summaryrefslogtreecommitdiffstats
path: root/tools/perf/builtin-annotate.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/perf/builtin-annotate.c')
-rw-r--r--tools/perf/builtin-annotate.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index f07b23011b22..ebb628332a6e 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -30,6 +30,7 @@
#include "util/tool.h"
#include "util/data.h"
#include "arch/common.h"
+#include "util/block-range.h"
#include <dlfcn.h>
#include <linux/bitmap.h>
@@ -46,6 +47,103 @@ struct perf_annotate {
DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
};
+/*
+ * Given one basic block:
+ *
+ * from to branch_i
+ * * ----> *
+ * |
+ * | block
+ * v
+ * * ----> *
+ * from to branch_i+1
+ *
+ * where the horizontal are the branches and the vertical is the executed
+ * block of instructions.
+ *
+ * We count, for each 'instruction', the number of blocks that covered it as
+ * well as count the ratio each branch is taken.
+ *
+ * We can do this without knowing the actual instruction stream by keeping
+ * track of the address ranges. We break down ranges such that there is no
+ * overlap and iterate from the start until the end.
+ *
+ * @acme: once we parse the objdump output _before_ processing the samples,
+ * we can easily fold the branch.cycles IPC bits in.
+ */
+static void process_basic_block(struct addr_map_symbol *start,
+ struct addr_map_symbol *end,
+ struct branch_flags *flags)
+{
+ struct symbol *sym = start->sym;
+ struct annotation *notes = sym ? symbol__annotation(sym) : NULL;
+ struct block_range_iter iter;
+ struct block_range *entry;
+
+ /*
+ * Sanity; NULL isn't executable and the CPU cannot execute backwards
+ */
+ if (!start->addr || start->addr > end->addr)
+ return;
+
+ iter = block_range__create(start->addr, end->addr);
+ if (!block_range_iter__valid(&iter))
+ return;
+
+ /*
+ * First block in range is a branch target.
+ */
+ entry = block_range_iter(&iter);
+ assert(entry->is_target);
+ entry->entry++;
+
+ do {
+ entry = block_range_iter(&iter);
+
+ entry->coverage++;
+ entry->sym = sym;
+
+ if (notes)
+ notes->max_coverage = max(notes->max_coverage, entry->coverage);
+
+ } while (block_range_iter__next(&iter));
+
+ /*
+ * Last block in rage is a branch.
+ */
+ entry = block_range_iter(&iter);
+ assert(entry->is_branch);
+ entry->taken++;
+ if (flags->predicted)
+ entry->pred++;
+}
+
+static void process_branch_stack(struct branch_stack *bs, struct addr_location *al,
+ struct perf_sample *sample)
+{
+ struct addr_map_symbol *prev = NULL;
+ struct branch_info *bi;
+ int i;
+
+ if (!bs || !bs->nr)
+ return;
+
+ bi = sample__resolve_bstack(sample, al);
+ if (!bi)
+ return;
+
+ for (i = bs->nr - 1; i >= 0; i--) {
+ /*
+ * XXX filter against symbol
+ */
+ if (prev)
+ process_basic_block(prev, &bi[i].from, &bi[i].flags);
+ prev = &bi[i].to;
+ }
+
+ free(bi);
+}
+
static int perf_evsel__add_sample(struct perf_evsel *evsel,
struct perf_sample *sample,
struct addr_location *al,
@@ -72,6 +170,12 @@ static int perf_evsel__add_sample(struct perf_evsel *evsel,
return 0;
}
+ /*
+ * XXX filtered samples can still have branch entires pointing into our
+ * symbol and are missed.
+ */
+ process_branch_stack(sample->branch_stack, al, sample);
+
sample->period = 1;
sample->weight = 1;