Remove GCSE, ValueNumbering, and LoadValueNumbering. These have been deprecated for almost a year; it's finally time for them to go away.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54822 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 530 deletions

diff --git a/lib/Analysis/LoadValueNumbering.cpp b/lib/Analysis/LoadValueNumbering.cpp
deleted file mode 100644
index f99ebb4a83..0000000000
--- a/lib/Analysis/LoadValueNumbering.cpp
+++ /dev/null
@@ -1,530 +0,0 @@
-//===- LoadValueNumbering.cpp - Load Value #'ing Implementation -*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements a value numbering pass that value numbers load and call
-// instructions.  To do this, it finds lexically identical load instructions,
-// and uses alias analysis to determine which loads are guaranteed to produce
-// the same value.  To value number call instructions, it looks for calls to
-// functions that do not write to memory which do not have intervening
-// instructions that clobber the memory that is read from.
-//
-// This pass builds off of another value numbering pass to implement value
-// numbering for non-load and non-call instructions.  It uses Alias Analysis so
-// that it can disambiguate the load instructions.  The more powerful these base
-// analyses are, the more powerful the resultant value numbering will be.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/LoadValueNumbering.h"
-#include "llvm/Constants.h"
-#include "llvm/Function.h"
-#include "llvm/Instructions.h"
-#include "llvm/Pass.h"
-#include "llvm/Type.h"
-#include "llvm/Analysis/ValueNumbering.h"
-#include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/Analysis/Dominators.h"
-#include "llvm/Support/CFG.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Target/TargetData.h"
-#include <set>
-#include <algorithm>
-using namespace llvm;
-
-namespace {
-  // FIXME: This should not be a FunctionPass.
-  struct VISIBILITY_HIDDEN LoadVN : public FunctionPass, public ValueNumbering {
-    static char ID; // Class identification, replacement for typeinfo
-    LoadVN() : FunctionPass((intptr_t)&ID) {}
-
-    /// Pass Implementation stuff.  This doesn't do any analysis.
-    ///
-    bool runOnFunction(Function &) { return false; }
-
-    /// getAnalysisUsage - Does not modify anything.  It uses Value Numbering
-    /// and Alias Analysis.
-    ///
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const;
-
-    /// getEqualNumberNodes - Return nodes with the same value number as the
-    /// specified Value.  This fills in the argument vector with any equal
-    /// values.
-    ///
-    virtual void getEqualNumberNodes(Value *V1,
-                                     std::vector<Value*> &RetVals) const;
-
-    /// deleteValue - This method should be called whenever an LLVM Value is
-    /// deleted from the program, for example when an instruction is found to be
-    /// redundant and is eliminated.
-    ///
-    virtual void deleteValue(Value *V) {
-      getAnalysis<AliasAnalysis>().deleteValue(V);
-    }
-
-    /// copyValue - This method should be used whenever a preexisting value in
-    /// the program is copied or cloned, introducing a new value.  Note that
-    /// analysis implementations should tolerate clients that use this method to
-    /// introduce the same value multiple times: if the analysis already knows
-    /// about a value, it should ignore the request.
-    ///
-    virtual void copyValue(Value *From, Value *To) {
-      getAnalysis<AliasAnalysis>().copyValue(From, To);
-    }
-
-    /// getCallEqualNumberNodes - Given a call instruction, find other calls
-    /// that have the same value number.
-    void getCallEqualNumberNodes(CallInst *CI,
-                                 std::vector<Value*> &RetVals) const;
-  };
-}
-
-char LoadVN::ID = 0;
-// Register this pass...
-static RegisterPass<LoadVN>
-X("load-vn", "Load Value Numbering", false, true);
-
-// Declare that we implement the ValueNumbering interface
-static RegisterAnalysisGroup<ValueNumbering> Y(X);
-
-FunctionPass *llvm::createLoadValueNumberingPass() { return new LoadVN(); }
-
-
-/// getAnalysisUsage - Does not modify anything.  It uses Value Numbering and
-/// Alias Analysis.
-///
-void LoadVN::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.setPreservesAll();
-  AU.addRequiredTransitive<AliasAnalysis>();
-  AU.addRequired<ValueNumbering>();
-  AU.addRequiredTransitive<DominatorTree>();
-  AU.addRequiredTransitive<TargetData>();
-}
-
-static bool isPathTransparentTo(BasicBlock *CurBlock, BasicBlock *Dom,
-                                Value *Ptr, unsigned Size, AliasAnalysis &AA,
-                                std::set<BasicBlock*> &Visited,
-                                std::map<BasicBlock*, bool> &TransparentBlocks){
-  // If we have already checked out this path, or if we reached our destination,
-  // stop searching, returning success.
