2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
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9 * packaging of this file.
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12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief read/write analyze of graph argument, which have mode reference.
23 * @author Beyhan Veliev
37 #include "analyze_irg_args.h"
40 * Walk recursive the successors of a graph argument
41 * with mode reference and mark if it will be read,
44 * @param arg The graph argument with mode reference,
45 * that must be checked.
47 static ptr_access_kind analyze_arg(ir_node *arg, ptr_access_kind bits)
52 /* We must visit a node once to avoid endless recursion.*/
53 mark_irn_visited(arg);
55 for (i = get_irn_n_outs(arg) - 1; i >= 0; --i) {
56 succ = get_irn_out(arg, i);
59 if (irn_visited(succ))
62 /* We should not walk over the memory edge.*/
63 if (get_irn_mode(succ) == mode_M)
66 /* If we reach with the recursion a Call node and our reference
67 isn't the address of this Call we accept that the reference will
68 be read and written if the graph of the method represented by
69 "Call" isn't computed else we analyze that graph. If our
70 reference is the address of this
71 Call node that mean the reference will be read.*/
72 switch (get_irn_opcode(succ)) {
75 ir_node *ptr = get_Call_ptr(succ);
78 /* Hmm: not sure what this is, most likely a read */
79 bits |= ptr_access_read;
84 meth_ent = get_Global_entity(ptr);
86 for (p = get_Call_n_params(succ) - 1; p >= 0; --p) {
87 if (get_Call_param(succ, p) == arg) {
88 /* an arg can be used more than once ! */
89 bits |= get_method_param_access(meth_ent, p);
92 } else if (is_Sel(ptr) && get_irp_callee_info_state() == irg_callee_info_consistent) {
93 /* is be a polymorphic call but callee information is available */
94 int i, n_params = get_Call_n_params(succ);
96 /* simply look into ALL possible callees */
97 for (i = get_Call_n_callees(succ) - 1; i >= 0; --i) {
98 meth_ent = get_Call_callee(succ, i);
100 /* unknown_entity is used to signal that we don't know what is called */
101 if (meth_ent == unknown_entity) {
102 bits |= ptr_access_all;
106 for (p = n_params - 1; p >= 0; --p) {
107 if (get_Call_param(succ, p) == arg) {
108 /* an arg can be used more than once ! */
109 bits |= get_method_param_access(meth_ent, p);
113 } else /* can do anything */
114 bits |= ptr_access_all;
117 /* search stops here anyway */
121 /* We have reached a Store node => the reference is written or stored. */
122 if (get_Store_ptr(succ) == arg) {
124 bits |= ptr_access_write;
127 bits |= ptr_access_store;
130 /* search stops here anyway */
134 /* We have reached a Load node => the reference is read. */
135 bits |= ptr_access_read;
137 /* search stops here anyway */
141 /* our address is casted into something unknown. Break our search. */
142 bits = ptr_access_all;
149 /* If we know that, the argument will be read, write and stored, we
150 can break the recursion.*/
151 if (bits == ptr_access_all) {
152 bits = ptr_access_all;
157 * A calculation that do not lead to a reference mode ends our search.
158 * This is dangerous: It would allow to cast into integer and that cast back ...
159 * so, when we detect a Conv we go mad, see the Conv case above.
161 if (!mode_is_reference(get_irn_mode(succ)))
164 /* follow further the address calculation */
165 bits = analyze_arg(succ, bits);
167 set_irn_link(arg, NULL);
172 * Check if a argument of the ir graph with mode
173 * reference is read, write or both.
175 * @param irg The ir graph to analyze.
