Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 219 insertions, 0 deletions

diff --git a/gcc-4.9/gcc/sparseset.h b/gcc-4.9/gcc/sparseset.h
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+/* SparseSet implementation.
+   Copyright (C) 2007-2014 Free Software Foundation, Inc.
+   Contributed by Peter Bergner <bergner@vnet.ibm.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_SPARSESET_H
+#define GCC_SPARSESET_H
+
+/* Implementation of the Briggs and Torczon sparse set representation.
+   The sparse set representation was first published in:
+
+   "An Efficient Representation for Sparse Sets",
+   ACM LOPLAS, Vol. 2, Nos. 1-4, March-December 1993, Pages 59-69.
+
+   The sparse set representation is suitable for integer sets with a
+   fixed-size universe.  Two vectors are used to store the members of
+   the set.  If an element I is in the set, then sparse[I] is the
+   index of I in the dense vector, and dense[sparse[I]] == I.  The dense
+   vector works like a stack.  The size of the stack is the cardinality
+   of the set.
+
+   The following operations can be performed in O(1) time:
+
+     * clear			: sparseset_clear
+     * cardinality		: sparseset_cardinality
+     * set_size			: sparseset_size
+     * member_p			: sparseset_bit_p
+     * add_member		: sparseset_set_bit
+     * remove_member		: sparseset_clear_bit
+     * choose_one		: sparseset_pop
+
+   Additionally, the sparse set representation supports enumeration of
+   the members in O(N) time, where n is the number of members in the set.
+   The members of the set are stored cache-friendly in the dense vector.
+   This makes it a competitive choice for iterating over relatively sparse
+   sets requiring operations:
+
+     * forall			: EXECUTE_IF_SET_IN_SPARSESET
+     * set_copy			: sparseset_copy
+     * set_intersection		: sparseset_and
+     * set_union		: sparseset_ior
+     * set_difference		: sparseset_and_compl
+     * set_disjuction		: (not implemented)
+     * set_compare		: sparseset_equal_p
+
+   NB: It is OK to use remove_member during EXECUTE_IF_SET_IN_SPARSESET.
+   The iterator is updated for it.
+
+   Based on the efficiency of these operations, this representation of
+   sparse sets will often be superior to alternatives such as simple
+   bitmaps, linked-list bitmaps, array bitmaps, balanced binary trees,
+   hash tables, linked lists, etc., if the set is sufficiently sparse.
+   In the LOPLAS paper the cut-off point where sparse sets became faster
+   than simple bitmaps (see sbitmap.h) when N / U < 64 (where U is the
+   size of the universe of the set).
+
+   Because the set universe is fixed, the set cannot be resized.  For
+   sparse sets with initially unknown size, linked-list bitmaps are a
+   better choice, see bitmap.h.
+
+   Sparse sets storage requirements are relatively large: O(U) with a
+   larger constant than sbitmaps (if the storage requirement for an
+   sbitmap with universe U is S, then the storage required for a sparse
+   set for the same universe are 2*HOST_BITS_PER_WIDEST_FAST_INT * S).
