summaryrefslogtreecommitdiff
path: root/tools/perf/util/block-range.c
blob: 1be4326575013773749cda2d63e684867c5a0ca7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
// SPDX-License-Identifier: GPL-2.0
#include "block-range.h"
#include "annotate.h"
#include <assert.h>
#include <stdlib.h>

struct {
	struct rb_root root;
	u64 blocks;
} block_ranges;

static void block_range__debug(void)
{
	/*
	 * XXX still paranoid for now; see if we can make this depend on
	 * DEBUG=1 builds.
	 */
#if 1
	struct rb_node *rb;
	u64 old = 0; /* NULL isn't executable */

	for (rb = rb_first(&block_ranges.root); rb; rb = rb_next(rb)) {
		struct block_range *entry = rb_entry(rb, struct block_range, node);

		assert(old < entry->start);
		assert(entry->start <= entry->end); /* single instruction block; jump to a jump */

		old = entry->end;
	}
#endif
}

struct block_range *block_range__find(u64 addr)
{
	struct rb_node **p = &block_ranges.root.rb_node;
	struct rb_node *parent = NULL;
	struct block_range *entry;

	while (*p != NULL) {
		parent = *p;
		entry = rb_entry(parent, struct block_range, node);

		if (addr < entry->start)
			p = &parent->rb_left;
		else if (addr > entry->end)
			p = &parent->rb_right;
		else
			return entry;
	}

	return NULL;
}

static inline void rb_link_left_of_node(struct rb_node *left, struct rb_node *node)
{
	struct rb_node **p = &node->rb_left;
	while (*p) {
		node = *p;
		p = &node->rb_right;
	}
	rb_link_node(left, node, p);
}

static inline void rb_link_right_of_node(struct rb_node *right, struct rb_node *node)
{
	struct rb_node **p = &node->rb_right;
	while (*p) {
		node = *p;
		p = &node->rb_left;
	}
	rb_link_node(right, node, p);
}

/**
 * block_range__create
 * @start: branch target starting this basic block
 * @end:   branch ending this basic block
 *
 * Create all the required block ranges to precisely span the given range.
 */
struct block_range_iter block_range__create(u64 start, u64 end)
{
	struct rb_node **p = &block_ranges.root.rb_node;
	struct rb_node *n, *parent = NULL;
	struct block_range *next, *entry = NULL;
	struct block_range_iter iter = { NULL, NULL };

	while (*p != NULL) {
		parent = *p;
		entry = rb_entry(parent, struct block_range, node);

		if (start < entry->start)
			p = &parent->rb_left;
		else if (start > entry->end)
			p = &parent->rb_right;
		else
			break;
	}

	/*
	 * Didn't find anything.. there's a hole at @start, however @end might
	 * be inside/behind the next range.
	 */
	if (!*p) {
		if (!entry) /* tree empty */
			goto do_whole;

		/*
		 * If the last node is before, advance one to find the next.
		 */
		n = parent;
		if (entry->end < start) {
			n = rb_next(n);
			if (!n)
				goto do_whole;
		}
		next = rb_entry(n, struct block_range, node);

		if (next->start <= end) { /* add head: [start...][n->start...] */
			struct block_range *head = malloc(sizeof(struct block_range));
			if (!head)
				return iter;

			*head = (struct block_range){
				.start		= start,
				.end		= next->start - 1,
				.is_target	= 1,
				.is_branch	= 0,
			};

			rb_link_left_of_node(&head->node, &next->node);
			rb_insert_color(&head->node, &block_ranges.root);
			block_range__debug();

			iter.start = head;
			goto do_tail;
		}

do_whole:
		/*
		 * The whole [start..end] range is non-overlapping.
		 */
		entry = malloc(sizeof(struct block_range));
		if (!entry)
			return iter;

		*entry = (struct block_range){
			.start		= start,
			.end		= end,
			.is_target	= 1,
			.is_branch	= 1,
		};

		rb_link_node(&entry->node, parent, p);
		rb_insert_color(&entry->node, &block_ranges.root);
		block_range__debug();

		iter.start = entry;
		iter.end   = entry;
		goto done;
	}

	/*
	 * We found a range that overlapped with ours, split if needed.
	 */
	if (entry->start < start) { /* split: [e->start...][start...] */
		struct block_range *head = malloc(sizeof(struct block_range));
		if (!head)
			return iter;

