mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-02-24 00:29:37 +08:00
Code Issues Packages Projects Releases Wiki Activity

re PR middle-end/53153 (ice in tree_low_cst, at tree.c:6569)

Browse Source 
gcc/
	PR middle-end/53153
	* gimplify.c (preprocess_case_label_vec_for_gimple): New function,
	split out from ...
	(gimplify_switch_expr): ... here.
	* gimple.h (preprocess_case_label_vec_for_gimple): Add prototype.
	* tree-ssa-forwprop.c (simplify_gimple_switch_label_vec): New function
	to clean up case labels with values outside the index type range.
	(simplify_gimple_switch): Call it if something changed.
	Remove strange and unnecessary assert.

testsuite/
	PR middle-end/53153
	* gcc.dg/pr53153.c: New test.

From-SVN: r187048
This commit is contained in:
Steven Bosscher 2012-05-02 12:57:10 +00:00
parent 69416e98ff
commit 68e7284038
6 changed files with 335 additions and 150 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
gcc/ChangeLog
View File

@ -1,3 +1,15 @@
2012-05-02 Steven Bosscher <steven@gcc.gnu.org>
PR middle-end/53153
* gimplify.c (preprocess_case_label_vec_for_gimple): New function,
split out from ...
(gimplify_switch_expr): ... here.
* gimple.h (preprocess_case_label_vec_for_gimple): Add prototype.
* tree-ssa-forwprop.c (simplify_gimple_switch_label_vec): New function
to clean up case labels with values outside the index type range.
(simplify_gimple_switch): Call it if something changed.
Remove strange and unnecessary assert.
2012-05-02 Richard Guenther <rguenther@suse.de>
* fold-const.c (div_if_zero_remainder): sizetypes no longer

1
gcc/gimple.h
View File

@ -922,6 +922,7 @@ gimple gimple_build_transaction (gimple_seq, tree);
gimple gimple_build_predict (enum br_predictor, enum prediction);
enum gimple_statement_structure_enum gss_for_assign (enum tree_code);
void sort_case_labels (VEC(tree,heap) *);
void preprocess_case_label_vec_for_gimple (VEC(tree,heap) *, tree, tree *);
void gimple_set_body (tree, gimple_seq);
gimple_seq gimple_body (tree);
bool gimple_has_body_p (tree);

