| /* SparseSet implementation. |
| Copyright (C) 2007-2019 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/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "sparseset.h" |
| |
| /* Allocate and clear a n_elms SparseSet. */ |
| |
| sparseset |
| sparseset_alloc (SPARSESET_ELT_TYPE n_elms) |
| { |
| unsigned int n_bytes = sizeof (struct sparseset_def) |
| + ((n_elms - 1) * 2 * sizeof (SPARSESET_ELT_TYPE)); |
| |
| sparseset set = XNEWVAR (struct sparseset_def, n_bytes); |
| |
| /* Mark the sparseset as defined to silence some valgrind uninitialized |
| read errors when accessing set->sparse[n] when "n" is not, and never has |
| been, in the set. These uninitialized reads are expected, by design and |
| harmless. */ |
| VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (set, n_bytes)); |
| |
| set->dense = &(set->elms[0]); |
| set->sparse = &(set->elms[n_elms]); |
| set->size = n_elms; |
| sparseset_clear (set); |
| return set; |
| } |
| |
| /* Low level routine not meant for use outside of sparseset.[ch]. |
| Assumes idx1 < s->members and idx2 < s->members. */ |
| |
| static inline void |
| sparseset_swap (sparseset s, SPARSESET_ELT_TYPE idx1, SPARSESET_ELT_TYPE idx2) |
| { |
| SPARSESET_ELT_TYPE tmp = s->dense[idx2]; |
| sparseset_insert_bit (s, s->dense[idx1], idx2); |
| sparseset_insert_bit (s, tmp, idx1); |
| } |
| |
| /* Operation: S = S - {e} |
| Delete e from the set S if it is a member of S. */ |
| |
| void |
| sparseset_clear_bit (sparseset s, SPARSESET_ELT_TYPE e) |
| { |
| if (sparseset_bit_p (s, e)) |
| { |
| SPARSESET_ELT_TYPE idx = s->sparse[e]; |
| SPARSESET_ELT_TYPE iter = s->iter; |
| SPARSESET_ELT_TYPE mem = s->members - 1; |
| |
| /* If we are iterating over this set and we want to delete a |
| member we've already visited, then we swap the element we |
| want to delete with the element at the current iteration |
| index so that it plays well together with the code below |
| that actually removes the element. */ |
| if (s->iterating && idx <= iter) |
| { |
| if (idx < iter) |
| { |
| sparseset_swap (s, idx, iter); |
| idx = iter; |
| } |
| s->iter_inc = 0; |
| } |
| |
| /* Replace the element we want to delete with the last element |
| in the dense array and then decrement s->members, effectively |
| removing the element we want to delete. */ |
| sparseset_insert_bit (s, s->dense[mem], idx); |
| s->members = mem; |
| } |
| } |
| |
| /* Operation: D = S |
| Restrictions: none. */ |
| |
| void |
| sparseset_copy (sparseset d, sparseset s) |
| { |
| SPARSESET_ELT_TYPE i; |
| |
| if (d == s) |
| return; |
| |
| sparseset_clear (d); |
| for (i = 0; i < s->members; i++) |
| sparseset_insert_bit (d, s->dense[i], i); |
| d->members = s->members; |
| } |
| |
| /* Operation: D = A & B. |
| Restrictions: none. */ |
| |
| void |
| sparseset_and (sparseset d, sparseset a, sparseset b) |
| { |
| SPARSESET_ELT_TYPE e; |
| |
| if (a == b) |
| { |
| if (d != a) |
| sparseset_copy (d, a); |
| return; |
| } |
| |
| if (d == a || d == b) |
| { |
| sparseset s = (d == a) ? b : a; |
| |
| EXECUTE_IF_SET_IN_SPARSESET (d, e) |
| if (!sparseset_bit_p (s, e)) |
| sparseset_clear_bit (d, e); |
| } |
| else |
| { |
| sparseset sml, lrg; |
| |
| if (sparseset_cardinality (a) < sparseset_cardinality (b)) |
| { |
| sml = a; |
| lrg = b; |
| } |
| else |
| { |
| sml = b; |
| lrg = a; |
| } |
| |
| sparseset_clear (d); |
| EXECUTE_IF_SET_IN_SPARSESET (sml, e) |
| if (sparseset_bit_p (lrg, e)) |
| sparseset_set_bit (d, e); |
| } |
| } |
| |
| /* Operation: D = A & ~B. |
| Restrictions: D != B, unless D == A == B. */ |
| |
| void |
| sparseset_and_compl (sparseset d, sparseset a, sparseset b) |
| { |
| SPARSESET_ELT_TYPE e; |
| |
| if (a == b) |
| { |
| sparseset_clear (d); |
| return; |
| } |
| |
| gcc_assert (d != b); |
| |
| if (d == a) |
| { |
| if (sparseset_cardinality (d) < sparseset_cardinality (b)) |
| { |
| EXECUTE_IF_SET_IN_SPARSESET (d, e) |
| if (sparseset_bit_p (b, e)) |
| sparseset_clear_bit (d, e); |
| } |
| else |
| { |
| EXECUTE_IF_SET_IN_SPARSESET (b, e) |
| sparseset_clear_bit (d, e); |
| } |
| } |
| else |
| { |
| sparseset_clear (d); |
| EXECUTE_IF_SET_IN_SPARSESET (a, e) |
| if (!sparseset_bit_p (b, e)) |
| sparseset_set_bit (d, e); |
| } |
| } |
| |
| /* Operation: D = A | B. |
| Restrictions: none. */ |
| |
| void |
| sparseset_ior (sparseset d, sparseset a, sparseset b) |
| { |
| SPARSESET_ELT_TYPE e; |
| |
| if (a == b) |
| sparseset_copy (d, a); |
| else if (d == b) |
| { |
| EXECUTE_IF_SET_IN_SPARSESET (a, e) |
| sparseset_set_bit (d, e); |
| } |
| else |
| { |
| if (d != a) |
| sparseset_copy (d, a); |
| EXECUTE_IF_SET_IN_SPARSESET (b, e) |
| sparseset_set_bit (d, e); |
| } |
| } |
| |
| /* Operation: A == B |
| Restrictions: none. */ |
| |
| bool |
| sparseset_equal_p (sparseset a, sparseset b) |
| { |
| SPARSESET_ELT_TYPE e; |
| |
| if (a == b) |
| return true; |
| |
| if (sparseset_cardinality (a) != sparseset_cardinality (b)) |
| return false; |
| |
| EXECUTE_IF_SET_IN_SPARSESET (a, e) |
| if (!sparseset_bit_p (b, e)) |
| return false; |
| |
| return true; |
| } |
| |