2 * Copyright (C) 1995-2007 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 Compute an estimate of basic block executions.
23 * @author Adam M. Szalkowski
39 #include <gsl/gsl_linalg.h>
40 #include <gsl/gsl_vector.h>
42 #include "gaussjordan.h"
45 #include "firm_common_t.h"
51 #include "irgraph_t.h"
62 #define set_foreach(s,i) for((i)=set_first((s)); (i); (i)=set_next((s)))
64 #define MAX_INT_FREQ 1000000
66 typedef struct _freq_t {
72 typedef struct _walkerdata_t {
83 unsigned infeasible : 1;
87 cmp_freq(const void *a, const void *b, size_t size)
93 return !(p->irn == q->irn);
97 set_find_freq(set * set, const ir_node * irn)
102 return set_find(set, &query, sizeof(query), HASH_PTR(irn));
106 set_insert_freq(set * set, const ir_node * irn)
112 return set_insert(set, &query, sizeof(query), HASH_PTR(irn));
116 get_block_execfreq(const ir_exec_freq *ef, const ir_node * irn)
118 if(!ef->infeasible) {
119 set *freqs = ef->set;
121 assert(is_Block(irn));
122 freq = set_find_freq(freqs, irn);
125 assert(freq->freq >= 0);
133 get_block_execfreq_ulong(const ir_exec_freq *ef, const ir_node *bb)
135 double f = get_block_execfreq(ef, bb);
136 int res = (int) (f > ef->min_non_zero ? ef->m * f + ef->b : 1.0);
138 // printf("%20.6f %10d\n", f, res);
142 #define EPSILON 0.0001
143 #define UNDEF(x) !(x > EPSILON)
146 block_walker(ir_node * bb, void * data)
148 walkerdata_t *wd = data;
150 set_insert_freq(wd->set, bb);
151 set_irn_link(bb, (void*)wd->idx++);
156 solve_lgs(double * a_data, double * b_data, size_t size)
159 = gsl_matrix_view_array (a_data, size, size);
162 = gsl_vector_view_array (b_data, size);
164 gsl_vector *x = gsl_vector_alloc (size);
168 gsl_permutation * p = gsl_permutation_alloc (size);
170 gsl_linalg_LU_decomp (&m.matrix, p, &s);
172 gsl_linalg_LU_solve (&m.matrix, p, &b.vector, x);
174 gsl_permutation_free (p);
180 solve_lgs(double * A, double * b, size_t size)
182 if(firm_gaussjordansolve(A,b,size) == 0) {
191 get_cf_probability(ir_node *bb, int pos, double loop_weight)
195 const ir_node *pred = get_Block_cfgpred_block(bb, pos);
196 const ir_loop *pred_loop = get_irn_loop(pred);
197 int pred_depth = get_loop_depth(pred_loop);
198 const ir_edge_t *edge;
200 cur = get_loop_depth(get_irn_loop(bb)) < get_loop_depth(get_irn_loop(pred)) ? 1.0 : loop_weight;
202 foreach_block_succ(pred, edge) {
203 const ir_node *block = get_edge_src_irn(edge);
204 const ir_loop *loop = get_irn_loop(block);
205 int depth = get_loop_depth(loop);
206 sum += depth < pred_depth ? 1.0 : loop_weight;
212 static void exec_freq_node_info(void *ctx, FILE *f, const ir_node *irn)
215 ir_exec_freq *ef = ctx;
216 fprintf(f, "execution frequency: %g/%lu\n", get_block_execfreq(ef, irn), get_block_execfreq_ulong(ef, irn));
220 ir_exec_freq *create_execfreq(ir_graph *irg)
222 ir_exec_freq *execfreq = xmalloc(sizeof(execfreq[0]));
223 memset(execfreq, 0, sizeof(execfreq[0]));
224 execfreq->set = new_set(cmp_freq, 32);
226 memset(&execfreq->hook, 0, sizeof(execfreq->hook));
227 execfreq->hook.context = execfreq;
228 execfreq->hook.hook._hook_node_info = exec_freq_node_info;
229 register_hook(hook_node_info, &execfreq->hook);
235 void set_execfreq(ir_exec_freq *execfreq, const ir_node *block, double freq)
237 freq_t *f = set_insert_freq(execfreq->set, block);