		*head = (struct block_range){
			.start		= entry->start,
			.end		= start - 1,
			.is_target	= entry->is_target,
			.is_branch	= 0,

			.coverage	= entry->coverage,
			.entry		= entry->entry,
		};

		entry->start		= start;
		entry->is_target	= 1;
		entry->entry		= 0;

		rb_link_left_of_node(&head->node, &entry->node);
		rb_insert_color(&head->node, &block_ranges.root);
		block_range__debug();

	} else if (entry->start == start)
		entry->is_target = 1;

	iter.start = entry;

do_tail:
	/*
	 * At this point we've got: @iter.start = [@start...] but @end can still be
	 * inside or beyond it.
	 */
	entry = iter.start;
	for (;;) {
		/*
		 * If @end is inside @entry, split.
		 */
		if (end < entry->end) { /* split: [...end][...e->end] */
			struct block_range *tail = malloc(sizeof(struct block_range));
			if (!tail)
				return iter;

			*tail = (struct block_range){
				.start		= end + 1,
				.end		= entry->end,
				.is_target	= 0,
				.is_branch	= entry->is_branch,

				.coverage	= entry->coverage,
				.taken		= entry->taken,
				.pred		= entry->pred,
			};

			entry->end		= end;
			entry->is_branch	= 1;
			entry->taken		= 0;
			entry->pred		= 0;

			rb_link_right_of_node(&tail->node, &entry->node);
			rb_insert_color(&tail->node, &block_ranges.root);
			block_range__debug();

			iter.end = entry;
			goto done;
		}

		/*
		 * If @end matches @entry, done
		 */
		if (end == entry->end) {
			entry->is_branch = 1;
			iter.end = entry;
			goto done;
		}

		next = block_range__next(entry);
		if (!next)
			goto add_tail;

		/*
		 * If @end is in beyond @entry but not inside @next, add tail.
		 */
		if (end < next->start) { /* add tail: [...e->end][...end] */
			struct block_range *tail;
add_tail:
			tail = malloc(sizeof(struct block_range));
			if (!tail)
				return iter;

			*tail = (struct block_range){
				.start		= entry->end + 1,
				.end		= end,
				.is_target	= 0,
				.is_branch	= 1,
			};

			rb_link_right_of_node(&tail->node, &entry->node);
			rb_insert_color(&tail->node, &block_ranges.root);
			block_range__debug();

			iter.end = tail;
			goto done;
		}

		/*
		 * If there is a hole between @entry and @next, fill it.
		 */
		if (entry->end + 1 != next->start) {
			struct block_range *hole = malloc(sizeof(struct block_range));
			if (!hole)
				return iter;

			*hole = (struct block_range){
				.start		= entry->end + 1,
				.end		= next->start - 1,
				.is_target	= 0,
				.is_branch	= 0,
			};

			rb_link_left_of_node(&hole->node, &next->node);
			rb_insert_color(&hole->node, &block_ranges.root);
			block_range__debug();
		}

		entry = next;
	}

done:
	assert(iter.start->start == start && iter.start->is_target);
	assert(iter.end->end == end && iter.end->is_branch);

	block_ranges.blocks++;

	return iter;
}


/*
 * Compute coverage as:
 *
 *    br->coverage / br->sym->max_coverage
 *
 * This ensures each symbol has a 100% spot, to reflect that each symbol has a
 * most covered section.
 *
 * Returns [0-1] for coverage and -1 if we had no data what so ever or the
 * symbol does not exist.
 */
double block_range__coverage(struct block_range *br)
{
	struct symbol *sym;

	if (!br) {
		if (block_ranges.blocks)
			return 0;

		return -1;
	}

	sym = br->sym;
	if (!sym)
		return -1;

	return (double)br->coverage / symbol__annotation(sym)->max_coverage;
}