4 * File name: testprograms/array-stack_example.c
5 * Purpose: Show representation of array on stack.
6 * Author: Goetz Lindenmaier
10 * Copyright: (c) 1999-2003 Universität Karlsruhe
11 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
20 #include <libfirm/firm.h>
23 * imperative programs.
24 * It constructs the IR for the following program:
33 * The array is placed on the stack, i.e., a pointer to the array
34 * is obtained by selecting the ir_entity "a" from the stack. The variables
35 * on the stack are considered to be entities of the method, as locals
36 * of a method are only visible within the method. (An alternative to
37 * make the method owner of the stack variables is to give the ownership
38 * to the class representing the C-file. This would extend the visibility
39 * of the locals, though.)
43 #define OPTIMIZE_NODE 0
48 char *dump_file_suffix = "";
49 /* describes the general structure of a C-file */
50 ir_type *owner; /* the class standing for everything in this file */
51 ir_type *proc_main; /* Typeinformation for method main. */
52 ir_entity *proc_main_e; /* The ir_entity describing that method main is an
53 ir_entity of the fake class representing the file. */
55 /* describes types defined by the language */
58 /* describes the array and its fields. */
59 ir_entity *array_ent; /* the ir_entity representing the array as member
60 of the stack/method */
61 ir_type *array_type; /* the ir_type information for the array */
62 ir_entity *field_ent; /* the ir_entity representing a field of the
65 /* holds the graph and nodes. */
67 ir_node *array_ptr, *c3, *elt, *val, *x;
71 printf("\nCreating an IR graph: ARRAY-STACK_EXAMPLE...\n");
73 /* make basic ir_type information for primitive ir_type int.
74 In Sather primitive types are represented by a class.
75 This is the modeling appropriate for other languages.
76 Mode_i says that all language-integers shall be implemented
77 as a 32 bit processor-integer value. */
78 prim_t_int = new_type_primitive(new_id_from_chars ("int", 3), mode_Is);
80 /* build typeinformation of procedure main */
81 owner = new_type_class (new_id_from_chars ("ARRAY-STACK_EXAMPLE", 19));
82 proc_main = new_type_method(new_id_from_chars("main_tp", 7), 0, 1);
83 set_method_res_type(proc_main, 0, prim_t_int);
84 proc_main_e = new_entity (owner, new_id_from_chars ("main", 4), proc_main);
85 get_entity_ld_name(proc_main_e); /* force name mangling */
87 /* make ir_type information for the array and set the bounds */
91 array_type = new_type_array(new_id_from_chars("a_tp", 4), N_DIMS, prim_t_int);
92 current_ir_graph = get_const_code_irg();
93 set_array_bounds(array_type, 0,
94 new_Const(mode_Iu, new_tarval_from_long (L_BOUND, mode_Iu)),
95 new_Const(mode_Iu, new_tarval_from_long (U_BOUND, mode_Iu)));
97 main_irg = new_ir_graph (proc_main_e, 4);
99 /* The array is an ir_entity of the method, placed on the mehtod's own memory,
101 array_ent = new_entity(get_cur_frame_type(), new_id_from_chars("a", 1), array_type);
102 /* As the array is accessed by Sel nodes, we need information about
103 the ir_entity the node selects. Entities of an array are it's elements
104 which are, in this case, integers. */
105 /* change ir_entity owner types. */
106 field_ent = get_array_element_entity(array_type);
110 /* Now the "real" program: */
111 /* Select the array from the stack frame. */
112 array_ptr = new_simpleSel(get_store(), get_irg_frame(main_irg), array_ent);
113 /* Load element 3 of the array. For this first generate the pointer
114 to this the element by a select node. (Alternative: increase
115 array pointer by (three * elt_size), but this complicates some
116 optimizations.) The ir_type information accessible via the ir_entity
117 allows to generate the pointer increment later. */
118 c3 = new_Const (mode_Iu, new_tarval_from_long (3, mode_Iu));
122 elt = new_Sel(get_store(), array_ptr, 1, in, field_ent);
124 val = new_Load(get_store(), elt, mode_Is);
125 set_store(new_Proj(val, mode_M, pn_Load_M));
126 val = new_Proj(val, mode_Is, pn_Load_res);
128 /* return the result of procedure main */
133 x = new_Return (get_store (), 1, in);
135 mature_immBlock (get_irg_current_block(main_irg));
137 /* complete the end_block */
138 add_immBlock_pred (get_irg_end_block(main_irg), x);
139 mature_immBlock (get_irg_end_block(main_irg));
141 irg_finalize_cons (main_irg);
143 printf("Optimizing ...\n");
144 dead_node_elimination(main_irg);
146 /* verify the graph */
148 printf("Dumping the graph and a ir_type graph.\n");
149 dump_ir_block_graph (main_irg, dump_file_suffix);
150 dump_type_graph(main_irg, dump_file_suffix);
151 dump_ir_block_graph_w_types(main_irg, dump_file_suffix);
152 dump_all_types(dump_file_suffix);
153 printf("Use ycomp to view these graphs:\n");
154 printf("ycomp GRAPHNAME\n\n");