2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
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
36 #include "analyze_irg_args.h"
39 * Walk recursive the successors of a graph argument
40 * with mode reference and mark if it will be read,
43 * @param arg The graph argument with mode reference,
44 * that must be checked.
46 static ptr_access_kind analyze_arg(ir_node *arg, ptr_access_kind bits)
51 /* We must visit a node once to avoid endless recursion.*/
52 mark_irn_visited(arg);
54 for (i = get_irn_n_outs(arg) - 1; i >= 0; --i) {
55 succ = get_irn_out(arg, i);
58 if (irn_visited(succ))
61 /* We should not walk over the memory edge.*/
62 if (get_irn_mode(succ) == mode_M)
65 /* If we reach with the recursion a Call node and our reference
66 isn't the address of this Call we accept that the reference will
67 be read and written if the graph of the method represented by
68 "Call" isn't computed else we analyze that graph. If our
69 reference is the address of this
70 Call node that mean the reference will be read.*/
71 switch (get_irn_opcode(succ)) {
74 ir_node *ptr = get_Call_ptr(succ);
77 /* Hmm: not sure what this is, most likely a read */
78 bits |= ptr_access_read;
82 if (is_SymConst_addr_ent(ptr)) {
83 meth_ent = get_SymConst_entity(ptr);
85 for (p = get_Call_n_params(succ) - 1; p >= 0; --p) {
86 if (get_Call_param(succ, p) == arg) {
87 /* an arg can be used more than once ! */
88 bits |= get_method_param_access(meth_ent, p);
91 } else if (is_Sel(ptr) && get_irp_callee_info_state() == irg_callee_info_consistent) {
92 /* is be a polymorphic call but callee information is available */
93 int n_params = get_Call_n_params(succ);
96 /* simply look into ALL possible callees */
97 for (c = get_Call_n_callees(succ) - 1; c >= 0; --c) {
98 meth_ent = get_Call_callee(succ, c);
100 /* unknown_entity is used to signal that we don't know what is called */
101 if (is_unknown_entity(meth_ent)) {
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 void analyze_irg_args(ir_graph *irg)
243 if (irg == get_const_code_irg())
246 ent = get_irg_entity(irg);
250 if (! ent->attr.mtd_attr.param_access)
251 analyze_ent_args(ent);
254 ptr_access_kind get_method_param_access(ir_entity *ent, size_t pos)
257 ir_type *mtp = get_entity_type(ent);
258 int is_variadic = get_method_variadicity(mtp) == variadicity_variadic;
260 assert(is_variadic || pos < get_method_n_params(mtp));
263 if (ent->attr.mtd_attr.param_access) {
264 if (pos < ARR_LEN(ent->attr.mtd_attr.param_access))
265 return ent->attr.mtd_attr.param_access[pos];
267 return ptr_access_all;
270 analyze_ent_args(ent);
272 if (pos < ARR_LEN(ent->attr.mtd_attr.param_access))
273 return ent->attr.mtd_attr.param_access[pos];
275 return ptr_access_all;
278 /* Weights for parameters */
280 null_weight = 0, /**< If can't be anything optimized. */
281 binop_weight = 1, /**< If the argument have mode_weight and take part in binop. */
282 const_binop_weight = 1, /**< If the argument have mode_weight and take part in binop with a constant.*/
283 cmp_weight = 4, /**< If the argument take part in cmp. */
284 const_cmp_weight = 10, /**< If the argument take part in cmp with a constant. */
285 indirect_call_weight = 125, /**< If the argument is the address of an indirect Call. */
289 * Compute the weight of a method parameter
291 * @param arg The parameter them weight muss be computed.
