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.
11 * Licensees holding valid libFirm Professional Edition licenses may use
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
39 #include "analyze_irg_args.h"
42 static void *VISITED = &v;
45 * Walk recursive the successors of a graph argument
46 * with mode reference and mark if it will be read,
49 * @param arg The graph argument with mode reference,
50 * that must be checked.
52 static unsigned analyze_arg(ir_node *arg, unsigned bits) {
56 /* We must visit a node once to avoid endless recursion.*/
57 set_irn_link(arg, VISITED);
59 for (i = get_irn_n_outs(arg) - 1; i >= 0; --i) {
60 succ = get_irn_out(arg, i);
63 if (get_irn_link(succ) == VISITED)
66 /* We should not walk over the memory edge.*/
67 if (get_irn_mode(succ) == mode_M)
70 /* If we reach with the recursion a Call node and our reference
71 isn't the address of this Call we accept that the reference will
72 be read and written if the graph of the method represented by
73 "Call" isn't computed else we analyze that graph. If our
74 reference is the address of this
75 Call node that mean the reference will be read.*/
76 switch (get_irn_opcode(succ)) {
79 ir_node *ptr = get_Call_ptr(succ);
82 /* Hmm: not sure what this is, most likely a read */
83 bits |= ptr_access_read;
88 meth_ent = get_Global_entity(ptr);
90 for (p = get_Call_n_params(succ) - 1; p >= 0; --p) {
91 if (get_Call_param(succ, p) == arg) {
92 /* an arg can be used more than once ! */
93 bits |= get_method_param_access(meth_ent, p);
96 } else if (is_Sel(ptr) && get_irp_callee_info_state() == irg_callee_info_consistent) {
97 /* is be a polymorphic call but callee information is available */
98 int i, n_params = get_Call_n_params(succ);
100 /* simply look into ALL possible callees */
101 for (i = get_Call_n_callees(succ) - 1; i >= 0; --i) {
102 meth_ent = get_Call_callee(succ, i);
104 /* unknown_entity is used to signal that we don't know what is called */
105 if (meth_ent == unknown_entity) {
106 bits |= ptr_access_all;
110 for (p = n_params - 1; p >= 0; --p) {
111 if (get_Call_param(succ, p) == arg) {
112 /* an arg can be used more than once ! */
113 bits |= get_method_param_access(meth_ent, p);
117 } else /* can do anything */
118 bits |= ptr_access_all;
121 /* search stops here anyway */
125 /* We have reached a Store node => the reference is written or stored. */
126 if (get_Store_ptr(succ) == arg) {
128 bits |= ptr_access_write;
131 bits |= ptr_access_store;
134 /* search stops here anyway */
138 /* We have reached a Load node => the reference is read. */
139 bits |= ptr_access_read;
141 /* search stops here anyway */
145 /* our address is casted into something unknown. Break our search. */
146 bits = ptr_access_all;
153 /* If we know that, the argument will be read, write and stored, we
154 can break the recursion.*/
155 if (bits == ptr_access_all) {
156 bits = ptr_access_all;
161 * A calculation that do not lead to a reference mode ends our search.
162 * This is dangerous: It would allow to cast into integer and that cast back ...
163 * so, when we detect a Conv we go mad, see the Conv case above.
165 if (!mode_is_reference(get_irn_mode(succ)))
168 /* follow further the address calculation */
169 bits = analyze_arg(succ, bits);
171 set_irn_link(arg, NULL);
176 * Check if a argument of the ir graph with mode
177 * reference is read, write or both.
179 * @param irg The ir graph to analyze.
181 static void analyze_ent_args(ir_entity *ent) {
183 ir_node *irg_args, *arg;
188 ptr_access_kind *rw_info;
190 mtp = get_entity_type(ent);
191 nparams = get_method_n_params(mtp);
193 ent->attr.mtd_attr.param_access = NEW_ARR_F(ptr_access_kind, nparams);
195 /* If the method haven't parameters we have
201 irg = get_entity_irg(ent);
203 /* we have not yet analyzed the graph, set ALL access for pointer args */
204 for (i = nparams - 1; i >= 0; --i) {
205 ir_type *type = get_method_param_type(mtp, i);
206 ent->attr.mtd_attr.param_access[i] = is_Pointer_type(type) ? ptr_access_all : ptr_access_none;
210 /* no graph, no better info */
214 assure_irg_outs(irg);
216 irg_args = get_irg_args(irg);
218 /* A array to save the information for each argument with
220 NEW_ARR_A(ptr_access_kind, rw_info, nparams);
222 /* We initialize the element with none state. */
223 for (i = nparams - 1; i >= 0; --i)
224 rw_info[i] = ptr_access_none;
226 /* search for arguments with mode reference
228 for (i = get_irn_n_outs(irg_args) - 1; i >= 0; --i) {
229 arg = get_irn_out(irg_args, i);
230 arg_mode = get_irn_mode(arg);
231 proj_nr = get_Proj_proj(arg);
233 if (mode_is_reference(arg_mode))
234 rw_info[proj_nr] |= analyze_arg(arg, rw_info[proj_nr]);
237 /* copy the temporary info */
238 memcpy(ent->attr.mtd_attr.param_access, rw_info,
239 nparams * sizeof(ent->attr.mtd_attr.param_access[0]));
242 printf("\n%s:\n", get_entity_name(ent));
243 for (i = 0; i < nparams; ++i) {
244 if (is_Pointer_type(get_method_param_type(mtp, i)))
245 if (ent->attr.mtd_attr.param_access[i] != ptr_access_none) {
246 printf(" Pointer Arg %d access: ", i);
247 if (ent->attr.mtd_attr.param_access[i] & ptr_access_read)
249 if (ent->attr.mtd_attr.param_access[i] & ptr_access_write)
251 if (ent->attr.mtd_attr.param_access[i] & ptr_access_store)
260 * Analyze how pointer arguments of a given
261 * ir graph are accessed.