328
gcc/gimplify.c
View File

@ -1538,7 +1538,7 @@ gimplify_statement_list (tree *expr_p, gimple_seq *pre_p)
return GS_ALL_DONE;
}
/* Compare two case labels. Because the front end should already have
made sure that case ranges do not overlap, it is enough to only compare
the CASE_LOW values of each case label. */
@ -1565,8 +1565,179 @@ sort_case_labels (VEC(tree,heap)* label_vec)
{
VEC_qsort (tree, label_vec, compare_case_labels);
}
/* Prepare a vector of case labels to be used in a GIMPLE_SWITCH statement.
/* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
LABELS is a vector that contains all case labels to look at.
INDEX_TYPE is the type of the switch index expression. Case labels
in LABELS are discarded if their values are not in the value range
covered by INDEX_TYPE. The remaining case label values are folded
to INDEX_TYPE.
If a default case exists in LABELS, it is removed from LABELS and
returned in DEFAULT_CASEP. If no default case exists, but the
case labels already cover the whole range of INDEX_TYPE, a default
case is returned pointing to one of the existing case labels.
Otherwise DEFAULT_CASEP is set to NULL_TREE.
DEFAULT_CASEP may be NULL, in which case the above comment doesn't
apply and no action is taken regardless of whether a default case is
found or not. */
void
preprocess_case_label_vec_for_gimple (VEC(tree,heap) *labels,
tree index_type,
tree *default_casep)
{
tree min_value, max_value;
tree default_case = NULL_TREE;
size_t i, len;
i = 0;
min_value = TYPE_MIN_VALUE (index_type);
max_value = TYPE_MAX_VALUE (index_type);
while (i < VEC_length (tree, labels))
{
tree elt = VEC_index (tree, labels, i);
tree low = CASE_LOW (elt);
tree high = CASE_HIGH (elt);
bool remove_element = FALSE;
if (low)
{
gcc_checking_assert (TREE_CODE (low) == INTEGER_CST);
gcc_checking_assert (!high || TREE_CODE (high) == INTEGER_CST);
/* This is a non-default case label, i.e. it has a value.
See if the case label is reachable within the range of
the index type. Remove out-of-range case values. Turn
case ranges into a canonical form (high > low strictly)
and convert the case label values to the index type.
NB: The type of gimple_switch_index() may be the promoted
type, but the case labels retain the original type. */
if (high)
{
/* This is a case range. Discard empty ranges.
If the bounds or the range are equal, turn this
into a simple (one-value) case. */
int cmp = tree_int_cst_compare (high, low);
if (cmp < 0)
remove_element = TRUE;
else if (cmp == 0)
high = NULL_TREE;
}
if (! high)
{
/* If the simple case value is unreachable, ignore it. */
if ((TREE_CODE (min_value) == INTEGER_CST
&& tree_int_cst_compare (low, min_value) < 0)
|| (TREE_CODE (max_value) == INTEGER_CST
&& tree_int_cst_compare (low, max_value) > 0))
remove_element = TRUE;
else
low = fold_convert (index_type, low);
}
else
{
/* If the entire case range is unreachable, ignore it. */
if ((TREE_CODE (min_value) == INTEGER_CST
&& tree_int_cst_compare (high, min_value) < 0)
|| (TREE_CODE (max_value) == INTEGER_CST
&& tree_int_cst_compare (low, max_value) > 0))
remove_element = TRUE;
else
{
/* If the lower bound is less than the index type's
minimum value, truncate the range bounds. */
if (TREE_CODE (min_value) == INTEGER_CST
&& tree_int_cst_compare (low, min_value) < 0)
low = min_value;
low = fold_convert (index_type, low);
/* If the upper bound is greater than the index type's
maximum value, truncate the range bounds. */
if (TREE_CODE (max_value) == INTEGER_CST
&& tree_int_cst_compare (high, max_value) > 0)
high = max_value;
high = fold_convert (index_type, high);
}
}
CASE_LOW (elt) = low;
CASE_HIGH (elt) = high;
}
else
{
gcc_assert (!default_case);
default_case = elt;
/* The default case must be passed separately to the
gimple_build_switch routines. But if DEFAULT_CASEP
is NULL, we do not remove the default case (it would
be completely lost). */
if (default_casep)
remove_element = TRUE;
}
if (remove_element)
VEC_ordered_remove (tree, labels, i);
else
i++;
}
len = i;
if (!VEC_empty (tree, labels))
sort_case_labels (labels);
if (default_casep && !default_case)
{
/* If the switch has no default label, add one, so that we jump
around the switch body. If the labels already cover the whole
range of the switch index_type, add the default label pointing
to one of the existing labels. */
if (len
&& TYPE_MIN_VALUE (index_type)
&& TYPE_MAX_VALUE (index_type)
&& tree_int_cst_equal (CASE_LOW (VEC_index (tree, labels, 0)),
TYPE_MIN_VALUE (index_type)))
{
tree low, high = CASE_HIGH (VEC_index (tree, labels, len - 1));
if (!high)
high = CASE_LOW (VEC_index (tree, labels, len - 1));
if (tree_int_cst_equal (high, TYPE_MAX_VALUE (index_type)))
{
for (i = 1; i < len; i++)
{
high = CASE_LOW (VEC_index (tree, labels, i));
low = CASE_HIGH (VEC_index (tree, labels, i - 1));
if (!low)
low = CASE_LOW (VEC_index (tree, labels, i - 1));
if ((TREE_INT_CST_LOW (low) + 1
!= TREE_INT_CST_LOW (high))
|| (TREE_INT_CST_HIGH (low)
+ (TREE_INT_CST_LOW (high) == 0)
!= TREE_INT_CST_HIGH (high)))
break;
}
if (i == len)
{
