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author | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
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committer | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
commit | 1bc5aee63eb72b341f506ad058502cd0361f0d10 (patch) | |
tree | c607e8252f3405424ff15bc2d00aa38dadbb2518 /gcc-4.9/gcc/pointer-set.c | |
parent | 283a0bf58fcf333c58a2a92c3ebbc41fb9eb1fdb (diff) | |
download | toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.gz toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.bz2 toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.zip |
Initial checkin of GCC 4.9.0 from trunk (r208799).
Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba
Diffstat (limited to 'gcc-4.9/gcc/pointer-set.c')
-rw-r--r-- | gcc-4.9/gcc/pointer-set.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/pointer-set.c b/gcc-4.9/gcc/pointer-set.c new file mode 100644 index 000000000..8b6a73257 --- /dev/null +++ b/gcc-4.9/gcc/pointer-set.c @@ -0,0 +1,271 @@ +/* Set operations on pointers + Copyright (C) 2004-2014 Free Software Foundation, Inc. + +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 "pointer-set.h" + + +/* Use the multiplicative method, as described in Knuth 6.4, to obtain + a hash code for P in the range [0, MAX). MAX == 2^LOGMAX. + + Summary of this method: Multiply p by some number A that's + relatively prime to 2^sizeof(size_t). The result is two words. + Discard the most significant word, and return the most significant + N bits of the least significant word. As suggested by Knuth, our + choice for A is the integer part of (ULONG_MAX + 1.0) / phi, where phi + is the golden ratio. + + We don't need to do anything special for full-width multiplication + because we're only interested in the least significant word of the + product, and unsigned arithmetic in C is modulo the word size. */ + +static inline size_t +hash1 (const void *p, unsigned long max, unsigned long logmax) +{ +#if HOST_BITS_PER_LONG == 32 + const unsigned long A = 0x9e3779b9u; +#elif HOST_BITS_PER_LONG == 64 + const unsigned long A = 0x9e3779b97f4a7c16ul; +#else + const unsigned long A + = (ULONG_MAX + 1.0L) * 0.6180339887498948482045868343656381177203L; +#endif + const unsigned long shift = HOST_BITS_PER_LONG - logmax; + + return ((A * (uintptr_t) p) >> shift) & (max - 1); +} + + +/* Allocate an empty pointer set. */ +struct pointer_set_t * +pointer_set_create (void) +{ + struct pointer_set_t *result = XNEW (struct pointer_set_t); + + result->n_elements = 0; + result->log_slots = 8; + result->n_slots = (size_t) 1 << result->log_slots; + + result->slots = XCNEWVEC (const void *, result->n_slots); + return result; +} + +/* Reclaims all memory associated with PSET. */ +void +pointer_set_destroy (struct pointer_set_t *pset) +{ + XDELETEVEC (pset->slots); + XDELETE (pset); +} + + +/* Lookup the slot for the pointer P and return true if it exists, + otherwise return false in which case *IX points to the slot that + would be used on insertion. */ + +bool +pointer_set_lookup (const pointer_set_t *pset, const void *p, size_t *ix) +{ + size_t n = hash1 (p, pset->n_slots, pset->log_slots); + + while (true) + { + if (pset->slots[n] == p) + { + *ix = n; + return true; + } + else if (pset->slots[n] == 0) + { + *ix = n; + return false; + } + else + { + ++n; + if (n == pset->n_slots) + n = 0; + } + } +} + +/* Returns nonzero if PSET contains P. P must be nonnull. + + Collisions are resolved by linear probing. */ +int +pointer_set_contains (const struct pointer_set_t *pset, const void *p) +{ + size_t n; + return pointer_set_lookup (pset, p, &n); +} + +/* Inserts P into PSET if it wasn't already there. Returns nonzero + if it was already there. P must be nonnull. */ +int +pointer_set_insert (struct pointer_set_t *pset, const void *p) +{ + size_t n; + + /* For simplicity, expand the set even if P is already there. This can be + superfluous but can happen at