3 * File name: testprograms/if_while_example.c
4 * Purpose: Shows more complex control flow.
5 * Author: Christian Schaefer, Goetz Lindenmaier
9 * Copyright: (c) 1999-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
15 #include <libfirm/firm.h>
18 * This file constructs the ir for the following pseudo-program:
28 * while (0 == 0) loop {
46 ir_node *b, *x, *r, *t, *f;
48 printf("\nCreating an IR graph: IF_WHILE_EXAMPLE...\n");
51 turn_off_edge_labels();
54 set_opt_constant_folding(0); /* so that the stupid tests are not optimized. */
55 /* if optimized no path to End remains!! */
58 /*** Make basic ir_type information for primitive ir_type int. ***/
59 prim_t_int = new_type_primitive(new_id_from_chars ("int", 3), mode_Iu);
61 #define METHODNAME "main"
65 proc_main = new_type_method(new_id_from_chars(METHODNAME, strlen(METHODNAME)),
67 set_method_res_type(proc_main, 0, prim_t_int);
68 owner = new_type_class (new_id_from_chars ("IF_WHILE_EXAMPLE", 16));
69 ent = new_entity (owner, new_id_from_chars ("main", 4), proc_main);
70 get_entity_ld_name(ent);
72 /* Generates start and end blocks and nodes and a first, initial block */
73 irg = new_ir_graph (ent, 4);
75 /* Generate two constants */
76 set_value(0, new_Const(mode_Iu, new_tarval_from_long(0, mode_Iu)));
77 set_value(1, new_Const(mode_Iu, new_tarval_from_long(1, mode_Iu)));
78 mature_immBlock(get_irg_current_block(irg));
80 /* Generate a conditional branch */
83 /* generate the fall through block and add all cfg edges */
85 add_immBlock_pred(r, x);
89 /* generate a block for the loop header and the conditional branch */
91 add_immBlock_pred(r, x);
92 x = new_Cond(new_Proj(new_Cmp(new_Const(mode_Iu, new_tarval_from_long(0, mode_Iu)),
93 new_Const(mode_Iu, new_tarval_from_long(0, mode_Iu))),
95 f = new_Proj(x, mode_X, pn_Cond_false);
96 t = new_Proj(x, mode_X, pn_Cond_true);
98 /* generate the block for the loop body */
100 add_immBlock_pred(b,t);
102 add_immBlock_pred(r, x);
105 /* the code in the loop body,
106 as we are dealing with local variables only the dataflow edges
108 set_value(2, get_value(0, mode_Iu));
109 set_value(0, get_value(1, mode_Iu));
110 set_value(1, get_value(2, mode_Iu));
113 /* generate the return block */
115 add_immBlock_pred(r, f);
120 in[0] = new_Sub(get_value(0, mode_Iu), get_value(1, mode_Iu), mode_Iu);
122 x = new_Return(get_store(), 1, in);
125 /* finalize the end block generated in new_ir_graph() */
126 add_immBlock_pred(get_irg_end_block(irg), x);
127 mature_immBlock(get_irg_end_block(irg));
129 irg_finalize_cons(irg);
131 printf("Optimizing ...\n");
133 local_optimize_graph(irg);
134 dead_node_elimination(irg);
136 compute_irg_outs(irg);
138 /* verify the graph */
141 /* output the vcg file */
142 printf("Done building the graph. Dumping it with out-edges.\n");
144 dump_ir_graph(irg, 0);
145 printf("Use ycomp to view this graph:\n");
146 printf("ycomp GRAPHNAME\n\n");