tree label = CASE_LABEL (VEC_index (tree, labels, 0));
default_case = build_case_label (NULL_TREE, NULL_TREE,
label);
}
}
}
}
if (default_casep)
*default_casep = default_case;
}
/* Gimplify a SWITCH_EXPR, and collect the vector of labels it can
branch to. */
static enum gimplify_status
@ -1588,9 +1759,7 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p)
{
VEC (tree,heap) *labels;
VEC (tree,heap) *saved_labels;
tree min_value, max_value;
tree default_case = NULL_TREE;
size_t i, len;
gimple gimple_switch;
/* If someone can be bothered to fill in the labels, they can
@ -1606,155 +1775,22 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p)
labels = gimplify_ctxp->case_labels;
gimplify_ctxp->case_labels = saved_labels;
i = 0;
min_value = TYPE_MIN_VALUE (index_type);
max_value = TYPE_MAX_VALUE (index_type);
while (i < VEC_length (tree, labels))
{
tree elt = VEC_index (tree, labels, i);
tree low = CASE_LOW (elt);
tree high = CASE_HIGH (elt);
bool remove_element = FALSE;
if (low)
{
gcc_checking_assert (TREE_CODE (low) == INTEGER_CST);
gcc_checking_assert (!high || TREE_CODE (high) == INTEGER_CST);
/* This is a non-default case label, i.e. it has a value.
See if the case label is reachable within the range of
the index type. Remove out-of-range case values. Turn
case ranges into a canonical form (high > low strictly)
and convert the case label values to the index type.
NB: The type of gimple_switch_index() may be the promoted
type, but the case labels retain the original type. */
if (high)
{
/* This is a case range. Discard empty ranges.
If the bounds or the range are equal, turn this
into a simple (one-value) case. */
int cmp = tree_int_cst_compare (high, low);
if (cmp < 0)
remove_element = TRUE;
else if (cmp == 0)
high = NULL_TREE;
}
if (! high)
{
/* If the simple case value is unreachable, ignore it. */
if ((TREE_CODE (min_value) == INTEGER_CST
&& tree_int_cst_compare (low, min_value) < 0)
|| (TREE_CODE (max_value) == INTEGER_CST
&& tree_int_cst_compare (low, max_value) > 0))
remove_element = TRUE;
else
low = fold_convert (index_type, low);
}
else
{
/* If the entire case range is unreachable, ignore it. */
if ((TREE_CODE (min_value) == INTEGER_CST
&& tree_int_cst_compare (high, min_value) < 0)
|| (TREE_CODE (max_value) == INTEGER_CST
&& tree_int_cst_compare (low, max_value) > 0))
remove_element = TRUE;
else
{
/* If the lower bound is less than the index type's
minimum value, truncate the range bounds. */
if (TREE_CODE (min_value) == INTEGER_CST
&& tree_int_cst_compare (low, min_value) < 0)
low = min_value;
low = fold_convert (index_type, low);
/* If the upper bound is greater than the index type's
maximum value, truncate the range bounds. */
if (TREE_CODE (max_value) == INTEGER_CST
&& tree_int_cst_compare (high, max_value) > 0)
high = max_value;
high = fold_convert (index_type, high);
}
}
CASE_LOW (elt) = low;
CASE_HIGH (elt) = high;
}
else
{
/* The default case must be the last label in the list. */
gcc_assert (!default_case);
default_case = elt;
remove_element = TRUE;
}
if (remove_element)
VEC_ordered_remove (tree, labels, i);
else
i++;
}
len = i;
if (!VEC_empty (tree, labels))
sort_case_labels (labels);
preprocess_case_label_vec_for_gimple (labels, index_type,
&default_case);
if (!default_case)
{
/* If the switch has no default label, add one, so that we jump
around the switch body. If the labels already cover the whole
range of the switch index_type, add the default label pointing
to one of the existing labels. */
if (len
&& TYPE_MIN_VALUE (index_type)
&& TYPE_MAX_VALUE (index_type)
&& tree_int_cst_equal (CASE_LOW (VEC_index (tree, labels, 0)),
TYPE_MIN_VALUE (index_type)))
{
tree low, high = CASE_HIGH (VEC_index (tree, labels, len - 1));
if (!high)
high = CASE_LOW (VEC_index (tree, labels, len - 1));
if (tree_int_cst_equal (high, TYPE_MAX_VALUE (index_type)))
{
for (i = 1; i < len; i++)
{
high = CASE_LOW (VEC_index (tree, labels, i));
low = CASE_HIGH (VEC_index (tree, labels, i - 1));
if (!low)
low = CASE_LOW (VEC_index (tree, labels, i - 1));
if ((TREE_INT_CST_LOW (low) + 1
!= TREE_INT_CST_LOW (high))
|| (TREE_INT_CST_HIGH (low)
+ (TREE_INT_CST_LOW (high) == 0)
!= TREE_INT_CST_HIGH (high)))
break;
}
if (i == len)
{
tree label = CASE_LABEL (VEC_index (tree, labels, 0));
default_case = build_case_label (NULL_TREE, NULL_TREE,
label);
}
}
}
gimple new_default;
if (!default_case)
{
gimple new_default;
default_case
= build_case_label (NULL_TREE, NULL_TREE,
create_artificial_label (UNKNOWN_LOCATION));
new_default = gimple_build_label (CASE_LABEL (default_case));
gimplify_seq_add_stmt (&switch_body_seq, new_default);
}
default_case
= build_case_label (NULL_TREE, NULL_TREE,
create_artificial_label (UNKNOWN_LOCATION));
new_default = gimple_build_label (CASE_LABEL (default_case));
gimplify_seq_add_stmt (&switch_body_seq, new_default);
}
gimple_switch = gimple_build_switch_vec (SWITCH_COND (switch_expr),
default_case, labels);
default_case, labels);
gimplify_seq_add_stmt (pre_p, gimple_switch);
gimplify_seq_add_seq (pre_p, switch_body_seq);
VEC_free(tree, heap, labels);