263 * @param irg The ir graph to analyze.
265 void analyze_irg_args(ir_graph *irg) {
268 if (irg == get_const_code_irg())
271 ent = get_irg_entity(irg);
275 if (! ent->attr.mtd_attr.param_access)
276 analyze_ent_args(ent);
280 * Compute for a method with pointer parameter(s)
281 * if they will be read or written.
283 ptr_access_kind get_method_param_access(ir_entity *ent, int pos)
286 ir_type *mtp = get_entity_type(ent);
287 int is_variadic = get_method_variadicity(mtp) == variadicity_variadic;
289 assert(0 <= pos && (is_variadic || pos < get_method_n_params(mtp)));
292 if (ent->attr.mtd_attr.param_access) {
293 if (pos < ARR_LEN(ent->attr.mtd_attr.param_access))
294 return ent->attr.mtd_attr.param_access[pos];
296 return ptr_access_all;
299 analyze_ent_args(ent);
301 if (pos < ARR_LEN(ent->attr.mtd_attr.param_access))
302 return ent->attr.mtd_attr.param_access[pos];
304 return ptr_access_all;
307 /* Weights for parameters */
309 null_weight = 0, /**< If can't be anything optimized. */
310 binop_weight = 1, /**< If the argument have mode_weight and take part in binop. */
311 const_binop_weight = 1, /**< If the argument have mode_weight and take part in binop with a constant.*/
312 cmp_weight = 4, /**< If the argument take part in cmp. */
313 const_cmp_weight = 10, /**< If the argument take part in cmp with a constant. */
314 indirect_call_weight = 125, /**< If the argument is the address of an indirect Call. */
318 * Compute the weight of a method parameter
320 * @param arg The parameter them weight muss be computed.
322 static unsigned calc_method_param_weight(ir_node *arg) {
325 unsigned weight = null_weight;
327 /* We mark the nodes to avoid endless recursion */
328 set_irn_link(arg, VISITED);
330 for (i = get_irn_n_outs(arg) - 1; i >= 0; i--) {
331 succ = get_irn_out(arg, i);
334 if (get_irn_link(succ) == VISITED)
337 /* We should not walk over the memory edge.*/
338 if (get_irn_mode(succ) == mode_M)
341 switch (get_irn_opcode(succ)) {
343 if (get_Call_ptr(succ) == arg) {
344 /* the arguments is used as an pointer input for a call,
345 we can probably change an indirect Call into a direct one. */
346 weight += indirect_call_weight;
350 /* We have reached a cmp and we must increase the
351 weight with the cmp_weight. */
352 if (get_Cmp_left(succ) == arg)
353 op = get_Cmp_right(succ);
355 op = get_Cmp_left(succ);
357 if (is_irn_constlike(op)) {
358 weight += const_cmp_weight;
360 weight += cmp_weight;
363 /* the argument is used for a SwitchCond, a big win */
364 weight += const_cmp_weight * get_irn_n_outs(succ);
367 /* when looking backward we might find Id nodes */
368 weight += calc_method_param_weight(succ);
371 /* unoptimized tuple */
372 for (j = get_Tuple_n_preds(succ) - 1; j >= 0; --j) {
373 ir_node *pred = get_Tuple_pred(succ, j);
375 /* look for Proj(j) */
376 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
377 ir_node *succ_succ = get_irn_out(succ, k);
378 if (is_Proj(succ_succ)) {
379 if (get_Proj_proj(succ_succ) == j) {
381 weight += calc_method_param_weight(succ_succ);
384 /* this should NOT happen */
391 if (is_binop(succ)) {
392 /* We have reached a BinOp and we must increase the
393 weight with the binop_weight. If the other operand of the
394 BinOp is a constant we increase the weight with const_binop_weight
395 and call the function recursive.
397 if (get_binop_left(succ) == arg)
398 op = get_binop_right(succ);
400 op = get_binop_left(succ);
402 if (is_irn_constlike(op)) {
403 weight += const_binop_weight;
404 weight += calc_method_param_weight(succ);
406 weight += binop_weight;
407 } else if (is_unop(succ)) {
408 /* We have reached a binop and we must increase the
409 weight with the const_binop_weight and call the function recursive.*/
410 weight += const_binop_weight;
411 weight += calc_method_param_weight(succ);
416 set_irn_link(arg, NULL);
421 * Calculate a weight for each argument of an entity.
423 * @param ent The entity of the ir_graph.
425 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);
462 printf("\n%s:\n", get_entity_name(ent));
463 for (i = nparams - 1; i >= 0; --i)
464 printf("The weight of argument %i is %f \n", i, ent->param_weight[i]);
469 * Returns for a method the 'weight' that every parameter
470 * has on optimization possibility. Higher values allows
471 * higher optimization with procedure cloning.
473 * The values are calculation on demand only.
475 * @param ent the entity to analyze
476 * @param pos the argument number
478 * @return the parameter weight or null_weight if pos is greater
479 * than the number of arguments.
481 unsigned get_method_param_weight(ir_entity *ent, int pos)
483 if (ent->attr.mtd_attr.param_weight) {
484 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
485 return ent->attr.mtd_attr.param_weight[pos];
490 analyze_method_params_weight(ent);
492 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
493 return ent->attr.mtd_attr.param_weight[pos];
499 * Analyze argument's weight of a given
502 * @param irg The ir graph to analyze.
504 void analyze_irg_args_weight(ir_graph *irg) {
507 ent = get_irg_entity(irg);
511 if (! ent->attr.mtd_attr.param_weight)
512 analyze_method_params_weight(ent);