Temporarily revert "[ScheduleDAGInstrs::buildSchedGraph()] Handling o…

…f memory dependecies rewritten."

Some buildbot failures needs to be debugged.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259213 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/PseudoSourceValue.h

@@ -27,8 +27,6 @@ class MachineMemOperand;
 class raw_ostream;
 
 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MMO);
-class PseudoSourceValue;
-raw_ostream &operator<<(raw_ostream &OS, const PseudoSourceValue* PSV);
 
 /// Special value supplied for machine level alias analysis. It indicates that
 /// a memory access references the functions stack frame (e.g., a spill slot),
@@ -47,8 +45,6 @@ class PseudoSourceValue {
 
 private:
   PSVKind Kind;
-  friend raw_ostream &llvm::operator<<(raw_ostream &OS,
-                                       const PseudoSourceValue* PSV);
 
   friend class MachineMemOperand; // For printCustom().
 

include/llvm/CodeGen/ScheduleDAG.h

@@ -396,17 +396,6 @@ namespace llvm {
     /// specified node.
     bool addPred(const SDep &D, bool Required = true);
 
-    /// addPredBarrier - This adds a barrier edge to SU by calling
-    /// addPred(), with latency 0 generally or latency 1 for a store
-    /// followed by a load.
-    bool addPredBarrier(SUnit *SU) {
-      SDep Dep(SU, SDep::Barrier);
-      unsigned TrueMemOrderLatency =
-        ((SU->getInstr()->mayStore() && this->getInstr()->mayLoad()) ? 1 : 0);
-      Dep.setLatency(TrueMemOrderLatency);
-      return addPred(Dep);
-    }
-
     /// removePred - This removes the specified edge as a pred of the current
     /// node if it exists.  It also removes the current node as a successor of
     /// the specified node.

include/llvm/CodeGen/ScheduleDAGInstrs.h

@@ -15,14 +15,12 @@
 #ifndef LLVM_CODEGEN_SCHEDULEDAGINSTRS_H
 #define LLVM_CODEGEN_SCHEDULEDAGINSTRS_H
 
-#include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SparseMultiSet.h"
 #include "llvm/ADT/SparseSet.h"
 #include "llvm/CodeGen/ScheduleDAG.h"
 #include "llvm/CodeGen/TargetSchedule.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Target/TargetRegisterInfo.h"
-#include <list>
 
 namespace llvm {
   class MachineFrameInfo;
@@ -86,10 +84,6 @@ namespace llvm {
   typedef SparseMultiSet<VReg2SUnitOperIdx, VirtReg2IndexFunctor>
     VReg2SUnitOperIdxMultiMap;
 
-  typedef PointerUnion<const Value *, const PseudoSourceValue *> ValueType;
-  typedef SmallVector<PointerIntPair<ValueType, 1, bool>, 4>
-          UnderlyingObjectsVector;
-
   /// ScheduleDAGInstrs - A ScheduleDAG subclass for scheduling lists of
   /// MachineInstrs.
   class ScheduleDAGInstrs : public ScheduleDAG {
@@ -155,66 +149,10 @@ namespace llvm {
     /// Tracks the last instructions in this region using each virtual register.
     VReg2SUnitOperIdxMultiMap CurrentVRegUses;
 
-    AliasAnalysis *AAForDep;
-
-    /// Remember a generic side-effecting instruction as we proceed.
-    /// No other SU ever gets scheduled around it (except in the special
-    /// case of a huge region that gets reduced).
-    SUnit *BarrierChain;
-
-  public:
-
-    /// A list of SUnits, used in Value2SUsMap, during DAG construction.
-    /// Note: to gain speed it might be worth investigating an optimized
-    /// implementation of this data structure, such as a singly linked list
-    /// with a memory pool (SmallVector was tried but slow and SparseSet is not
-    /// applicable).
-    typedef std::list<SUnit *> SUList;
-  protected:
-    /// A map from ValueType to SUList, used during DAG construction,
-    /// as a means of remembering which SUs depend on which memory
-    /// locations.
-    class Value2SUsMap;
-
-    /// Remove in FIFO order some SUs from huge maps.
-    void reduceHugeMemNodeMaps(Value2SUsMap &stores,
-                               Value2SUsMap &loads, unsigned N);
-
-    /// Add a chain edge between SUa and SUb, but only if both AliasAnalysis
-    /// and Target fail to deny the dependency.
-    void addChainDependency(SUnit *SUa, SUnit *SUb,
-                            unsigned Latency = 0);
-
-    /// Add dependencies as needed from all SUs in list to SU.
-    void addChainDependencies(SUnit *SU, SUList &sus, unsigned Latency) {
-      for (auto *su : sus)
-        addChainDependency(SU, su, Latency);
-    }
-
-    /// Add dependencies as needed from all SUs in map, to SU.
-    void addChainDependencies(SUnit *SU, Value2SUsMap &Val2SUsMap);
-
-    /// Add dependencies as needed to SU, from all SUs mapped to V.
-    void addChainDependencies(SUnit *SU, Value2SUsMap &Val2SUsMap,
-                              ValueType V);
-
-    /// Add barrier chain edges from all SUs in map, and then clear
-    /// the map. This is equivalent to insertBarrierChain(), but
-    /// optimized for the common case where the new BarrierChain (a
-    /// global memory object) has a higher NodeNum than all SUs in
-    /// map. It is assumed BarrierChain has been set before calling
-    /// this.
-    void addBarrierChain(Value2SUsMap &map);
-
-    /// Insert a barrier chain in a huge region, far below current
-    /// SU. Add barrier chain edges from all SUs in map with higher
-    /// NodeNums than this new BarrierChain, and remove them from
-    /// map. It is assumed BarrierChain has been set before calling
-    /// this.
-    void insertBarrierChain(Value2SUsMap &map);
-
-    /// For an unanalyzable memory access, this Value is used in maps.
-    UndefValue *UnknownValue;
+    /// PendingLoads - Remember where unknown loads are after the most recent
+    /// unknown store, as we iterate. As with Defs and Uses, this is here
+    /// to minimize construction/destruction.
+    std::vector<SUnit *> PendingLoads;
 
     /// DbgValues - Remember instruction that precedes DBG_VALUE.
     /// These are generated by buildSchedGraph but persist so they can be