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tree-vrp.c (find_case_label_ranges): New function. 

2012-08-01  Tom de Vries  <tom@codesourcery.com>

	* tree-vrp.c (find_case_label_ranges): New function.
	(vrp_visit_switch_stmt, simplify_switch_using_ranges): Use
	find_case_label_ranges instead of find_case_label_range.  Handle second
	range.

From-SVN: r190043
This commit is contained in:
Tom de Vries 2012-08-01 16:53:05 +00:00 committed by Tom de Vries
parent 5f564b8f56
commit 8bb37e9ad3
2 changed files with 107 additions and 6 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2012-08-01 Tom de Vries <tom@codesourcery.com>
* tree-vrp.c (find_case_label_ranges): New function.
(vrp_visit_switch_stmt, simplify_switch_using_ranges): Use
find_case_label_ranges instead of find_case_label_range. Handle second
range.
2012-08-01 Michael Matz <matz@suse.de>
* tree-complex.c (init_parameter_lattice_values): Don't call var_ann.

106
gcc/tree-vrp.c
View File

@ -6754,6 +6754,84 @@ find_case_label_range (gimple stmt, tree min, tree max, size_t *min_idx,
}
}
/* Searches the case label vector VEC for the ranges of CASE_LABELs that are
used in range VR. The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and
MAX_IDX2. If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1.
Returns true if the default label is not needed. */
static bool
find_case_label_ranges (gimple stmt, value_range_t *vr, size_t *min_idx1,
size_t *max_idx1, size_t *min_idx2,
size_t *max_idx2)
{
size_t i, j, k, l;
unsigned int n = gimple_switch_num_labels (stmt);
bool take_default;
tree case_low, case_high;
tree min = vr->min, max = vr->max;
gcc_checking_assert (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE);
take_default = !find_case_label_range (stmt, min, max, &i, &j);
/* Set second range to emtpy. */
*min_idx2 = 1;
*max_idx2 = 0;
if (vr->type == VR_RANGE)
{
*min_idx1 = i;
*max_idx1 = j;
return !take_default;
}
/* Set first range to all case labels. */
*min_idx1 = 1;
*max_idx1 = n - 1;
if (i > j)
return false;
/* Make sure all the values of case labels [i , j] are contained in
range [MIN, MAX]. */
case_low = CASE_LOW (gimple_switch_label (stmt, i));
case_high = CASE_HIGH (gimple_switch_label (stmt, j));
if (tree_int_cst_compare (case_low, min) < 0)
i += 1;
if (case_high != NULL_TREE
&& tree_int_cst_compare (max, case_high) < 0)
j -= 1;
if (i > j)
return false;
/* If the range spans case labels [i, j], the corresponding anti-range spans
the labels [1, i - 1] and [j + 1, n - 1]. */
k = j + 1;
l = n - 1;
if (k > l)
{
k = 1;
l = 0;
}
j = i - 1;
i = 1;
if (i > j)
{
i = k;
j = l;
k = 1;
l = 0;
}
*min_idx1 = i;
*max_idx1 = j;
*min_idx2 = k;
*max_idx2 = l;
return false;
}
/* Visit switch statement STMT. If we can determine which edge
will be taken out of STMT's basic block, record it in
*TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
@ -6764,7 +6842,7 @@ vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p)
{
tree op, val;
value_range_t *vr;
size_t i = 0, j = 0;
size_t i = 0, j = 0, k, l;
bool take_default;
*taken_edge_p = NULL;
@ -6782,12 +6860,13 @@ vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p)
fprintf (dump_file, "\n");
}
if (vr->type != VR_RANGE
if ((vr->type != VR_RANGE
&& vr->type != VR_ANTI_RANGE)
|| symbolic_range_p (vr))
return SSA_PROP_VARYING;
/* Find the single edge that is taken from the switch expression. */
take_default = !find_case_label_range (stmt, vr->min, vr->max, &i, &j);
take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
/* Check if the range spans no CASE_LABEL. If so, we only reach the default
label */
@ -6821,6 +6900,16 @@ vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p)
return SSA_PROP_VARYING;
}
}
for (; k <= l; ++k)
{
if (CASE_LABEL (gimple_switch_label (stmt, k)) != CASE_LABEL (val))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " not a single destination for this "
"range\n");
return SSA_PROP_VARYING;
}
}
}
*taken_edge_p = find_edge (gimple_bb (stmt),
@ -8215,18 +8304,20 @@ simplify_switch_using_ranges (gimple stmt)
size_t i = 0, j = 0, n, n2;
tree vec2;
switch_update su;
size_t k = 1, l = 0;
if (TREE_CODE (op) == SSA_NAME)
{
vr = get_value_range (op);
/* We can only handle integer ranges. */
if (vr->type != VR_RANGE
if ((vr->type != VR_RANGE
&& vr->type != VR_ANTI_RANGE)
|| symbolic_range_p (vr))
return false;
/* Find case label for min/max of the value range. */
take_default = !find_case_label_range (stmt, vr->min, vr->max, &i, &j);
take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
}
else if (TREE_CODE (op) == INTEGER_CST)
{
@ -8253,7 +8344,7 @@ simplify_switch_using_ranges (gimple stmt)
return false;
/* Build a new vector of taken case labels. */
vec2 = make_tree_vec (j - i + 1 + (int)take_default);
vec2 = make_tree_vec (j - i + 1 + l - k + 1 + (int)take_default);
n2 = 0;
/* Add the default edge, if necessary. */
@ -8263,6 +8354,9 @@ simplify_switch_using_ranges (gimple stmt)
for (; i <= j; ++i, ++n2)
TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, i);
for (; k <= l; ++k, ++n2)
TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, k);
/* Mark needed edges. */
for (i = 0; i < n2; ++i)
{