+
+ /* Perform simple redundant store elimination. */
+ if (gimple_assign_single_p (stmt)
+ && TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
+ {
+ tree lhs = gimple_assign_lhs (stmt);
+ tree rhs = gimple_assign_rhs1 (stmt);
+ tree cached_lhs;
+ gimple new_stmt;
+ if (TREE_CODE (rhs) == SSA_NAME)
+ {
+ tree tem = SSA_NAME_VALUE (rhs);
+ if (tem)
+ rhs = tem;
+ }
+ /* Build a new statement with the RHS and LHS exchanged. */
+ if (TREE_CODE (rhs) == SSA_NAME)
+ {
+ gimple defstmt = SSA_NAME_DEF_STMT (rhs);
+ new_stmt = gimple_build_assign (rhs, lhs);
+ SSA_NAME_DEF_STMT (rhs) = defstmt;
+ }
+ else
+ new_stmt = gimple_build_assign (rhs, lhs);
+ gimple_set_vuse (new_stmt, gimple_vuse (stmt));
+ cached_lhs = lookup_avail_expr (new_stmt, false);
+ if (cached_lhs
+ && rhs == cached_lhs)
+ {
+ basic_block bb = gimple_bb (stmt);
+ int lp_nr = lookup_stmt_eh_lp (stmt);
+ unlink_stmt_vdef (stmt);
+ gsi_remove (&si, true);
+ if (lp_nr != 0)
+ {
+ bitmap_set_bit (need_eh_cleanup, bb->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Flagged to clear EH edges.\n");
+ }
+ return;
+ }
+ }