ConstantRangesSet renamed to IntegersSubset. CRSBuilder renamed to IntegersSubsetMapping.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157612 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/IntegersSubsetMapping.h

@@ -0,0 +1,241 @@
+//===- CRSBuilder.h - ConstantRangesSet Builder -----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// @file
+/// CRSBuilder allows to build and parse ConstantRangesSet objects.
+/// There is such features like add/remove range, or combine
+/// Two ConstantRangesSet object with neighboring ranges merging.
+/// Set IsReadonly=true if you want to operate with "const ConstantInt" and
+/// "const ConstantRangesSet" objects.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CRSBUILDER_H_
+#define CRSBUILDER_H_
+
+#include "llvm/Support/IntegersSubset.h"
+#include <list>
+#include <map>
+#include <vector>
+
+namespace llvm {
+
+template <class SuccessorClass>
+class IntegersSubsetMapping {
+public:
+  
+  typedef IntegersSubset::Range RangeTy;
+  
+  struct RangeEx : public RangeTy {
+    typedef IntegersSubset::Range RangeTy;
+    RangeEx() : Weight(1) {}
+    RangeEx(const RangeTy &R) : RangeTy(R.Low, R.High), Weight(1) {}
+    RangeEx(const IntItem &C) : RangeTy(C), Weight(1) {}
+    RangeEx(const IntItem &L, const IntItem &H) : RangeTy(L, H), Weight(1) {}
+    RangeEx(const IntItem &L, const IntItem &H, unsigned W) :
+      RangeTy(L, H), Weight(W) {}
+    unsigned Weight;
+  };
+
+  typedef std::pair<RangeEx, SuccessorClass*> Cluster;
+
+protected:
+
+  typedef std::vector<Cluster> CaseItems;
+  typedef typename CaseItems::iterator CaseItemIt;
+  typedef typename CaseItems::const_iterator CaseItemConstIt;
+  
+  typedef std::list<RangeTy> RangesCollection;
+  typedef typename RangesCollection::iterator RangesCollectionIt;
+  
+  typedef std::map<SuccessorClass*, RangesCollection > CRSMap;
+  typedef typename CRSMap::iterator CRSMapIt;
+
+  struct ClustersCmp {
+    bool operator()(const Cluster &C1, const Cluster &C2) {
+      return C1.first < C2.first;
+    }
+  };
+  
+  CaseItems Items;
+  bool Sorted;
+  
+  bool isIntersected(CaseItemIt& LItem, CaseItemIt& RItem) {
+    return LItem->first.High->uge(RItem->first.Low);
+  }
+
+  bool isJoinable(CaseItemIt& LItem, CaseItemIt& RItem) {
+    if (LItem->second != RItem->second) {
+      assert(!isIntersected(LItem, RItem) &&
+             "Intersected items with different successors!");
+      return false;
+    }
+    APInt RLow = RItem->first.Low;
+    if (RLow != APInt::getNullValue(RLow.getBitWidth()))
+      --RLow;
+    return LItem->first.High->uge(RLow);
+  }
+  
+  void sort() {
+    if (!Sorted) {
+      std::sort(Items.begin(), Items.end(), ClustersCmp());
+      Sorted = true;
+    }
+  }
+
+  IntegersSubset getCase(RangesCollection& Src) {
+    std::vector<Constant*> Elts;
+    Elts.reserve(Src.size());
+    for (RangesCollectionIt i = Src.begin(), e = Src.end(); i != e; ++i) {
+      RangeTy &R = *i;
+      std::vector<Constant*> r;
+      if (R.isSingleNumber()) {
+        r.reserve(2);
+        // FIXME: Since currently we have ConstantInt based numbers
+        // use hack-conversion of IntItem to ConstantInt
+        r.push_back(R.Low.toConstantInt());
+        r.push_back(R.High.toConstantInt());
+      } else {
+        r.reserve(1);
+        r.push_back(R.Low.toConstantInt());
+      }
+      Constant *CV = ConstantVector::get(r);
+      Elts.push_back(CV);    
+    }
+    ArrayType *ArrTy =
+        ArrayType::get(Elts.front()->getType(), (uint64_t)Elts.size());
+    Constant *Array = ConstantArray::get(ArrTy, Elts);
+    return IntegersSubset(Array);     
+  }  
+  
+public:
+  
+  // Don't public CaseItems itself. Don't allow edit the Items directly. 
