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stmt.c (cost_table_, [...]): Remove. 

* stmt.c (cost_table_, use_cost_table, cost_table_initialize,
	COST_TABLE): Remove.
	(estimate_case_costs): Remove.
	(expand_case): Do not call estimate_case_costs
	to set use_cost_table.
	(balance_case_nodes): Do not use use_cost_table.

From-SVN: r186526
This commit is contained in:
Steven Bosscher 2012-04-17 12:02:30 +00:00
parent 1ab24192d5
commit c5c20c556b
2 changed files with 12 additions and 131 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
gcc/ChangeLog
View File

@ -1,3 +1,12 @@
2012-04-17 Steven Bosscher <steven@gcc.gnu.org>
* stmt.c (cost_table_, use_cost_table, cost_table_initialize,
COST_TABLE): Remove.
(estimate_case_costs): Remove.
(expand_case): Do not call estimate_case_costs
to set use_cost_table.
(balance_case_nodes): Do not use use_cost_table.
2012-04-16 Jan Hubicka <jh@suse.cz>
* cgraph.c (cgraph_hash, assembler_name_hash): Remove.

134
gcc/stmt.c
View File

@ -98,16 +98,6 @@ struct case_node
typedef struct case_node case_node;
typedef struct case_node *case_node_ptr;
/* These are used by estimate_case_costs and balance_case_nodes. */
/* This must be a signed type, and non-ANSI compilers lack signed char. */
static short cost_table_[129];
static int use_cost_table;
static int cost_table_initialized;
/* Special care is needed because we allow -1, but TREE_INT_CST_LOW
is unsigned. */
#define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
static int n_occurrences (int, const char *);
static bool tree_conflicts_with_clobbers_p (tree, HARD_REG_SET *);
@ -117,7 +107,6 @@ static bool check_unique_operand_names (tree, tree, tree);
static char *resolve_operand_name_1 (char *, tree, tree, tree);
static void expand_null_return_1 (void);
static void expand_value_return (rtx);
static int estimate_case_costs (case_node_ptr);
static bool lshift_cheap_p (void);
static int case_bit_test_cmp (const void *, const void *);
static void emit_case_bit_tests (tree, tree, tree, tree, case_node_ptr, rtx);
@ -2304,7 +2293,6 @@ expand_case (gimple stmt)
decision tree an unconditional jump to the
default code is emitted. */
use_cost_table = estimate_case_costs (case_list);
balance_case_nodes (&case_list, NULL);
emit_case_nodes (index, case_list, default_label, index_type);
if (default_label)
@ -2403,86 +2391,6 @@ do_jump_if_equal (enum machine_mode mode, rtx op0, rtx op1, rtx label,
NULL_RTX, NULL_RTX, label, -1);
}
/* Not all case values are encountered equally. This function
uses a heuristic to weight case labels, in cases where that
looks like a reasonable thing to do.
Right now, all we try to guess is text, and we establish the
following weights:
chars above space: 16
digits: 16
default: 12
space, punct: 8
tab: 4
newline: 2
other "\" chars: 1
remaining chars: 0
If we find any cases in the switch that are not either -1 or in the range
of valid ASCII characters, or are control characters other than those
commonly used with "\", don't treat this switch scanning text.
Return 1 if these nodes are suitable for cost estimation, otherwise
return 0. */
static int
estimate_case_costs (case_node_ptr node)
{
tree min_ascii = integer_minus_one_node;
tree max_ascii = build_int_cst (TREE_TYPE (node->high), 127);
case_node_ptr n;
int i;
/* If we haven't already made the cost table, make it now. Note that the
lower bound of the table is -1, not zero. */
if (! cost_table_initialized)
{
cost_table_initialized = 1;
for (i = 0; i < 128; i++)
{
if (ISALNUM (i))
COST_TABLE (i) = 16;
else if (ISPUNCT (i))
COST_TABLE (i) = 8;
else if (ISCNTRL (i))
COST_TABLE (i) = -1;
}
COST_TABLE (' ') = 8;
COST_TABLE ('\t') = 4;
COST_TABLE ('\0') = 4;
COST_TABLE ('\n') = 2;
COST_TABLE ('\f') = 1;
COST_TABLE ('\v') = 1;
COST_TABLE ('\b') = 1;
}
/* See if all the case expressions look like text. It is text if the
constant is >= -1 and the highest constant is <= 127. Do all comparisons
as signed arithmetic since we don't want to ever access cost_table with a
value less than -1. Also check that none of the constants in a range
are strange control characters. */
for (n = node; n; n = n->right)
{
if (tree_int_cst_lt (n->low, min_ascii)
|| tree_int_cst_lt (max_ascii, n->high))
return 0;
for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
if (COST_TABLE (i) < 0)
return 0;
}
/* All interesting values are within the range of interesting
ASCII characters. */
return 1;
}
/* Take an ordered list of case nodes
and transform them into a near optimal binary tree,
on the assumption that any target code selection value is as
@ -2501,7 +2409,6 @@ balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
np = *head;
if (np)
{
int cost = 0;
int i = 0;
int ranges = 0;
case_node_ptr *npp;
@ -2512,14 +2419,7 @@ balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
while (np)
{
if (!tree_int_cst_equal (np->low, np->high))
{
ranges++;
if (use_cost_table)
cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
}
if (use_cost_table)
cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
ranges++;
i++;
np = np->right;
@ -2530,37 +2430,9 @@ balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
/* Split this list if it is long enough for that to help. */
npp = head;
left = *npp;
if (use_cost_table)
{
/* Find the place in the list that bisects the list's total cost,
Here I gets half the total cost. */
int n_moved = 0;
i = (cost + 1) / 2;
while (1)
{
/* Skip nodes while their cost does not reach that amount. */
if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
if (i <= 0)
break;
npp = &(*npp)->right;
n_moved += 1;
}
if (n_moved == 0)
{
/* Leave this branch lopsided, but optimize left-hand
side and fill in `parent' fields for right-hand side. */
np = *head;
np->parent = parent;
balance_case_nodes (&np->left, np);
for (; np->right; np = np->right)
np->right->parent = np;
return;
}
}
/* If there are just three nodes, split at the middle one. */
else if (i == 3)
if (i == 3)
npp = &(*npp)->right;
else
{