1 /* Copyright (c) 2002 by Universität Karlsruhe (TH). All Rights Reserved */
3 * Time-stamp: <Monday, 04.11.2002, 17:28:27 goetz@i44pc2.info.uni-karlsruhe.de>
10 Helper functions for exceptions
14 liekweg - Mar 4, 2002: Created.
21 static char* exc_strings [] = {
22 "Invalid", /* invalid */
23 "Normal", /* normal */
24 "Entry", /* entry to region */
25 "Exit", /* exit of region */
26 "Handler", /* entry to handler */
32 Return true iff (block b is a handler entry AND a dominates b) OR
33 (b has a CFG successor that is both a handler entry AND is dominated
36 static bool has_handler (ir_graph *graph, ir_node *b, ir_node *a)
39 int n = get_irn_n_outs (b);
42 assert (0 && "Wrongly implemented");
43 /* must check for _immediate_ dominance !!! */
45 if (is_handler_entry (graph, b) && dominates (graph, a, b))
48 for (i = 0; i < n; i ++)
50 succ = get_irn_out (b, i);
52 if (has_handler (graph, succ, a))
60 Return true iff the given node represents an exception jump
62 static bool is_exc_jmp (ir_node *node)
64 ir_op *op = get_irn_op (node);
66 /* Proj_X (Load), Proj_X (Sto), Proj_X (Div_Int),
67 Proj_X (Raise), Proj_X (Call), Proj_X (Alloc) */
70 op = get_irn_op (get_Proj_pred (node));
72 assert ((is_fragile_op(get_Proj_pred(node))) &&
73 (op != op_Bad) /*&& (op != op_Unknown)*/ &&
74 (get_irn_mode(node) == mode_X));/* Check for proper Proj attr */
84 Return true iff the given node represents a normal cfg jump
87 static bool is_cfg_jmp (ir_node *node)
89 ir_op *op = get_irn_op (node);
93 op = get_irn_op (get_Proj_pred (node));
95 /* Proj_X (Proj_Cmp (Cond)) */
97 return (true); /* check for op == op_Cmp and op == op_Cond */
105 Return true iff a new exception region must be left upon entry of this block.
107 If all CFG preds of this block are exception jumps, then we must
110 bool is_handler_entry (ir_graph *graph, ir_node *block)
112 bool is_entry = true;
114 int n = get_irn_arity (block);
116 if (exc_invalid == get_Block_exc (block))
118 for (i = 0; (i < n) && (is_entry == true); i ++)
119 if (is_exc_jmp (get_irn_n (block, i)))
124 if (true == is_entry)
125 set_Block_exc (block, exc_handler);
128 return (exc_handler == get_Block_exc (block));
132 Return true iff a new exception region must be started upon entry of this block.
134 If this block immediately dominates a handler entry, we must return true.
136 bool is_region_entry (ir_graph *graph, ir_node *block)
138 assert (0 && "Not implemented");
140 if (exc_invalid == get_Block_exc (block))
143 int n = get_irn_n_outs (block);
146 bool no_handler = true;
148 for (i = 0; (i < n) && (no_handler == true); i ++)
150 succ = get_irn_out (block, i);
152 if (has_handler (graph, succ, block))
156 if (false == no_handler)
157 set_Block_exc (block, exc_region);
160 return (exc_region == get_Block_exc (block));
166 Return true iff this block is part of handler code.
168 If this block is dominated by a block for which {@link
169 is_handler_entry} is true, then this block is part of the handler.
171 bool is_handler_block (ir_graph *graph, ir_node *block)
173 assert (0 && "Not implemented");
175 if (exc_invalid == get_Block_exc (block))
177 bool no_handler = true;
178 dom_env_t *env = get_dom_env (graph, block);
179 int block_index = env->index_a;
180 bs_t block_mask = 0x00000001 << block_index;
181 int n_blocks = env->dt->n_blocks;
184 for (i = 0; (i < n_blocks) && (no_handler == true); i ++)
185 if (0 != (env->dt->masks [i] & block_mask)) /* if dominator */
186 if (is_handler_entry (graph, env->dt->blocks [i])) /* is handler entry */
189 delete_dom_env (env);
191 if (false == no_handler)
192 set_Block_exc (block, exc_handler);
195 return (exc_handler == get_Block_exc (block));
199 Convert a value of type exc_t to a descriptive string.
200 Returns a reference to a statically allocated, constant string.
203 const char *exc_to_string (exc_t exc)
205 int exc_val = (int) exc;
207 assert ((0 <= (int) exc_val) && (exc_val < (int) exc_max));
209 return (exc_strings [exc_val]);