struct cse_reg_info
{
- /* Next in hash chain. */
- struct cse_reg_info *hash_next;
-
- /* The next cse_reg_info structure in the free or used list. */
- struct cse_reg_info *next;
-
- /* Search key */
- unsigned int regno;
+ /* The timestamp at which this register is initialized. */
+ unsigned int timestamp;
/* The quantity number of the register's current contents. */
int reg_qty;
unsigned int subreg_ticked;
};
-/* We maintain a linked list of cse_reg_info instances, which is
- partitioned into two pieces. The first part, pointed to by
- cse_reg_info_list, is a list of those entries that are in use. The
- second part, pointed to by cse_reg_info_list_free, is a list of
- those entries that are not in use.
-
- We combine these two parts into one linked list for efficiency.
- Specifically, when we take an element from the second part and want
- to move it to the first part, all we have to do is move the pointer
- cse_reg_info_list_free to the next element. Also, if we wish to
- move all elements into the second part, we just have to move the
- pointer to the first element of the list. */
-
-/* A linked list of cse_reg_info entries that have been allocated so
- far. */
-static struct cse_reg_info *cse_reg_info_list;
-
-/* A pointer to the first unused entry in the above linked list. */
-static struct cse_reg_info *cse_reg_info_list_free;
+/* A table of cse_reg_info indexed by register numbers. */
+struct cse_reg_info *cse_reg_info_table;
-/* A mapping from registers to cse_reg_info data structures. */
-#define REGHASH_SHIFT 7
-#define REGHASH_SIZE (1 << REGHASH_SHIFT)
-#define REGHASH_MASK (REGHASH_SIZE - 1)
-static struct cse_reg_info *reg_hash[REGHASH_SIZE];
+/* The size of the above table. */
+static unsigned int cse_reg_info_table_size;
-#define REGHASH_FN(REGNO) \
- (((REGNO) ^ ((REGNO) >> REGHASH_SHIFT)) & REGHASH_MASK)
+/* The index of the first entry that has not been initialized. */
+static unsigned int cse_reg_info_table_first_uninitialized;
-/* The last lookup we did into the cse_reg_info_tree. This allows us
- to cache repeated lookups. */
-static unsigned int cached_regno;
-static struct cse_reg_info *cached_cse_reg_info;
+/* The timestamp at the beginning of the current run of
+ cse_basic_block. We increment this variable at at the beginning of
+ the current run of cse_basic_block. The timestamp field of a
+ cse_reg_info entry matches the value of this variable if and only
+ if the entry has been initialized during the current run of
+ cse_basic_block. */
+static unsigned int cse_reg_info_timestamp;
/* A HARD_REG_SET containing all the hard registers for which there is
currently a REG expression in the hash table. Note the difference
#define COST(X) (REG_P (X) ? 0 : notreg_cost (X, SET))
#define COST_IN(X,OUTER) (REG_P (X) ? 0 : notreg_cost (X, OUTER))
-/* Get the info associated with register N. */
-
-#define GET_CSE_REG_INFO(N) \
- (((N) == cached_regno && cached_cse_reg_info) \
- ? cached_cse_reg_info : get_cse_reg_info ((N)))
-
/* Get the number of times this register has been updated in this
basic block. */
-#define REG_TICK(N) ((GET_CSE_REG_INFO (N))->reg_tick)
+#define REG_TICK(N) (get_cse_reg_info (N)->reg_tick)
/* Get the point at which REG was recorded in the table. */
-#define REG_IN_TABLE(N) ((GET_CSE_REG_INFO (N))->reg_in_table)
+#define REG_IN_TABLE(N) (get_cse_reg_info (N)->reg_in_table)
/* Get the SUBREG set at the last increment to REG_TICK (-1 if not a
SUBREG). */
-#define SUBREG_TICKED(N) ((GET_CSE_REG_INFO (N))->subreg_ticked)
+#define SUBREG_TICKED(N) (get_cse_reg_info (N)->subreg_ticked)
/* Get the quantity number for REG. */
-#define REG_QTY(N) ((GET_CSE_REG_INFO (N))->reg_qty)
+#define REG_QTY(N) (get_cse_reg_info (N)->reg_qty)
/* Determine if the quantity number for register X represents a valid index
into the qty_table. */
static void count_reg_usage (rtx, int *, int);
static int check_for_label_ref (rtx *, void *);
extern void dump_class (struct table_elt*);
-static struct cse_reg_info * get_cse_reg_info (unsigned int);
+static void get_cse_reg_info_1 (unsigned int regno);
