {
-    assert(getState().isValidState() &&
-           "Attempted to manifest an invalid state!");
-
-    ChangeStatus HasChanged = ChangeStatus::UNCHANGED;
-
-    for (Instruction *I : NoReturnCalls) {
-      BasicBlock *BB = I->getParent();
-
-      /// Invoke is replaced with a call and unreachable is placed after it.
-      if (auto *II = dyn_cast<InvokeInst>(I)) {
-        changeToCall(II);
-        changeToUnreachable(BB->getTerminator(), /* UseLLVMTrap */ false);
-        LLVM_DEBUG(dbgs() << "[AAIsDead] Replaced invoke with call inst\n");
-        continue;
-      }
-
-      SplitBlock(BB, I->getNextNode());
-      changeToUnreachable(BB->getTerminator(), /* UseLLVMTrap */ false);
-      HasChanged = ChangeStatus::CHANGED;
-    }
-
-    return HasChanged;
-  }
-
-  /// See AbstractAttribute::updateImpl(...).
-  ChangeStatus updateImpl(Attributor &A) override;
-
-  /// See AAIsDead::isAssumedDead().
-  bool isAssumedDead(BasicBlock *BB) const override {
-    if (!getAssumed())
-      return false;
-    return !AssumedLiveBlocks.count(BB);
-  }
-
-  /// See AAIsDead::isKnownDead().
-  bool isKnownDead(BasicBlock *BB) const override {
-    if (!getKnown())
-      return false;
-    return !AssumedLiveBlocks.count(BB);
-  }
-
-  /// Collection of to be explored paths.
-  SmallSetVector<Instruction *, 8> ToBeExploredPaths;
-
-  /// Collection of all assumed live BasicBlocks.
-  DenseSet<BasicBlock *> AssumedLiveBlocks;
-
-  /// Collection of calls with noreturn attribute, assumed or knwon.
-  SmallSetVector<Instruction *, 4> NoReturnCalls;
-};
-
-bool AAIsDeadFunction::explorePath(Attributor &A, Instruction *I) {
-  BasicBlock *BB = I->getParent();
-
-  while (I) {
-    ImmutableCallSite ICS(I);
-
-    if (ICS) {
-      auto *NoReturnAA = A.getAAFor<AANoReturn>(*this, *I);
-
-      if (NoReturnAA && NoReturnAA->isAssumedNoReturn()) {
-        if (!NoReturnCalls.insert(I))
-          // If I is already in the NoReturnCalls set, then it stayed noreturn
-          // and we didn't discover any new instructions.
-          return false;
-
-        // Discovered new noreturn call, return true to indicate that I is not
-        // noreturn anymore and should be deleted from NoReturnCalls.
-        return true;
-      }
-
-      if (ICS.hasFnAttr(Attribute::NoReturn)) {
-        if(!NoReturnCalls.insert(I))
-          return false;
-
-        return true;
-      }
-    }
-
-    I = I->getNextNode();
-  }
-
-  // get new paths (reachable blocks).
-  for (BasicBlock *SuccBB : successors(BB)) {
-    Instruction *Inst = &(SuccBB->front());
-    AssumedLiveBlocks.insert(SuccBB);
-    ToBeExploredPaths.insert(Inst);
-  }
-
-  return true;
-}
-
-ChangeStatus AAIsDeadFunction::updateImpl(Attributor &A) {
-  Function &F = getAnchorScope();
-
-  // Temporary collection to iterate over existing noreturn instructions. This
-  // will alow easier modification of NoReturnCalls collection
-  SmallVector<Instruction *, 8> NoReturnChanged;
-  ChangeStatus Status = ChangeStatus::UNCHANGED;
-
-  for (Instruction *I : NoReturnCalls)
-    NoReturnChanged.push_back(I);
-
-  for (Instruction *I : NoReturnChanged) {
-    size_t Size = ToBeExploredPaths.size();
-
-    // Still noreturn.
-    if (!explorePath(A, I))
-      continue;
-
-    NoReturnCalls.remove(I);
-
-    // No new paths.
-    if (Size == ToBeExploredPaths.size())
-      continue;
-
-    // At least one new path.
-    Status = ChangeStatus::CHANGED;
-
-    // explore new paths.
-    while (Size != ToBeExploredPaths.size())
-      explorePath(A, ToBeExploredPaths[Size++]);
-  }
-
-  LLVM_DEBUG(dbgs() << "[AAIsDead] AssumedLiveBlocks: "
-                    << AssumedLiveBlocks.size()
-                    << "Total number of blocks: " << F.size() << "\n");
-
-  return Status;
-}
-
 /// ----------------------------------------------------------------------------
 ///                               Attributor
 /// ----------------------------------------------------------------------------
@@ -1798,9 +1627,6 @@ void Attributor::identifyDefaultAbstractAttributes(
   // Every function might be "will-return".
   registerAA(*new AAWillReturnFunction(F, InfoCache));
 
-  // Check for dead BasicBlocks in every function.
-  registerAA(*new AAIsDeadFunction(F, InfoCache));
-
   // Walk all instructions to find more attribute opportunities and also
   // interesting instructions that might be queried by abstract attributes
   // during their initialization or update.
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 62c7dd6b71f..be160541117 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1964,7 +1964,7 @@ unsigned llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap,
 }
 
 /// changeToCall - Convert the specified invoke into a normal call.
-void llvm::changeToCall(InvokeInst *II, DomTreeUpdater *DTU = nullptr) {
+static void changeToCall(InvokeInst *II, DomTreeUpdater *DTU = nullptr) {
   SmallVector<Value*, 8> Args(II->arg_begin(), II->arg_end());
   SmallVector<OperandBundleDef, 1> OpBundles;
   II->getOperandBundlesAsDefs(OpBundles);