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.
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 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 /* describes the general structure of a C-file */
49 type *owner; /* the class standing for everything in this file */
50 type *proc_main; /* Typeinformation for method main. */
51 entity *proc_main_e; /* The entity describing that method main is an
52 entity of the fake class representing the file. */
54 /* describes types defined by the language */
57 /* describes the array and its fields. */
58 entity *array_ent; /* the entity representing the array as member
59 of the stack/method */
60 type *array_type; /* the type information for the array */
61 entity *field_ent; /* the entity representing a field of the
64 /* holds the graph and nodes. */
66 ir_node *array_ptr, *c3, *elt, *val, *x;
70 printf("\nCreating an IR graph: ARRAY-STACK_EXAMPLE...\n");
72 /* make basic type information for primitive type int.
73 In Sather primitive types are represented by a class.
74 This is the modeling appropriate for other languages.
75 Mode_i says that all language-integers shall be implemented
76 as a 32 bit processor-integer value. */
77 prim_t_int = new_type_primitive(new_id_from_chars ("int", 3), mode_Is);
79 /* build typeinformation of procedure main */
80 owner = new_type_class (new_id_from_chars ("ARRAY-STACK_EXAMPLE", 19));
81 proc_main = new_type_method(new_id_from_chars("main_tp", 7), 0, 1);
82 set_method_res_type(proc_main, 0, prim_t_int);
83 proc_main_e = new_entity (owner, new_id_from_chars ("main", 4), proc_main);
84 get_entity_ld_name(proc_main_e); /* force name mangling */
86 /* make type information for the array and set the bounds */
90 array_type = new_type_array(new_id_from_chars("a_tp", 4), N_DIMS, prim_t_int);
91 current_ir_graph = get_const_code_irg();
92 set_array_bounds(array_type, 0,
93 new_Const(mode_Iu, new_tarval_from_long (L_BOUND, mode_Iu)),
94 new_Const(mode_Iu, new_tarval_from_long (U_BOUND, mode_Iu)));
96 main_irg = new_ir_graph (proc_main_e, 4);
98 /* The array is an entity of the method, placed on the mehtod's own memory,
100 array_ent = new_entity(get_cur_frame_type(), new_id_from_chars("a", 1), array_type);
101 /* As the array is accessed by Sel nodes, we need information about
102 the entity the node selects. Entities of an array are it's elements
103 which are, in this case, integers. */
104 /* change entity owner types. */
105 field_ent = get_array_element_entity(array_type);
109 /* Now the "real" program: */
110 /* Select the array from the stack frame. */
111 array_ptr = new_simpleSel(get_store(), get_irg_frame(main_irg), array_ent);
112 /* Load element 3 of the array. For this first generate the pointer
113 to this the element by a select node. (Alternative: increase
114 array pointer by (three * elt_size), but this complicates some
115 optimizations.) The type information accessible via the entity
116 allows to generate the pointer increment later. */
117 c3 = new_Const (mode_Iu, new_tarval_from_long (3, mode_Iu));
121 elt = new_Sel(get_store(), array_ptr, 1, in, field_ent);
123 val = new_Load(get_store(), elt, mode_Is);
124 set_store(new_Proj(val, mode_M, 0));
125 val = new_Proj(val, mode_Is, 2);
127 /* return the result of procedure main */
132 x = new_Return (get_store (), 1, in);
134 mature_immBlock (get_irg_current_block(main_irg));
136 /* complete the end_block */
137 add_immBlock_pred (get_irg_end_block(main_irg), x);
138 mature_immBlock (get_irg_end_block(main_irg));
140 irg_finalize_cons (main_irg);
142 printf("Optimizing ...\n");
143 dead_node_elimination(main_irg);
145 /* verify the graph */
147 char *dump_file_suffix = "";
148 printf("Dumping the graph and a 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 xvcg to view these graphs:\n");
154 printf("/ben/goetz/bin/xvcg GRAPHNAME\n\n");