242 compute_execfreq(ir_graph * irg, double loop_weight)
258 ef = xmalloc(sizeof(ef[0]));
259 memset(ef, 0, sizeof(ef[0]));
260 ef->min_non_zero = 1e50; /* initialize with a reasonable large number. */
261 freqs = ef->set = new_set(cmp_freq, 32);
263 construct_cf_backedges(irg);
264 /* TODO: edges are corrupt for EDGE_KIND_BLOCK after the local optimize
265 graph phase merges blocks in the x86 backend */
266 edges_deactivate(irg);
268 /* edges_assure(irg); */
273 irg_block_walk_graph(irg, block_walker, NULL, &wd);
275 size = set_count(freqs);
276 matrix = xmalloc(size*size*sizeof(*matrix));
277 memset(matrix, 0, size*size*sizeof(*matrix));
278 rhs = xmalloc(size*sizeof(*rhs));
279 memset(rhs, 0, size*sizeof(*rhs));
281 set_foreach(freqs, freq) {
282 ir_node *bb = (ir_node *)freq->irn;
283 size_t idx = (int)get_irn_link(bb);
285 matrix[idx * (size + 1)] = -1.0;
287 if (bb == get_irg_start_block(irg)) {
288 rhs[(int)get_irn_link(bb)] = -1.0;
292 for(i = get_Block_n_cfgpreds(bb) - 1; i >= 0; --i) {
293 ir_node *pred = get_Block_cfgpred_block(bb, i);
294 size_t pred_idx = (int)get_irn_link(pred);
296 // matrix[pred_idx + idx*size] += 1.0/(double)get_Block_n_cfg_outs(pred);
297 matrix[pred_idx + idx * size] += get_cf_probability(bb, i, loop_weight);
301 x = solve_lgs(matrix, rhs, size);
303 DEBUG_ONLY(ir_fprintf(stderr, "Debug Warning: Couldn't estimate execution frequencies for %+F\n", irg));
308 set_foreach(freqs, freq) {
309 const ir_node *bb = freq->irn;
310 size_t idx = PTR_TO_INT(get_irn_link(bb));
313 freq->freq = UNDEF(gsl_vector_get(x, idx)) ? EPSILON : gsl_vector_get(x, idx);
315 freq->freq = UNDEF(x[idx]) ? EPSILON : x[idx];
318 /* get the maximum exec freq */
319 ef->max = MAX(ef->max, freq->freq);
321 /* Get the minimum non-zero execution frequency. */
323 ef->min_non_zero = MIN(ef->min_non_zero, freq->freq);
326 /* compute m and b of the transformation used to convert the doubles into scaled ints */
328 double smallest_diff = 1.0;
330 double l2 = ef->min_non_zero;
333 double h1 = MAX_INT_FREQ;
335 double *fs = malloc(set_count(freqs) * sizeof(fs[0]));
338 set_foreach(freqs, freq)
339 fs[n++] = freq->freq;
342 * find the smallest difference of the execution frequencies
343 * we try to ressolve it with 1 integer.
345 for(i = 0; i < n; ++i) {
349 for(j = i + 1; j < n; ++j) {
350 double diff = fabs(fs[i] - fs[j]);
353 smallest_diff = MIN(diff, smallest_diff);
357 /* according to that the slope of the translation function is 1.0 / smallest diff */
358 ef->m = 1.0 / smallest_diff;
360 /* the abscissa is then given by */
361 ef->b = l1 - ef->m * l2;
364 * if the slope is so high that the largest integer would be larger than MAX_INT_FREQ
365 * set the largest int freq to that upper limit and recompute the translation function
367 if(ef->m * h2 + ef->b > MAX_INT_FREQ) {
368 ef->m = (h1 - l1) / (h2 - l2);
369 ef->b = l1 - ef->m * l2;
372 // printf("smallest_diff: %g, l1: %f, h1: %f, l2: %f, h2: %f, m: %f, b: %f\n", smallest_diff, l1, h1, l2, h2, ef->m, ef->b);
379 memset(&ef->hook, 0, sizeof(ef->hook));
380 ef->hook.context = ef;
381 ef->hook.hook._hook_node_info = exec_freq_node_info;
382 register_hook(hook_node_info, &ef->hook);
392 free_execfreq(ir_exec_freq *ef)
395 unregister_hook(hook_node_info, &ef->hook);