+  // Just present the user way to iterate over the internal collection
+  // sharing iterator, begin() and end(). Editing should be controlled by
+  // factory.
+  typedef CaseItemIt RangeIterator;
+  
+  typedef std::pair<SuccessorClass*, IntegersSubset> Case;
+  typedef std::list<Case> Cases;
+  
+  IntegersSubsetMapping() {
+    Items.reserve(32);
+    Sorted = false;
+  }
+  
+  bool verify(RangeIterator& errItem) {
+    if (Items.empty())
+      return true;
+    sort();
+    for (CaseItemIt i = Items.begin(), j = i+1, e = Items.end();
+         j != e; i = j++) {
+      if (isIntersected(j, i) && j->second != i->second) {
+        errItem = j;
+        return false;
+      }
+    }
+    return true;
+  }
+  
+  void optimize() {
+    if (Items.size() < 2)
+      return;
+    sort();
+    CaseItems OldItems = Items;
+    Items.clear();
+    IntItem *Low = &OldItems.begin()->first.Low;
+    IntItem *High = &OldItems.begin()->first.High;
+    unsigned Weight = 1;
+    SuccessorClass *Successor = OldItems.begin()->second;
+    for (CaseItemIt i = OldItems.begin(), j = i+1, e = OldItems.end();
+        j != e; i = j++) {
+      if (isJoinable(i, j)) {
+        IntItem *CurHigh = &j->first.High;
+        ++Weight;
+        if ((*CurHigh)->ugt(*High))
+          High = CurHigh;
+      } else {
+        RangeEx R(*Low, *High, Weight);
+        add(R, Successor);
+        Low = &j->first.Low;
+        High = &j->first.High; 
+        Weight = 1;
+        Successor = j->second;
+      }
+    }
+    RangeEx R(*Low, *High, Weight);
+    add(R, Successor);
+    // We recollected the Items, but we kept it sorted.
+    Sorted = true;
+  }
+  
+  /// Adds a constant value.
+  void add(const IntItem &C, SuccessorClass *S = 0) {
+    RangeTy R(C);
+    add(R, S);
+  }
+  
+  /// Adds a range.
+  void add(const IntItem &Low, const IntItem &High, SuccessorClass *S = 0) {
+    RangeTy R(Low, High);
+    add(R, S);
+  }
+  void add(const RangeTy &R, SuccessorClass *S = 0) {
+    RangeEx REx = R;
+    add(REx, S);
+  }   
+  void add(const RangeEx &R, SuccessorClass *S = 0) {
+    Items.push_back(std::make_pair(R, S));
+    Sorted = false;
+  }  
+  
+  /// Adds all ranges and values from given ranges set to the current
+  /// CRSBuilder object.
+  void add(const IntegersSubset &CRS, SuccessorClass *S = 0) {
+    for (unsigned i = 0, e = CRS.getNumItems(); i < e; ++i) {
+      RangeTy R = CRS.getItem(i);
+      add(R, S);
+    }
+  }
+  
+  /// Removes items from set.
+  void removeItem(RangeIterator i) { Items.erase(i); }
+  
+  /// Builds the finalized case objects.
+  void getCases(Cases& TheCases) {
+    CRSMap TheCRSMap;
+    for (RangeIterator i = this->begin(); i != this->end(); ++i)
+      TheCRSMap[i->second].push_back(i->first);
+    for (CRSMapIt i = TheCRSMap.begin(), e = TheCRSMap.end(); i != e; ++i)
+      TheCases.push_back(std::make_pair(i->first, getCase(i->second)));
+  }
+  
+  /// Builds the finalized case objects ignoring successor values, as though
+  /// all ranges belongs to the same successor.
+  IntegersSubset getCase() {
+    RangesCollection Ranges;
+    for (RangeIterator i = this->begin(); i != this->end(); ++i)
+      Ranges.push_back(i->first);
+    return getCase(Ranges);
+  }  
+  
+  /// Returns true if there is no ranges and values inside.
+  bool empty() const { return Items.empty(); }
+  
+  RangeIterator begin() { return Items.begin(); }
+  RangeIterator end() { return Items.end(); }
+};
+
+class BasicBlock;
+typedef IntegersSubsetMapping<BasicBlock> IntegersSubsetToBB;
+
+}
+
+#endif /* CRSBUILDER_H_ */