177 static void analyze_ent_args(ir_entity *ent)
180 ir_node *irg_args, *arg;
185 ptr_access_kind *rw_info;
187 mtp = get_entity_type(ent);
188 nparams = get_method_n_params(mtp);
190 ent->attr.mtd_attr.param_access = NEW_ARR_F(ptr_access_kind, nparams);
192 /* If the method haven't parameters we have
198 irg = get_entity_irg(ent);
200 /* we have not yet analyzed the graph, set ALL access for pointer args */
201 for (i = nparams - 1; i >= 0; --i) {
202 ir_type *type = get_method_param_type(mtp, i);
203 ent->attr.mtd_attr.param_access[i] = is_Pointer_type(type) ? ptr_access_all : ptr_access_none;
207 /* no graph, no better info */
211 assure_irg_outs(irg);
213 irg_args = get_irg_args(irg);
215 /* A array to save the information for each argument with
217 NEW_ARR_A(ptr_access_kind, rw_info, nparams);
219 /* We initialize the element with none state. */
220 for (i = nparams - 1; i >= 0; --i)
221 rw_info[i] = ptr_access_none;
223 /* search for arguments with mode reference
225 for (i = get_irn_n_outs(irg_args) - 1; i >= 0; --i) {
226 arg = get_irn_out(irg_args, i);
227 arg_mode = get_irn_mode(arg);
228 proj_nr = get_Proj_proj(arg);
230 if (mode_is_reference(arg_mode))
231 rw_info[proj_nr] |= analyze_arg(arg, rw_info[proj_nr]);
234 /* copy the temporary info */
235 memcpy(ent->attr.mtd_attr.param_access, rw_info,
236 nparams * sizeof(ent->attr.mtd_attr.param_access[0]));
239 printf("\n%s:\n", get_entity_name(ent));
240 for (i = 0; i < nparams; ++i) {
241 if (is_Pointer_type(get_method_param_type(mtp, i)))
242 if (ent->attr.mtd_attr.param_access[i] != ptr_access_none) {
243 printf(" Pointer Arg %d access: ", i);
244 if (ent->attr.mtd_attr.param_access[i] & ptr_access_read)
246 if (ent->attr.mtd_attr.param_access[i] & ptr_access_write)
248 if (ent->attr.mtd_attr.param_access[i] & ptr_access_store)
257 * Analyze how pointer arguments of a given
258 * ir graph are accessed.
260 * @param irg The ir graph to analyze.
262 void analyze_irg_args(ir_graph *irg)
266 if (irg == get_const_code_irg())
269 ent = get_irg_entity(irg);
273 if (! ent->attr.mtd_attr.param_access)
274 analyze_ent_args(ent);
278 * Compute for a method with pointer parameter(s)
279 * if they will be read or written.
281 ptr_access_kind get_method_param_access(ir_entity *ent, size_t pos)
284 ir_type *mtp = get_entity_type(ent);
285 int is_variadic = get_method_variadicity(mtp) == variadicity_variadic;
287 assert(is_variadic || pos < get_method_n_params(mtp));
290 if (ent->attr.mtd_attr.param_access) {
291 if (pos < ARR_LEN(ent->attr.mtd_attr.param_access))
292 return ent->attr.mtd_attr.param_access[pos];
294 return ptr_access_all;
297 analyze_ent_args(ent);
299 if (pos < ARR_LEN(ent->attr.mtd_attr.param_access))
300 return ent->attr.mtd_attr.param_access[pos];
302 return ptr_access_all;
305 /* Weights for parameters */
307 null_weight = 0, /**< If can't be anything optimized. */
308 binop_weight = 1, /**< If the argument have mode_weight and take part in binop. */
309 const_binop_weight = 1, /**< If the argument have mode_weight and take part in binop with a constant.*/
310 cmp_weight = 4, /**< If the argument take part in cmp. */
311 const_cmp_weight = 10, /**< If the argument take part in cmp with a constant. */
312 indirect_call_weight = 125, /**< If the argument is the address of an indirect Call. */
316 * Compute the weight of a method parameter
318 * @param arg The parameter them weight muss be computed.
