Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/ADT/edit_distance.h b/linux-x64/clang/include/llvm/ADT/edit_distance.h
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+//===-- llvm/ADT/edit_distance.h - Array edit distance function --- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a Levenshtein distance function that works for any two
+// sequences, with each element of each sequence being analogous to a character
+// in a string.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_EDIT_DISTANCE_H
+#define LLVM_ADT_EDIT_DISTANCE_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include <algorithm>
+#include <memory>
+
+namespace llvm {
+
+/// \brief Determine the edit distance between two sequences.
+///
+/// \param FromArray the first sequence to compare.
+///
+/// \param ToArray the second sequence to compare.
+///
+/// \param AllowReplacements whether to allow element replacements (change one
+/// element into another) as a single operation, rather than as two operations
+/// (an insertion and a removal).
+///
+/// \param MaxEditDistance If non-zero, the maximum edit distance that this
+/// routine is allowed to compute. If the edit distance will exceed that
+/// maximum, returns \c MaxEditDistance+1.
+///
+/// \returns the minimum number of element insertions, removals, or (if
+/// \p AllowReplacements is \c true) replacements needed to transform one of
+/// the given sequences into the other. If zero, the sequences are identical.
+template<typename T>
+unsigned ComputeEditDistance(ArrayRef<T> FromArray, ArrayRef<T> ToArray,
+ bool AllowReplacements = true,
+ unsigned MaxEditDistance = 0) {
+ // The algorithm implemented below is the "classic"
+ // dynamic-programming algorithm for computing the Levenshtein
+ // distance, which is described here:
+ //
+ // http://en.wikipedia.org/wiki/Levenshtein_distance
+ //
+ // Although the algorithm is typically described using an m x n
+ // array, only one row plus one element are used at a time, so this
+ // implementation just keeps one vector for the row. To update one entry,
+ // only the entries to the left, top, and top-left are needed. The left
+ // entry is in Row[x-1], the top entry is what's in Row[x] from the last
+ // iteration, and the top-left entry is stored in Previous.
+ typename ArrayRef<T>::size_type m = FromArray.size();
+ typename ArrayRef<T>::size_type n = ToArray.size();
+
+ const unsigned SmallBufferSize = 64;
+ unsigned SmallBuffer[SmallBufferSize];
+ std::unique_ptr<unsigned[]> Allocated;
+ unsigned *Row = SmallBuffer;
+ if (n + 1 > SmallBufferSize) {
+ Row = new unsigned[n + 1];
+ Allocated.reset(Row);
+ }
+
+ for (unsigned i = 1; i <= n; ++i)
+ Row[i] = i;
+
+ for (typename ArrayRef<T>::size_type y = 1; y <= m; ++y) {
+ Row[0] = y;
+ unsigned BestThisRow = Row[0];
+
+ unsigned Previous = y - 1;
+ for (typename ArrayRef<T>::size_type x = 1; x <= n; ++x) {
+ int OldRow = Row[x];
+ if (AllowReplacements) {
+ Row[x] = std::min(
+ Previous + (FromArray[y-1] == ToArray[x-1] ? 0u : 1u),
+ std::min(Row[x-1], Row[x])+1);
+ }
+ else {
+ if (FromArray[y-1] == ToArray[x-1]) Row[x] = Previous;
+ else Row[x] = std::min(Row[x-1], Row[x]) + 1;
+ }
+ Previous = OldRow;
+ BestThisRow = std::min(BestThisRow, Row[x]);
+ }
+
+ if (MaxEditDistance && BestThisRow > MaxEditDistance)
+ return MaxEditDistance + 1;
+ }
+
+ unsigned Result = Row[n];
+ return Result;
+}
+
+} // End llvm namespace
+
+#endif