-  if (CurBlock == Dom || !Visited.insert(CurBlock).second)
-    return true;
-
-  // Check whether this block is known transparent or not.
-  std::map<BasicBlock*, bool>::iterator TBI =
-    TransparentBlocks.find(CurBlock);
-
-  if (TBI == TransparentBlocks.end()) {
-    // If this basic block can modify the memory location, then the path is not
-    // transparent!
-    if (AA.canBasicBlockModify(*CurBlock, Ptr, Size)) {
-      TransparentBlocks.insert(TBI, std::make_pair(CurBlock, false));
-      return false;
-    }
-    TransparentBlocks.insert(TBI, std::make_pair(CurBlock, true));
-  } else if (!TBI->second)
-    // This block is known non-transparent, so that path can't be either.
-    return false;
-
-  // The current block is known to be transparent.  The entire path is
-  // transparent if all of the predecessors paths to the parent is also
-  // transparent to the memory location.
-  for (pred_iterator PI = pred_begin(CurBlock), E = pred_end(CurBlock);
-       PI != E; ++PI)
-    if (!isPathTransparentTo(*PI, Dom, Ptr, Size, AA, Visited,
-                             TransparentBlocks))
-      return false;
-  return true;
-}
-
-/// getCallEqualNumberNodes - Given a call instruction, find other calls that
-/// have the same value number.
-void LoadVN::getCallEqualNumberNodes(CallInst *CI,
-                                     std::vector<Value*> &RetVals) const {
-  Function *CF = CI->getCalledFunction();
-  if (CF == 0) return;  // Indirect call.
-  AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
-  AliasAnalysis::ModRefBehavior MRB = AA.getModRefBehavior(CI);
-  if (MRB != AliasAnalysis::DoesNotAccessMemory &&
-      MRB != AliasAnalysis::OnlyReadsMemory)
-    return;  // Nothing we can do for now.
-
-  // Scan all of the arguments of the function, looking for one that is not
-  // global.  In particular, we would prefer to have an argument or instruction
-  // operand to chase the def-use chains of.
-  Value *Op = CF;
-  for (User::op_iterator i = CI->op_begin() + 1, e = CI->op_end(); i != e; ++i)
-    if (isa<Argument>(*i) ||
-        isa<Instruction>(*i)) {
-      Op = *i;
-      break;
-    }
-
-  // Identify all lexically identical calls in this function.
-  std::vector<CallInst*> IdenticalCalls;
-
-  Function *CIFunc = CI->getParent()->getParent();
-  for (Value::use_iterator UI = Op->use_begin(), E = Op->use_end(); UI != E;
-       ++UI)
-    if (CallInst *C = dyn_cast<CallInst>(*UI))
-      if (C->getNumOperands() == CI->getNumOperands() &&
-          C->getOperand(0) == CI->getOperand(0) &&
-          C->getParent()->getParent() == CIFunc && C != CI) {
-        bool AllOperandsEqual = true;
-        for (User::op_iterator i = CI->op_begin() + 1, j = C->op_begin() + 1,
-             e = CI->op_end(); i != e; ++i, ++j)
-          if (*j != *i) {
-            AllOperandsEqual = false;
-            break;
-          }
-
-        if (AllOperandsEqual)
-          IdenticalCalls.push_back(C);
-      }
-
-  if (IdenticalCalls.empty()) return;
-
-  // Eliminate duplicates, which could occur if we chose a value that is passed
-  // into a call site multiple times.
-  std::sort(IdenticalCalls.begin(), IdenticalCalls.end());
-  IdenticalCalls.erase(std::unique(IdenticalCalls.begin(),IdenticalCalls.end()),
-                       IdenticalCalls.end());
-
-  // If the call reads memory, we must make sure that there are no stores
-  // between the calls in question.
-  //
-  // FIXME: This should use mod/ref information.  What we really care about it
-  // whether an intervening instruction could modify memory that is read, not
-  // ANY memory.
-  //
-  if (MRB == AliasAnalysis::OnlyReadsMemory) {
-    DominatorTree &DT = getAnalysis<DominatorTree>();
-    BasicBlock *CIBB = CI->getParent();
-    for (unsigned i = 0; i != IdenticalCalls.size(); ++i) {
-      CallInst *C = IdenticalCalls[i];
-      bool CantEqual = false;
-
-      if (DT.dominates(CIBB, C->getParent())) {
-        // FIXME: we currently only handle the case where both calls are in the
-        // same basic block.
