+++ /dev/null
---- /dev/null
-+++ b/make/target/gcc/4.7.0/920-tree-ssa-tail-merge.patch
-@@ -0,0 +1,244 @@
-+This patch refers to:
-+
-+http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52734
-+http://gcc.gnu.org/bugzilla/attachment.cgi?id=27014&action=diff&context=patch&collapsed=&headers=1&format=raw
-+
-+--- gcc/tree-ssa-tail-merge.c
-++++ 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);
-+ }
-+ }
-+ }
-+--- gcc/testsuite/gcc.dg/pr52734.c
-++++ gcc/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;
-++}
-++