+static struct cse_reg_info * get_cse_reg_info (unsigned int regno);
static int check_dependence (rtx *, void *);
static void flush_hash_table (void);
}
\f
-static struct cse_reg_info *
-get_cse_reg_info (unsigned int regno)
-{
- struct cse_reg_info **hash_head = ®_hash[REGHASH_FN (regno)];
- struct cse_reg_info *p;
+/* Initialize CSE_REG_INFO_TABLE. */
- for (p = *hash_head; p != NULL; p = p->hash_next)
- if (p->regno == regno)
- break;
-
- if (p == NULL)
+static void
+init_cse_reg_info (unsigned int nregs)
+{
+ /* Do we need to grow the table? */
+ if (nregs > cse_reg_info_table_size)
{
- /* Get a new cse_reg_info structure. */
- if (cse_reg_info_list_free)
+ unsigned int new_size;
+
+ if (cse_reg_info_table_size < 2048)
{
- p = cse_reg_info_list_free;
- cse_reg_info_list_free = p->next;
+ /* Compute a new size that is a power of 2 and no smaller
+ than the large of NREGS and 64. */
+ new_size = (cse_reg_info_table_size
+ ? cse_reg_info_table_size : 64);
+
+ while (new_size < nregs)
+ new_size *= 2;
}
else
{
- p = xmalloc (sizeof (struct cse_reg_info));
- p->next = cse_reg_info_list;
- cse_reg_info_list = p;
+ /* If we need a big table, allocate just enough to hold
+ NREGS registers. */
+ new_size = nregs;
}
- /* Insert into hash table. */
- p->hash_next = *hash_head;
- *hash_head = p;
+ /* Reallocate the table with NEW_SIZE entries. */
+ cse_reg_info_table = xrealloc (cse_reg_info_table,
+ (sizeof (struct cse_reg_info)
+ * new_size));
+ cse_reg_info_table_size = new_size;
+ }
+
+ /* Do we have all of the first NREGS entries initialized? */
+ if (cse_reg_info_table_first_uninitialized < nregs)
+ {
+ unsigned int old_timestamp = cse_reg_info_timestamp - 1;
+ unsigned int i;
+
+ /* Put the old timestamp on newly allocated entries so that they
+ will all be considered out of date. We do not touch those
+ entries beyond the first NREGS entries to be nice to the
+ virtual memory. */
+ for (i = cse_reg_info_table_first_uninitialized; i < nregs; i++)
+ cse_reg_info_table[i].timestamp = old_timestamp;
- /* Initialize it. */
- p->reg_tick = 1;
- p->reg_in_table = -1;
- p->subreg_ticked = -1;
- p->reg_qty = -regno - 1;
- p->regno = regno;
+ cse_reg_info_table_first_uninitialized = nregs;
}
+}
+
+/* Given REGNO, ensure that a cse_reg_info entry exists for REGNO by
+ growing the cse_reg_info_table and/or initializing the entry for
+ REGNO. */
+
+static void
+get_cse_reg_info_1 (unsigned int regno)
+{
+ /* Set TIMESTAMP field to CSE_REG_INFO_TIMESTAMP so that this
+ entry will be considered to have been initialized. */
+ cse_reg_info_table[regno].timestamp = cse_reg_info_timestamp;
+
+ /* Initialize the rest of the entry. */
+ cse_reg_info_table[regno].reg_tick = 1;
+ cse_reg_info_table[regno].reg_in_table = -1;
+ cse_reg_info_table[regno].subreg_ticked = -1;
+ cse_reg_info_table[regno].reg_qty = -regno - 1;
+}
+
+/* Find a cse_reg_info entry for REGNO. */
- /* Cache this lookup; we tend to be looking up information about the
- same register several times in a row. */
- cached_regno = regno;
- cached_cse_reg_info = p;
+static inline struct cse_reg_info *
+get_cse_reg_info (unsigned int regno)
+{
+ struct cse_reg_info *p = &cse_reg_info_table[regno];
+
+ /* If we are looking for REGNO that is different from the last
+ look-up, make sure the entry for REGNO exists and has been
+ initialized. */
+ if (p->timestamp != cse_reg_info_timestamp)
+ get_cse_reg_info_1 (regno);
return p;
}
next_qty = 0;
- /* Clear out hash table state for this pass. */
-
- memset (reg_hash, 0, sizeof reg_hash);
-
- cse_reg_info_list_free = cse_reg_info_list;
-
- cached_cse_reg_info = 0;
+ /* Invalidate cse_reg_info_table and its cache. */
+ cse_reg_info_timestamp++;
+ /* Clear out hash table state for this pass. */
CLEAR_HARD_REG_SET (hard_regs_in_table);
/* The per-quantity values used to be initialized here, but it is
rtx insn = f;
int i;
+ init_cse_reg_info (nregs);
+
val.path = xmalloc (sizeof (struct branch_path)
* PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH));
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