-        if (CIBB != C->getParent()) {
-          CantEqual = true;
-        } else {
-          Instruction *First = CI, *Second = C;
-          if (!DT.dominates(CI, C))
-            std::swap(First, Second);
-
-          // Scan the instructions between the calls, checking for stores or
-          // calls to dangerous functions.
-          BasicBlock::iterator I = First;
-          for (++First; I != BasicBlock::iterator(Second); ++I) {
-            if (isa<StoreInst>(I)) {
-              // FIXME: We could use mod/ref information to make this much
-              // better!
-              CantEqual = true;
-              break;
-            } else if (CallInst *CI = dyn_cast<CallInst>(I)) {
-              if (!AA.onlyReadsMemory(CI)) {
-                CantEqual = true;
-                break;
-              }
-            } else if (I->mayWriteToMemory()) {
-              CantEqual = true;
-              break;
-            }
-          }
-        }
-
-      } else if (DT.dominates(C->getParent(), CIBB)) {
-        // FIXME: We could implement this, but we don't for now.
-        CantEqual = true;
-      } else {
-        // FIXME: if one doesn't dominate the other, we can't tell yet.
-        CantEqual = true;
-      }
-
-
-      if (CantEqual) {
-        // This call does not produce the same value as the one in the query.
-        std::swap(IdenticalCalls[i--], IdenticalCalls.back());
-        IdenticalCalls.pop_back();
-      }
-    }
-  }
-
-  // Any calls that are identical and not destroyed will produce equal values!
-  for (unsigned i = 0, e = IdenticalCalls.size(); i != e; ++i)
-    RetVals.push_back(IdenticalCalls[i]);
-}
-
-// getEqualNumberNodes - Return nodes with the same value number as the
-// specified Value.  This fills in the argument vector with any equal values.
-//
-void LoadVN::getEqualNumberNodes(Value *V,
-                                 std::vector<Value*> &RetVals) const {
-  // If the alias analysis has any must alias information to share with us, we
-  // can definitely use it.
-  if (isa<PointerType>(V->getType()))
-    getAnalysis<AliasAnalysis>().getMustAliases(V, RetVals);
-
-  if (!isa<LoadInst>(V)) {
-    if (CallInst *CI = dyn_cast<CallInst>(V))
-      getCallEqualNumberNodes(CI, RetVals);
-
-    // Not a load instruction?  Just chain to the base value numbering
-    // implementation to satisfy the request...
-    assert(&getAnalysis<ValueNumbering>() != (ValueNumbering*)this &&
-           "getAnalysis() returned this!");
-
-    return getAnalysis<ValueNumbering>().getEqualNumberNodes(V, RetVals);
-  }
-
-  // Volatile loads cannot be replaced with the value of other loads.
-  LoadInst *LI = cast<LoadInst>(V);
-  if (LI->isVolatile())
-    return getAnalysis<ValueNumbering>().getEqualNumberNodes(V, RetVals);
-
-  Value *LoadPtr = LI->getOperand(0);
-  BasicBlock *LoadBB = LI->getParent();
-  Function *F = LoadBB->getParent();
-
-  // Find out how many bytes of memory are loaded by the load instruction...
-  unsigned LoadSize = getAnalysis<TargetData>().getTypeStoreSize(LI->getType());
-  AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
-
-  // Figure out if the load is invalidated from the entry of the block it is in
-  // until the actual instruction.  This scans the block backwards from LI.  If
-  // we see any candidate load or store instructions, then we know that the
-  // candidates have the same value # as LI.
-  bool LoadInvalidatedInBBBefore = false;
-  for (BasicBlock::iterator I = LI; I != LoadBB->begin(); ) {
-    --I;
-    if (I == LoadPtr) {
-      // If we run into an allocation of the value being loaded, then the
-      // contents are not initialized.
-      if (isa<AllocationInst>(I))
-        RetVals.push_back(UndefValue::get(LI->getType()));
-
-      // Otherwise, since this is the definition of what we are loading, this
-      // loaded value cannot occur before this block.
-      LoadInvalidatedInBBBefore = true;
-      break;
-    } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-      // If this instruction is a candidate load before LI, we know there are no
-      // invalidating instructions between it and LI, so they have the same
-      // value number.
