3 * File name: testprograms/irr_loop_example.c
4 * Purpose: Test Phi construction with irregular 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.
21 * This file constructs a control flow with an unreachable
22 * loop _and_ an unreachable endless loop. This looks like:
24 * LoopBlock2 LoopBlock2'
28 * LoopBlock1 StartBlock LoopBlock1'
41 int main(int argc, char **argv)
43 ir_graph *irg; /* this variable contains the irgraph */
44 type *owner; /* the class in which this method is defined */
45 type *proc_main; /* typeinformation for the method main */
46 entity *ent; /* represents this method as entity of owner */
47 ir_node *returnBlock, *loopBlock1, *loopBlock2, *x, *c1, *c2, *t, *f;
53 set_opt_constant_folding (0); /* so that the stupid tests are not optimized. */
55 set_opt_dead_node_elimination(1);
57 /* FIRM was designed for oo languages where all methods belong to a class.
58 * For imperative languages like C we view a file as a large class containing
59 * all functions as methods in this file.
60 * Therefore we define a class "empty" according to the file name
61 * with a method main as an entity.
63 #define CLASSNAME "DEAD_LOOP"
64 #define METHODNAME "main"
67 printf("\nCreating an IR graph: %s...\n", CLASSNAME);
69 owner = new_type_class (new_id_from_str (CLASSNAME));
70 proc_main = new_type_method(new_id_from_str(METHODNAME), NRARGS, NRES);
71 ent = new_entity (owner, new_id_from_str (METHODNAME), proc_main);
72 get_entity_ld_name(ent); /* To enforce name mangling for vcg graph name */
74 #define NUM_OF_LOCAL_VARS 0
76 irg = new_ir_graph (ent, NUM_OF_LOCAL_VARS);
78 returnBlock = get_irg_current_block(irg);
81 /* Make the unreachable loop */
82 loopBlock1 = new_immBlock();
83 loopBlock2 = new_immBlock();
85 add_in_edge(loopBlock1, x);
86 mature_block(loopBlock1);
88 switch_block(loopBlock1);
89 c1 = new_Const (mode_Is, new_tarval_from_long (1, mode_Is));
90 c2 = new_Const (mode_Is, new_tarval_from_long (2, mode_Is));
91 x = new_Cond(new_Proj(new_Cmp(c1, c2), mode_b, Eq));
92 f = new_Proj(x, mode_X, 0);
93 t = new_Proj(x, mode_X, 1);
94 add_in_edge(loopBlock2, t);
95 add_in_edge(returnBlock, f);
96 mature_block(loopBlock2);
99 /* Make the unreachable, endless loop */
100 loopBlock1 = new_immBlock();
101 loopBlock2 = new_immBlock();
103 add_in_edge(loopBlock1, x);
104 mature_block(loopBlock1);
106 switch_block(loopBlock1);
108 add_in_edge(loopBlock2, x);
109 add_End_keepalive(get_irg_end(irg), x);
110 mature_block(loopBlock2);
112 /* Make the return block */
113 switch_block(returnBlock);
114 x = new_Return (get_store(), 0, NULL);
115 mature_block (get_irg_current_block(irg));
117 add_in_edge (get_irg_end_block(irg), x);
118 mature_block (get_irg_end_block(irg));
122 printf("Optimizing ...\n");
123 dead_node_elimination(irg);
125 /* verify the graph */
128 printf("Dumping the graph and a control flow graph.\n");
129 turn_off_edge_labels();
130 dump_keepalive_edges(1);
131 dump_consts_local(1);
132 dump_ir_block_graph (irg);
135 printf("Running analyses.\n");
138 construct_backedges(irg);
140 printf("Dumping the graph with analyses information.\n");
143 dump_dominator_information();
144 dump_loop_information();
145 dump_backedge_information(1);
147 dump_ir_block_graph (irg);
149 printf("Use xvcg to view these graphs:\n");
150 printf("/ben/goetz/bin/xvcg GRAPHNAME\n\n");