1 // SPDX-License-Identifier: GPL-2.0
2 #include "block-range.h"
3 #include "annotate.h"
4 #include <assert.h>
5 #include <stdlib.h>
6
7 struct {
8 struct rb_root root;
9 u64 blocks;
10 } block_ranges;
11
12 static void block_range__debug(void)
13 {
14 #ifndef NDEBUG
15 struct rb_node *rb;
16 u64 old = 0; /* NULL isn't executable */
17
18 for (rb = rb_first(&block_ranges.root); rb; rb = rb_next(rb)) {
19 struct block_range *entry = rb_entry(rb, struct block_range, node);
20
21 assert(old < entry->start);
22 assert(entry->start <= entry->end); /* single instruction block; jump to a jump */
23
24 old = entry->end;
25 }
26 #endif
27 }
28
29 struct block_range *block_range__find(u64 addr)
30 {
31 struct rb_node **p = &block_ranges.root.rb_node;
32 struct rb_node *parent = NULL;
33 struct block_range *entry;
34
35 while (*p != NULL) {
36 parent = *p;
37 entry = rb_entry(parent, struct block_range, node);
38
39 if (addr < entry->start)
40 p = &parent->rb_left;
41 else if (addr > entry->end)
42 p = &parent->rb_right;
43 else
44 return entry;
45 }
46
47 return NULL;
48 }
49
50 static inline void rb_link_left_of_node(struct rb_node *left, struct rb_node *node)
51 {
52 struct rb_node **p = &node->rb_left;
53 while (*p) {
54 node = *p;
55 p = &node->rb_right;
56 }
57 rb_link_node(left, node, p);
58 }
59
60 static inline void rb_link_right_of_node(struct rb_node *right, struct rb_node *node)
61 {
62 struct rb_node **p = &node->rb_right;
63 while (*p) {
64 node = *p;
65 p = &node->rb_left;
66 }
67 rb_link_node(right, node, p);
68 }
69
70 /**
71 * block_range__create
72 * @start: branch target starting this basic block
73 * @end: branch ending this basic block
74 *
75 * Create all the required block ranges to precisely span the given range.
76 */
77 struct block_range_iter block_range__create(u64 start, u64 end)
78 {
79 struct rb_node **p = &block_ranges.root.rb_node;
80 struct rb_node *n, *parent = NULL;
81 struct block_range *next, *entry = NULL;
82 struct block_range_iter iter = { NULL, NULL };
83
84 while (*p != NULL) {
85 parent = *p;
86 entry = rb_entry(parent, struct block_range, node);
87
88 if (start < entry->start)
89 p = &parent->rb_left;
90 else if (start > entry->end)
91 p = &parent->rb_right;
92 else
93 break;
94 }
95
96 /*
97 * Didn't find anything.. there's a hole at @start, however @end might
98 * be inside/behind the next range.
99 */
100 if (!*p) {
101 if (!entry) /* tree empty */
102 goto do_whole;
103
104 /*
105 * If the last node is before, advance one to find the next.
106 */
107 n = parent;
108 if (entry->end < start) {
109 n = rb_next(n);
110 if (!n)
111 goto do_whole;
112 }
113 next = rb_entry(n, struct block_range, node);
114
115 if (next->start <= end) { /* add head: [start...][n->start...] */
116 struct block_range *head = malloc(sizeof(struct block_range));
117 if (!head)
118 return iter;
119
120 *head = (struct block_range){
121 .start = start,
122 .end = next->start - 1,
123 .is_target = 1,
124 .is_branch = 0,
125 };
126
127 rb_link_left_of_node(&head->node, &next->node);
128 rb_insert_color(&head->node, &block_ranges.root);
129 block_range__debug();
130
131 iter.start = head;
132 goto do_tail;
133 }
134
135 do_whole:
136 /*
137 * The whole [start..end] range is non-overlapping.
138 */
139 entry = malloc(sizeof(struct block_range));
140 if (!entry)
141 return iter;
142
143 *entry = (struct block_range){
144 .start = start,
145 .end = end,
146 .is_target = 1,
147 .is_branch = 1,
148 };
149
150 rb_link_node(&entry->node, parent, p);
151 rb_insert_color(&entry->node, &block_ranges.root);
152 block_range__debug();
153
154 iter.start = entry;
155 iter.end = entry;
156 goto done;
157 }
158
159 /*
160 * We found a range that overlapped with ours, split if needed.
