1 /* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
2 ** All rights reserved.
4 ** Authors: Christian Schaefer, Goetz Lindenmaier
15 *** This file constructs the ir for the following pseudo-program:
18 *** if ((a > 2) && (a < 10))
24 int main(int argc, char **argv)
26 ir_graph *irg; /* this variable contains the irgraph */
27 type_class *owner; /* the class in which this method is defined */
28 entity *ent; /* represents this method as entity of owner */
29 ir_node *x, *x_then, *arg1, *c2, *c10, *cmpGt, *cmpLt, *and, *f, *t, *b;
31 printf("creating an IR graph: COND_EXAMPLE...\n");
36 /* FIRM was designed for oo languages where all methods belong to a class.
37 * For imperative languages like C we view a file as a large class containing
38 * all functions as methods in this file.
39 * Therefore we define a class "COND_EXAMPLE" with a method main as an
42 #define CLASSNAME "COND_EXAMPLE"
43 #define ENTITYNAME "main"
45 owner = new_type_class (id_from_str (CLASSNAME, strlen(CLASSNAME)));
46 ent = new_entity ((type *)owner, id_from_str (ENTITYNAME, strlen(ENTITYNAME)), NULL);
49 /* Generates the basic graph for the method represented by entity ent, that
50 * is, generates start and end blocks and nodes and a first, initial block.
51 * The constructor needs to know how many local variables the method has.
53 #define NUM_OF_LOCAL_VARS 1
55 irg = new_ir_graph (ent, NUM_OF_LOCAL_VARS);
57 /* get the first argument a of method main - see irgraph.h */
58 arg1 = new_Proj(irg->args, mode_i, 0);
60 /* arg1 as first first local variable - makes things simple */
63 /* the expression that evaluates the condition */
65 c2 = new_Const (mode_i, tarval_from_long (mode_i, 2));
66 cmpGt = new_Proj(new_Cmp(get_value(0, mode_i), c2), mode_b, Gt);
67 cmpGt = new_Conv(cmpGt, mode_i);
70 c10 = new_Const (mode_i, tarval_from_long (mode_i, 10));
71 cmpLt = new_Proj(new_Cmp(get_value(0, mode_i), c10), mode_b, Lt);
72 cmpLt = new_Conv(cmpLt, mode_i);
75 and = new_And(cmpGt, cmpLt, mode_i);
76 /* compare result and 0 because we have no cast from integer to bool */
77 and = new_Cmp(and, new_Const (mode_i, tarval_from_long (mode_i, 0)));
78 and = new_Proj(and, mode_b, Ne);
80 /* the conditional branch */
82 f = new_Proj (x, mode_X, 0); /* if condition is false */
83 t = new_Proj (x, mode_X, 1); /* if condition is true */
85 mature_block (irg->current_block);
87 /* generate and fill the then block */
90 set_value (0, new_Const (mode_i, tarval_from_long (mode_i, 1)));
94 /* generate the fall through block and add all cfg edges */
96 add_in_edge (b, x_then);
100 /* Generate the return node into current region. */
102 ir_node *in[1]; /* this is the array containing the return parameters */
103 in[0] = get_value(0, mode_i);
104 x = new_Return (get_store(), 1, in);
106 /* Now generate all instructions for this block and all its predecessor blocks
107 * so we can mature it. */
108 mature_block (irg->current_block);
110 /* This adds the in edge of the end block which originates at the return statement.
111 * The return node passes controlflow to the end block. */
112 add_in_edge (irg->end_block, x);
113 /* Now we can mature the end block as all it's predecessors are known. */
114 mature_block (irg->end_block);
116 printf("\nDone building the graph. Dumping it.\n");
117 dump_ir_block_graph (irg);
119 printf("use xvcg to view this graph:\n");
120 printf("/ben/trapp/bin/i486/xvcg GRAPHNAME\n");