-      if (LI->getOperand(0) == LoadPtr && !LI->isVolatile())
-        RetVals.push_back(I);
-    }
-
-    if (AA.getModRefInfo(I, LoadPtr, LoadSize) & AliasAnalysis::Mod) {
-      // If the invalidating instruction is a store, and its in our candidate
-      // set, then we can do store-load forwarding: the load has the same value
-      // # as the stored value.
-      if (StoreInst *SI = dyn_cast<StoreInst>(I))
-        if (SI->getOperand(1) == LoadPtr)
-          RetVals.push_back(I->getOperand(0));
-
-      LoadInvalidatedInBBBefore = true;
-      break;
-    }
-  }
-
-  // Figure out if the load is invalidated between the load and the exit of the
-  // block it is defined in.  While we are scanning the current basic block, if
-  // we see any candidate loads, then we know they have the same value # as LI.
-  //
-  bool LoadInvalidatedInBBAfter = false;
-  {
-    BasicBlock::iterator I = LI;
-    for (++I; I != LoadBB->end(); ++I) {
-      // If this instruction is a load, then this instruction returns the same
-      // value as LI.
-      if (isa<LoadInst>(I) && cast<LoadInst>(I)->getOperand(0) == LoadPtr)
-        RetVals.push_back(I);
-
-      if (AA.getModRefInfo(I, LoadPtr, LoadSize) & AliasAnalysis::Mod) {
-        LoadInvalidatedInBBAfter = true;
-        break;
-      }
-    }
-  }
-
-  // If the pointer is clobbered on entry and on exit to the function, there is
-  // no need to do any global analysis at all.
-  if (LoadInvalidatedInBBBefore && LoadInvalidatedInBBAfter)
-    return;
-
-  // Now that we know the value is not neccesarily killed on entry or exit to
-  // the BB, find out how many load and store instructions (to this location)
-  // live in each BB in the function.
-  //
-  std::map<BasicBlock*, unsigned>  CandidateLoads;
-  std::set<BasicBlock*> CandidateStores;
-
-  for (Value::use_iterator UI = LoadPtr->use_begin(), UE = LoadPtr->use_end();
-       UI != UE; ++UI)
-    if (LoadInst *Cand = dyn_cast<LoadInst>(*UI)) {// Is a load of source?
-      if (Cand->getParent()->getParent() == F &&   // In the same function?
-          // Not in LI's block?
-          Cand->getParent() != LoadBB && !Cand->isVolatile())
-        ++CandidateLoads[Cand->getParent()];       // Got one.
-    } else if (StoreInst *Cand = dyn_cast<StoreInst>(*UI)) {
-      if (Cand->getParent()->getParent() == F && !Cand->isVolatile() &&
-          Cand->getOperand(1) == LoadPtr) // It's a store THROUGH the ptr.
-        CandidateStores.insert(Cand->getParent());
-    }
-
-  // Get dominators.
-  DominatorTree &DT = getAnalysis<DominatorTree>();
-
-  // TransparentBlocks - For each basic block the load/store is alive across,
-  // figure out if the pointer is invalidated or not.  If it is invalidated, the
-  // boolean is set to false, if it's not it is set to true.  If we don't know
-  // yet, the entry is not in the map.
-  std::map<BasicBlock*, bool> TransparentBlocks;
-
-  // Loop over all of the basic blocks that also load the value.  If the value
-  // is live across the CFG from the source to destination blocks, and if the
-  // value is not invalidated in either the source or destination blocks, add it
-  // to the equivalence sets.
-  for (std::map<BasicBlock*, unsigned>::iterator
-         I = CandidateLoads.begin(), E = CandidateLoads.end(); I != E; ++I) {
-    bool CantEqual = false;
-
-    // Right now we only can handle cases where one load dominates the other.
-    // FIXME: generalize this!
-    BasicBlock *BB1 = I->first, *BB2 = LoadBB;
-    if (DT.dominates(BB1, BB2)) {
-      // The other load dominates LI.  If the loaded value is killed entering
-      // the LoadBB block, we know the load is not live.
-      if (LoadInvalidatedInBBBefore)
-        CantEqual = true;
-    } else if (DT.dominates(BB2, BB1)) {
-      std::swap(BB1, BB2);          // Canonicalize
-      // LI dominates the other load.  If the loaded value is killed exiting
-      // the LoadBB block, we know the load is not live.
-      if (LoadInvalidatedInBBAfter)
-        CantEqual = true;
-    } else {
-      // None of these loads can VN the same.