293 static unsigned calc_method_param_weight(ir_node *arg)
297 unsigned weight = null_weight;
299 /* We mark the nodes to avoid endless recursion */
300 mark_irn_visited(arg);
302 for (i = get_irn_n_outs(arg) - 1; i >= 0; i--) {
303 succ = get_irn_out(arg, i);
306 if (irn_visited(succ))
309 /* We should not walk over the memory edge.*/
310 if (get_irn_mode(succ) == mode_M)
313 switch (get_irn_opcode(succ)) {
315 if (get_Call_ptr(succ) == arg) {
316 /* the arguments is used as an pointer input for a call,
317 we can probably change an indirect Call into a direct one. */
318 weight += indirect_call_weight;
322 /* We have reached a cmp and we must increase the
323 weight with the cmp_weight. */
324 if (get_Cmp_left(succ) == arg)
325 op = get_Cmp_right(succ);
327 op = get_Cmp_left(succ);
329 if (is_irn_constlike(op)) {
330 weight += const_cmp_weight;
332 weight += cmp_weight;
335 /* the argument is used for a SwitchCond, a big win */
336 weight += const_cmp_weight * get_irn_n_outs(succ);
339 /* when looking backward we might find Id nodes */
340 weight += calc_method_param_weight(succ);
343 /* unoptimized tuple */
344 for (j = get_Tuple_n_preds(succ) - 1; j >= 0; --j) {
345 ir_node *pred = get_Tuple_pred(succ, j);
347 /* look for Proj(j) */
348 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
349 ir_node *succ_succ = get_irn_out(succ, k);
350 if (is_Proj(succ_succ)) {
351 if (get_Proj_proj(succ_succ) == j) {
353 weight += calc_method_param_weight(succ_succ);
356 /* this should NOT happen */
363 if (is_binop(succ)) {
364 /* We have reached a BinOp and we must increase the
365 weight with the binop_weight. If the other operand of the
366 BinOp is a constant we increase the weight with const_binop_weight
367 and call the function recursive.
369 if (get_binop_left(succ) == arg)
370 op = get_binop_right(succ);
372 op = get_binop_left(succ);
374 if (is_irn_constlike(op)) {
375 weight += const_binop_weight;
376 weight += calc_method_param_weight(succ);
378 weight += binop_weight;
379 } else if (is_unop(succ)) {
380 /* We have reached a binop and we must increase the
381 weight with the const_binop_weight and call the function recursive.*/
382 weight += const_binop_weight;
383 weight += calc_method_param_weight(succ);
388 set_irn_link(arg, NULL);
393 * Calculate a weight for each argument of an entity.
395 * @param ent The entity of the ir_graph.
397 static void analyze_method_params_weight(ir_entity *ent)
401 int nparams, i, proj_nr;
402 ir_node *irg_args, *arg;
404 mtp = get_entity_type(ent);
405 nparams = get_method_n_params(mtp);
407 /* allocate a new array. currently used as 'analysed' flag */
408 ent->attr.mtd_attr.param_weight = NEW_ARR_F(unsigned, nparams);
410 /* If the method haven't parameters we have nothing to do. */
414 /* First we initialize the parameter weights with 0. */
415 for (i = nparams - 1; i >= 0; i--)
416 ent->attr.mtd_attr.param_weight[i] = null_weight;
418 irg = get_entity_irg(ent);
420 /* no graph, no better info */
424 /* Call algorithm that computes the out edges */
425 assure_irg_outs(irg);
427 irg_args = get_irg_args(irg);
428 for (i = get_irn_n_outs(irg_args) - 1; i >= 0; --i) {
429 arg = get_irn_out(irg_args, i);
430 proj_nr = get_Proj_proj(arg);
431 ent->attr.mtd_attr.param_weight[proj_nr] += calc_method_param_weight(arg);
435 unsigned get_method_param_weight(ir_entity *ent, size_t pos)
437 if (ent->attr.mtd_attr.param_weight) {
438 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
439 return ent->attr.mtd_attr.param_weight[pos];
444 analyze_method_params_weight(ent);
446 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
447 return ent->attr.mtd_attr.param_weight[pos];
452 void analyze_irg_args_weight(ir_graph *irg)
454 ir_entity *entity = get_irg_entity(irg);
458 assert(is_method_entity(entity));
459 if (entity->attr.mtd_attr.param_weight != NULL)
462 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
463 inc_irg_visited(irg);
464 analyze_method_params_weight(entity);
465 ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);