+   Accessing the sparse vector is not very cache-friendly, but iterating
+   over the members in the set is cache-friendly because only the dense
+   vector is used.  */
+
+/* Data Structure used for the SparseSet representation.  */
+
+#define SPARSESET_ELT_BITS ((unsigned) HOST_BITS_PER_WIDEST_FAST_INT)
+#define SPARSESET_ELT_TYPE unsigned HOST_WIDEST_FAST_INT
+
+typedef struct sparseset_def
+{
+  SPARSESET_ELT_TYPE *dense;	/* Dense array.  */
+  SPARSESET_ELT_TYPE *sparse;	/* Sparse array.  */
+  SPARSESET_ELT_TYPE members;	/* Number of elements.  */
+  SPARSESET_ELT_TYPE size;	/* Maximum number of elements.  */
+  SPARSESET_ELT_TYPE iter;	/* Iterator index.  */
+  unsigned char iter_inc;	/* Iteration increment amount.  */
+  bool iterating;
+  SPARSESET_ELT_TYPE elms[2];   /* Combined dense and sparse arrays.  */
+} *sparseset;
+
+#define sparseset_free(MAP)  free(MAP)
+extern sparseset sparseset_alloc (SPARSESET_ELT_TYPE n_elms);
+extern void sparseset_clear_bit (sparseset, SPARSESET_ELT_TYPE);
+extern void sparseset_copy (sparseset, sparseset);
+extern void sparseset_and (sparseset, sparseset, sparseset);
+extern void sparseset_and_compl (sparseset, sparseset, sparseset);
+extern void sparseset_ior (sparseset, sparseset, sparseset);
+extern bool sparseset_equal_p (sparseset, sparseset);
+
+/* Operation: S = {}
+   Clear the set of all elements.  */
+
+static inline void
+sparseset_clear (sparseset s)
+{
+  s->members = 0;
+  s->iterating = false;
+}
+
+/* Return the number of elements currently in the set.  */
+
+static inline SPARSESET_ELT_TYPE
+sparseset_cardinality (sparseset s)
+{
+  return s->members;
+}
+
+/* Return the maximum number of elements this set can hold.  */
+
+static inline SPARSESET_ELT_TYPE
+sparseset_size (sparseset s)
+{
+  return s->size;
+}
+
+/* Return true if e is a member of the set S, otherwise return false.  */
+
+static inline bool
+sparseset_bit_p (sparseset s, SPARSESET_ELT_TYPE e)
+{
+  SPARSESET_ELT_TYPE idx;
+
+  gcc_checking_assert (e < s->size);
+
+  idx = s->sparse[e];
+
+  return idx < s->members && s->dense[idx] == e;
+}
+
+/* Low level insertion routine not meant for use outside of sparseset.[ch].
+   Assumes E is valid and not already a member of the set S.  */
+
+static inline void
+sparseset_insert_bit (sparseset s, SPARSESET_ELT_TYPE e, SPARSESET_ELT_TYPE idx)
+{
+  s->sparse[e] = idx;
+  s->dense[idx] = e;
+}
+
+/* Operation: S = S + {e}
+   Insert E into the set S, if it isn't already a member.  */
+
+static inline void
+sparseset_set_bit (sparseset s, SPARSESET_ELT_TYPE e)
+{
+  if (!sparseset_bit_p (s, e))
+    sparseset_insert_bit (s, e, s->members++);
+}
+
+/* Return and remove the last member added to the set S.  */
+
+static inline SPARSESET_ELT_TYPE
+sparseset_pop (sparseset s)
+{
+  SPARSESET_ELT_TYPE mem = s->members;
+
+  gcc_checking_assert (mem != 0);
+
+  s->members = mem - 1;
+  return s->dense[s->members];
+}
+
+static inline void
+sparseset_iter_init (sparseset s)
+{
+  s->iter = 0;
+  s->iter_inc = 1;
+  s->iterating = true;
+}
+
+static inline bool
+sparseset_iter_p (sparseset s)
+{
+  if (s->iterating && s->iter < s->members)
+    return true;
+  else
+    return s->iterating = false;
+}
+
+static inline SPARSESET_ELT_TYPE
+sparseset_iter_elm (sparseset s)
+{
+  return s->dense[s->iter];
+}
+
+static inline void
+sparseset_iter_next (sparseset s)
+{
+  s->iter += s->iter_inc;
+  s->iter_inc = 1;
+}
+
+#define EXECUTE_IF_SET_IN_SPARSESET(SPARSESET, ITER)			\
+  for (sparseset_iter_init (SPARSESET);					\
+       sparseset_iter_p (SPARSESET)					\
+       && (((ITER) = sparseset_iter_elm (SPARSESET)) || 1);		\
+       sparseset_iter_next (SPARSESET))
+
+#endif /* GCC_SPARSESET_H */