Merging r258184:

[oota-llvm.git] / include / llvm / ADT / IndexedMap.h

diff --git a/include/llvm/ADT/IndexedMap.h b/include/llvm/ADT/IndexedMap.h
index 2cf5990617accb7450f84d393c1f0253192438d4..5ba85c02792095ff75ef49e21ee1d172481234eb 100644 (file)
--- a/include/llvm/ADT/IndexedMap.h
+++ b/include/llvm/ADT/IndexedMap.h
@@ -1,13 +1,13 @@
-//===- DenseMap.h - A dense map implmentation -------------------*- C++ -*-===//
-// 
+//===- llvm/ADT/IndexedMap.h - An index map implementation ------*- C++ -*-===//
+//
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
 //===----------------------------------------------------------------------===//
 //
-// This file implements a dense map. A dense map template takes two
+// This file implements an indexed map. The index map template takes two
 // types. The first is the mapped type and the second is a functor
 // that maps its argument to a size_t. On instantiation a "null" value
 // can be provided to be used as a "does not exist" indicator in the
@@ -17,31 +17,31 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_DENSEMAP_H
-#define SUPPORT_DENSEMAP_H
+#ifndef LLVM_ADT_INDEXEDMAP_H
+#define LLVM_ADT_INDEXEDMAP_H
 
-#include <vector>
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include <cassert>
+#include <functional>
 
 namespace llvm {
 
-  struct IdentityFunctor : std::unary_function<unsigned, unsigned> {
-    unsigned operator()(unsigned Index) const {
-      return Index;
-    }
-  };
-
-  template <typename T, typename ToIndexT = IdentityFunctor>
-  class DenseMap {
+template <typename T, typename ToIndexT = llvm::identity<unsigned> >
+  class IndexedMap {
     typedef typename ToIndexT::argument_type IndexT;
-    typedef std::vector<T> StorageT;
+    // Prefer SmallVector with zero inline storage over std::vector. IndexedMaps
+    // can grow very large and SmallVector grows more efficiently as long as T
+    // is trivially copyable.
+    typedef SmallVector<T, 0> StorageT;
     StorageT storage_;
     T nullVal_;
     ToIndexT toIndex_;
 
   public:
-    DenseMap() : nullVal_(T()) { }
+    IndexedMap() : nullVal_(T()) { }
 
-    explicit DenseMap(const T& val) : nullVal_(val) { }
+    explicit IndexedMap(const T& val) : nullVal_(val) { }
 
     typename StorageT::reference operator[](IndexT n) {
       assert(toIndex_(n) < storage_.size() && "index out of bounds!");
@@ -53,6 +53,14 @@ namespace llvm {
       return storage_[toIndex_(n)];
     }
 
+    void reserve(typename StorageT::size_type s) {
+      storage_.reserve(s);
+    }
+
+    void resize(typename StorageT::size_type s) {
+      storage_.resize(s, nullVal_);
+    }
+
     void clear() {
       storage_.clear();
     }
@@ -60,7 +68,15 @@ namespace llvm {
     void grow(IndexT n) {
       unsigned NewSize = toIndex_(n) + 1;
       if (NewSize > storage_.size())
-        storage_.resize(NewSize, nullVal_);
+        resize(NewSize);
+    }
+
+    bool inBounds(IndexT n) const {
+      return toIndex_(n) < storage_.size();
+    }
+
+    typename StorageT::size_type size() const {
+      return storage_.size();
     }
   };