161 */
162 if (entry->start < start) { /* split: [e->start...][start...] */
163 struct block_range *head = malloc(sizeof(struct block_range));
164 if (!head)
165 return iter;
166
167 *head = (struct block_range){
168 .start = entry->start,
169 .end = start - 1,
170 .is_target = entry->is_target,
171 .is_branch = 0,
172
173 .coverage = entry->coverage,
174 .entry = entry->entry,
175 };
176
177 entry->start = start;
178 entry->is_target = 1;
179 entry->entry = 0;
180
181 rb_link_left_of_node(&head->node, &entry->node);
182 rb_insert_color(&head->node, &block_ranges.root);
183 block_range__debug();
184
185 } else if (entry->start == start)
186 entry->is_target = 1;
187
188 iter.start = entry;
189
190 do_tail:
191 /*
192 * At this point we've got: @iter.start = [@start...] but @end can still be
193 * inside or beyond it.
194 */
195 entry = iter.start;
196 for (;;) {
197 /*
198 * If @end is inside @entry, split.
199 */
200 if (end < entry->end) { /* split: [...end][...e->end] */
201 struct block_range *tail = malloc(sizeof(struct block_range));
202 if (!tail)
203 return iter;
204
205 *tail = (struct block_range){
206 .start = end + 1,
207 .end = entry->end,
208 .is_target = 0,
209 .is_branch = entry->is_branch,
210
211 .coverage = entry->coverage,
212 .taken = entry->taken,
213 .pred = entry->pred,
214 };
215
216 entry->end = end;
217 entry->is_branch = 1;
218 entry->taken = 0;
219 entry->pred = 0;
220
221 rb_link_right_of_node(&tail->node, &entry->node);
222 rb_insert_color(&tail->node, &block_ranges.root);
223 block_range__debug();
224
225 iter.end = entry;
226 goto done;
227 }
228
229 /*
230 * If @end matches @entry, done
231 */
232 if (end == entry->end) {
233 entry->is_branch = 1;
234 iter.end = entry;
235 goto done;
236 }
237
238 next = block_range__next(entry);
239 if (!next)
240 goto add_tail;
241
242 /*
243 * If @end is in beyond @entry but not inside @next, add tail.
244 */
245 if (end < next->start) { /* add tail: [...e->end][...end] */
246 struct block_range *tail;
247 add_tail:
248 tail = malloc(sizeof(struct block_range));
249 if (!tail)
250 return iter;
251
252 *tail = (struct block_range){
253 .start = entry->end + 1,
254 .end = end,
255 .is_target = 0,
256 .is_branch = 1,
257 };
258
259 rb_link_right_of_node(&tail->node, &entry->node);
260 rb_insert_color(&tail->node, &block_ranges.root);
261 block_range__debug();
262
263 iter.end = tail;
264 goto done;
265 }
266
267 /*
268 * If there is a hole between @entry and @next, fill it.
269 */
270 if (entry->end + 1 != next->start) {
271 struct block_range *hole = malloc(sizeof(struct block_range));
272 if (!hole)
273 return iter;
274
275 *hole = (struct block_range){
276 .start = entry->end + 1,
277 .end = next->start - 1,
278 .is_target = 0,
279 .is_branch = 0,
280 };
281
282 rb_link_left_of_node(&hole->node, &next->node);
283 rb_insert_color(&hole->node, &block_ranges.root);
284 block_range__debug();
285 }
286
287 entry = next;
288 }
289
290 done:
291 assert(iter.start->start == start && iter.start->is_target);
292 assert(iter.end->end == end && iter.end->is_branch);
293
294 block_ranges.blocks++;
295
296 return iter;
297 }
298
299
300 /*
301 * Compute coverage as:
302 *
303 * br->coverage / br->sym->max_coverage
304 *
305 * This ensures each symbol has a 100% spot, to reflect that each symbol has a
306 * most covered section.
307 *
308 * Returns [0-1] for coverage and -1 if we had no data what so ever or the
309 * symbol does not exist.
310 */
311 double block_range__coverage(struct block_range *br)
312 {
313 struct symbol *sym;
314 struct annotated_branch *branch;
315
316 if (!br) {
317 if (block_ranges.blocks)
318 return 0;
319
320 return -1;
321 }
322
323 sym = br->sym;
324 if (!sym)
325 return -1;
326
327 branch = symbol__annotation(sym)->branch;
328 if (!branch)
329 return -1;
330
331 return (double)br->coverage / branch->max_coverage;
332 }
333
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