contrib/gcc/tree-if-conv.c

35        o Replace phi nodes with conditional modify expr
302 if_convertible_phi_p (struct loop *loop, basic_block bb, tree phi)
307       print_generic_stmt (dump_file, phi, TDF_SLIM);
310   if (bb != loop->header && PHI_NUM_ARGS (phi) != 2)
313 	fprintf (dump_file, "More than two phi node args.\n");
317   if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
321       FOR_EACH_IMM_USE_FAST (use_p, imm_iter, PHI_RESULT (phi))
326 		fprintf (dump_file, "Difficult to handle this virtual phi.\n");
490    - If its basic blocks and phi nodes are if convertible. See above for
498   tree phi;
566       /* What about phi nodes ? */
567       phi = phi_nodes (bb);
569       /* Clear aux field of incoming edges to a bb with a phi node.  */
570       if (phi)
575       for (; phi; phi = PHI_CHAIN (phi))
576 	if (!if_convertible_phi_p (loop, bb, phi))
680    whose phi arguments are selected when cond is true.  */
794    When COND is true, phi arg from TRUE_BB is selected.
798 replace_phi_with_cond_modify_expr (tree phi, tree cond, basic_block true_bb,
806   gcc_assert (TREE_CODE (phi) == PHI_NODE);
809   gcc_assert (PHI_NUM_ARGS (phi) == 2);
812   bb = bb_for_stmt (phi);
817       arg_0 = PHI_ARG_DEF (phi, 1);
818       arg_1 = PHI_ARG_DEF (phi, 0);
822       arg_0 = PHI_ARG_DEF (phi, 0);
823       arg_1 = PHI_ARG_DEF (phi, 1);
827   rhs = build3 (COND_EXPR, TREE_TYPE (PHI_RESULT (phi)),
832   new_stmt = build2 (MODIFY_EXPR, TREE_TYPE (PHI_RESULT (phi)),
833 		     unshare_expr (PHI_RESULT (phi)), rhs);
835   /* Make new statement definition of the original phi result.  */
836   SSA_NAME_DEF_STMT (PHI_RESULT (phi)) = new_stmt;
844       fprintf (dump_file, "new phi replacement stmt\n");
849 /* Process phi nodes for the given  LOOP.  Replace phi nodes with cond
859   /* Replace phi nodes with cond. modify expr.  */
862       tree phi, cond;
870       phi = phi_nodes (bb);
875       if (phi)
878       while (phi)
880 	  tree next = PHI_CHAIN (phi);
881 	  replace_phi_with_cond_modify_expr (phi, cond, true_bb, &bsi);
882 	  release_phi_node (phi);
883 	  phi = next;
902   /* Process phi nodes to prepare blocks for merge.  */