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
37 #include "analyze_irg_args.h"
40 static void *VISITED = &v;
43 * Walk recursive the successors of a graph argument
44 * with mode reference and mark if it will be read,
47 * @param arg The graph argument with mode reference,
48 * that must be checked.
50 static unsigned analyze_arg(ir_node *arg, unsigned bits) {
54 /* We must visit a node once to avoid endless recursion.*/
55 set_irn_link(arg, VISITED);
57 for (i = get_irn_n_outs(arg) - 1; i >= 0; --i) {
58 succ = get_irn_out(arg, i);
61 if (get_irn_link(succ) == VISITED)
64 /* We should not walk over the memory edge.*/
65 if (get_irn_mode(succ) == mode_M)
68 /* If we reach with the recursion a Call node and our reference
69 isn't the address of this Call we accept that the reference will
70 be read and written if the graph of the method represented by
71 "Call" isn't computed else we analyze that graph. If our
72 reference is the address of this
73 Call node that mean the reference will be read.*/
74 switch (get_irn_opcode(succ)) {
77 ir_node *ptr = get_Call_ptr(succ);
80 /* Hmm: not sure what this is, most likely a read */
81 bits |= ptr_access_read;
86 meth_ent = get_Global_entity(ptr);
88 for (p = get_Call_n_params(succ) - 1; p >= 0; --p) {
89 if (get_Call_param(succ, p) == arg) {
90 /* an arg can be used more than once ! */
91 bits |= get_method_param_access(meth_ent, p);
94 } else if (is_Sel(ptr) && get_irp_callee_info_state() == irg_callee_info_consistent) {
95 /* is be a polymorphic call but callee information is available */
96 int i, n_params = get_Call_n_params(succ);
98 /* simply look into ALL possible callees */
99 for (i = get_Call_n_callees(succ) - 1; i >= 0; --i) {
100 meth_ent = get_Call_callee(succ, i);
102 /* unknown_entity is used to signal that we don't know what is called */
103 if (meth_ent == unknown_entity) {
104 bits |= ptr_access_all;
108 for (p = n_params - 1; p >= 0; --p) {
109 if (get_Call_param(succ, p) == arg) {
110 /* an arg can be used more than once ! */
111 bits |= get_method_param_access(meth_ent, p);
115 } else /* can do anything */
116 bits |= ptr_access_all;
119 /* search stops here anyway */
123 /* We have reached a Store node => the reference is written or stored. */
124 if (get_Store_ptr(succ) == arg) {
126 bits |= ptr_access_write;
129 bits |= ptr_access_store;
132 /* search stops here anyway */
136 /* We have reached a Load node => the reference is read. */
137 bits |= ptr_access_read;
139 /* search stops here anyway */
143 /* our address is casted into something unknown. Break our search. */
144 bits = ptr_access_all;
151 /* If we know that, the argument will be read, write and stored, we
152 can break the recursion.*/
153 if (bits == ptr_access_all) {
154 bits = ptr_access_all;
159 * A calculation that do not lead to a reference mode ends our search.
160 * This is dangerous: It would allow to cast into integer and that cast back ...
161 * so, when we detect a Conv we go mad, see the Conv case above.
163 if (!mode_is_reference(get_irn_mode(succ)))
166 /* follow further the address calculation */
167 bits = analyze_arg(succ, bits);
169 set_irn_link(arg, NULL);
174 * Check if a argument of the ir graph with mode
175 * reference is read, write or both.
177 * @param irg The ir graph to analyze.
179 static void analyze_ent_args(ir_entity *ent) {
181 ir_node *irg_args, *arg;
186 ptr_access_kind *rw_info;
188 mtp = get_entity_type(ent);
189 nparams = get_method_n_params(mtp);
191 ent->attr.mtd_attr.param_access = NEW_ARR_F(ptr_access_kind, nparams);
193 /* If the method haven't parameters we have
199 irg = get_entity_irg(ent);
201 /* we have not yet analyzed the graph, set ALL access for pointer args */
202 for (i = nparams - 1; i >= 0; --i) {
203 ir_type *type = get_method_param_type(mtp, i);
204 ent->attr.mtd_attr.param_access[i] = is_Pointer_type(type) ? ptr_access_all : ptr_access_none;
208 /* no graph, no better info */
212 assure_irg_outs(irg);
214 irg_args = get_irg_args(irg);
216 /* A array to save the information for each argument with
218 NEW_ARR_A(ptr_access_kind, rw_info, nparams);
220 /* We initialize the element with none state. */
221 for (i = nparams - 1; i >= 0; --i)
222 rw_info[i] = ptr_access_none;
224 /* search for arguments with mode reference
226 for (i = get_irn_n_outs(irg_args) - 1; i >= 0; --i) {
227 arg = get_irn_out(irg_args, i);
228 arg_mode = get_irn_mode(arg);
229 proj_nr = get_Proj_proj(arg);
231 if (mode_is_reference(arg_mode))
232 rw_info[proj_nr] |= analyze_arg(arg, rw_info[proj_nr]);
235 /* copy the temporary info */
236 memcpy(ent->attr.mtd_attr.param_access, rw_info,
237 nparams * sizeof(ent->attr.mtd_attr.param_access[0]));
240 printf("\n%s:\n", get_entity_name(ent));
241 for (i = 0; i < nparams; ++i) {
242 if (is_Pointer_type(get_method_param_type(mtp, i)))
243 if (ent->attr.mtd_attr.param_access[i] != ptr_access_none) {
244 printf(" Pointer Arg %d access: ", i);
245 if (ent->attr.mtd_attr.param_access[i] & ptr_access_read)
247 if (ent->attr.mtd_attr.param_access[i] & ptr_access_write)
249 if (ent->attr.mtd_attr.param_access[i] & ptr_access_store)
258 * Analyze how pointer arguments of a given
259 * ir graph are accessed.
