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--- a/gcc/tree-ssa-tail-merge.c
+++ b/gcc/tree-ssa-tail-merge.c
@@ -1033,7 +1033,7 @@ set_cluster (basic_block bb1, basic_bloc
gimple_bb (s2) are members of SAME_SUCC. */
static bool
-gimple_equal_p (same_succ same_succ, gimple s1, gimple s2)
+gimple_equal_p (same_succ same_succ, gimple s1, gimple s2, bool *gvn_used)
{
unsigned int i;
tree lhs1, lhs2;
@@ -1069,7 +1069,10 @@ gimple_equal_p (same_succ same_succ, gim
if (operand_equal_p (t1, t2, 0))
continue;
if (gvn_uses_equal (t1, t2))
- continue;
+ {
+ *gvn_used = true;
+ continue;
+ }
equal = false;
break;
}
@@ -1083,12 +1086,16 @@ gimple_equal_p (same_succ same_succ, gim
if (lhs1 == NULL_TREE || lhs2 == NULL_TREE)
return false;
if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME)
- return vn_valueize (lhs1) == vn_valueize (lhs2);
+ {
+ *gvn_used = true;
+ return vn_valueize (lhs1) == vn_valueize (lhs2);
+ }
return operand_equal_p (lhs1, lhs2, 0);
case GIMPLE_ASSIGN:
lhs1 = gimple_get_lhs (s1);
lhs2 = gimple_get_lhs (s2);
+ *gvn_used = true;
return (TREE_CODE (lhs1) == SSA_NAME
&& TREE_CODE (lhs2) == SSA_NAME
&& vn_valueize (lhs1) == vn_valueize (lhs2));
@@ -1096,15 +1103,23 @@ gimple_equal_p (same_succ same_succ, gim
case GIMPLE_COND:
t1 = gimple_cond_lhs (s1);
t2 = gimple_cond_lhs (s2);
- if (!operand_equal_p (t1, t2, 0)
- && !gvn_uses_equal (t1, t2))
- return false;
+ if (!operand_equal_p (t1, t2, 0))
+ {
+ if (gvn_uses_equal (t1, t2))
+ *gvn_used = true;
+ else
+ return false;
+ }
t1 = gimple_cond_rhs (s1);
t2 = gimple_cond_rhs (s2);
- if (!operand_equal_p (t1, t2, 0)
- && !gvn_uses_equal (t1, t2))
- return false;
+ if (!operand_equal_p (t1, t2, 0))
+ {
+ if (gvn_uses_equal (t1, t2))
+ *gvn_used = true;
+ else
+ return false;
+ }
code1 = gimple_expr_code (s1);
code2 = gimple_expr_code (s2);
@@ -1126,18 +1141,25 @@ gimple_equal_p (same_succ same_succ, gim
/* Let GSI skip backwards over local defs. */
static void
-gsi_advance_bw_nondebug_nonlocal (gimple_stmt_iterator *gsi)
+gsi_advance_bw_nondebug_nonlocal (gimple_stmt_iterator *gsi, tree *vuse)
{
gimple stmt;
+ tree lvuse;
while (true)
{
if (gsi_end_p (*gsi))
return;
stmt = gsi_stmt (*gsi);
+
+ lvuse = gimple_vuse (stmt);
+ if (lvuse != NULL_TREE)
+ *vuse = lvuse;
+
if (!(is_gimple_assign (stmt) && local_def (gimple_get_lhs (stmt))
&& !gimple_has_side_effects (stmt)))
return;
+
gsi_prev_nondebug (gsi);
}
}
@@ -1146,28 +1168,34 @@ gsi_advance_bw_nondebug_nonlocal (gimple
clusters them. */
static void
-find_duplicate (same_succ same_succ, basic_block bb1, basic_block bb2)
+find_duplicate (same_succ same_succ, basic_block bb1, basic_block bb2,
+ bool gvn_used)
{
gimple_stmt_iterator gsi1 = gsi_last_nondebug_bb (bb1);
gimple_stmt_iterator gsi2 = gsi_last_nondebug_bb (bb2);
+ tree vuse1 = NULL_TREE, vuse2 = NULL_TREE;
- gsi_advance_bw_nondebug_nonlocal (&gsi1);
- gsi_advance_bw_nondebug_nonlocal (&gsi2);
+ gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1);
+ gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2);
while (!gsi_end_p (gsi1) && !gsi_end_p (gsi2))
{
- if (!gimple_equal_p (same_succ, gsi_stmt (gsi1), gsi_stmt (gsi2)))
+ if (!gimple_equal_p (same_succ, gsi_stmt (gsi1), gsi_stmt (gsi2),
+ &gvn_used))
return;
gsi_prev_nondebug (&gsi1);
gsi_prev_nondebug (&gsi2);
- gsi_advance_bw_nondebug_nonlocal (&gsi1);
- gsi_advance_bw_nondebug_nonlocal (&gsi2);
+ gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1);
+ gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2);
}
if (!(gsi_end_p (gsi1) && gsi_end_p (gsi2)))
return;
+ if (gvn_used && vuse1 != vuse2)
+ return;
+
if (dump_file)
fprintf (dump_file, "find_duplicates: <bb %d> duplicate of <bb %d>\n",
bb1->index, bb2->index);
@@ -1179,7 +1207,7 @@ find_duplicate (same_succ same_succ, bas
E2 are equal. */
static bool
-same_phi_alternatives_1 (basic_block dest, edge e1, edge e2)
+same_phi_alternatives_1 (basic_block dest, edge e1, edge e2, bool *gvn_used)
{
int n1 = e1->dest_idx, n2 = e2->dest_idx;
gimple_stmt_iterator gsi;
@@ -1197,7 +1225,10 @@ same_phi_alternatives_1 (basic_block des
if (operand_equal_for_phi_arg_p (val1, val2))
continue;
if (gvn_uses_equal (val1, val2))
- continue;
+ {
+ *gvn_used = true;
+ continue;
+ }
return false;
}
@@ -1209,7 +1240,8 @@ same_phi_alternatives_1 (basic_block des
phi alternatives for BB1 and BB2 are equal. */
static bool
-same_phi_alternatives (same_succ same_succ, basic_block bb1, basic_block bb2)
+same_phi_alternatives (same_succ same_succ, basic_block bb1, basic_block bb2,
+ bool *gvn_used)
{
unsigned int s;
bitmap_iterator bs;
@@ -1227,7 +1259,7 @@ same_phi_alternatives (same_succ same_su
/* For all phis in bb, the phi alternatives for e1 and e2 need to have
the same value. */
- if (!same_phi_alternatives_1 (succ, e1, e2))
+ if (!same_phi_alternatives_1 (succ, e1, e2, gvn_used))
return false;
}
@@ -1301,6 +1333,7 @@ find_clusters_1 (same_succ same_succ)
bitmap_iterator bi, bj;
int nr_comparisons;
int max_comparisons = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_COMPARISONS);
+ bool gvn_used;
EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, 0, i, bi)
{
@@ -1333,10 +1366,11 @@ find_clusters_1 (same_succ same_succ)
if (!deps_ok_for_redirect (bb1, bb2))
continue;
- if (!(same_phi_alternatives (same_succ, bb1, bb2)))
+ gvn_used = false;
+ if (!(same_phi_alternatives (same_succ, bb1, bb2, &gvn_used)))
continue;
- find_duplicate (same_succ, bb1, bb2);
+ find_duplicate (same_succ, bb1, bb2, gvn_used);
}
}
}
--- /dev/null
+++ b/testsuite/gcc.dg/pr52734.c
@@ -0,0 +1,35 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+int bbb = 0;
+
+int __attribute__((noinline,noclone)) aaa(void)
+{
+ ++bbb;
+ return 0;
+}
+
+int __attribute__((noinline,noclone)) ccc(void)
+{
+ int ddd;
+ /* bbb == 0 */
+ if (aaa())
+ return bbb;
+
+ /* bbb == 1 */
+ ddd = bbb;
+ /* bbb == ddd == 1 */
+ if (aaa ())
+ return 0;
+ /* bbb == 2, ddd == 1 */
+
+ return ddd;
+}
+
+int main(void)
+{
+ if (ccc() != 1)
+ __builtin_abort();
+ return 0;
+}
+
|