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2012-05-02 Steven Bosscher <steven@gcc.gnu.org>
PR middle-end/53153
* gcc.dg/pr53153.c: New test.
2012-05-02 Richard Guenther <rguenther@suse.de>
* g++.dg/tree-ssa/pr19807.C: Adjust.

61
gcc/testsuite/gcc.dg/pr53153.c Normal file
View File

@ -0,0 +1,61 @@
/* { dg-do compile } */
/* { dg-options "-O2" } */
extern void bar (void);
/* Case 181 is not in the range for 'char'. */
void
foo1 (char *buf)
{
int x = *buf;
switch (x)
{
case -76:
case 65:
case 181:
bar();
}
}
/* All cases are below the range of char. */
void
foo2 (char *buf)
{
int x = *buf;
switch (x)
{
case -150:
case -140:
case -130:
bar();
}
}
/* All cases are above the range of char. */
void
foo3 (char *buf)
{
int x = *buf;
switch (x)
{
case 130:
case 140:
case 150: /* This case is not in the range for 'char'. */
bar();
}
}
/* The bounding cases are partially out of range for char. */
void
foo4 (char *buf)
{
int x = *buf;
switch (x)
{
case -130 ... -120:
case 100:
case 120 ... 130:
bar();
}
}

78
gcc/tree-ssa-forwprop.c
View File

@ -163,7 +163,7 @@ along with GCC; see the file COPYING3. If not see
static bool forward_propagate_addr_expr (tree name, tree rhs);
/* Set to true if we delete EH edges during the optimization. */
/* Set to true if we delete dead edges during the optimization. */
static bool cfg_changed;
static tree rhs_to_tree (tree type, gimple stmt);
@ -1319,6 +1319,78 @@ simplify_not_neg_expr (gimple_stmt_iterator *gsi_p)
return false;
}
/* Helper function for simplify_gimple_switch. Remove case labels that
have values outside the range of the new type. */
static void
simplify_gimple_switch_label_vec (gimple stmt, tree index_type)
{
unsigned int branch_num = gimple_switch_num_labels (stmt);
VEC(tree, heap) *labels = VEC_alloc (tree, heap, branch_num);
unsigned int i, len;
/* Collect the existing case labels in a VEC, and preprocess it as if
we are gimplifying a GENERIC SWITCH_EXPR. */
for (i = 1; i < branch_num; i++)
VEC_quick_push (tree, labels, gimple_switch_label (stmt, i));
preprocess_case_label_vec_for_gimple (labels, index_type, NULL);
/* If any labels were removed, replace the existing case labels
in the GIMPLE_SWITCH statement with the correct ones.
Note that the type updates were done in-place on the case labels,
so we only have to replace the case labels in the GIMPLE_SWITCH
if the number of labels changed. */
len = VEC_length (tree, labels);
if (len < branch_num - 1)
{
bitmap target_blocks;
edge_iterator ei;
edge e;
/* Corner case: *all* case labels have been removed as being
out-of-range for INDEX_TYPE. Push one label and let the
CFG cleanups deal with this further. */
if (len == 0)
{
tree label, elt;
label = CASE_LABEL (gimple_switch_default_label (stmt));
elt = build_case_label (build_int_cst (index_type, 0), NULL, label);
VEC_quick_push (tree, labels, elt);
len = 1;
}
for (i = 0; i < VEC_length (tree, labels); i++)
gimple_switch_set_label (stmt, i + 1, VEC_index (tree, labels, i));
for (i++ ; i < branch_num; i++)
gimple_switch_set_label (stmt, i, NULL_TREE);
gimple_switch_set_num_labels (stmt, len + 1);
/* Cleanup any edges that are now dead. */
target_blocks = BITMAP_ALLOC (NULL);
for (i = 0; i < gimple_switch_num_labels (stmt); i++)
{
tree elt = gimple_switch_label (stmt, i);
basic_block target = label_to_block (CASE_LABEL (elt));
bitmap_set_bit (target_blocks, target->index);
}
for (ei = ei_start (gimple_bb (stmt)->succs); (e = ei_safe_edge (ei)); )
{
if (! bitmap_bit_p (target_blocks, e->dest->index))
{
remove_edge (e);
cfg_changed = true;
free_dominance_info (CDI_DOMINATORS);
}
else
ei_next (&ei);
}
BITMAP_FREE (target_blocks);
}
VEC_free (tree, heap, labels);
}
/* STMT is a SWITCH_EXPR for which we attempt to find equivalent forms of
the condition which we may be able to optimize better. */
@ -1344,9 +1416,6 @@ simplify_gimple_switch (gimple stmt)
def = gimple_assign_rhs1 (def_stmt);
/* ??? Why was Jeff testing this? We are gimple... */
gcc_checking_assert (is_gimple_val (def));
to = TREE_TYPE (cond);
ti = TREE_TYPE (def);
@ -1367,6 +1436,7 @@ simplify_gimple_switch (gimple stmt)
if (!fail)
{
gimple_switch_set_index (stmt, def);
simplify_gimple_switch_label_vec (stmt, ti);
update_stmt (stmt);
return true;
}