261 * @param irg The ir graph to analyze.
263 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, int pos)
284 ir_type *mtp = get_entity_type(ent);
285 int is_variadic = get_method_variadicity(mtp) == variadicity_variadic;
287 assert(0 <= pos && (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) {
323 unsigned weight = null_weight;
325 /* We mark the nodes to avoid endless recursion */
326 set_irn_link(arg, VISITED);
328 for (i = get_irn_n_outs(arg) - 1; i >= 0; i--) {
329 succ = get_irn_out(arg, i);
332 if (get_irn_link(succ) == VISITED)
335 /* We should not walk over the memory edge.*/
336 if (get_irn_mode(succ) == mode_M)
339 switch (get_irn_opcode(succ)) {
341 if (get_Call_ptr(succ) == arg) {
342 /* the arguments is used as an pointer input for a call,
343 we can probably change an indirect Call into a direct one. */
344 weight += indirect_call_weight;
348 /* We have reached a cmp and we must increase the
349 weight with the cmp_weight. */
350 if (get_Cmp_left(succ) == arg)
351 op = get_Cmp_right(succ);
353 op = get_Cmp_left(succ);
355 if (is_irn_constlike(op)) {
356 weight += const_cmp_weight;
358 weight += cmp_weight;
361 /* the argument is used for a SwitchCond, a big win */
362 weight += const_cmp_weight * get_irn_n_outs(succ);
365 /* when looking backward we might find Id nodes */
366 weight += calc_method_param_weight(succ);
369 /* unoptimized tuple */
370 for (j = get_Tuple_n_preds(succ) - 1; j >= 0; --j) {
371 ir_node *pred = get_Tuple_pred(succ, j);
373 /* look for Proj(j) */
374 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
375 ir_node *succ_succ = get_irn_out(succ, k);
376 if (is_Proj(succ_succ)) {
377 if (get_Proj_proj(succ_succ) == j) {
379 weight += calc_method_param_weight(succ_succ);
382 /* this should NOT happen */
389 if (is_binop(succ)) {
390 /* We have reached a BinOp and we must increase the
391 weight with the binop_weight. If the other operand of the
392 BinOp is a constant we increase the weight with const_binop_weight
393 and call the function recursive.
395 if (get_binop_left(succ) == arg)
396 op = get_binop_right(succ);
398 op = get_binop_left(succ);
400 if (is_irn_constlike(op)) {
401 weight += const_binop_weight;
402 weight += calc_method_param_weight(succ);
404 weight += binop_weight;
405 } else if (is_unop(succ)) {
406 /* We have reached a binop and we must increase the
407 weight with the const_binop_weight and call the function recursive.*/
408 weight += const_binop_weight;
409 weight += calc_method_param_weight(succ);
414 set_irn_link(arg, NULL);
419 * Calculate a weight for each argument of an entity.
421 * @param ent The entity of the ir_graph.
423 static void analyze_method_params_weight(ir_entity *ent) {
426 int nparams, i, proj_nr;
427 ir_node *irg_args, *arg;
429 mtp = get_entity_type(ent);
430 nparams = get_method_n_params(mtp);
432 /* allocate a new array. currently used as 'analysed' flag */
433 ent->attr.mtd_attr.param_weight = NEW_ARR_F(unsigned, nparams);
435 /* If the method haven't parameters we have nothing to do. */
439 /* First we initialize the parameter weights with 0. */
440 for (i = nparams - 1; i >= 0; i--)
441 ent->attr.mtd_attr.param_weight[i] = null_weight;
443 irg = get_entity_irg(ent);
445 /* no graph, no better info */
449 /* Call algorithm that computes the out edges */
450 assure_irg_outs(irg);
452 irg_args = get_irg_args(irg);
453 for (i = get_irn_n_outs(irg_args) - 1; i >= 0; --i) {
454 arg = get_irn_out(irg_args, i);
455 proj_nr = get_Proj_proj(arg);
456 ent->attr.mtd_attr.param_weight[proj_nr] += calc_method_param_weight(arg);
460 printf("\n%s:\n", get_entity_name(ent));
461 for (i = nparams - 1; i >= 0; --i)
462 printf("The weight of argument %i is %f \n", i, ent->param_weight[i]);
467 * Returns for a method the 'weight' that every parameter
468 * has on optimization possibility. Higher values allows
469 * higher optimization with procedure cloning.
471 * The values are calculation on demand only.
473 * @param ent the entity to analyze
474 * @param pos the argument number
476 * @return the parameter weight or null_weight if pos is greater
477 * than the number of arguments.
479 unsigned get_method_param_weight(ir_entity *ent, int pos)
481 if (ent->attr.mtd_attr.param_weight) {
482 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
483 return ent->attr.mtd_attr.param_weight[pos];
488 analyze_method_params_weight(ent);
490 if (pos < ARR_LEN(ent->attr.mtd_attr.param_weight))
491 return ent->attr.mtd_attr.param_weight[pos];
497 * Analyze argument's weight of a given
500 * @param irg The ir graph to analyze.
502 void analyze_irg_args_weight(ir_graph *irg) {
505 ent = get_irg_entity(irg);
509 if (! ent->attr.mtd_attr.param_weight)
510 analyze_method_params_weight(ent);