diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7c3d87ad6a0e3a664acce94165228b060106c3b8..74c12b44709c78fa2c36741aab736d9f6bbd2e1a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2012-09-06 Richard Guenther <rguenther@suse.de>
+
+ PR tree-optimization/54498
+ * tree-ssa-alias.h (get_continuation_for_phi): Add flag to
+ abort when reaching an already visited region.
+ * tree-ssa-alias.c (maybe_skip_until): Likewise. And do it.
+ (get_continuation_for_phi_1): Likewise.
+ (walk_non_aliased_vuses): When we translated the reference,
+ abort when we re-visit a region.
+ * tree-ssa-pre.c (translate_vuse_through_block): Adjust.
+
2012-09-06 David Edelsohn <dje.gcc@gmail.com>
* config/rs6000/rs6000.c (rs6000_xcoff_asm_named_section): Add TLS
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 574f418447d42f5fa3fd73c980be08d9e97625f0..8d515703a775e4335d406fac8451388a1b4d5f29 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -1929,7 +1929,8 @@ stmt_kills_ref_p (gimple stmt, tree ref)
static bool
maybe_skip_until (gimple phi, tree target, ao_ref *ref,
- tree vuse, unsigned int *cnt, bitmap *visited)
+ tree vuse, unsigned int *cnt, bitmap *visited,
+ bool abort_on_visited)
{
basic_block bb = gimple_bb (phi);
@@ -1947,8 +1948,9 @@ maybe_skip_until (gimple phi, tree target, ao_ref *ref,
{
/* An already visited PHI node ends the walk successfully. */
if (bitmap_bit_p (*visited, SSA_NAME_VERSION (PHI_RESULT (def_stmt))))
- return true;
- vuse = get_continuation_for_phi (def_stmt, ref, cnt, visited);
+ return !abort_on_visited;
+ vuse = get_continuation_for_phi (def_stmt, ref, cnt,
+ visited, abort_on_visited);
if (!vuse)
return false;
continue;
@@ -1967,7 +1969,7 @@ maybe_skip_until (gimple phi, tree target, ao_ref *ref,
if (gimple_bb (def_stmt) != bb)
{
if (!bitmap_set_bit (*visited, SSA_NAME_VERSION (vuse)))
- return true;
+ return !abort_on_visited;
bb = gimple_bb (def_stmt);
}
vuse = gimple_vuse (def_stmt);
@@ -1981,7 +1983,8 @@ maybe_skip_until (gimple phi, tree target, ao_ref *ref,
static tree
get_continuation_for_phi_1 (gimple phi, tree arg0, tree arg1,
- ao_ref *ref, unsigned int *cnt, bitmap *visited)
+ ao_ref *ref, unsigned int *cnt,
+ bitmap *visited, bool abort_on_visited)
{
gimple def0 = SSA_NAME_DEF_STMT (arg0);
gimple def1 = SSA_NAME_DEF_STMT (arg1);
@@ -1994,14 +1997,16 @@ get_continuation_for_phi_1 (gimple phi, tree arg0, tree arg1,
&& dominated_by_p (CDI_DOMINATORS,
gimple_bb (def1), gimple_bb (def0))))
{
- if (maybe_skip_until (phi, arg0, ref, arg1, cnt, visited))
+ if (maybe_skip_until (phi, arg0, ref, arg1, cnt,
+ visited, abort_on_visited))
return arg0;
}
else if (gimple_nop_p (def1)
|| dominated_by_p (CDI_DOMINATORS,
gimple_bb (def0), gimple_bb (def1)))
{
- if (maybe_skip_until (phi, arg1, ref, arg0, cnt, visited))
+ if (maybe_skip_until (phi, arg1, ref, arg0, cnt,
+ visited, abort_on_visited))
return arg1;
}
/* Special case of a diamond:
@@ -2038,7 +2043,8 @@ get_continuation_for_phi_1 (gimple phi, tree arg0, tree arg1,
tree
get_continuation_for_phi (gimple phi, ao_ref *ref,
- unsigned int *cnt, bitmap *visited)
+ unsigned int *cnt, bitmap *visited,
+ bool abort_on_visited)
{
unsigned nargs = gimple_phi_num_args (phi);
@@ -2076,7 +2082,7 @@ get_continuation_for_phi (gimple phi, ao_ref *ref,
{
arg1 = PHI_ARG_DEF (phi, i);
arg0 = get_continuation_for_phi_1 (phi, arg0, arg1, ref,
- cnt, visited);
+ cnt, visited, abort_on_visited);
if (!arg0)
return NULL_TREE;
}
@@ -2113,6 +2119,7 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse,
bitmap visited = NULL;
void *res;
unsigned int cnt = 0;
+ bool translated = false;
timevar_push (TV_ALIAS_STMT_WALK);
@@ -2136,7 +2143,8 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse,
if (gimple_nop_p (def_stmt))
break;
else if (gimple_code (def_stmt) == GIMPLE_PHI)
- vuse = get_continuation_for_phi (def_stmt, ref, &cnt, &visited);
+ vuse = get_continuation_for_phi (def_stmt, ref, &cnt,
+ &visited, translated);
else
{
cnt++;
@@ -2155,6 +2163,7 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse,
else if (res != NULL)
break;
/* Translation succeeded, continue walking. */
+ translated = true;
}
vuse = gimple_vuse (def_stmt);
}
diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
index cdff3812181c21e9352f5b385ecb26028c7fe8ac..6f38f20bce580abeb79f481dae4cb4abc1752ed5 100644
--- a/gcc/tree-ssa-alias.h
+++ b/gcc/tree-ssa-alias.h
@@ -108,7 +108,7 @@ extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
extern bool call_may_clobber_ref_p (gimple, tree);
extern bool stmt_kills_ref_p (gimple, tree);
extern tree get_continuation_for_phi (gimple, ao_ref *,
- unsigned int *, bitmap *);
+ unsigned int *, bitmap *, bool);
extern void *walk_non_aliased_vuses (ao_ref *, tree,
void *(*)(ao_ref *, tree,
unsigned int, void *),
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index bb1a03dfe99752dbdb49eb3fc84d70dab6094029..e64d4f75a9b48ae2e1c28e04da524254ad572681 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -1291,7 +1291,7 @@ translate_vuse_through_block (VEC (vn_reference_op_s, heap) *operands,
unsigned int cnt;
/* Try to find a vuse that dominates this phi node by skipping
non-clobbering statements. */
- vuse = get_continuation_for_phi (phi, &ref, &cnt, &visited);
+ vuse = get_continuation_for_phi (phi, &ref, &cnt, &visited, false);
if (visited)
BITMAP_FREE (visited);
}