-      CantEqual = true;
-    }
-
-    if (!CantEqual) {
-      // Ok, at this point, we know that BB1 dominates BB2, and that there is
-      // nothing in the LI block that kills the loaded value.  Check to see if
-      // the value is live across the CFG.
-      std::set<BasicBlock*> Visited;
-      for (pred_iterator PI = pred_begin(BB2), E = pred_end(BB2); PI!=E; ++PI)
-        if (!isPathTransparentTo(*PI, BB1, LoadPtr, LoadSize, AA,
-                                 Visited, TransparentBlocks)) {
-          // None of these loads can VN the same.
-          CantEqual = true;
-          break;
-        }
-    }
-
-    // If the loads can equal so far, scan the basic block that contains the
-    // loads under consideration to see if they are invalidated in the block.
-    // For any loads that are not invalidated, add them to the equivalence
-    // set!
-    if (!CantEqual) {
-      unsigned NumLoads = I->second;
-      if (BB1 == LoadBB) {
-        // If LI dominates the block in question, check to see if any of the
-        // loads in this block are invalidated before they are reached.
-        for (BasicBlock::iterator BBI = I->first->begin(); ; ++BBI) {
-          if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
-            if (LI->getOperand(0) == LoadPtr && !LI->isVolatile()) {
-              // The load is in the set!
-              RetVals.push_back(BBI);
-              if (--NumLoads == 0) break;  // Found last load to check.
-            }
-          } else if (AA.getModRefInfo(BBI, LoadPtr, LoadSize)
-                                & AliasAnalysis::Mod) {
-            // If there is a modifying instruction, nothing below it will value
-            // # the same.
-            break;
-          }
-        }
-      } else {
-        // If the block dominates LI, make sure that the loads in the block are
-        // not invalidated before the block ends.
-        BasicBlock::iterator BBI = I->first->end();
-        while (1) {
-          --BBI;
-          if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
-            if (LI->getOperand(0) == LoadPtr && !LI->isVolatile()) {
-              // The load is the same as this load!
-              RetVals.push_back(BBI);
-              if (--NumLoads == 0) break;  // Found all of the laods.
-            }
-          } else if (AA.getModRefInfo(BBI, LoadPtr, LoadSize)
-                             & AliasAnalysis::Mod) {
-            // If there is a modifying instruction, nothing above it will value
-            // # the same.
-            break;
-          }
-        }
-      }
-    }
-  }
-
-  // Handle candidate stores.  If the loaded location is clobbered on entrance
-  // to the LoadBB, no store outside of the LoadBB can value number equal, so
-  // quick exit.
-  if (LoadInvalidatedInBBBefore)
-    return;
-
-  // Stores in the load-bb are handled above.
-  CandidateStores.erase(LoadBB);
-
-  for (std::set<BasicBlock*>::iterator I = CandidateStores.begin(),
-         E = CandidateStores.end(); I != E; ++I)
-    if (DT.dominates(*I, LoadBB)) {
-      BasicBlock *StoreBB = *I;
-
-      // Check to see if the path from the store to the load is transparent
-      // w.r.t. the memory location.
-      bool CantEqual = false;
-      std::set<BasicBlock*> Visited;
-      for (pred_iterator PI = pred_begin(LoadBB), E = pred_end(LoadBB);
-           PI != E; ++PI)
-        if (!isPathTransparentTo(*PI, StoreBB, LoadPtr, LoadSize, AA,
-                                 Visited, TransparentBlocks)) {
-          // None of these stores can VN the same.
-          CantEqual = true;
-          break;
-        }
-      Visited.clear();
-      if (!CantEqual) {
-        // Okay, the path from the store block to the load block is clear, and
-        // we know that there are no invalidating instructions from the start
-        // of the load block to the load itself.  Now we just scan the store
-        // block.
-
-        BasicBlock::iterator BBI = StoreBB->end();
-        while (1) {
-          assert(BBI != StoreBB->begin() &&
-                 "There is a store in this block of the pointer, but the store"
-                 " doesn't mod the address being stored to??  Must be a bug in"
-                 " the alias analysis implementation!");
-          --BBI;
-          if (AA.getModRefInfo(BBI, LoadPtr, LoadSize) & AliasAnalysis::Mod) {
-            // If the invalidating instruction is one of the candidates,
-            // then it provides the value the load loads.
-            if (StoreInst *SI = dyn_cast<StoreInst>(BBI))
-              if (SI->getOperand(1) == LoadPtr)
-                RetVals.push_back(SI->getOperand(0));
-            break;
-          }
-        }
-      }
-    }
-}