most once. */ + if (pset->n_elements > pset->n_slots / 4) + { + size_t old_n_slots = pset->n_slots; + const void **old_slots = pset->slots; + pset->log_slots = pset->log_slots + 1; + pset->n_slots = pset->n_slots * 2; + pset->slots = XCNEWVEC (const void *, pset->n_slots); + size_t i; + + for (i = 0; i < old_n_slots; ++i) + { + const void *value = old_slots[i]; + pointer_set_lookup (pset, value, &n); + pset->slots[n] = value; + } + + XDELETEVEC (old_slots); + } + + if (pointer_set_lookup (pset, p, &n)) + return 1; + + pset->slots[n] = p; + ++pset->n_elements; + return 0; +} + +/* Pass each pointer in PSET to the function in FN, together with the fixed + parameter DATA. If FN returns false, the iteration stops. */ + +void pointer_set_traverse (const struct pointer_set_t *pset, + bool (*fn) (const void *, void *), void *data) +{ + size_t i; + for (i = 0; i < pset->n_slots; ++i) + if (pset->slots[i] && !fn (pset->slots[i], data)) + break; +} + + +/* A pointer map is represented the same way as a pointer_set, so + the hash code is based on the address of the key, rather than + its contents. Null keys are a reserved value. Deletion is not + supported (yet). There is no mechanism for user control of hash + function, equality comparison, initial size, or resizing policy. */ + +struct pointer_map_t +{ + pointer_set_t pset; + void **values; +}; + +/* Allocate an empty pointer map. */ +struct pointer_map_t * +pointer_map_create (void) +{ + struct pointer_map_t *result = XNEW (struct pointer_map_t); + + result->pset.n_elements = 0; + result->pset.log_slots = 8; + result->pset.n_slots = (size_t) 1 << result->pset.log_slots; + + result->pset.slots = XCNEWVEC (const void *, result->pset.n_slots); + result->values = XCNEWVEC (void *, result->pset.n_slots); + return result; +} + +/* Reclaims all memory associated with PMAP. */ +void pointer_map_destroy (struct pointer_map_t *pmap) +{ + XDELETEVEC (pmap->pset.slots); + XDELETEVEC (pmap->values); + XDELETE (pmap); +} + +/* Returns a pointer to the value to which P maps, if PMAP contains P. P + must be nonnull. Return NULL if PMAP does not contain P. + + Collisions are resolved by linear probing. */ +void ** +pointer_map_contains (const struct pointer_map_t *pmap, const void *p) +{ + size_t n; + if (pointer_set_lookup (&pmap->pset, p, &n)) + return &pmap->values[n]; + else + return NULL; +} + +/* Inserts P into PMAP if it wasn't already there. Returns a pointer + to the value. P must be nonnull. */ +void ** +pointer_map_insert (struct pointer_map_t *pmap, const void *p) +{ + size_t n; + + /* For simplicity, expand the map even if P is already there. This can be + superfluous but can happen at most once. */ + if (pmap->pset.n_elements > pmap->pset.n_slots / 4) + { + size_t old_n_slots = pmap->pset.n_slots; + const void **old_keys = pmap->pset.slots; + void **old_values = pmap->values; + pmap->pset.log_slots = pmap->pset.log_slots + 1; + pmap->pset.n_slots = pmap->pset.n_slots * 2; + pmap->pset.slots = XCNEWVEC (const void *, pmap->pset.n_slots); + pmap->values = XCNEWVEC (void *, pmap->pset.n_slots); + size_t i; + + for (i = 0; i < old_n_slots; ++i) + if (old_keys[i]) + { + const void *key = old_keys[i]; + pointer_set_lookup (&pmap->pset, key, &n); + pmap->pset.slots[n] = key; + pmap->values[n] = old_values[i]; + } + + XDELETEVEC (old_keys); + XDELETEVEC (old_values); + } + + if (!pointer_set_lookup (&pmap->pset, p, &n)) + { + ++pmap->pset.n_elements; + pmap->pset.slots[n] = p; + } + + return &pmap->values[n]; +} + +/* Pass each pointer in PMAP to the function in FN, together with the pointer + to the value and the fixed parameter DATA. If FN returns false, the + iteration stops. */ + +void pointer_map_traverse (const struct pointer_map_t *pmap, + bool (*fn) (const void *, void **, void *), void *data) +{ + size_t i; + for (i = 0; i < pmap->pset.n_slots; ++i) + if (pmap->pset.slots[i] + && !fn (pmap->pset.slots[i], &pmap->values[i], data)) + break; +} |