------- Comment #12 from rguenth at gcc dot gnu dot org 2009-06-03 14:00
-------
The problem seems to be the asymmetry wrt handling of NAMEs vs. SSA_NAME
operands
in NARYs and REFERENCEs. We happily translate NAMEs and do not clean them
if they are in AVAIL_OUT, but we only can translate SSA_NAME operands if they
have a leader in the set we are currently translating (wtf?) and we clean
the NARYs and REFERENCEs that do not have their SSA_NAME operands in ANTIC_IN
itself.
Huh. Fixing both "fixes" the problem, but obviously results in larger ANTIC_IN
sets.
@@ -1466,13 +1499,15 @@ phi_translate_1 (pre_expr expr, bitmap_s
{
unsigned int op_val_id = VN_INFO (newnary.op[i])->value_id;
pre_expr leader = find_leader_in_sets (op_val_id, set1, set2);
- pre_expr result = phi_translate_1 (leader, set1, set2,
+ pre_expr result;
+ if (!leader)
+ leader = get_or_alloc_expr_for_name (newnary.op[i]);
+ result = phi_translate_1 (leader, set1, set2,
pred, phiblock, seen);
if (result && result != leader)
{
tree name = get_representative_for (result);
- if (!name)
- return NULL;
+ gcc_assert (name != NULL_TREE);
newnary.op[i] = name;
}
else if (!result)
@@ -1569,13 +1604,14 @@ phi_translate_1 (pre_expr expr, bitmap_s
{
unsigned int op_val_id = VN_INFO (op0)->value_id;
leader = find_leader_in_sets (op_val_id, set1, set2);
+ if (!leader)
+ leader = get_or_alloc_expr_for_name (op0);
opresult = phi_translate_1 (leader, set1, set2,
pred, phiblock, seen);
if (opresult && opresult != leader)
{
tree name = get_representative_for (opresult);
- if (!name)
- break;
+ gcc_assert (name != NULL_TREE);
op0 = name;
}
else if (!opresult)
@@ -1587,13 +1623,14 @@ phi_translate_1 (pre_expr expr, bitmap_s
{
unsigned int op_val_id = VN_INFO (op1)->value_id;
leader = find_leader_in_sets (op_val_id, set1, set2);
+ if (!leader)
+ leader = get_or_alloc_expr_for_name (op1);
opresult = phi_translate_1 (leader, set1, set2,
pred, phiblock, seen);
if (opresult && opresult != leader)
{
tree name = get_representative_for (opresult);
- if (!name)
- break;
+ gcc_assert (name != NULL_TREE);
op1 = name;
}
else if (!opresult)
@@ -1604,13 +1641,14 @@ phi_translate_1 (pre_expr expr, bitmap_s
{
unsigned int op_val_id = VN_INFO (op2)->value_id;
leader = find_leader_in_sets (op_val_id, set1, set2);
+ if (!leader)
+ leader = get_or_alloc_expr_for_name (op2);
opresult = phi_translate_1 (leader, set1, set2,
pred, phiblock, seen);
if (opresult && opresult != leader)
{
tree name = get_representative_for (opresult);
- if (!name)
- break;
+ gcc_assert (name != NULL_TREE);
op2 = name;
}
else if (!opresult)
@@ -2091,7 +2129,7 @@ clean (bitmap_set_t set, basic_block blo
for (i = 0; VEC_iterate (pre_expr, exprs, i, expr); i++)
{
- if (!valid_in_sets (set, NULL, expr, block))
+ if (!valid_in_sets (set, AVAIL_OUT (block), expr, block))
bitmap_remove_from_set (set, expr);
}
VEC_free (pre_expr, heap, exprs);
the fix results in some ICEs because we cannot insert though.
A fix the other way around is be possible as well, but it doesn't fix the
problem:
Index: tree-ssa-pre.c
===================================================================
--- tree-ssa-pre.c (revision 148119)
+++ tree-ssa-pre.c (working copy)
@@ -1717,6 +1717,10 @@ phi_translate_1 (pre_expr expr, bitmap_s
edge e;
gimple def_stmt;
tree name = PRE_EXPR_NAME (expr);
+ unsigned int name_val_id = VN_INFO (name)->value_id;
+ pre_expr leader = find_leader_in_sets (name_val_id, set1, set2);
+ if (!leader)
+ return NULL;
def_stmt = SSA_NAME_DEF_STMT (name);
if (gimple_code (def_stmt) == GIMPLE_PHI
@@ -2006,7 +2010,7 @@ valid_in_sets (bitmap_set_t set1, bitmap
switch (expr->kind)
{
case NAME:
- return bitmap_set_contains_expr (AVAIL_OUT (block), expr);
+ return union_contains_value (set1, set2, get_expr_value_id (expr));
case NARY:
{
unsigned int i;
Note that what is odd is that during clean () we use ANTIC_IN to clean
expressions but we change it at the same time. How are we sure that
clean (); clean () is a no-op?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40321
