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-rw-r--r--gcc/pointer-set.c166
1 files changed, 67 insertions, 99 deletions
diff --git a/gcc/pointer-set.c b/gcc/pointer-set.c
index 6c72883002e..ef44aca2d1f 100644
--- a/gcc/pointer-set.c
+++ b/gcc/pointer-set.c
@@ -21,21 +21,6 @@ along with GCC; see the file COPYING3. If not see
#include "system.h"
#include "pointer-set.h"
-/* A pointer set is represented as a simple open-addressing hash
- table. Simplifications: The hash code is based on the value of the
- pointer, not what it points to. The number of buckets is always a
- power of 2. Null pointers 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_set_t
-{
- size_t log_slots;
- size_t n_slots; /* n_slots = 2^log_slots */
- size_t n_elements;
-
- const void **slots;
-};
/* 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.
@@ -67,6 +52,7 @@ hash1 (const void *p, unsigned long max, unsigned long logmax)
return ((A * (uintptr_t) p) >> shift) & (max - 1);
}
+
/* Allocate an empty pointer set. */
struct pointer_set_t *
pointer_set_create (void)
@@ -89,20 +75,28 @@ pointer_set_destroy (struct pointer_set_t *pset)
XDELETE (pset);
}
-/* 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)
+/* 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)
- return 1;
+ {
+ *ix = n;
+ return true;
+ }
else if (pset->slots[n] == 0)
- return 0;
+ {
+ *ix = n;
+ return false;
+ }
else
{
++n;
@@ -112,23 +106,14 @@ pointer_set_contains (const struct pointer_set_t *pset, const void *p)
}
}
-/* Subroutine of pointer_set_insert. Return the insertion slot for P into
- an empty element of SLOTS, an array of length N_SLOTS. */
-static inline size_t
-insert_aux (const void *p, const void **slots, size_t n_slots, size_t log_slots)
+/* 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 = hash1 (p, n_slots, log_slots);
- while (true)
- {
- if (slots[n] == p || slots[n] == 0)
- return n;
- else
- {
- ++n;
- if (n == n_slots)
- n = 0;
- }
- }
+ size_t n;
+ return pointer_set_lookup (pset, p, &n);
}
/* Inserts P into PSET if it wasn't already there. Returns nonzero
@@ -142,26 +127,24 @@ pointer_set_insert (struct pointer_set_t *pset, const void *p)
superfluous but can happen at most once. */
if (pset->n_elements > pset->n_slots / 4)
{
- size_t new_log_slots = pset->log_slots + 1;
- size_t new_n_slots = pset->n_slots * 2;
- const void **new_slots = XCNEWVEC (const void *, new_n_slots);
+ 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 < pset->n_slots; ++i)
+ for (i = 0; i < old_n_slots; ++i)
{
- const void *value = pset->slots[i];
- n = insert_aux (value, new_slots, new_n_slots, new_log_slots);
- new_slots[n] = value;
+ const void *value = old_slots[i];
+ pointer_set_lookup (pset, value, &n);
+ pset->slots[n] = value;
}
- XDELETEVEC (pset->slots);
- pset->n_slots = new_n_slots;
- pset->log_slots = new_log_slots;
- pset->slots = new_slots;
+ XDELETEVEC (old_slots);
}
- n = insert_aux (p, pset->slots, pset->n_slots, pset->log_slots);
- if (pset->slots[n])
+ if (pointer_set_lookup (pset, p, &n))
return 1;
pset->slots[n] = p;
@@ -190,11 +173,7 @@ void pointer_set_traverse (const struct pointer_set_t *pset,
struct pointer_map_t
{
- size_t log_slots;
- size_t n_slots; /* n_slots = 2^log_slots */
- size_t n_elements;
-
- const void **keys;
+ pointer_set_t pset;
void **values;
};
@@ -204,19 +183,19 @@ pointer_map_create (void)
{
struct pointer_map_t *result = XNEW (struct pointer_map_t);
- result->n_elements = 0;
- result->log_slots = 8;
- result->n_slots = (size_t) 1 << result->log_slots;
+ result->pset.n_elements = 0;
+ result->pset.log_slots = 8;
+ result->pset.n_slots = (size_t) 1 << result->pset.log_slots;
- result->keys = XCNEWVEC (const void *, result->n_slots);
- result->values = XCNEWVEC (void *, result->n_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->keys);
+ XDELETEVEC (pmap->pset.slots);
XDELETEVEC (pmap->values);
XDELETE (pmap);
}
@@ -228,21 +207,11 @@ void pointer_map_destroy (struct pointer_map_t *pmap)
void **
pointer_map_contains (const struct pointer_map_t *pmap, const void *p)
{
- size_t n = hash1 (p, pmap->n_slots, pmap->log_slots);
-
- while (true)
- {
- if (pmap->keys[n] == p)
- return &pmap->values[n];
- else if (pmap->keys[n] == 0)
- return NULL;
- else
- {
- ++n;
- if (n == pmap->n_slots)
- n = 0;
- }
- }
+ 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
@@ -254,36 +223,34 @@ pointer_map_insert (struct pointer_map_t *pmap, const void *p)
/* For simplicity, expand the map even if P is already there. This can be
superfluous but can happen at most once. */
- if (pmap->n_elements > pmap->n_slots / 4)
+ if (pmap->pset.n_elements > pmap->pset.n_slots / 4)
{
- size_t new_log_slots = pmap->log_slots + 1;
- size_t new_n_slots = pmap->n_slots * 2;
- const void **new_keys = XCNEWVEC (const void *, new_n_slots);
- void **new_values = XCNEWVEC (void *, new_n_slots);
+ 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 < pmap->n_slots; ++i)
- if (pmap->keys[i])
+ for (i = 0; i < old_n_slots; ++i)
+ if (old_keys[i])
{
- const void *key = pmap->keys[i];
- n = insert_aux (key, new_keys, new_n_slots, new_log_slots);
- new_keys[n] = key;
- new_values[n] = pmap->values[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 (pmap->keys);
- XDELETEVEC (pmap->values);
- pmap->n_slots = new_n_slots;
- pmap->log_slots = new_log_slots;
- pmap->keys = new_keys;
- pmap->values = new_values;
+ XDELETEVEC (old_keys);
+ XDELETEVEC (old_values);
}
- n = insert_aux (p, pmap->keys, pmap->n_slots, pmap->log_slots);
- if (!pmap->keys[n])
+ if (!pointer_set_lookup (&pmap->pset, p, &n))
{
- ++pmap->n_elements;
- pmap->keys[n] = p;
+ ++pmap->pset.n_elements;
+ pmap->pset.slots[n] = p;
}
return &pmap->values[n];
@@ -297,7 +264,8 @@ 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->n_slots; ++i)
- if (pmap->keys[i] && !fn (pmap->keys[i], &pmap->values[i], data))
+ for (i = 0; i < pmap->pset.n_slots; ++i)
+ if (pmap->pset.slots[i]
+ && !fn (pmap->pset.slots[i], &pmap->values[i], data))
break;
}
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