320 static unsigned calc_method_param_weight(ir_node *arg)
324 unsigned weight = null_weight;
326 /* We mark the nodes to avoid endless recursion */
327 mark_irn_visited(arg);
329 for (i = get_irn_n_outs(arg) - 1; i >= 0; i--) {
330 succ = get_irn_out(arg, i);
333 if (irn_visited(succ))
336 /* We should not walk over the memory edge.*/
337 if (get_irn_mode(succ) == mode_M)
340 switch (get_irn_opcode(succ)) {
342 if (get_Call_ptr(succ) == arg) {
343 /* the arguments is used as an pointer input for a call,
344 we can probably change an indirect Call into a direct one. */
345 weight += indirect_call_weight;
349 /* We have reached a cmp and we must increase the
350 weight with the cmp_weight. */
351 if (get_Cmp_left(succ) == arg)
352 op = get_Cmp_right(succ);
354 op = get_Cmp_left(succ);
356 if (is_irn_constlike(op)) {
357 weight += const_cmp_weight;
359 weight += cmp_weight;
362 /* the argument is used for a SwitchCond, a big win */
363 weight += const_cmp_weight * get_irn_n_outs(succ);
366 /* when looking backward we might find Id nodes */
367 weight += calc_method_param_weight(succ);
370 /* unoptimized tuple */
371 for (j = get_Tuple_n_preds(succ) - 1; j >= 0; --j) {
372 ir_node *pred = get_Tuple_pred(succ, j);
374 /* look for Proj(j) */
375 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
376 ir_node *succ_succ = get_irn_out(succ, k);
377 if (is_Proj(succ_succ)) {
378 if (get_Proj_proj(succ_succ) == j) {
380 weight += calc_method_param_weight(succ_succ);
383 /* this should NOT happen */
390 if (is_binop(succ)) {
391 /* We have reached a BinOp and we must increase the
392 weight with the binop_weight. If the other operand of the
393 BinOp is a constant we increase the weight with const_binop_weight
394 and call the function recursive.
396 if (get_binop_left(succ) == arg)
397 op = get_binop_right(succ);
399 op = get_binop_left(succ);
401 if (is_irn_constlike(op)) {
402 weight += const_binop_weight;
403 weight += calc_method_param_weight(succ);
405 weight += binop_weight;
406 } else if (is_unop(succ)) {
407 /* We have reached a binop and we must increase the
408 weight with the const_binop_weight and call the function recursive.*/
409 weight += const_binop_weight;
410 weight += calc_method_param_weight(succ);
415 set_irn_link(arg, NULL);
420 * Calculate a weight for each argument of an entity.
422 * @param ent The entity of the ir_graph.
424 static void analyze_method_params_weight(ir_entity *ent)
428 int nparams, i, proj_nr;
429 ir_node *irg_args, *arg;
431 mtp = get_entity_type(ent);
432 nparams = get_method_n_params(mtp);
434 /* allocate a new array. currently used as 'analysed' flag */
435 ent->attr.mtd_attr.param_weight = NEW_ARR_F(unsigned, nparams);
437 /* If the method haven't parameters we have nothing to do. */
441 /* First we initialize the parameter weights with 0. */
442 for (i = nparams - 1; i >= 0; i--)
443 ent->attr.mtd_attr.param_weight[i] = null_weight;
445 irg = get_entity_irg(ent);
447 /* no graph, no better info */
451 /* Call algorithm that computes the out edges */
452 assure_irg_outs(irg);
454 irg_args = get_irg_args(irg);
455 for (i = get_irn_n_outs(irg_args) - 1; i >= 0; --i) {
456 arg = get_irn_out(irg_args, i);
457 proj_nr = get_Proj_proj(arg);
458 ent->attr.mtd_attr.param_weight[proj_nr] += calc_method_param_weight(arg);
463 * Returns for a method the 'weight' that every parameter
464 * has on optimization possibility. Higher values allows
465 * higher optimization with procedure cloning.
467 * The values are calculation on demand only.
469 * @param ent the entity to analyze
470 * @param pos the argument number
472 * @return the parameter weight or null_weight if pos is greater
473 * than the number of arguments.
475 unsigned get_method_param_weight(ir_entity *ent, size_t pos)
477 if (ent->attr.mtd_attr.param_weight) {
478 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
479 return ent->attr.mtd_attr.param_weight[pos];
484 analyze_method_params_weight(ent);
486 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
487 return ent->attr.mtd_attr.param_weight[pos];
493 * Analyze argument's weight of a given
496 * @param irg The ir graph to analyze.
498 void analyze_irg_args_weight(ir_graph *irg)
500 ir_entity *entity = get_irg_entity(irg);
504 assert(is_method_entity(entity));
505 if (entity->attr.mtd_attr.param_weight != NULL)
508 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
509 inc_irg_visited(irg);
510 analyze_method_params_weight(entity);
511 ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);