PR middle-end/44828

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-ter.c

diff --git a/gcc/tree-ssa-ter.c b/gcc/tree-ssa-ter.c
index 2f5b830..a997f78 100644 (file)
--- a/gcc/tree-ssa-ter.c
+++ b/gcc/tree-ssa-ter.c
@@ -616,6 +616,24 @@ find_replaceable_in_bb (temp_expr_table_p tab, basic_block bb)
                      }
                  }
 
+             /* If the stmt does a memory store and the replacement
+                is a load aliasing it avoid creating overlapping
+                assignments which we cannot expand correctly.  */
+             if (gimple_vdef (stmt)
+                 && gimple_assign_single_p (stmt))
+               {
+                 gimple def_stmt = SSA_NAME_DEF_STMT (use);
+                 while (is_gimple_assign (def_stmt)
+                        && gimple_assign_rhs_code (def_stmt) == SSA_NAME)
+                   def_stmt
+                     = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (def_stmt));
+                 if (gimple_vuse (def_stmt)
+                     && gimple_assign_single_p (def_stmt)
+                     && refs_may_alias_p (gimple_assign_lhs (stmt),
+                                          gimple_assign_rhs1 (def_stmt)))
+                   same_root_var = true;
+               }
+
              /* Mark expression as replaceable unless stmt is volatile or the
                 def variable has the same root variable as something in the
                 substitution list.  */